<?php
// admin/games/externalimport.php – Import games from external JSON export
declare(strict_types=1);

require __DIR__ . '/../inc/admin_boot.php';

$pdo = Database::pdo();
$err = '';
$msg = '';
$summary = null;

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    csrf_check();

    if (!isset($_FILES['file']) || !is_uploaded_file($_FILES['file']['tmp_name'])) {
        $err = 'Please choose a JSON export file.';
    } elseif ($_FILES['file']['error'] !== UPLOAD_ERR_OK) {
        $err = 'Upload failed with error code: '.$_FILES['file']['error'];
    } else {
        $raw = file_get_contents($_FILES['file']['tmp_name']);
        if ($raw === false || trim($raw) === '') {
            $err = 'The uploaded file appears to be empty.';
        } else {
            $data = json_decode($raw, true);
            if (!is_array($data) || !isset($data['games']) || !is_array($data['games'])) {
                $err = 'Invalid games export JSON format.';
            } else {
                try {
                    // Discover games table columns (excluding id and category_id)
                    $colStmt = $pdo->query("SHOW COLUMNS FROM games");
                    $gameCols = [];
                    while ($c = $colStmt->fetch(PDO::FETCH_ASSOC)) {
                        $name = (string)$c['Field'];
                        if ($name === 'id' || $name === 'category_id') {
                            continue;
                        }
                        $gameCols[] = $name;
                    }

                    // Discover categories table columns
                    $catStmt = $pdo->query("SHOW COLUMNS FROM categories");
                    $catCols = [];
                    while ($c = $catStmt->fetch(PDO::FETCH_ASSOC)) {
                        $catCols[] = (string)$c['Field'];
                    }
                    $hasCatSlug = in_array('slug', $catCols, true);

                    $inserted = 0;
                    $skipped  = 0;
                    $failed   = 0;
                    $errors   = [];

                    $categoryCache = [];

                    foreach ($data['games'] as $idx => $g) {
                        if (!is_array($g)) {
                            $failed++;
                            continue;
                        }

                        $fields = (isset($g['fields']) && is_array($g['fields'])) ? $g['fields'] : [];
                        $categoryName = trim((string)($g['category_name'] ?? ''));

                        // Duplicate detection:
                        $slug       = isset($fields['slug']) ? (string)$fields['slug'] : '';
                        $externalId = isset($fields['external_id']) ? (string)$fields['external_id'] : '';
                        $provider   = isset($fields['provider']) ? (string)$fields['provider'] : '';

                        $dupId = null;

                        if ($externalId !== '' && $provider !== '') {
                            $st = $pdo->prepare("SELECT id FROM games WHERE external_id = :eid AND provider = :prov LIMIT 1");
                            $st->execute([':eid'=>$externalId, ':prov'=>$provider]);
                            $dupId = $st->fetchColumn() ?: null;
                        }

                        if (!$dupId && $slug !== '') {
                            $st = $pdo->prepare("SELECT id FROM games WHERE slug = :slug LIMIT 1");
                            $st->execute([':slug'=>$slug]);
                            $dupId = $st->fetchColumn() ?: null;
                        }

                        if ($dupId) {
                            $skipped++;
                            continue;
                        }

                        // Resolve / create category by name
                        $categoryId = null;
                        if ($categoryName !== '') {
                            if (isset($categoryCache[$categoryName])) {
                                $categoryId = $categoryCache[$categoryName];
                            } else {
                                $st = $pdo->prepare("SELECT id FROM categories WHERE name = :n LIMIT 1");
                                $st->execute([':n'=>$categoryName]);
                                $categoryId = $st->fetchColumn();

                                if (!$categoryId) {
                                    if ($hasCatSlug) {
                                        // generate unique slug from name
                                        $base = strtolower(trim(preg_replace('/[^a-z0-9]+/i', '-', $categoryName), '-'));
                                        if ($base === '') {
                                            $base = 'category';
                                        }
                                        $slugCandidate = $base;
                                        $suffix = 2;
                                        while (true) {
                                            $st2 = $pdo->prepare("SELECT id FROM categories WHERE slug = :s LIMIT 1");
                                            $st2->execute([':s'=>$slugCandidate]);
                                            if (!$st2->fetchColumn()) {
                                                break;
                                            }
                                            $slugCandidate = $base.'-'.$suffix;
                                            $suffix++;
                                        }

