<?php
// Build an SQL seed of the vendor's course catalogue from its JSON export:
//
//   php tools/build-catalog-seed.php ~/ine-dl/all_courses_with_access.json > seeds/ine_catalog.sql
//
// The output is self-contained and idempotent — it creates `catalog_courses`
// if needed and upserts every course — so it can be applied to any install,
// before or after a code deploy, as many times as you like:
//
//   mysql coursehub < seeds/ine_catalog.sql && php scan.php
//
// The scan is what matches library folders to the seeded rows (course_meta).
// seeds/ is git-ignored: the file carries the vendor's course descriptions.
require_once __DIR__ . '/../includes/functions.php';

if (PHP_SAPI !== 'cli') {
    http_response_code(404);
    exit;
}

$src = $argv[1] ?? '';
if ($src === '' || !is_file($src)) {
    fwrite(STDERR, "usage: php tools/build-catalog-seed.php <all_courses.json> > seeds/ine_catalog.sql\n");
    exit(1);
}

ini_set('memory_limit', '512M');
$raw = file_get_contents($src);
$all = json_decode($raw, true);
if (!is_array($all)) {
    fwrite(STDERR, "not a JSON array: $src\n");
    exit(1);
}
// Some exports wrap the list.
if (isset($all['results']) && is_array($all['results'])) $all = $all['results'];
if (isset($all['courses']) && is_array($all['courses'])) $all = $all['courses'];

/** MySQL string literal (backslash escaping, the server's default mode). */
function sqlQuote(?string $v): string
{
    if ($v === null) return 'NULL';
    return "'" . str_replace(
        ["\\", "'", "\0", "\n", "\r", "\x1a"],
        ["\\\\", "\\'", "\\0", "\\n", "\\r", "\\Z"],
        $v
    ) . "'";
}

$json = fn(array $a) => json_encode($a, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

$rows    = [];
$skipped = 0;
foreach ($all as $entry) {
    if (!is_array($entry)) { $skipped++; continue; }
    $f = catalogFields($entry);
    if ($f['id'] === null || $f['name'] === null || $f['slug'] === null) { $skipped++; continue; }
    $rows[$f['id']] = [
        sqlQuote($f['id']), sqlQuote($f['name']), sqlQuote($f['slug']),
        sqlQuote(folderKeyFor($f['name'])), sqlQuote($f['vendor']), sqlQuote($f['difficulty']),
        sqlQuote($json($f['tags'])), sqlQuote($f['short_description']), sqlQuote($f['description']),
        sqlQuote($json($f['learning_paths'])), sqlQuote($json($f['categories'])),
        $f['duration_seconds'] === null ? 'NULL' : (string)$f['duration_seconds'],
        sqlQuote($f['url']),
    ];
}
ksort($rows);   // stable output: the same export always produces the same file

$cols = 'id, name, slug, folder_key, vendor, difficulty, tags, short_description, description,'
      . ' learning_paths, categories, duration_seconds, url';
$upd  = implode(', ', array_map(
    fn($c) => "$c = VALUES($c)",
    ['name', 'slug', 'folder_key', 'vendor', 'difficulty', 'tags', 'short_description',
     'description', 'learning_paths', 'categories', 'duration_seconds', 'url']
));

echo "-- CourseHub catalogue seed — generated by tools/build-catalog-seed.php\n";
echo '-- source: ' . basename($src) . ' (modified ' . gmdate('Y-m-d H:i:s', filemtime($src) ?: 0) . " UTC)\n";
echo '-- courses: ' . count($rows) . ($skipped ? " ($skipped entries skipped)" : '') . "\n";
echo "-- Safe to re-run: creates the table if needed and upserts by id.\n";
echo "SET NAMES utf8mb4;\n";
echo catalogCoursesDdl() . ";\n";
foreach (array_chunk(array_values($rows), 50) as $chunk) {
    echo "INSERT INTO catalog_courses ($cols) VALUES\n";
    echo implode(",\n", array_map(fn($r) => '(' . implode(', ', $r) . ')', $chunk));
    echo "\nON DUPLICATE KEY UPDATE $upd;\n";
}
fwrite(STDERR, 'wrote ' . count($rows) . " courses\n");