#! /usr/bin/node

/*
This script merges the product translations back to the product YAML files.

Requirements: NodeJS, run "npm ci" to install the needed NPM packages

Usage:

  merge_po <translations_dir> <products_dir>
*/

const fs = require("fs");
const process = require("process");
const path = require("path");

const { parseDocument, isCollection } = require("yaml");
const { globSync } = require("glob");
const gettextParser = require("gettext-parser");

/**
 * Translation object with original text, its translations and the locale name.
 */
class Translation {
  msgid;
  msgstr;
  locale;

  /**
   * Constructor
   * @param {string} msgid - the original text
   * @param {string} msgstr - the translation
   * @param {string} locale - the locale
   */
  constructor(msgid, msgstr, locale) {
    this.msgid = msgid;
    this.msgstr = msgstr;
    this.locale = locale;
  }

  /**
   * Read all translations (PO files) in the specified directory
   * @param {string} dir - input directory for reading the the PO files
   * @returns {Translation[]} list of found translations
   */
  static read(dir) {
    const ret = [];
    // sort the files so the translations in the YAML files are also sorted
    const files = globSync(dir + "/*.po").sort();

    files.forEach((f) => {
      console.log(`Reading ${f}`);

      const locale = path.basename(f, ".po");
      const input = fs.readFileSync(f, "utf-8");
      const po = gettextParser.po.parse(input);

      // translations for the default (empty) context
      const translations = po.translations[""];

      Object.values(translations).forEach((t) => {
        if (t.msgid !== "") {
          ret.push(new Translation(t.msgid, t.msgstr[0], locale));
        }
      });
    });

    return ret;
  }
}

/**
 * YAML product file
 */
class YamlProduct {
  file;
  document;

  /**
   * Constructor
   * @param {string} file - the path to the YAML file
   */
  constructor(file) {
    this.file = file;
    // parse the file
    const data = fs.readFileSync(this.file, "utf-8");
    this.document = parseDocument(data);
  }

  /**
   * Read all product definitions (YAML files) in the specified directory
   * @param {string} dir - input directory for reading the the PO files
   * @returns {YamlProduct[]} all found products
   */
  static read(dir) {
    const ret = [];
    const files = globSync(dir + "/*.y{a,}ml");
    return files.map((f) => {
      console.log(`Reading ${f}`);
      return new YamlProduct(f);
    });
  }

  /**
   * Find the matching translations in the list and add them to the YAML document
   * @param {Translation[]} translations
   */
  addTranslations(translations) {
    const description = this.document.get("description");
    const newTranslations = {};

    translations.forEach((t) => {
      if (t.msgid === description && t.msgstr?.length > 0) {
        newTranslations[t.locale] = t.msgstr;
      }
    });

    // add or update the translations depending on whether they already exist
    if (Object.keys(newTranslations).length > 0) {
      this.document.setIn(["translations", "description"], newTranslations);
    }

    const modes = this.document.get("modes");
    if (modes && isCollection(modes)) {
      modes.items.forEach((mode) => {
        const modeId = mode.get("id");
        const modeName = mode.get("name");
        const modeDescription = mode.get("description");

        const nameTranslations = {};
        const descTranslations = {};

        translations.forEach((t) => {
          if (t.msgstr?.length > 0) {
            if (t.msgid === modeName) {
              nameTranslations[t.locale] = t.msgstr;
            }
            if (t.msgid === modeDescription) {
              descTranslations[t.locale] = t.msgstr;
            }
          }
        });

        if (Object.keys(nameTranslations).length > 0) {
          this.document.setIn(
            ["translations", "mode", modeId, "name"],
            nameTranslations,
          );
        }
        if (Object.keys(descTranslations).length > 0) {
          this.document.setIn(
            ["translations", "mode", modeId, "description"],
            descTranslations,
          );
        }
      });
    }
  }

  /**
   * Convert back the parsed YAML to String
   * @returns {string} new update YAML data
   */
  dump() {
    return this.document.toString();
  }

  /**
   * Save the current YAML data back to the file, the original content is
   * overwritten.
   */
  save() {
    console.log(`Writing ${this.file}`);
    fs.writeFileSync(this.file, this.dump(), "utf-8");
  }
}

// script arguments (the first arg is executor path ("/usr/bin/node"),
// the second is name of this script)
const [, , translations_dir, products_dir] = process.argv;

if (!translations_dir || !products_dir) {
  console.log("ERROR: missing argument");
  process.exit(1);
}

// read all YAML products and all translations
const translations = Translation.read(translations_dir);
const products = YamlProduct.read(products_dir);

// inject the translations to the products and save the changes
products.forEach((p) => {
  p.addTranslations(translations);
  p.save();
});