#!/usr/bin/env node
/**
 * Lightweight migration runner for Supabase.
 * Similar to Laravel's `artisan migrate`.
 *
 * Usage:
 *   npm run migrate              - Apply all pending migrations
 *   npm run migrate:status       - Show status of all migrations
 *   npm run migrate:rollback     - Rollback the last applied migration
 *
 * Env (loaded from .env automatically via --env-file):
 *   SUPABASE_DB_URL or DATABASE_URL  postgres connection string
 */
import fs from 'fs';
import path from 'path';
import { fileURLToPath } from 'url';
import { Pool } from 'pg';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const migrationsDir = path.resolve(__dirname, '..', 'supabase', 'migrations');
const args = process.argv.slice(2);
const command = args[0]; // --status | --rollback | undefined (= migrate)

function buildConnectionString() {
  // Direct override takes precedence
  if (process.env.SUPABASE_DB_URL) return process.env.SUPABASE_DB_URL;
  if (process.env.DATABASE_URL) return process.env.DATABASE_URL;

  // Derive from VITE_SUPABASE_URL + SUPABASE_DB_PASSWORD
  const supabaseUrl = process.env.VITE_SUPABASE_URL;
  const dbPassword = process.env.SUPABASE_DB_PASSWORD;

  if (supabaseUrl && dbPassword) {
    // Extract project ref from https://[ref].supabase.co
    const match = supabaseUrl.match(/https:\/\/([^.]+)\.supabase\.co/);
    if (!match) {
      console.error('❌  VITE_SUPABASE_URL hat ein unerwartetes Format.');
      process.exit(1);
    }
    const ref = match[1];
    return `postgresql://postgres:${encodeURIComponent(dbPassword)}@db.${ref}.supabase.co:5432/postgres`;
  }

  return null;
}

const connectionString = buildConnectionString();

if (!connectionString) {
  console.error('❌  Keine Datenbankverbindung konfiguriert.');
  console.error('    Füge SUPABASE_DB_PASSWORD zu deiner .env hinzu (Passwort aus Supabase → Settings → Database).');
  console.error('    Alternativ: SUPABASE_DB_URL=postgresql://... direkt setzen.');
  process.exit(1);
}

if (!fs.existsSync(migrationsDir)) {
  console.error(`❌  Migrations directory not found: ${migrationsDir}`);
  process.exit(1);
}

const pool = new Pool({ connectionString });

async function ensureMigrationsTable(client) {
  await client.query(`
    create table if not exists public.schema_migrations (
      id        serial      primary key,
      filename  text        not null unique,
      applied_at timestamptz not null default now()
    );
  `);
}

async function getApplied(client) {
  const { rows } = await client.query(
    'select filename, applied_at from public.schema_migrations order by filename'
  );
  return rows;
}

function listMigrationFiles() {
  return fs
    .readdirSync(migrationsDir)
    .filter((f) => f.endsWith('.sql'))
    .sort();
}

async function applyMigration(client, filename) {
  const filePath = path.join(migrationsDir, filename);
  const sql = fs.readFileSync(filePath, 'utf8');
  console.log(`  → Applying: ${filename}`);
  await client.query('begin');
  try {
    await client.query(sql);
    await client.query(
      'insert into public.schema_migrations (filename) values ($1)',
      [filename]
    );
    await client.query('commit');
    console.log(`  ✓ Done:     ${filename}`);
  } catch (err) {
    await client.query('rollback');
    console.error(`  ✗ Failed:   ${filename}\n    ${err.message}`);
    throw err;
  }
}

async function cmdMigrate(client) {
  await ensureMigrationsTable(client);
  const applied = new Set((await getApplied(client)).map((r) => r.filename));
  const pending = listMigrationFiles().filter((f) => !applied.has(f));

  if (pending.length === 0) {
    console.log('✔  Nothing to migrate – all migrations are up to date.');
    return;
  }

  console.log(`\nRunning ${pending.length} migration(s)...\n`);
  for (const file of pending) {
    await applyMigration(client, file);
  }
  console.log(`\n✔  ${pending.length} migration(s) applied successfully.`);
}

async function cmdStatus(client) {
  await ensureMigrationsTable(client);
  const appliedRows = await getApplied(client);
  const appliedMap = new Map(appliedRows.map((r) => [r.filename, r.applied_at]));
  const files = listMigrationFiles();

  if (files.length === 0) {
    console.log('No migration files found.');
    return;
  }

  console.log('\n  Status     Migration');
  console.log('  ─────────  ' + '─'.repeat(50));
  for (const file of files) {
    if (appliedMap.has(file)) {
      const ts = new Date(appliedMap.get(file)).toLocaleString('de-AT');
      console.log(`  ✓ applied  ${file}  (${ts})`);
    } else {
      console.log(`  ○ pending  ${file}`);
    }
  }

  const pendingCount = files.filter((f) => !appliedMap.has(f)).length;
  console.log(`\n  ${appliedMap.size} applied, ${pendingCount} pending.\n`);
}

async function cmdRollback(client) {
  await ensureMigrationsTable(client);
  const applied = await getApplied(client);

  if (applied.length === 0) {
    console.log('Nothing to rollback – no migrations have been applied.');
    return;
  }

  const last = applied[applied.length - 1];
  console.log(`\nRolling back: ${last.filename}`);

  // Check for a corresponding .down.sql file
  const downFile = path.join(
    migrationsDir,
    last.filename.replace('.sql', '.down.sql')
  );

  await client.query('begin');
  try {
    if (fs.existsSync(downFile)) {
      const sql = fs.readFileSync(downFile, 'utf8');
      await client.query(sql);
      console.log(`  ✓ Ran down-migration: ${path.basename(downFile)}`);
    } else {
      console.warn(`  ⚠  No down-migration file found (${path.basename(downFile)})`);
      console.warn('     Only removing the migration record, schema changes are NOT reverted.');
    }
    await client.query(
      'delete from public.schema_migrations where filename = $1',
      [last.filename]
    );
    await client.query('commit');
    console.log(`✔  Rolled back: ${last.filename}\n`);
  } catch (err) {
    await client.query('rollback');
    console.error(`✗  Rollback failed: ${err.message}`);
    throw err;
  }
}

async function run() {
  const client = await pool.connect();
  try {
    if (command === '--status') {
      await cmdStatus(client);
    } else if (command === '--rollback') {
      await cmdRollback(client);
    } else {
      await cmdMigrate(client);
    }
  } finally {
    client.release();
    await pool.end();
  }
}

run().catch((err) => {
  console.error('\n❌  Migration runner failed:', err.message);
  process.exit(1);
});