<?php
/**
 * Export legacy user password hashes into a SQL file suitable for updating the new DB.
 * Usage: php scripts/export_legacy_passwords.php /path/to/out.sql
 * If no path provided, writes to scripts/legacy-passwords-export.sql
 */
require __DIR__ . '/../vendor/autoload.php';
$app = require __DIR__ . '/../bootstrap/app.php';
$app->make(\Illuminate\Contracts\Console\Kernel::class)->bootstrap();

use Illuminate\Support\Facades\DB;

$outPath = $argv[1] ?? __DIR__ . '/legacy-passwords-export.sql';

try {
    DB::connection('legacy')->getPdo();
} catch (\Throwable $e) {
    fwrite(STDERR, "Legacy DB connection not available: " . $e->getMessage() . PHP_EOL);
    exit(2);
}

$now = date('Y-m-d H:i:s');

$fh = fopen($outPath, 'wb');
if ($fh === false) {
    fwrite(STDERR, "Could not open output file: {$outPath}\n");
    exit(3);
}

fwrite($fh, "-- Legacy password export\n");
fwrite($fh, "-- Generated: {$now}\n");
fwrite($fh, "-- Source: legacy DB (read-only)\n\n");
fwrite($fh, "SET NAMES utf8mb4;\n");
fwrite($fh, "USE `" . DB::getDatabaseName() . "`;\n");
fwrite($fh, "START TRANSACTION;\n\n");

$exported = 0;

DB::connection('legacy')
    ->table('users')
    ->select(['user_id', 'password2', 'password'])
    ->orderBy('user_id')
    ->chunk(500, function ($rows) use (&$fh, &$exported, $now) {
        foreach ($rows as $r) {
            $id = (int) ($r->user_id ?? 0);
            $hash = trim((string) ($r->password2 ?: $r->password ?: ''));
            if ($id === 0 || $hash === '') {
                continue;
            }

            // detect common hash types
            $algo = 'unknown';
            if (preg_match('/^\$2[aby]\$/', $hash)) {
                $algo = 'bcrypt';
            } elseif (preg_match('/^\$argon2/', $hash)) {
                $algo = 'argon2';
            }

            // escape for SQL single-quoted literal
            $escaped = str_replace(['\\', "'"], ['\\\\', "\\'"], $hash);

            fwrite($fh, "-- user_id={$id}  legacy_algo={$algo}\n");
            fwrite($fh, "SAVEPOINT sp_{$id};\n");
            fwrite($fh, "UPDATE `users` SET `password` = '{$escaped}', `legacy_password_algo` = '" . $algo . "', `needs_password_reset` = 1, `updated_at` = '{$now}' WHERE `id` = {$id};\n\n");

            $exported++;
        }
    });

fwrite($fh, "COMMIT;\n\n");
fwrite($fh, "-- Exported: {$exported} user(s)\n");
fclose($fh);

fwrite(STDOUT, "Wrote {$exported} rows to: {$outPath}\n");

exit(0);