/**
 * News-API Client
 *
 * Handles communication with news-api MongoDB and data transformation
 * to sapiens-mobile schema format.
 */

import { MongoClient, Db, ObjectId } from 'mongodb';
import fs from 'fs';
import path from 'path';

const MONGODB_URL = process.env.MONGODB_URL || 'mongodb://localhost:27017';
const DB_NAME = 'ai_writer_db';

// Cache for outlets data (loaded from outlets-extracted.json)
let outlets: {
  people: any[];
  topics: any[];
  companies: any[];
} | null = null;

// MongoDB client
let client: MongoClient | null = null;
let db: Db | null = null;

/**
 * Initialize MongoDB connection
 */
export async function connectToNewsAPI(): Promise<void> {
  if (client) return; // Already connected

  try {
    client = new MongoClient(MONGODB_URL);
    await client.connect();
    db = client.db(DB_NAME);
    console.log(`Connected to news-api MongoDB: ${DB_NAME}`);
  } catch (error) {
    console.error('Failed to connect to news-api MongoDB:', error);
    throw error;
  }
}

/**
 * Load outlets from outlets-extracted.json
 */
export function loadOutlets(): any {
  if (outlets) return outlets;

  try {
    const outletsPath = path.resolve(process.cwd(), 'outlets-extracted.json');
    const data = fs.readFileSync(outletsPath, 'utf-8');
    outlets = JSON.parse(data);
    console.log(`Loaded outlets: ${outlets!.people.length} people, ${outlets!.topics.length} topics, ${outlets!.companies.length} companies`);
    return outlets;
  } catch (error) {
    console.error('Failed to load outlets from outlets-extracted.json:', error);
    throw error;
  }
}

