import type {
  AtomConstructorBinding,
  AtomId,
  AttachmentOwner,
  Binding,
  BoundDependency,
  Conformance,
  DependencyBinding,
  DependencyPort,
  EdgeCardinality,
  EdgeDefinition,
  EdgeEndpoint,
  EdgeEndpointConstraint,
  EdgePrimitive,
  EdgeProjectionId,
  EdgeTypeId,
  InterfaceMember,
  InterfaceOperation,
  InterfaceOperationMode,
  InterfaceRevision,
  InterfaceRevisionId,
  OperationId,
  OwnedAttachment,
  PackageExport,
  PackageOperationExport,
  PackageRevision,
  PackageRevisionId,
  PersistentAttachment,
  SlotId,
  SourceRevision,
  StatePrimitive,
  StateSlotDefinition,
  ValueType,
  WorkspaceRevision,
} from "./types.js";
import { valueType } from "./types.js";

export type CapabilityValidationIssueCode =
  | "invalid-semantic-major"
  | "duplicate-conformance-id"
  | "required-value"
  | "invalid-source"
  | "invalid-value-type"
  | "invalid-operation"
  | "duplicate-atom"
  | "duplicate-attachment"
  | "duplicate-projection"
  | "duplicate-interface-revision"
  | "duplicate-interface-member"
  | "duplicate-interface-operation"
  | "duplicate-package-revision"
  | "duplicate-package-export"
  | "duplicate-dependency-port"
  | "duplicate-conformance"
  | "duplicate-operation-binding"
  | "duplicate-relationship-materialization"
  | "duplicate-constructor"
  | "unresolved-reference"
  | "invalid-attachment"
  | "invalid-state-binding"
  | "invalid-edge-binding"
  | "invalid-package-binding"
  | "invalid-dependency-binding"
  | "private-attachment-access"
  | "incompatible-package-receiver"
  | "unsatisfied-interface"
  | "cyclic-conformance-requirement"
  | "missing-operation-binding"
  | "unknown-operation-binding"
  | "invalid-constructor"
  | "invalid-relationship-materialization";

export interface CapabilityValidationIssue {
  code: CapabilityValidationIssueCode;
  path: string;
  message: string;
}

interface InterfaceOperationEntry {
  operation: InterfaceOperation;
  member: InterfaceMember;
}

interface InterfaceIndexEntry {
  revision: InterfaceRevision;
  operations: Map<OperationId, InterfaceOperationEntry>;
}

interface PackageIndexEntry {
  revision: PackageRevision;
  exports: Map<string, PackageExport>;
}

interface AttachmentIndexEntry extends OwnedAttachment {
  path: string;
}

interface ValidationIndexes {
  atoms: Map<string, WorkspaceRevision["atoms"][number]>;
  interfaces: Map<string, InterfaceIndexEntry>;
  packages: Map<string, PackageIndexEntry>;
  conformances: Map<string, Conformance>;
  conformancePaths: Map<string, string>;
  attachments: Map<string, AttachmentIndexEntry>;
  projections: Map<
    string,
    { edge: EdgeDefinition; endpoint: EdgeEndpoint; endpointIndex: 0 | 1 }
  >;
  constructors: Map<AtomId, AtomConstructorBinding>;
}

const hasText = (value: string) => value.trim().length > 0;

const conformanceKey = (
  atomId: AtomId,
  interfaceRevisionId: InterfaceRevisionId,
): string => `${atomId}\u0000${interfaceRevisionId}`;

const attachmentKey = (attachment: PersistentAttachment): string =>
  `${attachment.kind}\u0000${attachment.id}`;

const issue = (
  issues: CapabilityValidationIssue[],
  code: CapabilityValidationIssueCode,
  path: string,
  message: string,
) => issues.push({ code, path, message });

const requireText = (
  issues: CapabilityValidationIssue[],
  value: string,
  path: string,
  label: string,
) => {
  if (!hasText(value)) {
    issue(issues, "required-value", path, `${label} is required`);
  }
};

const typeLabel = (type: ValueType): string => {
  switch (type.kind) {
    case "builtin":
    case "scalar":
      return type.name;
    case "message":
      return `message:${type.descriptorId}`;
    case "record":
      return `record{${Object.keys(type.fields).sort().map((key) => `${key}:${typeLabel(type.fields[key])}`).join(";")}}`;
    case "object-ref":
      return type.expectation.kind === "atom"
        ? `object:atom:${type.expectation.atomId}`
        : `object:interface:${type.expectation.interfaceRevisionId}`;
    case "optional":
      return `optional<${typeLabel(type.value)}>`;
    case "list":
      return `list<${typeLabel(type.value)}>`;
  }
};

export const valueTypesEqual = (left: ValueType, right: ValueType): boolean => {
  if (left.kind !== right.kind) {
    return false;
  }
  switch (left.kind) {
    case "builtin":
    case "scalar":
      return left.name === (right as typeof left).name;
    case "message":
      return left.descriptorId === (right as typeof left).descriptorId;
    case "record": {
      const other = (right as typeof left).fields;
      return Object.keys(left.fields).length === Object.keys(other).length && Object.entries(left.fields).every(([key, value]) => Object.hasOwn(other, key) && valueTypesEqual(value, other[key]));
    }
    case "object-ref": {
      const other = (right as typeof left).expectation;
      if (left.expectation.kind !== other.kind) {
        return false;
      }
      return left.expectation.kind === "atom"
        ? left.expectation.atomId ===
            (other as typeof left.expectation).atomId
        : left.expectation.interfaceRevisionId ===
            (other as typeof left.expectation).interfaceRevisionId;
    }
    case "optional":
    case "list":
      return valueTypesEqual(left.value, (right as typeof left).value);
  }
};

const constraintsEqual = (
  left: EdgeEndpointConstraint,
  right: EdgeEndpointConstraint,
) =>
  left.kind === right.kind &&
  (left.kind === "atom"
    ? left.atomId === (right as typeof left).atomId
    : left.interfaceRevisionId === (right as typeof left).interfaceRevisionId);

const sourceRequiredFields: Array<[keyof SourceRevision, string]> = [
  ["repository", "repository"],
  ["commit", "commit"],
];

const validateSource = (
  issues: CapabilityValidationIssue[],
  source: SourceRevision,
  path: string,
) => {
  for (const [key, label] of sourceRequiredFields) {
    if (!hasText(source[key])) {
      issue(
        issues,
        "invalid-source",
        `${path}.${key}`,
        `Source ${label} is required`,
      );
    }
  }
};

const validateValueType = (
  issues: CapabilityValidationIssue[],
  type: ValueType,
  path: string,
  indexes: Pick<ValidationIndexes, "atoms" | "interfaces">,
) => {
  switch (type.kind) {
    case "record":
      for (const [name, field] of Object.entries(type.fields)) {
        if (!/^[A-Za-z_][A-Za-z0-9_]*$/.test(name)) issue(issues, "invalid-value-type", path, "Invalid record field name");
        validateValueType(issues, field, `${path}.fields.${name}`, indexes);
      }
      return;
    case "builtin":
    case "scalar":
      return;
    case "message":
      requireText(
        issues,
        type.descriptorId,
        `${path}.descriptorId`,
        "Message descriptor identity",
      );
      return;
    case "optional":
    case "list":
      validateValueType(issues, type.value, `${path}.value`, indexes);
      return;
    case "object-ref":
      if (type.expectation.kind === "atom") {
        if (!indexes.atoms.has(type.expectation.atomId)) {
          issue(
            issues,
            "unresolved-reference",
            `${path}.expectation.atomId`,
            `Unknown atom ${type.expectation.atomId}`,
          );
        }
      } else if (
        !indexes.interfaces.has(type.expectation.interfaceRevisionId)
      ) {
        issue(
          issues,
          "unresolved-reference",
          `${path}.expectation.interfaceRevisionId`,
          `Unknown interface revision ${type.expectation.interfaceRevisionId}`,
        );
      }
  }
};

const validateConstraint = (
  issues: CapabilityValidationIssue[],
  constraint: EdgeEndpointConstraint,
  path: string,
  indexes: Pick<ValidationIndexes, "atoms" | "interfaces">,
) => {
  if (constraint.kind === "atom") {
    if (!indexes.atoms.has(constraint.atomId)) {
      issue(
        issues,
        "unresolved-reference",
        `${path}.atomId`,
        `Unknown atom ${constraint.atomId}`,
      );
    }
  } else if (!indexes.interfaces.has(constraint.interfaceRevisionId)) {
    issue(
      issues,
      "unresolved-reference",
      `${path}.interfaceRevisionId`,
      `Unknown interface revision ${constraint.interfaceRevisionId}`,
    );
  }
};

