#!/usr/bin/env node
/**
 * Legacy classroom migration — P4 tooling.
 *
 * Scans the server classrooms dir (`data/classrooms/*.json`) and re-packages
 * every classroom into a published frozen bundle (design doc §7 "旧课件迁移":
 * migration = re-packaging, the packager consumes classroom-storage data
 * directly).
 *
 * Byte resolution: media/narration bytes must come from somewhere the server
 * can reach. Pass `--resolver <module>` to load a module exporting
 * `createResolvers(): Promise<ClassroomByteResolvers>` (e.g. wired to the
 * asset registry). Without a resolver, classrooms whose media is only in
 * learner browsers are reported as `incomplete` — re-publish those from the
 * ops workbench instead (which packages from IndexedDB).
 *
 * Usage:
 *   npx tsx scripts/migrate-coursewares.ts --base-url https://ops.example.com
 *   npx tsx scripts/migrate-coursewares.ts --resolver ./scripts/asset-resolvers.mjs
 *
 * Exit codes: 0 = all migrated or cleanly reported; 1 = hard error.
 */

import { migrateAllClassrooms, type ClassroomByteResolvers } from '@/lib/courseware-repo/migrate';
import { createLogger } from '@/lib/logger';

const log = createLogger('MigrateCLI');

function parseArgs(argv: string[]): { baseUrl: string; resolver?: string; classroomsDir?: string } {
  const args: Record<string, string> = {};
  for (let i = 0; i < argv.length; i++) {
    const arg = argv[i];
    if (arg.startsWith('--')) {
      const key = arg.slice(2);
      const value = argv[i + 1];
      if (value && !value.startsWith('--')) {
        args[key] = value;
        i++;
      } else {
        args[key] = 'true';
      }
    }
  }
  return {
    baseUrl: args['base-url'] ?? 'http://localhost:3000',
    resolver: args['resolver'],
    classroomsDir: args['classrooms-dir'],
  };
}

async function main() {
  const { baseUrl, resolver, classroomsDir } = parseArgs(process.argv.slice(2));

  let resolvers: ClassroomByteResolvers | undefined;
  if (resolver) {
    const resolverModule = await import(resolver);
    const factory = resolverModule.createResolvers ?? resolverModule.default;
    if (typeof factory !== 'function') {
      throw new Error(`Resolver module ${resolver} must export createResolvers()`);
    }
    resolvers = await factory();
    log.info('Loaded byte resolvers from', resolver);
  } else {
    log.warn(
      'No resolver: classrooms whose media lives only in learner browsers will be reported incomplete. ' +
        'Re-publish those from the ops workbench (export menu → 发布课件).',
    );
  }

  const report = await migrateAllClassrooms({ baseUrl, resolvers, classroomsDir });

  console.log('\n=== 迁移报告 (Migration report) ===');
  console.log(`已发布 published: ${report.published.length}`);
  for (const item of report.published) {
    if (item.status !== 'published') continue;
    console.log(`  ✓ ${item.classroomId} → ${item.coursewareId} v${item.version}`);
  }
  console.log(`未完成 incomplete: ${report.incomplete.length}`);
  for (const item of report.incomplete) {
    if (item.status !== 'incomplete') continue;
    console.log(`  ✗ ${item.classroomId} (${item.missing.length} missing resources)`);
    for (const line of item.missing.slice(0, 8)) console.log(`      - ${line}`);
    if (item.missing.length > 8) console.log(`      … ${item.missing.length - 8} more`);
  }
  console.log(`跳过 skipped: ${report.skipped.length}`, report.skipped.join(', ') || '');

  if (report.incomplete.length > 0) {
    console.log('\n提示：未完成的课件请用运营端发布工作台重新发布（媒体在浏览器端时服务端无法取到字节）。');
  }
}

main().catch((error) => {
  log.error('Migration failed:', error);
  process.exitCode = 1;
});