const path = require('path');
const Database = require('better-sqlite3');
const sqliteVec = require('sqlite-vec');
const config = require('./config');

const dbPath = path.resolve(__dirname, '..', config.database.path || './archive.sqlite');
const db = new Database(dbPath);
sqliteVec.load(db);

db.pragma('journal_mode = WAL');

db.exec(`
  CREATE TABLE IF NOT EXISTS articles (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    title TEXT NOT NULL,
    description TEXT,
    content TEXT,
    image TEXT,
    content_status TEXT,
    content_error TEXT,
    content_attempted_at TEXT,
    is_index_page INTEGER NOT NULL DEFAULT 0,
    url TEXT NOT NULL UNIQUE,
    normalized_title TEXT NOT NULL,
    source TEXT NOT NULL,
    pub_date TEXT,
    ingested_at TEXT NOT NULL DEFAULT (datetime('now'))
  );
`);

function rebuildArticlesTableIfNeeded() {
  const indexes = db.prepare(`PRAGMA index_list('articles')`).all();
  const hasUniqueNormalizedTitleIndex = indexes.some((index) => {
    if (index.origin !== 'u' || !index.name) {
      return false;
    }

    const columns = db.prepare(`PRAGMA index_info('${index.name.replace(/'/g, "''")}')`).all();
    return columns.length === 1 && columns[0].name === 'normalized_title';
  });

  if (!hasUniqueNormalizedTitleIndex) {
    return;
  }

  db.exec(`
    BEGIN;

    CREATE TABLE articles_rebuild (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      title TEXT NOT NULL,
      description TEXT,
      content TEXT,
      image TEXT,
      content_status TEXT,
      content_error TEXT,
      content_attempted_at TEXT,
      is_index_page INTEGER NOT NULL DEFAULT 0,
      url TEXT NOT NULL UNIQUE,
      normalized_title TEXT NOT NULL,
      source TEXT NOT NULL,
      pub_date TEXT,
      ingested_at TEXT NOT NULL DEFAULT (datetime('now'))
    );

    INSERT INTO articles_rebuild (
      id,
      title,
      description,
      content,
      image,
      content_status,
      content_error,
      content_attempted_at,
      is_index_page,
      url,
      normalized_title,
      source,
      pub_date,
      ingested_at
    )
    SELECT
      id,
      title,
      description,
      content,
      image,
      content_status,
      content_error,
      content_attempted_at,
      0,
      url,
      normalized_title,
      source,
      pub_date,
      ingested_at
    FROM articles;

    DROP TABLE articles;
    ALTER TABLE articles_rebuild RENAME TO articles;

    COMMIT;
  `);
}

rebuildArticlesTableIfNeeded();

db.exec(`
  CREATE INDEX IF NOT EXISTS idx_articles_source ON articles(source);
  CREATE INDEX IF NOT EXISTS idx_articles_pub_date ON articles(pub_date);
  CREATE INDEX IF NOT EXISTS idx_articles_ingested_at ON articles(ingested_at);
  CREATE INDEX IF NOT EXISTS idx_articles_normalized_title ON articles(normalized_title);
`);

db.exec(`
  CREATE VIRTUAL TABLE IF NOT EXISTS article_embeddings USING vec0(
    article_id INTEGER PRIMARY KEY,
    embedding FLOAT[1024]
  );
`);

db.exec(`
  CREATE TABLE IF NOT EXISTS query_embeddings (
    query TEXT PRIMARY KEY,
    embedding BLOB NOT NULL,
    created_at TEXT NOT NULL DEFAULT (datetime('now'))
  );
`);

for (const statement of [
  'ALTER TABLE articles ADD COLUMN image TEXT',
  'ALTER TABLE articles ADD COLUMN content_status TEXT',
  'ALTER TABLE articles ADD COLUMN content_error TEXT',
  'ALTER TABLE articles ADD COLUMN content_attempted_at TEXT',
  'ALTER TABLE articles ADD COLUMN is_index_page INTEGER NOT NULL DEFAULT 0'
]) {
  try {
    db.exec(statement);
  } catch (error) {
    if (!String(error.message).includes('duplicate column name')) {
      throw error;
    }
  }
}

db.exec(`
  UPDATE articles
  SET is_index_page = 1
  WHERE is_index_page = 0
    AND (
      LOWER(url) LIKE '%/category/%'
      OR LOWER(url) LIKE '%/categories/%'
      OR LOWER(url) LIKE '%/tag/%'
      OR LOWER(url) LIKE '%/tags/%'
      OR LOWER(url) LIKE '%/topic/%'
      OR LOWER(url) LIKE '%/topics/%'
      OR LOWER(url) LIKE '%/section/%'
      OR LOWER(url) LIKE '%/sections/%'
      OR LOWER(url) LIKE '%/archive%'
      OR LOWER(url) LIKE '%/archives/%'
      OR LOWER(url) LIKE '%/authors/%'
      OR LOWER(url) LIKE '%/search%'
      OR LOWER(title) LIKE '%category%'
      OR LOWER(title) LIKE '%archives%'
      OR LOWER(title) LIKE '%archive%'
      OR LOWER(title) LIKE '%latest news%'
    )
`);

module.exports = db;