const emitsEvents = (mode: InterfaceOperationMode) =>
  mode === "watch-start" || mode === "subscribe";

const validateOperationEventShape = (
  issues: CapabilityValidationIssue[],
  operation: Pick<InterfaceOperation, "mode" | "eventType">,
  path: string,
) => {
  if (emitsEvents(operation.mode) && operation.eventType === undefined) {
    issue(
      issues,
      "invalid-operation",
      `${path}.eventType`,
      `${operation.mode} operations require an event type`,
    );
  }
  if (!emitsEvents(operation.mode) && operation.eventType !== undefined) {
    issue(
      issues,
      "invalid-operation",
      `${path}.eventType`,
      `${operation.mode} operations must not declare an event type`,
    );
  }
};

interface OperationSignature {
  mode: InterfaceOperationMode;
  inputType: ValueType;
  outputType: ValueType;
  eventType?: ValueType;
}

const signaturesMatch = (
  operation: OperationSignature,
  implementation: OperationSignature,
) =>
  operation.mode === implementation.mode &&
  valueTypesEqual(operation.inputType, implementation.inputType) &&
  valueTypesEqual(operation.outputType, implementation.outputType) &&
  (operation.eventType === undefined
    ? implementation.eventType === undefined
    : implementation.eventType !== undefined &&
      valueTypesEqual(operation.eventType, implementation.eventType));

const describeSignature = (signature: OperationSignature) => {
  const event = signature.eventType
    ? ` emits ${typeLabel(signature.eventType)}`
    : "";
  return `${signature.mode} ${typeLabel(signature.inputType)} -> ${typeLabel(signature.outputType)}${event}`;
};

export const statePrimitiveSignature = (
  slot: StateSlotDefinition,
  primitive: StatePrimitive,
): OperationSignature => {
  const writeType =
    slot.storagePolicy.kind === "crdt-document"
      ? slot.storagePolicy.updateType
      : slot.valueType;
  switch (primitive) {
    case "read":
      return {
        mode: "call",
        inputType: valueType.unit,
        outputType: slot.valueType,
      };
    case "write":
      return {
        mode: "call",
        inputType: writeType,
        outputType: valueType.unit,
      };
    case "watch-start":
      return {
        mode: "watch-start",
        inputType: valueType.unit,
        outputType: valueType.watchHandle,
        eventType: slot.valueType,
      };
    case "watch-stop":
      return {
        mode: "watch-stop",
        inputType: valueType.watchHandle,
        outputType: valueType.unit,
      };
  }
};

const constraintValueType = (constraint: EdgeEndpointConstraint): ValueType =>
  constraint.kind === "atom"
    ? valueType.atomRef(constraint.atomId)
    : valueType.interfaceRef(constraint.interfaceRevisionId);

export const cardinalityValueType = (
  constraint: EdgeEndpointConstraint,
  cardinality: EdgeCardinality,
): ValueType => {
  const target = constraintValueType(constraint);
  switch (cardinality) {
    case "exactly-one":
      return target;
    case "optional-one":
      return valueType.optional(target);
    case "many":
    case "many-unique":
      return valueType.list(target);
  }
};

const edgeProjection = (
  edge: EdgeDefinition,
  projectionId: EdgeProjectionId,
) => {
  const index = edge.endpoints.findIndex(
    (endpoint) => endpoint.projectionId === projectionId,
  );
  if (index !== 0 && index !== 1) {
    return undefined;
  }
  const endpointIndex = index as 0 | 1;
  return {
    endpoint: edge.endpoints[endpointIndex],
    target: edge.endpoints[endpointIndex === 0 ? 1 : 0],
    endpointIndex,
  };
};

export const edgePrimitiveSignature = (
  edge: EdgeDefinition,
  projectionId: EdgeProjectionId,
  primitive: EdgePrimitive,
): OperationSignature | undefined => {
  const projection = edgeProjection(edge, projectionId);
  if (!projection) {
    return undefined;
  }
  const targetType = constraintValueType(projection.target.constraint);
  const resolvedType = cardinalityValueType(
    projection.target.constraint,
    projection.endpoint.cardinality,
  );
  switch (primitive) {
    case "resolve":
      return {
        mode: "call",
        inputType: valueType.unit,
        outputType: resolvedType,
      };
    case "connect":
    case "disconnect":
      return {
        mode: "call",
        inputType: targetType,
        outputType: valueType.unit,
      };
    case "watch-start":
      return {
        mode: "watch-start",
        inputType: valueType.unit,
        outputType: valueType.watchHandle,
        eventType: resolvedType,
      };
    case "watch-stop":
      return {
        mode: "watch-stop",
        inputType: valueType.watchHandle,
        outputType: valueType.unit,
      };
  }
};

const atomSatisfiesConstraint = (
  atomId: AtomId,
  constraint: EdgeEndpointConstraint,
  conformances: ReadonlyMap<string, Conformance>,
) =>
  constraint.kind === "atom"
    ? constraint.atomId === atomId
    : conformances.has(conformanceKey(atomId, constraint.interfaceRevisionId));

const constraintSatisfiesConstraint = (
  actual: EdgeEndpointConstraint,
  required: EdgeEndpointConstraint,
  conformances: ReadonlyMap<string, Conformance>,
) => constraintsEqual(actual, required) || (
  actual.kind === "atom" &&
  required.kind === "interface" &&
  atomSatisfiesConstraint(actual.atomId, required, conformances)
);

const canAccessAttachment = (
  owner: AttachmentOwner,
  conformance: Pick<Conformance, "atomId" | "interfaceRevisionId"> | undefined,
) =>
  owner.kind === "workspace" || (
    conformance !== undefined &&
    owner.atomId === conformance.atomId &&
    owner.interfaceRevisionId === conformance.interfaceRevisionId
  );

const collectIdentityIndexes = (
  workspace: WorkspaceRevision,
  issues: CapabilityValidationIssue[],
): ValidationIndexes => {
  const atoms = new Map<string, WorkspaceRevision["atoms"][number]>();
  for (const [index, atom] of workspace.atoms.entries()) {
    const path = `atoms[${index}]`;
    requireText(issues, atom.id, `${path}.id`, "Atom ID");
    requireText(issues, atom.displayName, `${path}.displayName`, "Atom name");
    if (atoms.has(atom.id)) {
      issue(issues, "duplicate-atom", `${path}.id`, `Duplicate atom ${atom.id}`);
    } else {
      atoms.set(atom.id, atom);
    }
  }

  const interfaces = new Map<string, InterfaceIndexEntry>();
  for (const [interfaceIndex, revision] of workspace.interfaceImports.entries()) {
    const path = `interfaceImports[${interfaceIndex}]`;
    requireText(issues, revision.interfaceId, `${path}.interfaceId`, "Interface ID");
    requireText(
      issues,
      revision.revisionId,
      `${path}.revisionId`,
      "Interface revision ID",
    );
    requireText(issues, revision.displayName, `${path}.displayName`, "Interface name");
    validateSource(issues, revision.source, `${path}.source`);
    const memberIds = new Set<string>();
    const operations = new Map<OperationId, InterfaceOperationEntry>();
    for (const [memberIndex, member] of revision.members.entries()) {
      const memberPath = `${path}.members[${memberIndex}]`;
      requireText(issues, member.id, `${memberPath}.id`, "Member ID");
      requireText(issues, member.displayName, `${memberPath}.displayName`, "Member name");
      if (memberIds.has(member.id)) {
        issue(
          issues,
          "duplicate-interface-member",
          `${memberPath}.id`,
          `Duplicate member ${member.id}`,
        );
      }
      memberIds.add(member.id);
      for (const [operationIndex, operation] of member.operations.entries()) {
        const operationPath = `${memberPath}.operations[${operationIndex}]`;
        requireText(issues, operation.id, `${operationPath}.id`, "Operation ID");
        requireText(
          issues,
          operation.displayName,
          `${operationPath}.displayName`,
          "Operation name",
        );
        validateOperationEventShape(issues, operation, operationPath);
        if (operations.has(operation.id)) {
          issue(
            issues,
            "duplicate-interface-operation",
            `${operationPath}.id`,
            `Duplicate operation ${operation.id}`,
          );
        } else {
          operations.set(operation.id, { operation, member });
        }
      }
    }
    if (interfaces.has(revision.revisionId)) {
      issue(
        issues,
        "duplicate-interface-revision",
        `${path}.revisionId`,
        `Duplicate interface revision ${revision.revisionId}`,
      );
    } else {
      interfaces.set(revision.revisionId, { revision, operations });
    }
  }

