import fs from "node:fs/promises";
import mariadb from "mariadb";

async function readEnv() {
  return Object.fromEntries(
    (await fs.readFile(".env", "utf8"))
      .split(/\r?\n/)
      .map((line) => line.trim())
      .filter((line) => line && !line.startsWith("#") && line.includes("="))
      .map((line) => {
        const index = line.indexOf("=");
        return [line.slice(0, index).trim(), line.slice(index + 1).trim()];
      }),
  );
}

async function queryRows(connection, sql, params = []) {
  const rows = await connection.query(sql, params);
  return Array.isArray(rows) ? rows.filter((row) => row && typeof row === "object" && !("meta" in row)) : [];
}

async function tableExists(connection, schema, table) {
  const rows = await queryRows(
    connection,
    "SELECT 1 FROM information_schema.tables WHERE table_schema = ? AND table_name = ? LIMIT 1",
    [schema, table],
  );
  return rows.length > 0;
}

async function columnExists(connection, schema, table, column) {
  const rows = await queryRows(
    connection,
    "SELECT 1 FROM information_schema.columns WHERE table_schema = ? AND table_name = ? AND column_name = ? LIMIT 1",
    [schema, table, column],
  );
  return rows.length > 0;
}

async function addColumnIfMissing(connection, schema, table, column, definition) {
  if (await columnExists(connection, schema, table, column)) return;
  await connection.query(`ALTER TABLE \`${schema}\`.\`${table}\` ADD COLUMN \`${column}\` ${definition}`);
}

const env = await readEnv();
const catalogDb = env.DB_NAME || "9bplus";
const scrapeDb = env.SCRAPE_DB_NAME || "catalog_scrape";
const connection = await mariadb.createConnection({
  host: env.DB_HOST || "127.0.0.1",
  port: Number(env.DB_PORT || 3306),
  user: env.DB_USER || "root",
  password: env.DB_PASSWORD || "",
  multipleStatements: false,
  bigIntAsNumber: true,
});

try {
  await connection.query(`CREATE DATABASE IF NOT EXISTS \`${scrapeDb}\` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci`);
  const schemaSql = await fs.readFile("sql/local-scrape-db.sql", "utf8");
  for (const statement of schemaSql.split(/;\s*(?:\r?\n|$)/).map((item) => item.trim()).filter(Boolean)) {
    await connection.query(statement);
  }

  await addColumnIfMissing(connection, scrapeDb, "scrape_sources", "legacy_catalog_source_id", "BIGINT UNSIGNED NULL");
  await addColumnIfMissing(connection, scrapeDb, "scrape_sources", "fallback_source_type", "VARCHAR(64) NOT NULL DEFAULT 'none'");
  await addColumnIfMissing(connection, scrapeDb, "scrape_sources", "access_mode", "VARCHAR(64) NOT NULL DEFAULT 'browser'");
  await addColumnIfMissing(connection, scrapeDb, "scrape_sources", "browser_engine", "VARCHAR(32) NOT NULL DEFAULT 'default'");
  await addColumnIfMissing(connection, scrapeDb, "scrape_sources", "browser_headless", "TINYINT(1) NOT NULL DEFAULT 0");
  await addColumnIfMissing(connection, scrapeDb, "scrape_sources", "wait_after_load_ms", "INT UNSIGNED NOT NULL DEFAULT 3000");
  await addColumnIfMissing(connection, scrapeDb, "scrape_sources", "note", "TEXT NULL");

  if (!(await tableExists(connection, catalogDb, "ps_product_catalog_source"))) {
    throw new Error(`Source table ${catalogDb}.ps_product_catalog_source does not exist.`);
  }
  if (!(await tableExists(connection, catalogDb, "ps_product_catalog_manufacturer_source"))) {
    throw new Error(`Mapping table ${catalogDb}.ps_product_catalog_manufacturer_source does not exist.`);
  }

  await connection.query(`
    INSERT INTO \`${scrapeDb}\`.scrape_sources (
      legacy_catalog_source_id,
      source_key,
      source_name,
      source_type,
      base_url,
      enabled,
      priority,
      search_primary_key,
      search_fallback_keys,
      fallback_source_type,
      search_url_template,
      fallback_url_template,
      search_context_keys,
      access_mode,
      browser_engine,
      browser_headless,
      wait_after_load_ms,
      note
    )
    SELECT
      id_product_catalog_source,
      source_key,
      source_name,
      source_type,
      base_url,
      enabled,
      priority,
      search_primary_key,
      search_fallback_keys,
      COALESCE(fallback_source_type, 'none'),
      search_url_template,
      fallback_url_template,
      search_context_keys,
      COALESCE(access_mode, 'browser'),
      COALESCE(browser_engine, 'default'),
      COALESCE(browser_headless, 0),
      COALESCE(wait_after_load_ms, 3000),
      note
    FROM \`${catalogDb}\`.ps_product_catalog_source
    ON DUPLICATE KEY UPDATE
      source_key = VALUES(source_key),
      source_name = VALUES(source_name),
      source_type = VALUES(source_type),
      base_url = VALUES(base_url),
      enabled = VALUES(enabled),
      priority = VALUES(priority),
      search_primary_key = VALUES(search_primary_key),
      search_fallback_keys = VALUES(search_fallback_keys),
      fallback_source_type = VALUES(fallback_source_type),
      search_url_template = VALUES(search_url_template),
      fallback_url_template = VALUES(fallback_url_template),
      search_context_keys = VALUES(search_context_keys),
      access_mode = VALUES(access_mode),
      browser_engine = VALUES(browser_engine),
      browser_headless = VALUES(browser_headless),
      wait_after_load_ms = VALUES(wait_after_load_ms),
      note = VALUES(note)
  `);

  await connection.query(`
    INSERT INTO \`${scrapeDb}\`.scrape_manufacturer_sources (
      manufacturer_id,
      source_id,
      enabled,
      priority
    )
    SELECT
      ms.id_manufacturer,
      ss.id,
      ms.enabled,
      ms.priority
    FROM \`${catalogDb}\`.ps_product_catalog_manufacturer_source ms
    JOIN \`${scrapeDb}\`.scrape_sources ss
      ON ss.legacy_catalog_source_id = ms.id_product_catalog_source
    ON DUPLICATE KEY UPDATE
      enabled = VALUES(enabled),
      priority = VALUES(priority)
  `);

  const sources = await queryRows(connection, `SELECT COUNT(*) AS total FROM \`${scrapeDb}\`.scrape_sources`);
  const mappings = await queryRows(connection, `SELECT COUNT(*) AS total FROM \`${scrapeDb}\`.scrape_manufacturer_sources`);
  console.log(`Scrape mapping migration ready: ${sources[0]?.total || 0} sources, ${mappings[0]?.total || 0} manufacturer mappings.`);
} finally {
  await connection.end();
}