<?php
/**
 * scripts/backfill_blind_index.php
 *
 * يملأ أعمدة الفهرس الأعمى للسجلات الموجودة.
 *
 * الاستخدام:
 *   php backfill_blind_index.php            # تشغيل فعلي
 *   php backfill_blind_index.php --dry-run  # عرض ما سيحدث دون كتابة
 *   php backfill_blind_index.php --table=driver --batch=200
 *
 * آمن للتشغيل والخدمة تعمل:
 *   - لا يقرأ ولا يكتب أي عمود مشفّر، يكتب أعمدة الفهرس فقط.
 *   - يعمل على دفعات مع فاصل قصير حتى لا يضغط القاعدة.
 *   - قابل لإعادة التشغيل: يتخطى الصفوف المملوءة ما لم يُمرَّر --force.
 */

declare(strict_types=1);

if (PHP_SAPI !== 'cli') {
    http_response_code(403);
    exit("This script runs from the command line only.\n");
}

require_once __DIR__ . '/../core/bootstrap.php';
require_once __DIR__ . '/../core/Security/BlindIndex.php';

$options = getopt('', ['dry-run', 'force', 'table::', 'batch::']);
$dryRun  = isset($options['dry-run']);
$force   = isset($options['force']);
$only    = $options['table'] ?? null;
$batch   = max(50, (int) ($options['batch'] ?? 500));

/** @var EncryptionHelper $encryptionHelper */
global $encryptionHelper;

try {
    $blind = new BlindIndex();
} catch (RuntimeException $e) {
    exit("✘ " . $e->getMessage() . "\n");
}

$con = Database::get('main');

$targets = [
    'driver' => [
        'phone_bidx' => ['scope' => 'driver.phone', 'columns' => ['phone']],
        'email_bidx' => ['scope' => 'driver.email', 'columns' => ['email']],
        'name_bidx'  => ['scope' => 'driver.name',  'columns' => ['first_name', 'last_name']],
    ],
    'passengers' => [
        'phone_bidx' => ['scope' => 'passengers.phone', 'columns' => ['phone']],
        'email_bidx' => ['scope' => 'passengers.email', 'columns' => ['email']],
        'name_bidx'  => ['scope' => 'passengers.name',  'columns' => ['first_name', 'last_name']],
    ],
    'adminUser' => [
        'phone_bidx' => ['scope' => 'adminUser.phone', 'columns' => ['phone']],
        'email_bidx' => ['scope' => 'adminUser.email', 'columns' => ['email']],
    ],
];

echo $dryRun ? "── DRY RUN — nothing will be written ──\n" : "── Backfilling blind indexes ──\n";

foreach ($targets as $table => $fields) {
    if ($only && $only !== $table) continue;

    echo "\n[$table]\n";

    $sourceColumns = [];
    foreach ($fields as $spec) {
        foreach ($spec['columns'] as $c) $sourceColumns[$c] = true;
    }
    $select = 'id, ' . implode(', ', array_keys($sourceColumns));

    $where = $force ? '' : ' WHERE ' . implode(' OR ', array_map(
        fn($f) => "`$f` IS NULL",
        array_keys($fields)
    ));

    try {
        $rows = $con->query("SELECT $select FROM `$table`$where")->fetchAll(PDO::FETCH_ASSOC);
    } catch (PDOException $e) {
        echo "  ✘ skipped: " . $e->getMessage() . "\n";
        continue;
    }

    $total = count($rows);
    echo "  rows to process: $total\n";
    if ($total === 0) continue;

    $updated = 0;
    $failed  = 0;

    foreach (array_chunk($rows, $batch) as $chunk) {
        if (!$dryRun) $con->beginTransaction();

        foreach ($chunk as $row) {
            $set = [];
            $params = [':id' => $row['id']];

            foreach ($fields as $column => $spec) {
                // فك التشفير لقراءة القيمة الأصلية — القيمة المخزَّنة لا تتغير.
                $parts = [];
                foreach ($spec['columns'] as $src) {
                    $plain = $encryptionHelper->decryptData($row[$src] ?? null);
                    if ($plain === false) {
                        $failed++;
                        $parts = [];
                        break;
                    }
                    if ($plain !== '') $parts[] = $plain;
                }
                if (!$parts) continue;

                $value = implode(' ', $parts);
                $index = $blind->index($spec['scope'], $value);
                if ($index === null) continue;

                $set[] = "`$column` = :$column";
                $params[":$column"] = $index;
            }

            if (!$set) continue;

            if ($dryRun) {
                $updated++;
                continue;
            }

            $stmt = $con->prepare("UPDATE `$table` SET " . implode(', ', $set) . " WHERE id = :id");
            $stmt->execute($params);
            $updated++;
        }

        if (!$dryRun) $con->commit();
        usleep(50_000); // نفس متعمّد حتى لا تُحتكر القاعدة أثناء الخدمة
        echo "  … $updated/$total\n";
    }

    echo "  ✔ indexed: $updated" . ($failed ? "  (undecryptable values skipped: $failed)" : '') . "\n";
}

echo "\nDone." . ($dryRun ? " (dry run — re-run without --dry-run to apply)" : '') . "\n";