  const packages = new Map<string, PackageIndexEntry>();
  for (const [packageIndex, revision] of workspace.packageImports.entries()) {
    const path = `packageImports[${packageIndex}]`;
    if (revision.semanticMajor !== undefined && (!Number.isSafeInteger(revision.semanticMajor) || revision.semanticMajor < 1)) {
      issue(issues, "invalid-semantic-major", `${path}.semanticMajor`, "Semantic major must be a positive safe integer");
    }
    requireText(issues, revision.packageId, `${path}.packageId`, "Package ID");
    requireText(
      issues,
      revision.revisionId,
      `${path}.revisionId`,
      "Package revision ID",
    );
    requireText(issues, revision.displayName, `${path}.displayName`, "Package name");
    validateSource(issues, revision.source, `${path}.source`);
    const exports = new Map<string, PackageExport>();
    for (const [exportIndex, entry] of revision.exports.entries()) {
      const exportPath = `${path}.exports[${exportIndex}]`;
      requireText(issues, entry.id, `${exportPath}.id`, "Package export ID");
      requireText(issues, entry.displayName, `${exportPath}.displayName`, "Package export name");
      if (exports.has(entry.id)) {
        issue(
          issues,
          "duplicate-package-export",
          `${exportPath}.id`,
          `Duplicate package export ${entry.id}`,
        );
      } else {
        exports.set(entry.id, entry);
      }
      const portIds = new Set<string>();
      for (const [portIndex, port] of entry.dependencyPorts.entries()) {
        const portPath = `${exportPath}.dependencyPorts[${portIndex}]`;
        requireText(issues, port.id, `${portPath}.id`, "Dependency port ID");
        requireText(issues, port.displayName, `${portPath}.displayName`, "Dependency port name");
        if (portIds.has(port.id)) {
          issue(
            issues,
            "duplicate-dependency-port",
            `${portPath}.id`,
            `Duplicate dependency port ${port.id}`,
          );
        }
        portIds.add(port.id);
      }
    }
    if (packages.has(revision.revisionId)) {
      issue(
        issues,
        "duplicate-package-revision",
        `${path}.revisionId`,
        `Duplicate package revision ${revision.revisionId}`,
      );
    } else {
      packages.set(revision.revisionId, { revision, exports });
    }
  }

  const conformances = new Map<string, Conformance>();
  const conformancePaths = new Map<string, string>();
  const conformanceIds = new Set<string>();
  for (const [index, conformance] of workspace.conformances.entries()) {
    const path = `conformances[${index}]`;
    if (conformance.semanticMajor !== undefined && (!Number.isSafeInteger(conformance.semanticMajor) || conformance.semanticMajor < 1)) {
      issue(issues, "invalid-semantic-major", `${path}.semanticMajor`, "Semantic major must be a positive safe integer");
    }
    if (conformance.id !== undefined) {
      requireText(issues, conformance.id, `${path}.id`, "Conformance ID");
      if (conformanceIds.has(conformance.id)) issue(issues, "duplicate-conformance-id", `${path}.id`, `Duplicate conformance ID ${conformance.id}`);
      conformanceIds.add(conformance.id);
    }
    const key = conformanceKey(conformance.atomId, conformance.interfaceRevisionId);
    if (conformances.has(key)) {
      issue(
        issues,
        "duplicate-conformance",
        path,
        `Duplicate conformance for ${conformance.atomId} as ${conformance.interfaceRevisionId}`,
      );
    } else {
      conformances.set(key, conformance);
      conformancePaths.set(key, path);
    }
  }

  const constructors = new Map<AtomId, AtomConstructorBinding>();
  for (const [index, constructor] of workspace.constructors.entries()) {
    const path = `constructors[${index}]`;
    if (constructors.has(constructor.atomId)) {
      issue(
        issues,
        "duplicate-constructor",
        path,
        `Atom ${constructor.atomId} has more than one constructor`,
      );
    } else {
      constructors.set(constructor.atomId, constructor);
    }
  }

  const attachments = new Map<string, AttachmentIndexEntry>();
  const projections = new Map<
    string,
    { edge: EdgeDefinition; endpoint: EdgeEndpoint; endpointIndex: 0 | 1 }
  >();
  const addAttachment = (
    attachment: PersistentAttachment,
    owner: AttachmentOwner,
    path: string,
  ) => {
    const key = attachmentKey(attachment);
    if (attachments.has(key)) {
      issue(
        issues,
        "duplicate-attachment",
        `${path}.id`,
        `Duplicate ${attachment.kind} attachment ${attachment.id}`,
      );
    } else {
      attachments.set(key, { attachment, owner, path });
    }
    if (attachment.kind === "edge") {
      for (const [endpointIndex, endpoint] of attachment.endpoints.entries()) {
        const endpointPath = `${path}.endpoints[${endpointIndex}]`;
        if (projections.has(endpoint.projectionId)) {
          issue(
            issues,
            "duplicate-projection",
            `${endpointPath}.projectionId`,
            `Duplicate edge projection ${endpoint.projectionId}`,
          );
        } else {
          projections.set(endpoint.projectionId, {
            edge: attachment,
            endpoint,
            endpointIndex: endpointIndex as 0 | 1,
          });
        }
      }
    }
  };
  for (const [index, attachment] of workspace.sharedAttachments.entries()) {
    addAttachment(attachment, { kind: "workspace" }, `sharedAttachments[${index}]`);
  }
  for (const [conformanceIndex, conformance] of workspace.conformances.entries()) {
    for (const [attachmentIndex, attachment] of conformance.privateAttachments.entries()) {
      addAttachment(
        attachment,
        {
          kind: "conformance",
          atomId: conformance.atomId,
          interfaceRevisionId: conformance.interfaceRevisionId,
        },
        `conformances[${conformanceIndex}].privateAttachments[${attachmentIndex}]`,
      );
    }
  }

  return {
    atoms,
    interfaces,
    packages,
    conformances,
    conformancePaths,
    attachments,
    projections,
    constructors,
  };
};

const validateInterfaces = (
  workspace: WorkspaceRevision,
  issues: CapabilityValidationIssue[],
  indexes: ValidationIndexes,
) => {
  for (const [interfaceIndex, revision] of workspace.interfaceImports.entries()) {
    const path = `interfaceImports[${interfaceIndex}]`;
    for (const [memberIndex, member] of revision.members.entries()) {
      const memberPath = `${path}.members[${memberIndex}]`;
      if (member.kind === "value") {
        validateValueType(issues, member.valueType, `${memberPath}.valueType`, indexes);
      } else if (member.kind === "relationship") {
        validateConstraint(issues, member.target, `${memberPath}.target`, indexes);
      } else {
        validateValueType(issues, member.inputType, `${memberPath}.inputType`, indexes);
        validateValueType(issues, member.outputType, `${memberPath}.outputType`, indexes);
      }
      for (const [operationIndex, operation] of member.operations.entries()) {
        const operationPath = `${memberPath}.operations[${operationIndex}]`;
        validateValueType(issues, operation.inputType, `${operationPath}.inputType`, indexes);
        validateValueType(issues, operation.outputType, `${operationPath}.outputType`, indexes);
        if (operation.eventType) {
          validateValueType(issues, operation.eventType, `${operationPath}.eventType`, indexes);
        }
      }
    }
  }
};

const validateAttachments = (
  issues: CapabilityValidationIssue[],
  indexes: ValidationIndexes,
) => {
  for (const { attachment, owner, path } of indexes.attachments.values()) {
    requireText(issues, attachment.id, `${path}.id`, `${attachment.kind} attachment ID`);
    requireText(issues, attachment.displayName, `${path}.displayName`, `${attachment.kind} name`);
    if (attachment.kind === "state") {
      if (!indexes.atoms.has(attachment.attachedTo)) {
        issue(
          issues,
          "unresolved-reference",
          `${path}.attachedTo`,
          `Unknown atom ${attachment.attachedTo}`,
        );
      }
      validateValueType(issues, attachment.valueType, `${path}.valueType`, indexes);
      const containsRpcType = (type: ValueType): boolean => type.kind === "object-ref" || type.kind === "record" || ((type.kind === "optional" || type.kind === "list") && containsRpcType(type.value));
      if (containsRpcType(attachment.valueType) || (attachment.storagePolicy.kind === "crdt-document" && containsRpcType(attachment.storagePolicy.updateType))) {
        issue(issues, "invalid-attachment", `${path}.valueType`, "Managed object references belong in graph relationships, not ordinary state; record types are RPC-only");
      }
      if (attachment.storagePolicy.kind === "crdt-document") {
        validateValueType(
          issues,
          attachment.storagePolicy.updateType,
          `${path}.storagePolicy.updateType`,
          indexes,
        );
      }
      if (owner.kind === "conformance") {
        if (attachment.attachedTo !== owner.atomId) {
          issue(
            issues,
            "invalid-attachment",
            `${path}.attachedTo`,
            `Private state must attach to its conformance atom ${owner.atomId}`,
          );
        }
      }
      continue;
    }

