import path from 'path';
import { CatalogImportOptions, runCatalogImport } from '../services/catalogImport.service';

const parseArgs = (args: string[]): CatalogImportOptions => {
  const options: Partial<CatalogImportOptions> = {};
  const positional: string[] = [];

  for (let index = 0; index < args.length; index += 1) {
    const argument = args[index];
    if (!argument.startsWith('--')) {
      positional.push(argument);
      continue;
    }

    const [flag, inlineValue] = argument.split('=', 2);
    const nextValue = (): string => {
      if (inlineValue !== undefined) return inlineValue;
      const value = args[index + 1];
      if (!value || value.startsWith('--')) throw new Error(`${flag} requires a value.`);
      index += 1;
      return value;
    };

    if (flag === '--workbook') options.workbookPath = nextValue();
    else if (flag === '--dry-run') options.dryRun = true;
    else if (flag === '--no-resume') options.resume = false;
    else if (flag === '--assets') {
      const value = nextValue();
      if (value !== 'download') {
        throw new Error('--assets must be "download". Remote book images are not allowed.');
      }
      options.assetMode = 'download';
    } else if (flag === '--concurrency') options.concurrency = Number(nextValue());
    else if (flag === '--batch-size') options.batchSize = Number(nextValue());
    else if (flag === '--logs-dir') options.logsDir = nextValue();
    else if (flag === '--storage-dir') options.storageDir = nextValue();
    else if (flag === '--asset-public-base-url') options.assetPublicBaseUrl = nextValue();
    else if (flag === '--catalogue-map') options.catalogueMapPath = nextValue();
    else throw new Error(`Unknown option: ${flag}`);
  }

  options.workbookPath =
    options.workbookPath ?? positional[0] ?? process.env.CATALOG_WORKBOOK_PATH;
  if (!options.workbookPath) {
    throw new Error(
      'Workbook path is required. Use --workbook <path> or set CATALOG_WORKBOOK_PATH.'
    );
  }
  if (options.concurrency !== undefined && !Number.isFinite(options.concurrency)) {
    throw new Error('--concurrency must be a number.');
  }
  if (options.batchSize !== undefined && !Number.isFinite(options.batchSize)) {
    throw new Error('--batch-size must be a number.');
  }

  return options as CatalogImportOptions;
};

const main = async (): Promise<void> => {
  const options = parseArgs(process.argv.slice(2));
  options.workbookPath = path.resolve(options.workbookPath);
  const summary = await runCatalogImport(options);
  process.stdout.write(`${JSON.stringify(summary, null, 2)}\n`);
};

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