import fs from "node:fs";
import { readdir } from "node:fs/promises";
import path from "node:path";
import dbClient from "./index.js";

const __dirname = import.meta.dirname;

const createMigrationTable = () => {
  return dbClient.query(`
      CREATE TABLE IF NOT EXISTS migrations (
        id VARCHAR(255) PRIMARY KEY,
        name VARCHAR(255),
        executed_at TIMESTAMP
      )
    `);
}

const getMigrationsFiles = () => {
  try {
    return readdir(path.resolve(__dirname, "./migrations"));
  } catch(err) {
    return new Error("[Migration] getMigrations err: ", err);
  }
};

const runMigrations = async () => {
  try {
    // Create migration table if needed
    await createMigrationTable();

    const migrationFiles = await getMigrationsFiles();
    const migrationsDb = await dbClient.query("SELECT name FROM migrations WHERE executed_at IS NOT NULL");
    const migrationsToRun = migrationFiles.filter(m => !migrationsDb.rows.map(m => m.name).includes(m));

    console.log("[Migration] migrations to run: ", migrationsToRun);

    for (const migration of migrationsToRun) {
      await dbClient.query("BEGIN");
      const sqlQuery = fs.readFileSync(path.resolve(__dirname, `./migrations/${migration}`), "utf-8");
      try {
        await dbClient.query(sqlQuery);

        await dbClient.query({
          text: "INSERT INTO migrations(id, name, executed_at) VALUES($1, $2, $3)",
          values: [migration.slice(0, -4), migration, new Date().toISOString().slice(0, 19).replace('T', ' ')]
        });

        await dbClient.query("COMMIT");
      } catch(err) {
        console.log(err);
        await dbClient.query("ROLLBACK");
      }
    }

    console.log("[Migration]: SUCCESS");
  } catch (err) {
    console.error("Error", err);
    process.exit(1);
  }
};

// Run this from CLI
if (import.meta.main) {
  console.log("Run migrations");
  runMigrations()
    .then(() => process.exit(0))
    .catch(() => process.exit(1));
}