    if (attachment.endpoints.length !== 2) {
      issue(
        issues,
        "invalid-attachment",
        `${path}.endpoints`,
        `Edge ${attachment.id} must have exactly two endpoints`,
      );
    }
    for (const [endpointIndex, endpoint] of attachment.endpoints.entries()) {
      const endpointPath = `${path}.endpoints[${endpointIndex}]`;
      if (endpoint.keyType !== undefined && (!["string", "boolean", "int64"].includes(endpoint.keyType) || endpoint.ordered || !["many", "many-unique"].includes(endpoint.cardinality))) {
        issue(issues, "invalid-attachment", `${endpointPath}.keyType`, "Keyed projections require string/boolean/int64 keys, many cardinality, and no ordering");
      }
      requireText(issues, endpoint.projectionId, `${endpointPath}.projectionId`, "Projection ID");
      if (endpoint.onDelete !== undefined && !["restrict", "detach", "cascade-other"].includes(endpoint.onDelete)) {
        issue(issues, "invalid-attachment", `${endpointPath}.onDelete`, "Deletion policy must be restrict, detach, or cascade-other");
      }
      requireText(issues, endpoint.displayName, `${endpointPath}.displayName`, "Projection name");
      validateConstraint(issues, endpoint.constraint, `${endpointPath}.constraint`, indexes);
    }
    if (attachment.endpoints.every((endpoint) => endpoint.keyType)) issue(issues, "invalid-attachment", `${path}.endpoints`, "A v0 map has one keyed projection and one unkeyed inverse");
    if (owner.kind === "conformance") {
      if (
        !attachment.endpoints.some((endpoint) =>
          atomSatisfiesConstraint(owner.atomId, endpoint.constraint, indexes.conformances),
        )
      ) {
        issue(
          issues,
          "invalid-attachment",
          `${path}.endpoints`,
          `Private edge has no endpoint compatible with conformance atom ${owner.atomId}`,
        );
      }
    }
  }
};

const uniquePrimitiveList = (
  issues: CapabilityValidationIssue[],
  primitives: readonly string[],
  path: string,
) => {
  if (primitives.length === 0) {
    issue(issues, "invalid-dependency-binding", path, "Dependency port requires at least one primitive");
  }
  const seen = new Set<string>();
  for (const primitive of primitives) {
    if (seen.has(primitive)) {
      issue(
        issues,
        "invalid-dependency-binding",
        path,
        `Dependency primitive ${primitive} is listed more than once`,
      );
    }
    seen.add(primitive);
  }
};

const validatePackages = (
  workspace: WorkspaceRevision,
  issues: CapabilityValidationIssue[],
  indexes: ValidationIndexes,
) => {
  for (const [packageIndex, revision] of workspace.packageImports.entries()) {
    const path = `packageImports[${packageIndex}]`;
    for (const [exportIndex, entry] of revision.exports.entries()) {
      const exportPath = `${path}.exports[${exportIndex}]`;
      validateValueType(issues, entry.inputType, `${exportPath}.inputType`, indexes);
      validateValueType(issues, entry.outputType, `${exportPath}.outputType`, indexes);
      if (entry.kind === "operation") {
        validateOperationEventShape(issues, entry, exportPath);
        if (entry.eventType) {
          validateValueType(issues, entry.eventType, `${exportPath}.eventType`, indexes);
        }
        if (entry.receiverRequirement.kind === "exact-atom") {
          if (!indexes.atoms.has(entry.receiverRequirement.atomId)) {
            issue(
              issues,
              "unresolved-reference",
              `${exportPath}.receiverRequirement.atomId`,
              `Unknown atom ${entry.receiverRequirement.atomId}`,
            );
          }
        } else if (entry.receiverRequirement.kind === "all-interfaces") {
          const seen = new Set<string>();
          for (const [requirementIndex, interfaceRevisionId] of
            entry.receiverRequirement.interfaceRevisionIds.entries()) {
            const requirementPath = `${exportPath}.receiverRequirement.interfaceRevisionIds[${requirementIndex}]`;
            if (!indexes.interfaces.has(interfaceRevisionId)) {
              issue(
                issues,
                "unresolved-reference",
                requirementPath,
                `Unknown interface revision ${interfaceRevisionId}`,
              );
            }
            if (seen.has(interfaceRevisionId)) {
              issue(
                issues,
                "invalid-operation",
                requirementPath,
                `Receiver interface ${interfaceRevisionId} is duplicated`,
              );
            }
            seen.add(interfaceRevisionId);
          }
        }
      } else if (entry.kind === "constructor") {
        if (!indexes.atoms.has(entry.constructsAtom)) {
          issue(
            issues,
            "unresolved-reference",
            `${exportPath}.constructsAtom`,
            `Unknown atom ${entry.constructsAtom}`,
          );
        }
        const expected = valueType.atomRef(entry.constructsAtom);
        if (!valueTypesEqual(entry.outputType, expected)) {
          issue(
            issues,
            "invalid-constructor",
            `${exportPath}.outputType`,
            `Constructor must return ${typeLabel(expected)}, not ${typeLabel(entry.outputType)}`,
          );
        }
      }

      for (const [portIndex, port] of entry.dependencyPorts.entries()) {
        const portPath = `${exportPath}.dependencyPorts[${portIndex}]`;
        switch (port.requirement.kind) {
          case "state":
            validateValueType(issues, port.requirement.valueType, `${portPath}.requirement.valueType`, indexes);
            uniquePrimitiveList(issues, port.requirement.primitives, `${portPath}.requirement.primitives`);
            break;
          case "edge":
            validateConstraint(issues, port.requirement.target, `${portPath}.requirement.target`, indexes);
            uniquePrimitiveList(issues, port.requirement.primitives, `${portPath}.requirement.primitives`);
            break;
          case "interface":
            if (!indexes.interfaces.has(port.requirement.interfaceRevisionId)) {
              issue(
                issues,
                "unresolved-reference",
                `${portPath}.requirement.interfaceRevisionId`,
                `Unknown interface revision ${port.requirement.interfaceRevisionId}`,
              );
            }
            break;
          case "constructor":
            if (port.requirement.inputType) validateValueType(issues, port.requirement.inputType, `${portPath}.requirement.inputType`, indexes);
            if (!indexes.atoms.has(port.requirement.atomId)) {
              issue(
                issues,
                "unresolved-reference",
                `${portPath}.requirement.atomId`,
                `Unknown atom ${port.requirement.atomId}`,
              );
            }
        }
      }
    }
  }
};

const findAttachment = <Kind extends PersistentAttachment["kind"]>(
  indexes: ValidationIndexes,
  kind: Kind,
  id: Kind extends "state" ? SlotId : EdgeTypeId,
): AttachmentIndexEntry | undefined => indexes.attachments.get(`${kind}\u0000${id}`);

const validateAttachmentAccess = (
  issues: CapabilityValidationIssue[],
  entry: AttachmentIndexEntry,
  conformance: Pick<Conformance, "atomId" | "interfaceRevisionId"> | undefined,
  path: string,
) => {
  if (!canAccessAttachment(entry.owner, conformance)) {
    issue(
      issues,
      "private-attachment-access",
      path,
      `Attachment ${entry.attachment.id} is private to conformance ${
        entry.owner.kind === "conformance"
          ? `${entry.owner.atomId} as ${entry.owner.interfaceRevisionId}`
          : ""
      }`,
    );
    return false;
  }
  return true;
};

const validateTraversal = (
  issues: CapabilityValidationIssue[],
  indexes: ValidationIndexes,
  atomId: AtomId,
  traversal: { edgeTypeId: EdgeTypeId; projectionId: EdgeProjectionId },
  path: string,
  conformance?: Pick<Conformance, "atomId" | "interfaceRevisionId">,
) => {
  const attachment = findAttachment(indexes, "edge", traversal.edgeTypeId);
  if (!attachment || attachment.attachment.kind !== "edge") {
    issue(
      issues,
      "invalid-dependency-binding",
      `${path}.edgeTypeId`,
      `Unknown traversal edge ${traversal.edgeTypeId}`,
    );
    return undefined;
  }
  const projection = edgeProjection(attachment.attachment, traversal.projectionId);
  if (!projection) {
    issue(
      issues,
      "invalid-dependency-binding",
      `${path}.projectionId`,
      `Traversal projection ${traversal.projectionId} is not on edge ${traversal.edgeTypeId}`,
    );
    return undefined;
  }
  if (!projection.endpoint.publicTraversal) validateAttachmentAccess(issues, attachment, conformance, `${path}.edgeTypeId`);
  if (!atomSatisfiesConstraint(atomId, projection.endpoint.constraint, indexes.conformances)) {
    issue(
      issues,
      "invalid-dependency-binding",
      `${path}.projectionId`,
      `Traversal projection ${traversal.projectionId} cannot originate at receiver atom ${atomId}`,
    );
  }
  if (projection.endpoint.cardinality !== "exactly-one") {
    issue(
      issues,
      "invalid-dependency-binding",
      `${path}.projectionId`,
      "Dependency traversal must select exactly one object",
    );
  }
  return projection;
};