// Multi-language translations for outlet names
const OUTLET_TRANSLATIONS: Record<string, Record<string, string>> = {
  '도널드-트럼프': {
    en: 'Donald Trump',
    ja: 'ドナルド・トランプ',
    zh_cn: '唐纳德·特朗普',
    zh_tw: '唐納德·川普',
    de: 'Donald Trump',
    fr: 'Donald Trump',
    es: 'Donald Trump',
    it: 'Donald Trump'
  },
  '온유': {
    en: 'Onew',
    ja: 'オンユ',
    zh_cn: '温流',
    zh_tw: '溫流',
    de: 'Onew',
    fr: 'Onew',
    es: 'Onew',
    it: 'Onew'
  },
  '사토시-나카모토': {
    en: 'Satoshi Nakamoto',
    ja: 'サトシ・ナカモト',
    zh_cn: '中本聪',
    zh_tw: '中本聰',
    de: 'Satoshi Nakamoto',
    fr: 'Satoshi Nakamoto',
    es: 'Satoshi Nakamoto',
    it: 'Satoshi Nakamoto'
  },
  '일론-머스크': {
    en: 'Elon Musk',
    ja: 'イーロン・マスク',
    zh_cn: '埃隆·马斯克',
    zh_tw: '伊隆·馬斯克',
    de: 'Elon Musk',
    fr: 'Elon Musk',
    es: 'Elon Musk',
    it: 'Elon Musk'
  },
  '매기-강': {
    en: 'Maggie Kang',
    ja: 'マギー・カン',
    zh_cn: '玛吉·姜',
    zh_tw: '瑪姬·姜',
    de: 'Maggie Kang',
    fr: 'Maggie Kang',
    es: 'Maggie Kang',
    it: 'Maggie Kang'
  },
  '제롬-파월': {
    en: 'Jerome Powell',
    ja: 'ジェローム・パウエル',
    zh_cn: '杰罗姆·鲍威尔',
    zh_tw: '傑羅姆·鮑威爾',
    de: 'Jerome Powell',
    fr: 'Jerome Powell',
    es: 'Jerome Powell',
    it: 'Jerome Powell'
  },
  '블라디미르-푸틴': {
    en: 'Vladimir Putin',
    ja: 'ウラジーミル・プーチン',
    zh_cn: '弗拉基米尔·普京',
    zh_tw: '弗拉基米爾·普丁',
    de: 'Wladimir Putin',
    fr: 'Vladimir Poutine',
    es: 'Vladímir Putin',
    it: 'Vladimir Putin'
  },
  '조-바이든': {
    en: 'Joe Biden',
    ja: 'ジョー・バイデン',
    zh_cn: '乔·拜登',
    zh_tw: '喬·拜登',
    de: 'Joe Biden',
    fr: 'Joe Biden',
    es: 'Joe Biden',
    it: 'Joe Biden'
  },
  '블랙핑크': {
    en: 'BLACKPINK',
    ja: 'ブラックピンク',
    zh_cn: 'BLACKPINK',
    zh_tw: 'BLACKPINK',
    de: 'BLACKPINK',
    fr: 'BLACKPINK',
    es: 'BLACKPINK',
    it: 'BLACKPINK'
  },
  '구글': {
    en: 'Google',
    ja: 'グーグル',
    zh_cn: '谷歌',
    zh_tw: '谷歌',
    de: 'Google',
    fr: 'Google',
    es: 'Google',
    it: 'Google'
  },
  '마이크로소프트': {
    en: 'Microsoft',
    ja: 'マイクロソフト',
    zh_cn: '微软',
    zh_tw: '微軟',
    de: 'Microsoft',
    fr: 'Microsoft',
    es: 'Microsoft',
    it: 'Microsoft'
  },
  '넷플릭스': {
    en: 'Netflix',
    ja: 'ネットフリックス',
    zh_cn: '奈飞',
    zh_tw: 'Netflix',
    de: 'Netflix',
    fr: 'Netflix',
    es: 'Netflix',
    it: 'Netflix'
  },
  '메타': {
    en: 'Meta',
    ja: 'メタ',
    zh_cn: 'Meta',
    zh_tw: 'Meta',
    de: 'Meta',
    fr: 'Meta',
    es: 'Meta',
    it: 'Meta'
  },
  '삼성전자': {
    en: 'Samsung Electronics',
    ja: 'サムスン電子',
    zh_cn: '三星电子',
    zh_tw: '三星電子',
    de: 'Samsung Electronics',
    fr: 'Samsung Electronics',
    es: 'Samsung Electronics',
    it: 'Samsung Electronics'
  },
  '아마존': {
    en: 'Amazon',
    ja: 'アマゾン',
    zh_cn: '亚马逊',
    zh_tw: '亞馬遜',
    de: 'Amazon',
    fr: 'Amazon',
    es: 'Amazon',
    it: 'Amazon'
  },
  '샤이니': {
    en: 'SHINee',
    ja: 'シャイニー',
    zh_cn: 'SHINee',
    zh_tw: 'SHINee',
    de: 'SHINee',
    fr: 'SHINee',
    es: 'SHINee',
    it: 'SHINee'
  }
};

/**
 * Translate outlet name and description based on language
 */
function translateOutlet(outlet: any, language: string): any {
  // If Korean, return original
  if (language === 'ko') {
    return outlet;
  }

  // Check if we have a translation for this outlet ID
  let displayName = outlet.name;
  if (OUTLET_TRANSLATIONS[outlet.id] && OUTLET_TRANSLATIONS[outlet.id][language]) {
    displayName = OUTLET_TRANSLATIONS[outlet.id][language];
  } else if (/[가-힣]/.test(outlet.name)) {
    // Fallback: If name contains Korean characters but no translation,
    // keep the Korean name as is
    displayName = outlet.name;
  }

  // Translate description pattern
  const descriptionTranslations: Record<string, string> = {
    'en': `News and updates about ${displayName}`,
    'ja': `${displayName}に関するニュースと最新情報`,
    'zh_cn': `关于${displayName}的新闻和更新`,
    'zh_tw': `關於${displayName}的新聞和更新`,
    'de': `Nachrichten und Updates über ${displayName}`,
    'fr': `Actualités et mises à jour sur ${displayName}`,
    'es': `Noticias y actualizaciones sobre ${displayName}`,
    'it': `Notizie e aggiornamenti su ${displayName}`
  };

  return {
    ...outlet,
    name: displayName,
    description: descriptionTranslations[language] || outlet.description
  };
}

/**
 * Get all outlets or by category
 */
export function getOutlets(category?: string, language = 'ko'): any[] {
  const allOutlets = loadOutlets();