                                        $ins = $pdo->prepare("INSERT INTO categories (name, slug) VALUES (:n, :s)");
                                        $ins->execute([':n'=>$categoryName, ':s'=>$slugCandidate]);
                                    } else {
                                        $ins = $pdo->prepare("INSERT INTO categories (name) VALUES (:n)");
                                        $ins->execute([':n'=>$categoryName]);
                                    }
                                    $categoryId = (int)$pdo->lastInsertId();
                                }

                                $categoryCache[$categoryName] = (int)$categoryId;
                            }
                        }

                        if (!$fields) {
                            $failed++;
                            continue;
                        }

                        // Build insert columns intersection
                        $insertCols = [];
                        $params = [];

                        foreach ($gameCols as $col) {
                            if (array_key_exists($col, $fields)) {
                                $insertCols[] = $col;
                                $params[':'.$col] = $fields[$col];
                            }
                        }

                        if ($categoryId) {
                            $insertCols[] = 'category_id';
                            $params[':category_id'] = $categoryId;
                        }

                        if (!$insertCols) {
                            $failed++;
                            continue;
                        }

                        $colSql   = implode(',', $insertCols);
                        $paramSql = implode(',', array_keys($params));
                        $sql      = "INSERT INTO games ($colSql) VALUES ($paramSql)";

                        try {
                            $st = $pdo->prepare($sql);
                            $st->execute($params);
                            $inserted++;
                        } catch (Throwable $e) {
                            $failed++;
                            if ($failed <= 5) {
                                $errors[] = 'Game #'.($idx + 1).': '.$e->getMessage();
                            }
                        }
                    }

                    $summary = [
                        'inserted' => $inserted,
                        'skipped'  => $skipped,
                        'failed'   => $failed,
                        'errors'   => $errors,
                    ];

                    if ($inserted > 0) {
                        $msg = "Imported {$inserted} external game(s). Skipped {$skipped}, failed {$failed}.";
                    } else {
                        $err = "Nothing imported. Skipped {$skipped}, failed {$failed}.";
                    }
                } catch (Throwable $e) {
                    $err = 'Import failed: '.$e->getMessage();
                }
            }
        }
    }
}

require __DIR__ . '/../inc/header.php';
?>
<section class="section">
  <div class="container">
    <div class="level">
      <div class="level-left">
        <h1 class="title">External Games Import</h1>
      </div>
      <div class="level-right">
        <a class="button is-light" href="/admin/games/manage.php">Back to games</a>
      </div>
    </div>

    <?php if($msg): ?><div class="notification is-success"><?= h($msg) ?></div><?php endif; ?>
    <?php if($err): ?><div class="notification is-danger"><?= h($err) ?></div><?php endif; ?>

    <?php if ($summary): ?>
      <article class="message is-info">
        <div class="message-header">
          <p>Import summary</p>
        </div>
        <div class="message-body">
          <ul>
            <li><strong>Inserted:</strong> <?= (int)$summary['inserted'] ?></li>
            <li><strong>Skipped (duplicates):</strong> <?= (int)$summary['skipped'] ?></li>
            <li><strong>Failed:</strong> <?= (int)$summary['failed'] ?></li>
          </ul>
          <?php if (!empty($summary['errors'])): ?>
            <hr>
            <p><strong>Sample errors:</strong></p>
            <ul>
              <?php foreach ($summary['errors'] as $e): ?>
                <li><?= h($e) ?></li>
              <?php endforeach; ?>
            </ul>
          <?php endif; ?>
        </div>
      </article>
    <?php endif; ?>

    <div class="box" style="max-width: 640px;">
      <h2 class="subtitle">Upload external export JSON</h2>
      <p class="mb-3">
        Export games from another installation using the
        <strong>“Export as JSON”</strong> bulk action in its admin panel, then upload
        the JSON file here to import.
      </p>

      <form method="post" enctype="multipart/form-data">
        <?php csrf_field(); ?>
        <div class="field">
          <label class="label">Export file (.json)</label>
          <div class="control">
            <input class="input" type="file" name="file" accept=".json,application/json" required>
          </div>
          <p class="help">The file should be generated by the games export feature.</p>
        </div>

        <div class="field">
          <button class="button is-primary">
            <span class="icon"><i class="fas fa-file-import"></i></span>
            <span>Import external games</span>
          </button>
        </div>
      </form>
    </div>
  </div>
</section>

<?php require __DIR__ . '/../inc/footer.php'; ?>