const validateBoundDependencies = (
  issues: CapabilityValidationIssue[],
  params: {
    dependencies: BoundDependency[];
    dependencyPorts: DependencyPort[];
    atomId: AtomId;
    conformance?: Pick<Conformance, "atomId" | "interfaceRevisionId">;
    path: string;
    indexes: ValidationIndexes;
    requirementGraph: Map<string, Set<string>>;
    graphSourceKey?: string;
  },
) => {
  const ports = new Map(params.dependencyPorts.map((port) => [port.id, port]));
  const bindings = new Map<string, BoundDependency>();
  for (const [index, dependency] of params.dependencies.entries()) {
    const path = `${params.path}.dependencies[${index}]`;
    if (bindings.has(dependency.portId)) {
      issue(
        issues,
        "invalid-dependency-binding",
        `${path}.portId`,
        `Dependency port ${dependency.portId} is bound more than once`,
      );
      continue;
    }
    bindings.set(dependency.portId, dependency);
    const port = ports.get(dependency.portId);
    if (!port) {
      issue(
        issues,
        "invalid-dependency-binding",
        `${path}.portId`,
        `Unknown dependency port ${dependency.portId}`,
      );
      continue;
    }
    const requirement = port.requirement;
    const binding = dependency.binding;
    if (requirement.kind !== binding.kind) {
      issue(
        issues,
        "invalid-dependency-binding",
        `${path}.binding`,
        `Port ${port.id} requires ${requirement.kind}, not ${binding.kind}`,
      );
      continue;
    }
    switch (requirement.kind) {
      case "state": {
        const stateBinding = binding as Extract<DependencyBinding, { kind: "state" }>;
        const attachment = findAttachment(params.indexes, "state", stateBinding.slotId);
        if (!attachment || attachment.attachment.kind !== "state") {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding.slotId`,
            `Unknown state attachment ${stateBinding.slotId}`,
          );
          break;
        }
        validateAttachmentAccess(issues, attachment, params.conformance, `${path}.binding.slotId`);
        const traversal = stateBinding.via
          ? validateTraversal(
              issues,
              params.indexes,
              params.atomId,
              stateBinding.via,
              `${path}.binding.via`,
              params.conformance,
            )
          : undefined;
        if (
          stateBinding.via
            ? traversal && !atomSatisfiesConstraint(
                attachment.attachment.attachedTo,
                traversal.target.constraint,
                params.indexes.conformances,
              )
            : attachment.attachment.attachedTo !== params.atomId
        ) {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding.slotId`,
            stateBinding.via
              ? `State ${stateBinding.slotId} is not attached to the traversal target`
              : `State ${stateBinding.slotId} is not attached to receiver atom ${params.atomId}`,
          );
        }
        if (!valueTypesEqual(requirement.valueType, attachment.attachment.valueType)) {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding.slotId`,
            `State port expects ${typeLabel(requirement.valueType)}, not ${typeLabel(attachment.attachment.valueType)}`,
          );
        }
        break;
      }
      case "edge": {
        const edgeBinding = binding as Extract<DependencyBinding, { kind: "edge" }>;
        const attachment = findAttachment(params.indexes, "edge", edgeBinding.edgeTypeId);
        if (!attachment || attachment.attachment.kind !== "edge") {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding.edgeTypeId`,
            `Unknown edge attachment ${edgeBinding.edgeTypeId}`,
          );
          break;
        }
        validateAttachmentAccess(issues, attachment, params.conformance, `${path}.binding.edgeTypeId`);
        const projection = edgeProjection(attachment.attachment, edgeBinding.projectionId);
        if (!projection) {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding.projectionId`,
            `Projection ${edgeBinding.projectionId} is not on edge ${edgeBinding.edgeTypeId}`,
          );
          break;
        }
        const traversal = edgeBinding.via
          ? validateTraversal(
              issues,
              params.indexes,
              params.atomId,
              edgeBinding.via,
              `${path}.binding.via`,
              params.conformance,
            )
          : undefined;
        const originMatches = edgeBinding.via
          ? traversal && (
              projection.endpoint.constraint.kind === "atom"
                ? atomSatisfiesConstraint(
                    projection.endpoint.constraint.atomId,
                    traversal.target.constraint,
                    params.indexes.conformances,
                  )
                : constraintsEqual(projection.endpoint.constraint, traversal.target.constraint)
            )
          : atomSatisfiesConstraint(
              params.atomId,
              projection.endpoint.constraint,
              params.indexes.conformances,
            );
        if (!originMatches) {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding.projectionId`,
            edgeBinding.via
              ? `Projection ${edgeBinding.projectionId} cannot originate at the traversal target`
              : `Projection ${edgeBinding.projectionId} cannot originate at receiver atom ${params.atomId}`,
          );
        }
        if (
          !constraintSatisfiesConstraint(
            projection.target.constraint,
            requirement.target,
            params.indexes.conformances,
          ) ||
          requirement.cardinality !== projection.endpoint.cardinality
        ) {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding`,
            `Edge port target or cardinality does not match projection ${edgeBinding.projectionId}`,
          );
        }
        break;
      }
      case "interface": {
        const interfaceBinding = binding as Extract<
          DependencyBinding,
          { kind: "interface" }
        >;
        if (interfaceBinding.interfaceRevisionId !== requirement.interfaceRevisionId) {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding.interfaceRevisionId`,
            `Interface port requires ${requirement.interfaceRevisionId}`,
          );
          break;
        }
        const traversal = interfaceBinding.via
          ? validateTraversal(
              issues,
              params.indexes,
              params.atomId,
              interfaceBinding.via,
              `${path}.binding.via`,
              params.conformance,
            )
          : undefined;
        const candidateAtoms = interfaceBinding.via
          ? traversal
            ? [...params.indexes.atoms.keys()].filter((atomId) =>
                atomSatisfiesConstraint(
                  atomId as AtomId,
                  traversal.target.constraint,
                  params.indexes.conformances,
                )) as AtomId[]
            : []
          : [params.atomId];
        for (const atomId of candidateAtoms) {
          const targetKey = conformanceKey(atomId, requirement.interfaceRevisionId);
          if (!params.indexes.conformances.has(targetKey)) {
            issue(
              issues,
              "unsatisfied-interface",
              `${path}.binding.interfaceRevisionId`,
              `${interfaceBinding.via ? "Related" : "Receiver"} atom ${atomId} does not conform to ${requirement.interfaceRevisionId}`,
            );
          } else if (params.graphSourceKey) {
            params.requirementGraph.get(params.graphSourceKey)?.add(targetKey);
          }
        }
        break;
      }
      case "constructor": {
        const constructorBinding = binding as Extract<DependencyBinding, { kind: "constructor" }>;
        if (constructorBinding.atomId !== requirement.atomId) {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding.atomId`,
            `Constructor port requires atom ${requirement.atomId}`,
          );
        }
        if (!params.indexes.constructors.has(requirement.atomId)) {
          issue(
            issues,
            "invalid-dependency-binding",
            `${path}.binding.atomId`,
            `Atom ${requirement.atomId} has no constructor binding`,
          );
        }
        if (requirement.inputType) {
          const selected = params.indexes.constructors.get(requirement.atomId);
          const implementation = selected ? params.indexes.packages.get(selected.packageRevisionId)?.exports.get(selected.exportId) : undefined;
          if (implementation && !valueTypesEqual(requirement.inputType, implementation.inputType)) {
            issue(issues, "invalid-dependency-binding", `${path}.binding.atomId`,
              `Constructor port requires input ${typeLabel(requirement.inputType)}, but selected constructor accepts ${typeLabel(implementation.inputType)}`);
          }
        }
        break;
      }
    }
  }
  for (const port of params.dependencyPorts) {
    if (!bindings.has(port.id)) {
      issue(
        issues,
        "invalid-dependency-binding",
        `${params.path}.dependencies`,
        `Missing binding for dependency port ${port.id}`,
      );
    }
  }
};