  // Add focusSubject to each outlet (using name as focusSubject)
  const addFocusSubject = (outlets: any[]) =>
    outlets.map(outlet => {
      const translated = translateOutlet(outlet, language);
      return {
        ...translated,
        focusSubject: translated.name || translated.id,
        avatar: translated.image
      };
    });

  if (!category) {
    return [
      ...addFocusSubject(allOutlets.people),
      ...addFocusSubject(allOutlets.topics),
      ...addFocusSubject(allOutlets.companies)
    ];
  }

  switch (category) {
    case 'people':
      return addFocusSubject(allOutlets.people);
    case 'topics':
      return addFocusSubject(allOutlets.topics);
    case 'companies':
      return addFocusSubject(allOutlets.companies);
    default:
      return [];
  }
}

/**
 * Get outlet by ID
 */
export function getOutletById(id: string, language = 'ko'): any | null {
  const allOutlets = getOutlets(undefined, language);
  const outlet = allOutlets.find(outlet => outlet.id === id);

  if (!outlet) return null;

  // Add focusSubject and avatar if not present
  return {
    ...outlet,
    focusSubject: outlet.focusSubject || outlet.name || outlet.id,
    avatar: outlet.avatar || outlet.image
  };
}

/**
 * Get articles for an outlet
 */
export async function getArticlesByOutlet(outletId: string, limit = 50, language = 'en'): Promise<any[]> {
  await connectToNewsAPI();
  if (!db) throw new Error('Database not connected');

  const outlet = getOutletById(outletId);
  if (!outlet) return [];

  const articleIds = outlet.articles.slice(0, limit).map((id: string) => new ObjectId(id));

  // First, get news_ids from English collection
  const enCollection = db.collection('articles_en');
  const enArticles = await enCollection.find({
    _id: { $in: articleIds }
  }, { projection: { news_id: 1, _id: 1 } }).toArray();

  const newsIds = enArticles.map((a: any) => a.news_id).filter(Boolean);

  if (newsIds.length === 0) return [];

  // Then get articles from target language collection using news_ids
  const collectionName = `articles_${language}`;
  const collection = db.collection(collectionName);
  const articles = await collection.find({
    news_id: { $in: newsIds }
  }).toArray();

  // Create a map from news_id to both article and English ID
  const newsIdToData = new Map(articles.map((a: any) => {
    const enArticle = enArticles.find(en => en.news_id === a.news_id);
    return [a.news_id, { article: a, englishId: enArticle?._id.toString() }];
  }));

  // Sort articles in the same order as outlet.articles
  const sortedArticles = enArticles
    .map((en: any) => {
      const data = newsIdToData.get(en.news_id);
      return data ? { ...data.article, _englishId: data.englishId } : null;
    })
    .filter(Boolean);

  return sortedArticles.map(a => transformArticle(a, a._englishId));
}

/**
 * Get article by news_id (preferred for cross-language support)
 */
export async function getArticleByNewsId(newsId: string, language = 'en'): Promise<any | null> {
  await connectToNewsAPI();
  if (!db) throw new Error('Database not connected');

  console.log(`[newsapi-client.getArticleByNewsId] newsId=${newsId}, language=${language}`);

  const collectionName = `articles_${language}`;
  const collection = db.collection(collectionName);

  const article = await collection.findOne({ news_id: newsId });

  if (!article) {
    console.log(`[newsapi-client.getArticleByNewsId] Article not found in ${collectionName}`);
    return null;
  }

  // Get English article ID for outlet lookup
  const enCollection = db.collection('articles_en');
  const enArticle = await enCollection.findOne(
    { news_id: newsId },
    { projection: { _id: 1 } }
  );

  console.log(`[newsapi-client.getArticleByNewsId] Found article in ${collectionName}: ${article.title}`);
  return transformArticle(article, enArticle?._id.toString());
}

/**
 * Get article by ID (for backward compatibility)
 */
export async function getArticleById(id: string, language = 'en'): Promise<any | null> {
  await connectToNewsAPI();
  if (!db) throw new Error('Database not connected');

  console.log(`[newsapi-client.getArticleById] id=${id}, language=${language}`);

  // First, try to find the article directly in the requested language collection
  const collectionName = `articles_${language}`;
  const collection = db.collection(collectionName);
  let article = await collection.findOne({ _id: new ObjectId(id) });

  if (article) {
    console.log(`[newsapi-client.getArticleById] Found article directly in ${collectionName}: ${article.title}`);
    return transformArticle(article, id); // Pass the ID as englishArticleId
  }

