<?php
/**
 * Database Migration Runner
 * Usage: php migrate.php
 *
 * - Scans migrations/*.sql in filename order
 * - Skips files already recorded in wms.schema_migrations
 * - Each .sql file must declare its target DB on the first line:
 *     -- db: wms
 *   or
 *     -- db: wms2
 * - Stops on first error and reports the failed file
 */

define('ROOT', __DIR__);

require ROOT . '/app/config.php';

// ── Connections ────────────────────────────────────────────────────────────
function connect(string $host, string $user, string $pass, string $db): PDO
{
    $pdo = new PDO("mysql:host=$host;dbname=$db;charset=utf8", $user, $pass, [
        PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => true,
    ]);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    return $pdo;
}

$pdo_wms  = connect($db_server, $db_user, $db_pass, $db_database);
$pdo_wms2 = connect($db_server2, $db_user2, $db_pass2, $db_database2);

// ── Ensure tracking table exists ───────────────────────────────────────────
$pdo_wms->exec("
    CREATE TABLE IF NOT EXISTS `schema_migrations` (
        `version`    varchar(64) NOT NULL,
        `applied_at` datetime    NOT NULL DEFAULT current_timestamp(),
        PRIMARY KEY (`version`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3
");

// ── Load already-applied versions ─────────────────────────────────────────
$applied = $pdo_wms->query("SELECT version FROM schema_migrations")
    ->fetchAll(PDO::FETCH_COLUMN);
$applied = array_flip($applied);

// ── Scan migration files ───────────────────────────────────────────────────
$files = glob(ROOT . '/migrations/*.sql');
sort($files);

if (empty($files)) {
    echo "No migration files found in migrations/\n";
    exit(0);
}

$pending = array_filter($files, fn($f) => !isset($applied[basename($f)]));

if (empty($pending)) {
    echo "Nothing to migrate — all migrations already applied.\n";
    exit(0);
}

// ── Run pending migrations ─────────────────────────────────────────────────
foreach ($pending as $file) {
    $name = basename($file);
    $sql  = file_get_contents($file);

    // Read target DB from first line: -- db: wms   or   -- db: wms2
    $first_line = strtok($sql, "\n");
    if (!preg_match('/^--\s*db:\s*(wms2?)\s*$/i', $first_line, $m)) {
        echo "[SKIP]  $name — missing '-- db: wms' or '-- db: wms2' on line 1\n";
        continue;
    }

    $target = strtolower($m[1]);
    $pdo    = ($target === 'wms2') ? $pdo_wms2 : $pdo_wms;

    echo "[RUN]   $name → $target ... ";

    try {
        foreach (split_statements($sql) as $stmt) {
            if (trim($stmt) !== '') {
                $st = $pdo->query($stmt);
                if ($st) $st->closeCursor();
            }
        }

        $pdo_wms->prepare("INSERT INTO schema_migrations (version) VALUES (?)")
            ->execute([$name]);

        echo "OK\n";

    } catch (PDOException $e) {
        echo "FAILED\n";
        echo "[ERROR] " . $e->getMessage() . "\n";
        echo "Migration halted. Fix $name and re-run.\n";
        exit(1);
    }
}

echo "Done.\n";

// ── Helpers ────────────────────────────────────────────────────────────────
function split_statements(string $sql): array
{
    // Strip comments, then split on semicolons
    $sql = preg_replace('/--[^\n]*\n/', "\n", $sql);
    $sql = preg_replace('/\/\*.*?\*\//s', '', $sql);
    return explode(';', $sql);
}