const validatePackageReceiver = (
  issues: CapabilityValidationIssue[],
  params: {
    entry: PackageOperationExport;
    atomId: AtomId;
    path: string;
    indexes: ValidationIndexes;
    requirementGraph: Map<string, Set<string>>;
    graphSourceKey: string;
  },
) => {
  const receiver = params.entry.receiverRequirement;
  if (receiver.kind === "exact-atom" && receiver.atomId !== params.atomId) {
    issue(
      issues,
      "incompatible-package-receiver",
      params.path,
      `Package export requires atom ${receiver.atomId}, not ${params.atomId}`,
    );
  }
  if (receiver.kind === "all-interfaces") {
    for (const requiredInterface of receiver.interfaceRevisionIds) {
      const targetKey = conformanceKey(params.atomId, requiredInterface);
      if (!params.indexes.conformances.has(targetKey)) {
        issue(
          issues,
          "unsatisfied-interface",
          params.path,
          `Atom ${params.atomId} does not conform to ${requiredInterface}`,
        );
      } else {
        params.requirementGraph.get(params.graphSourceKey)?.add(targetKey);
      }
    }
  }
};

const validateConformances = (
  workspace: WorkspaceRevision,
  issues: CapabilityValidationIssue[],
  indexes: ValidationIndexes,
) => {
  const requirementGraph = new Map<string, Set<string>>();
  for (const key of indexes.conformances.keys()) {
    requirementGraph.set(key, new Set());
  }

  for (const [index, conformance] of workspace.conformances.entries()) {
    const path = `conformances[${index}]`;
    const key = conformanceKey(conformance.atomId, conformance.interfaceRevisionId);
    if (!indexes.atoms.has(conformance.atomId)) {
      issue(
        issues,
        "unresolved-reference",
        `${path}.atomId`,
        `Unknown atom ${conformance.atomId}`,
      );
    }
    const interfaceEntry = indexes.interfaces.get(conformance.interfaceRevisionId);
    if (!interfaceEntry) {
      issue(
        issues,
        "unresolved-reference",
        `${path}.interfaceRevisionId`,
        `Unknown interface revision ${conformance.interfaceRevisionId}`,
      );
      continue;
    }

    const bindings = new Map<OperationId, Binding>();
    for (const [bindingIndex, entry] of conformance.operationBindings.entries()) {
      const bindingPath = `${path}.operationBindings[${bindingIndex}]`;
      if (bindings.has(entry.operationId)) {
        issue(
          issues,
          "duplicate-operation-binding",
          `${bindingPath}.operationId`,
          `Operation ${entry.operationId} is bound more than once`,
        );
        continue;
      }
      bindings.set(entry.operationId, entry.binding);
      const operationEntry = interfaceEntry.operations.get(entry.operationId);
      if (!operationEntry) {
        issue(
          issues,
          "unknown-operation-binding",
          `${bindingPath}.operationId`,
          `Operation ${entry.operationId} does not belong to interface ${conformance.interfaceRevisionId}`,
        );
        continue;
      }
      const operation = operationEntry.operation;
      const binding = entry.binding;
      if (binding.kind === "state") {
        const attachment = findAttachment(indexes, "state", binding.slotId);
        if (!attachment || attachment.attachment.kind !== "state") {
          issue(
            issues,
            "invalid-state-binding",
            `${bindingPath}.binding.slotId`,
            `Unknown state attachment ${binding.slotId}`,
          );
          continue;
        }
        validateAttachmentAccess(issues, attachment, conformance, `${bindingPath}.binding.slotId`);
        if (attachment.attachment.attachedTo !== conformance.atomId) {
          issue(
            issues,
            "invalid-state-binding",
            `${bindingPath}.binding.slotId`,
            `State ${binding.slotId} is not attached to atom ${conformance.atomId}`,
          );
        }
        if (operationEntry.member.kind !== "value") {
          issue(
            issues,
            "invalid-state-binding",
            `${bindingPath}.binding`,
            "State primitives may only implement value members",
          );
        }
        const expected = statePrimitiveSignature(attachment.attachment, binding.primitive);
        if (!signaturesMatch(operation, expected)) {
          issue(
            issues,
            "invalid-state-binding",
            `${bindingPath}.binding`,
            `State primitive provides ${describeSignature(expected)}, but operation requires ${describeSignature(operation)}`,
          );
        }
        continue;
      }

      if (binding.kind === "edge") {
        const attachment = findAttachment(indexes, "edge", binding.edgeTypeId);
        if (!attachment || attachment.attachment.kind !== "edge") {
          issue(
            issues,
            "invalid-edge-binding",
            `${bindingPath}.binding.edgeTypeId`,
            `Unknown edge attachment ${binding.edgeTypeId}`,
          );
          continue;
        }
        validateAttachmentAccess(issues, attachment, conformance, `${bindingPath}.binding.edgeTypeId`);
        const projection = edgeProjection(attachment.attachment, binding.projectionId);
        const relationshipMember = operationEntry.member.kind === "relationship"
          ? operationEntry.member
          : undefined;
        const operationEdge = relationshipMember
          ? {
              ...attachment.attachment,
              endpoints: attachment.attachment.endpoints.map((endpoint, index) =>
                index === (projection?.endpointIndex === 0 ? 1 : 0)
                  ? { ...endpoint, constraint: relationshipMember.target }
                  : endpoint,
              ) as [EdgeEndpoint, EdgeEndpoint],
            }
          : attachment.attachment;
        const expected = edgePrimitiveSignature(
          operationEdge,
          binding.projectionId,
          binding.primitive,
        );
        if (!projection || !expected) {
          issue(
            issues,
            "invalid-edge-binding",
            `${bindingPath}.binding.projectionId`,
            `Projection ${binding.projectionId} is not on edge ${binding.edgeTypeId}`,
          );
          continue;
        }
        if (!atomSatisfiesConstraint(conformance.atomId, projection.endpoint.constraint, indexes.conformances)) {
          issue(
            issues,
            "invalid-edge-binding",
            `${bindingPath}.binding.projectionId`,
            `Projection ${binding.projectionId} cannot originate at atom ${conformance.atomId}`,
          );
        }
        if (operationEntry.member.kind !== "relationship") {
          issue(
            issues,
            "invalid-edge-binding",
            `${bindingPath}.binding`,
            "Edge primitives may only implement relationship members",
          );
        } else if (
          !constraintSatisfiesConstraint(
            projection.target.constraint,
            operationEntry.member.target,
            indexes.conformances,
          ) ||
          operationEntry.member.cardinality !== projection.endpoint.cardinality
        ) {
          issue(
            issues,
            "invalid-edge-binding",
            `${bindingPath}.binding`,
            "Edge projection target or cardinality does not match relationship member",
          );
        }
        if (!signaturesMatch(operation, expected)) {
          issue(
            issues,
            "invalid-edge-binding",
            `${bindingPath}.binding`,
            `Edge primitive provides ${describeSignature(expected)}, but operation requires ${describeSignature(operation)}`,
          );
        }
        continue;
      }

      const packageEntry = indexes.packages.get(binding.packageRevisionId);
      const packageExport = packageEntry?.exports.get(binding.exportId);
      if (!packageEntry) {
        issue(
          issues,
          "invalid-package-binding",
          `${bindingPath}.binding.packageRevisionId`,
          `Unknown package revision ${binding.packageRevisionId}`,
        );
        continue;
      }
      if (!packageExport) {
        issue(
          issues,
          "invalid-package-binding",
          `${bindingPath}.binding.exportId`,
          `Unknown export ${binding.exportId} in package ${binding.packageRevisionId}`,
        );
        continue;
      }
      if (packageExport.kind !== "operation") {
        issue(
          issues,
          "invalid-package-binding",
          `${bindingPath}.binding.exportId`,
          `Package export ${binding.exportId} is ${packageExport.kind}, not an operation`,
        );
        continue;
      }
      if (!signaturesMatch(operation, packageExport)) {
        issue(
          issues,
          "invalid-package-binding",
          `${bindingPath}.binding.exportId`,
          `Package export provides ${describeSignature(packageExport)}, but operation requires ${describeSignature(operation)}`,
        );
      }
      validatePackageReceiver(issues, {
        entry: packageExport,
        atomId: conformance.atomId,
        path: `${bindingPath}.binding.exportId`,
        indexes,
        requirementGraph,
        graphSourceKey: key,
      });
      validateBoundDependencies(issues, {
        dependencies: binding.dependencies,
        dependencyPorts: packageExport.dependencyPorts,
        atomId: conformance.atomId,
        conformance,
        path: `${bindingPath}.binding`,
        indexes,
        requirementGraph,
        graphSourceKey: key,
      });
    }

