TypeScript Rewrite: I18n command

src/cli.ts

@@ -1,7 +1,10 @@
 import { createApp } from './app.js';
+import { registerI18nCommand } from './commands/i18n.js';
 
 const program = createApp();
 
+registerI18nCommand(program);
+
 program.parseAsync(process.argv).catch((err) => {
   console.error(err instanceof Error ? err.message : String(err));
   process.exit(1);

src/commands/i18n.ts

@@ -0,0 +1,229 @@
+import type { Command } from 'commander';
+import fs from 'fs-extra';
+import path from 'node:path';
+import { getConfig } from '../config.js';
+import * as output from '../utils/output.js';
+import type { I18nResolvedConfig } from '../types.js';
+
+/**
+ * Registers the `i18n` command with the CLI program.
+ *
+ * @since TBD
+ *
+ * @param {Command} program - The Commander.js program instance.
+ *
+ * @returns {void}
+ */
+export function registerI18nCommand(program: Command): void {
+  program
+    .command('i18n')
+    .description('Fetches language files for the project.')
+    .option('--retries <number>', 'How many retries we do for each file.', '3')
+    .option('--root <dir>', 'Set the root directory for downloading language files.')
+    .action(async (options: { retries?: string; root?: string }) => {
+      const config = getConfig();
+      const i18nConfigs = config.getI18n();
+      const cwd = options.root ?? config.getWorkingDir();
+      const maxRetries = parseInt(options.retries ?? '3', 10);
+
+      if (i18nConfigs.length === 0) {
+        output.log('No i18n configuration found. Skipping.');
+        return;
+      }
+
+      for (const i18nConfig of i18nConfigs) {
+        const result = await downloadLanguageFiles(i18nConfig, cwd, maxRetries);
+
+        if (result !== 0) {
+          process.exitCode = result;
+          return;
+        }
+      }
+    });
+}
+
+/**
+ * Downloads language files for a single i18n configuration.
+ *
+ * @since TBD
+ *
+ * @param {I18nResolvedConfig} config - The resolved i18n configuration for this translation source.
+ * @param {string} cwd - The current working directory.
+ * @param {number} maxRetries - The maximum number of retry attempts for failed downloads.
+ *
+ * @returns {Promise<number>} 0 on success, 1 on failure.
+ */
+async function downloadLanguageFiles(
+  config: I18nResolvedConfig,
+  cwd: string,
+  maxRetries: number
+): Promise<number> {
+  const projectUrl = config.url
+    .replace('{slug}', config.slug)
+    .replace('%slug%', config.slug);
+
+  output.log(`Fetching language files for ${config.textdomain} from ${projectUrl}`);
+
+  let data: TranslationApiResponse;
+
+  try {
+    const response = await fetch(projectUrl);
+    if (!response.ok) {
+      output.error(`Failed to fetch project data from ${projectUrl}`);
+      return 1;
+    }
+    data = (await response.json()) as TranslationApiResponse;
+  } catch (err) {
+    output.error(`Failed to fetch translation data: ${err}`);
+    return 1;
+  }
+
+  if (
+    !data.translation_sets ||
+    !Array.isArray(data.translation_sets) ||
+    data.translation_sets.length === 0
+  ) {
+    output.error(`Failed to fetch translation sets from ${projectUrl}`);
+    return 1;
+  }
+
+  const minimumPercentage = config.filter.minimum_percentage;
+
+  const langDir = path.resolve(cwd, config.path);
+  await fs.mkdirp(langDir);
+
+  const promises: Promise<void>[] = [];
+
+  for (const translation of data.translation_sets) {
+    // Skip when translations are zero.
+    if (translation.current_count === 0) {
+      continue;
+    }
+
+    // Skip any translation set that doesn't match our min translated.
+    if (minimumPercentage > translation.percent_translated) {
+      continue;
+    }
+
+    for (const format of config.formats) {
+      const promise = downloadAndSaveTranslation(
+        config,
+        translation,
+        format,
+        projectUrl,
+        langDir,
+        maxRetries
+      );
+      promises.push(promise);