  // If not found, the ID might be from English collection
  // Try to find it in English collection and get its news_id
  const enCollection = db.collection('articles_en');
  const enArticle = await enCollection.findOne(
    { _id: new ObjectId(id) },
    { projection: { news_id: 1 } }
  );

  console.log(`[newsapi-client.getArticleById] Checked English collection, news_id: ${enArticle?.news_id}`);

  if (!enArticle || !enArticle.news_id) {
    console.log(`[newsapi-client.getArticleById] Article not found in any collection`);
    return null;
  }

  // If requesting English, get it from English collection
  if (language === 'en') {
    const enFullArticle = await enCollection.findOne({ _id: new ObjectId(id) });
    if (!enFullArticle) return null;
    console.log(`[newsapi-client.getArticleById] Returning English article: ${enFullArticle.title}`);
    return transformArticle(enFullArticle);
  }

  // For other languages, get article using news_id
  console.log(`[newsapi-client.getArticleById] Querying ${collectionName} with news_id: ${enArticle.news_id}`);
  article = await collection.findOne({ news_id: enArticle.news_id });

  if (!article) {
    console.log(`[newsapi-client.getArticleById] No article found in ${collectionName} with news_id ${enArticle.news_id}`);
    return null;
  }

  console.log(`[newsapi-client.getArticleById] Found article in ${collectionName}: ${article.title}`);
  return transformArticle(article, id); // Pass the English ID
}

/**
 * Search articles
 */
export async function searchArticles(query: string, limit = 20, language = 'en'): Promise<any[]> {
  await connectToNewsAPI();
  if (!db) throw new Error('Database not connected');

  const collectionName = `articles_${language}`;
  const collection = db.collection(collectionName);
  const articles = await collection.find({
    $or: [
      { title: { $regex: query, $options: 'i' } },
      { summary: { $regex: query, $options: 'i' } },
      { body: { $regex: query, $options: 'i' } }
    ]
  }).limit(limit).toArray();

  return articles.map(transformArticle);
}

/**
 * Transform news-api article to sapiens-mobile format
 */
function transformArticle(article: any, englishArticleId?: string): any {
  // Find which outlet this article belongs to
  // Use englishArticleId if provided (for non-English articles), otherwise use current article's _id
  const allOutlets = getOutlets();
  const articleIdStr = englishArticleId || article._id.toString();
  const outlet = allOutlets.find(o => o.articles.includes(articleIdStr));

  // Extract the first image or use default
  const images = article.images || [];
  const thumbnail = images.length > 0 ? images[0] : '/api/assets/default-article.png';

  // Format time ago
  const publishedAt = article.created_at || new Date();
  const now = new Date();
  const diffInMinutes = Math.floor((now.getTime() - new Date(publishedAt).getTime()) / 60000);
  const clampedMinutes = Math.max(1, Math.min(59, diffInMinutes));

  // Ensure tags is always an array of strings
  let tags: string[] = [];
  if (article.subtopics) {
    if (Array.isArray(article.subtopics)) {
      tags = article.subtopics
        .map((t: any) => {
          if (typeof t === 'string') return t;
          if (t && typeof t === 'object' && t.title) return t.title;
          return null;
        })
        .filter((t: any) => t !== null);
    } else if (typeof article.subtopics === 'string') {
      tags = [article.subtopics];
    }
  }

  return {
    id: article._id.toString(),
    newsId: article.news_id || article._id.toString(), // Add news_id for cross-language navigation
    title: article.title || 'Untitled',
    summary: article.summary || '',
    body: article.body || article.summary || '',
    thumbnail,
    publishedAt: publishedAt,
    timeAgo: `${clampedMinutes} min ago`,
    outletId: outlet?.id || 'unknown',
    outletName: outlet?.name || 'Unknown',
    tags,
    subtopics: article.subtopics || [],
    viewCount: 0,
    category: outlet?.category || 'topics'
  };
}

/**
 * Close MongoDB connection
 */
export async function closeNewsAPIConnection(): Promise<void> {
  if (client) {
    await client.close();
    client = null;
    db = null;
    console.log('Closed news-api MongoDB connection');
  }
}