    const materializedMembers = new Set<string>();
    for (const [materializationIndex, materialization] of
      (conformance.relationshipMaterializations ?? []).entries()) {
      const materializationPath =
        `${path}.relationshipMaterializations[${materializationIndex}]`;
      if (materializedMembers.has(materialization.memberId)) {
        issue(
          issues,
          "duplicate-relationship-materialization",
          materializationPath,
          `Relationship ${materialization.memberId} has more than one materialization recipe`,
        );
        continue;
      }
      materializedMembers.add(materialization.memberId);
      const member = interfaceEntry.revision.members.find((entry) =>
        entry.id === materialization.memberId);
      if (!member || member.kind !== "relationship") {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.memberId`,
          `Member ${materialization.memberId} is not a relationship on ${conformance.interfaceRevisionId}`,
        );
        continue;
      }
      if (member.cardinality !== "optional-one") {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.memberId`,
          "A lazily constructed relationship must be optional-one before construction",
        );
      }
      const resolveOperation = member.operations.find((entry) =>
        entry.displayName === "resolve");
      const resolveBinding = resolveOperation
        ? bindings.get(resolveOperation.id)
        : undefined;
      if (!resolveBinding || resolveBinding.kind !== "edge") {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.memberId`,
          "A materialized relationship must bind its resolve operation to an edge",
        );
        continue;
      }
      if (resolveBinding.edgeTypeId !== materialization.edgeTypeId) {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.edgeTypeId`,
          "Materialization and relationship resolution must use the same edge",
        );
      }
      const attachment = findAttachment(indexes, "edge", materialization.edgeTypeId);
      if (!attachment || attachment.attachment.kind !== "edge") {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.edgeTypeId`,
          `Unknown materialization edge ${materialization.edgeTypeId}`,
        );
        continue;
      }
      validateAttachmentAccess(
        issues,
        attachment,
        conformance,
        `${materializationPath}.edgeTypeId`,
      );
      const hostProjection = edgeProjection(
        attachment.attachment,
        resolveBinding.projectionId,
      );
      const constructedProjection = edgeProjection(
        attachment.attachment,
        materialization.constructedProjectionId,
      );
      if (!hostProjection || !constructedProjection ||
          hostProjection.endpointIndex === constructedProjection.endpointIndex) {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.constructedProjectionId`,
          "Materialization must connect through the opposite projection of the resolved edge",
        );
        continue;
      }
      if (!atomSatisfiesConstraint(
        materialization.constructorAtomId,
        member.target,
        indexes.conformances,
      )) {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.constructorAtomId`,
          `Constructed atom ${materialization.constructorAtomId} does not satisfy the relationship target`,
        );
      }
      if (!atomSatisfiesConstraint(
        materialization.constructorAtomId,
        constructedProjection.endpoint.constraint,
        indexes.conformances,
      ) || !atomSatisfiesConstraint(
        conformance.atomId,
        constructedProjection.target.constraint,
        indexes.conformances,
      )) {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.constructedProjectionId`,
          "Constructed projection does not connect the constructed atom back to the host atom",
        );
      }
      const constructor = indexes.constructors.get(materialization.constructorAtomId);
      const constructorExport = constructor
        ? indexes.packages.get(constructor.packageRevisionId)?.exports.get(constructor.exportId)
        : undefined;
      if (!constructor || !constructorExport || constructorExport.kind !== "constructor") {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.constructorAtomId`,
          `Constructed atom ${materialization.constructorAtomId} has no valid constructor`,
        );
      } else if (!valueTypesEqual(
        constructorExport.inputType,
        valueType.atomRef(conformance.atomId),
      )) {
        issue(
          issues,
          "invalid-relationship-materialization",
          `${materializationPath}.constructorAtomId`,
          `Component constructor must accept ${typeLabel(valueType.atomRef(conformance.atomId))}`,
        );
      }
    }

    for (const operation of interfaceEntry.operations.values()) {
      if (!bindings.has(operation.operation.id)) {
        issue(
          issues,
          "missing-operation-binding",
          `${path}.operationBindings`,
          `Missing binding for operation ${operation.operation.id}`,
        );
      }
    }
  }

  const visitState = new Map<string, "visiting" | "visited">();
  const visit = (key: string, stack: string[]) => {
    const state = visitState.get(key);
    if (state === "visited") {
      return;
    }
    if (state === "visiting") {
      const cycleStart = stack.indexOf(key);
      const cycle = [...stack.slice(Math.max(0, cycleStart)), key];
      issue(
        issues,
        "cyclic-conformance-requirement",
        indexes.conformancePaths.get(key) ?? "conformances",
        `Cyclic conformance requirement: ${cycle.join(" -> ")}`,
      );
      return;
    }
    visitState.set(key, "visiting");
    for (const dependency of requirementGraph.get(key) ?? []) {
      visit(dependency, [...stack, key]);
    }
    visitState.set(key, "visited");
  };
  for (const key of requirementGraph.keys()) {
    visit(key, []);
  }
};

const validateConstructors = (
  workspace: WorkspaceRevision,
  issues: CapabilityValidationIssue[],
  indexes: ValidationIndexes,
) => {
  const noGraph = new Map<string, Set<string>>();
  for (const [index, constructor] of workspace.constructors.entries()) {
    const path = `constructors[${index}]`;
    if (!indexes.atoms.has(constructor.atomId)) {
      issue(issues, "invalid-constructor", `${path}.atomId`, `Unknown atom ${constructor.atomId}`);
    }
    const packageEntry = indexes.packages.get(constructor.packageRevisionId);
    const packageExport = packageEntry?.exports.get(constructor.exportId);
    if (!packageEntry) {
      issue(
        issues,
        "invalid-constructor",
        `${path}.packageRevisionId`,
        `Unknown package revision ${constructor.packageRevisionId}`,
      );
      continue;
    }
    if (!packageExport) {
      issue(
        issues,
        "invalid-constructor",
        `${path}.exportId`,
        `Unknown export ${constructor.exportId}`,
      );
      continue;
    }
    if (packageExport.kind !== "constructor") {
      issue(
        issues,
        "invalid-constructor",
        `${path}.exportId`,
        `Export ${constructor.exportId} is ${packageExport.kind}, not a constructor`,
      );
      continue;
    }
    if (packageExport.constructsAtom !== constructor.atomId) {
      issue(
        issues,
        "invalid-constructor",
        `${path}.exportId`,
        `Export constructs ${packageExport.constructsAtom}, not ${constructor.atomId}`,
      );
    }
    validateBoundDependencies(issues, {
      dependencies: constructor.dependencies,
      dependencyPorts: packageExport.dependencyPorts,
      atomId: constructor.atomId,
      path,
      indexes,
      requirementGraph: noGraph,
    });
  }
};

export const validateWorkspaceRevision = (
  workspace: WorkspaceRevision,
): CapabilityValidationIssue[] => {
  const issues: CapabilityValidationIssue[] = [];
  requireText(issues, workspace.id, "id", "Workspace revision ID");
  requireText(issues, workspace.workspaceId, "workspaceId", "Workspace ID");
  requireText(issues, workspace.sourceRootCommit, "sourceRootCommit", "Source root commit");
  const indexes = collectIdentityIndexes(workspace, issues);
  validateInterfaces(workspace, issues, indexes);
  validateAttachments(issues, indexes);
  validatePackages(workspace, issues, indexes);
  validateConformances(workspace, issues, indexes);
  validateConstructors(workspace, issues, indexes);
  return issues;
};

export interface CompiledConformance {
  source: Conformance;
  operationBindings: ReadonlyMap<OperationId, Binding>;
}

export interface CompiledWorkspaceRevision {
  source: WorkspaceRevision;
  atoms: ReadonlyMap<AtomId, WorkspaceRevision["atoms"][number]>;
  interfaces: ReadonlyMap<InterfaceRevisionId, InterfaceRevision>;
  packages: ReadonlyMap<PackageRevisionId, PackageRevision>;
  attachments: ReadonlyMap<string, OwnedAttachment>;
  conformances: ReadonlyMap<string, CompiledConformance>;
  constructors: ReadonlyMap<AtomId, AtomConstructorBinding>;
}

export type CompileWorkspaceRevisionResult =
  | { ok: true; plan: CompiledWorkspaceRevision }
  | { ok: false; issues: CapabilityValidationIssue[] };

export const compileWorkspaceRevision = (
  workspace: WorkspaceRevision,
): CompileWorkspaceRevisionResult => {
  const snapshot = structuredClone(workspace) as WorkspaceRevision;
  const issues = validateWorkspaceRevision(snapshot);
  if (issues.length > 0) {
    return { ok: false, issues };
  }