+    }
+  }
+
+  await Promise.all(promises);
+
+  return 0;
+}
+
+/**
+ * Downloads and saves a single translation file with retry support.
+ *
+ * @since TBD
+ *
+ * @param {I18nResolvedConfig} config - The resolved i18n configuration.
+ * @param {TranslationSet} translation - The translation set to download.
+ * @param {string} format - The file format to download (e.g. "po", "mo").
+ * @param {string} projectUrl - The base project API URL.
+ * @param {string} langDir - The absolute path to the language files directory.
+ * @param {number} maxRetries - The maximum number of retry attempts.
+ * @param {number} tried - The current attempt count.
+ *
+ * @returns {Promise<void>}
+ */
+async function downloadAndSaveTranslation(
+  config: I18nResolvedConfig,
+  translation: TranslationSet,
+  format: string,
+  projectUrl: string,
+  langDir: string,
+  maxRetries: number,
+  tried = 0
+): Promise<void> {
+  const translationUrl = `${projectUrl}/${translation.locale}/${translation.slug}/export-translations?format=${format}`;
+
+  if (tried >= maxRetries) {
+    output.error(
+      `Failed to fetch translation from ${translationUrl} too many times, bailing on ${translation.slug}`
+    );
+    return;
+  }
+
+  tried++;
+
+  try {
+    const response = await fetch(translationUrl);
+
+    const filename = config.file_format
+      .replace('%domainPath%', config.path)
+      .replace('%textdomain%', config.textdomain)
+      .replace('%locale%', translation.locale ?? '')
+      .replace('%wp_locale%', translation.wp_locale ?? '')
+      .replace('%format%', format);
+
+    const buffer = Buffer.from(await response.arrayBuffer());
+
+    if (buffer.byteLength < 200) {
+      output.error(`Failed to fetch translation from ${translationUrl}`);
+
+      // Not sure if 2 seconds is needed, but it prevents the firewall from catching us.
+      await new Promise(resolve => setTimeout(resolve, 2000));
+
+      // Retries to download this file.
+      return downloadAndSaveTranslation(
+        config, translation, format, projectUrl, langDir, maxRetries, tried
+      );
+    }
+
+    const filePath = path.join(langDir, filename);
+    await fs.writeFile(filePath, buffer);
+
+    // Verify the written file size matches the response size.
+    const stat = await fs.stat(filePath);
+    if (stat.size !== buffer.byteLength) {
+      output.error(
+        `Failed to save the translation from ${translationUrl} to ${filePath}`
+      );
+
+      // Delete the file in that case.
+      await fs.unlink(filePath).catch(() => {});
+
+      // Not sure if 2 seconds is needed, but it prevents the firewall from catching us.
+      await new Promise(resolve => setTimeout(resolve, 2000));
+
+      // Retries to download this file.
+      return downloadAndSaveTranslation(
+        config, translation, format, projectUrl, langDir, maxRetries, tried
+      );
+    }
+
+    output.log(`* Translation created for ${filePath}`);
+  } catch {
+    output.error(`Failed to fetch translation from ${translationUrl}`);
+
+    await new Promise(resolve => setTimeout(resolve, 2000));
+
+    return downloadAndSaveTranslation(
+      config, translation, format, projectUrl, langDir, maxRetries, tried
+    );
+  }
+}
+
+interface TranslationApiResponse {
+  translation_sets: TranslationSet[];
+}
+
+interface TranslationSet {
+  locale: string;
+  wp_locale?: string;
+  slug: string;
+  current_count: number;
+  percent_translated: number;
+}

src/models/i18n-config.ts

@@ -0,0 +1,14 @@
+import type { I18nResolvedConfig } from '../types.js';
+
+/**
+ * Creates a resolved i18n configuration object.
+ *
+ * @since TBD
+ *
+ * @param {I18nResolvedConfig} config - The i18n configuration to clone.
+ *
+ * @returns {I18nResolvedConfig} A new copy of the i18n configuration object.
+ */
+export function createI18nConfig(config: I18nResolvedConfig): I18nResolvedConfig {
+  return { ...config };
+}