#!/usr/bin/env node

import { readFile } from "node:fs/promises";
import process from "node:process";
import { compileCapabilitySource } from "./parser.js";
import { capabilityId } from "../capability-model/types.js";
import { compileWorkspaceRevision } from "../capability-model/validation.js";

const usage = `usage: quixos-capability-compile [--check]
       [--workspace-id ID] [--workspace-revision-id ID]
       [--source-root-commit GIT_REV] <workspace.qx | ->

Parses, lowers, and validates a Quixos capability workspace. By default the
checked semantic workspace revision is written as JSON. --check emits no JSON.
The identity overrides instantiate a checked built-in/template assembly for one
real workspace; both must be supplied together.`;

const parseArgs = (args: string[]) => {
  let checkOnly = false;
  let workspaceId: string | undefined;
  let workspaceRevisionId: string | undefined;
  let sourceRootCommit: string | undefined;
  const positional: string[] = [];
  for (let index = 0; index < args.length; index += 1) {
    const argument = args[index]!;
    if (argument === "--check") checkOnly = true;
    else if (argument === "--workspace-id") workspaceId = args[++index];
    else if (argument === "--workspace-revision-id") workspaceRevisionId = args[++index];
    else if (argument === "--source-root-commit") sourceRootCommit = args[++index];
    else if (argument === "-") positional.push(argument);
    else if (argument.startsWith("-")) throw new Error(usage);
    else positional.push(argument);
  }
  if (positional.length !== 1 || Boolean(workspaceId) !== Boolean(workspaceRevisionId)) {
    throw new Error(usage);
  }
  return { checkOnly, workspaceId, workspaceRevisionId, sourceRootCommit, fileName: positional[0]! };
};

const main = async () => {
  const args = process.argv.slice(2);
  if (args.includes("--help") || args.includes("-h")) {
    process.stdout.write(`${usage}\n`);
    return;
  }
  const {
    checkOnly,
    workspaceId,
    workspaceRevisionId,
    sourceRootCommit,
    fileName,
  } = parseArgs(args);
  const source =
    fileName === "-"
      ? await new Promise<string>((resolve, reject) => {
          const chunks: Buffer[] = [];
          process.stdin.on("data", (chunk: Buffer) => chunks.push(chunk));
          process.stdin.on("end", () => resolve(Buffer.concat(chunks).toString("utf8")));
          process.stdin.on("error", reject);
        })
      : await readFile(fileName, "utf8");
  const result = compileCapabilitySource(source, fileName);
  if (!result.ok) {
    for (const diagnostic of result.diagnostics) {
      const location = diagnostic.line
        ? `${diagnostic.fileName}:${diagnostic.line}:${diagnostic.column + 1}`
        : `${diagnostic.fileName}${diagnostic.path ? `:${diagnostic.path}` : ""}`;
      process.stderr.write(
        `${location}: ${diagnostic.phase} ${diagnostic.code}: ${diagnostic.message}\n`,
      );
    }
    process.exitCode = 1;
    return;
  }
  const workspace = workspaceId && workspaceRevisionId
    ? {
        ...result.workspace,
        workspaceId: capabilityId.workspace(workspaceId),
        id: capabilityId.workspaceRevision(workspaceRevisionId),
        ...(sourceRootCommit ? { sourceRootCommit } : {}),
      }
    : { ...result.workspace, ...(sourceRootCommit ? { sourceRootCommit } : {}) };
  const instantiated = compileWorkspaceRevision(workspace);
  if (!instantiated.ok) {
    throw new Error(instantiated.issues.map((issue) => `${issue.path}: ${issue.message}`).join("\n"));
  }
  if (!checkOnly) {
    process.stdout.write(`${JSON.stringify(workspace, null, 2)}\n`);
  }
};

main().catch((error: unknown) => {
  process.stderr.write(`${error instanceof Error ? error.message : String(error)}\n`);
  process.exitCode = 1;
});