  const attachments = new Map<string, OwnedAttachment>();
  for (const attachment of snapshot.sharedAttachments) {
    attachments.set(attachmentKey(attachment), {
      attachment,
      owner: { kind: "workspace" },
    });
  }
  const conformances = new Map<string, CompiledConformance>();
  for (const conformance of snapshot.conformances) {
    for (const attachment of conformance.privateAttachments) {
      attachments.set(attachmentKey(attachment), {
        attachment,
        owner: {
          kind: "conformance",
          atomId: conformance.atomId,
          interfaceRevisionId: conformance.interfaceRevisionId,
        },
      });
    }
    conformances.set(
      conformanceKey(conformance.atomId, conformance.interfaceRevisionId),
      {
        source: conformance,
        operationBindings: new Map(
          conformance.operationBindings.map((entry) => [entry.operationId, entry.binding]),
        ),
      },
    );
  }
  return {
    ok: true,
    plan: {
      source: snapshot,
      atoms: new Map(snapshot.atoms.map((atom) => [atom.id, atom])),
      interfaces: new Map(
        snapshot.interfaceImports.map((revision) => [revision.revisionId, revision]),
      ),
      packages: new Map(
        snapshot.packageImports.map((revision) => [revision.revisionId, revision]),
      ),
      attachments,
      conformances,
      constructors: new Map(snapshot.constructors.map((entry) => [entry.atomId, entry])),
    },
  };
};

export const resolveConformance = (
  plan: CompiledWorkspaceRevision,
  atomId: AtomId,
  interfaceRevisionId: InterfaceRevisionId,
): CompiledConformance | undefined =>
  plan.conformances.get(conformanceKey(atomId, interfaceRevisionId));

export const resolveOperationBinding = (
  plan: CompiledWorkspaceRevision,
  atomId: AtomId,
  interfaceRevisionId: InterfaceRevisionId,
  operationId: OperationId,
): Binding | undefined =>
  resolveConformance(plan, atomId, interfaceRevisionId)?.operationBindings.get(
    operationId,
  );

export type ResolvedOperationPlan =
  | {
      kind: "state";
      binding: Extract<Binding, { kind: "state" }>;
      attachment: OwnedAttachment & { attachment: StateSlotDefinition };
    }
  | {
      kind: "edge";
      binding: Extract<Binding, { kind: "edge" }>;
      attachment: OwnedAttachment & { attachment: EdgeDefinition };
    }
  | {
      kind: "package";
      binding: Extract<Binding, { kind: "package" }>;
      packageRevision: PackageRevision;
      packageExport: PackageOperationExport;
      dependencies: Array<{
        port: DependencyPort;
        binding: DependencyBinding;
      }>;
    };

export const resolveOperationPlan = (
  plan: CompiledWorkspaceRevision,
  atomId: AtomId,
  interfaceRevisionId: InterfaceRevisionId,
  operationId: OperationId,
): ResolvedOperationPlan | undefined => {
  const binding = resolveOperationBinding(plan, atomId, interfaceRevisionId, operationId);
  if (!binding) {
    return undefined;
  }
  if (binding.kind === "state") {
    const owned = plan.attachments.get(`state\u0000${binding.slotId}`);
    if (!owned || owned.attachment.kind !== "state") {
      return undefined;
    }
    return {
      kind: "state",
      binding,
      attachment: owned as OwnedAttachment & {
        attachment: StateSlotDefinition;
      },
    };
  }
  if (binding.kind === "edge") {
    const owned = plan.attachments.get(`edge\u0000${binding.edgeTypeId}`);
    if (!owned || owned.attachment.kind !== "edge") {
      return undefined;
    }
    return {
      kind: "edge",
      binding,
      attachment: owned as OwnedAttachment & { attachment: EdgeDefinition },
    };
  }
  const packageRevision = plan.packages.get(binding.packageRevisionId);
  const packageExport = packageRevision?.exports.find(
    (entry): entry is PackageOperationExport =>
      entry.id === binding.exportId && entry.kind === "operation",
  );
  if (!packageRevision || !packageExport) {
    return undefined;
  }
  const bound = new Map(binding.dependencies.map((entry) => [entry.portId, entry.binding]));
  return {
    kind: "package",
    binding,
    packageRevision,
    packageExport,
    dependencies: packageExport.dependencyPorts.map((port) => ({
      port,
      binding: bound.get(port.id)!,
    })),
  };
};

export interface CapabilityClosure {
  conformances: Array<{
    atomId: AtomId;
    interfaceRevisionId: InterfaceRevisionId;
  }>;
  packageRevisionIds: PackageRevisionId[];
  attachmentIds: Array<SlotId | EdgeTypeId>;
  constructorAtomIds: AtomId[];
}

export const computeCapabilityClosure = (
  plan: CompiledWorkspaceRevision,
  roots: Array<{ atomId: AtomId; interfaceRevisionId: InterfaceRevisionId }>,
): CapabilityClosure => {
  const conformances = new Map<string, {
    atomId: AtomId;
    interfaceRevisionId: InterfaceRevisionId;
  }>();
  const packages = new Set<PackageRevisionId>();
  const attachments = new Set<SlotId | EdgeTypeId>();
  const constructors = new Set<AtomId>();
  const queued = [...roots];
  const visited = new Set<string>();
  const sourceConformances = new Map(
    [...plan.conformances].map(([key, value]) => [key, value.source]),
  );

  const includeDependencies = (
    atomId: AtomId,
    dependencies: readonly BoundDependency[],
  ) => {
    for (const dependency of dependencies) {
      switch (dependency.binding.kind) {
        case "state":
          attachments.add(dependency.binding.slotId);
          if (dependency.binding.via) {
            attachments.add(dependency.binding.via.edgeTypeId);
          }
          break;
        case "edge":
          attachments.add(dependency.binding.edgeTypeId);
          if (dependency.binding.via) {
            attachments.add(dependency.binding.via.edgeTypeId);
          }
          break;
        case "interface": {
          if (dependency.binding.via) {
            attachments.add(dependency.binding.via.edgeTypeId);
          }
          const targetAtoms = dependency.binding.via
            ? (() => {
                const attachment = plan.attachments.get(
                  `edge\u0000${dependency.binding.via!.edgeTypeId}`,
                )?.attachment;
                if (!attachment || attachment.kind !== "edge") return [];
                const projection = edgeProjection(
                  attachment,
                  dependency.binding.via!.projectionId,
                );
                return projection
                  ? [...plan.atoms.keys()].filter((candidate) =>
                      atomSatisfiesConstraint(
                        candidate,
                        projection.target.constraint,
                        sourceConformances,
                      ))
                  : [];
              })()
            : [atomId];
          for (const targetAtom of targetAtoms) {
            queued.push({
              atomId: targetAtom,
              interfaceRevisionId: dependency.binding.interfaceRevisionId,
            });
          }
          break;
        }
        case "constructor": {
          constructors.add(dependency.binding.atomId);
          const constructor = plan.constructors.get(dependency.binding.atomId);
          if (constructor) {
            packages.add(constructor.packageRevisionId);
            includeDependencies(dependency.binding.atomId, constructor.dependencies);
          }
        }
      }
    }
  };

  while (queued.length > 0) {
    const root = queued.shift()!;
    const key = conformanceKey(root.atomId, root.interfaceRevisionId);
    if (visited.has(key)) {
      continue;
    }
    visited.add(key);
    const conformance = plan.conformances.get(key);
    if (!conformance) {
      continue;
    }
    conformances.set(key, {
      atomId: conformance.source.atomId,
      interfaceRevisionId: conformance.source.interfaceRevisionId,
    });
    for (const binding of conformance.operationBindings.values()) {
      if (binding.kind === "state") {
        attachments.add(binding.slotId);
      } else if (binding.kind === "edge") {
        attachments.add(binding.edgeTypeId);
      } else {
        packages.add(binding.packageRevisionId);
        includeDependencies(root.atomId, binding.dependencies);
        const packageRevision = plan.packages.get(binding.packageRevisionId);
        const operation = packageRevision?.exports.find(
          (entry): entry is PackageOperationExport =>
            entry.id === binding.exportId && entry.kind === "operation",
        );
        if (operation?.receiverRequirement.kind === "all-interfaces") {
          for (const interfaceRevisionId of operation.receiverRequirement
            .interfaceRevisionIds) {
            queued.push({ atomId: root.atomId, interfaceRevisionId });
          }
        }
      }
    }
    for (const materialization of
      conformance.source.relationshipMaterializations ?? []) {
      attachments.add(materialization.edgeTypeId);
      constructors.add(materialization.constructorAtomId);
      const constructor = plan.constructors.get(materialization.constructorAtomId);
      if (constructor) {
        packages.add(constructor.packageRevisionId);
        includeDependencies(materialization.constructorAtomId, constructor.dependencies);
      }
    }
  }

  return {
    conformances: [...conformances.entries()]
      .sort(([left], [right]) => left.localeCompare(right))
      .map(([, conformance]) => conformance),
    packageRevisionIds: [...packages].sort(),
    attachmentIds: [...attachments].sort(),
    constructorAtomIds: [...constructors].sort(),
  };
};