<?php

/**

 * Database connection (PDO singleton) and CRUD helpers.

 * All queries use prepared statements.

 */

require_once __DIR__ . '/../config.php';

function db(): PDO

{

    static $pdo = null;

    if ($pdo === null) {

        $dsn = 'mysql:host=' . DB_HOST . ';dbname=' . DB_NAME . ';charset=' . DB_CHARSET;

        $pdo = new PDO($dsn, DB_USER, DB_PASS, [

            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,

            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,

            PDO::ATTR_EMULATE_PREPARES   => false,

        ]);

    }

    return $pdo;

}

// ---- Repositories -----------------------------------------------------------

/**

 * Sort options for the repository list, keyed by the value used in the URL.

 * Each value is a fixed ORDER BY clause (never interpolate user input directly).

 */

const REPO_SORTS = [

    'newest' => 'created_at DESC, id DESC',

    'oldest' => 'created_at ASC, id ASC',

    'name'   => 'name ASC, id ASC',

    'slug'   => 'slug ASC',

];

function get_repositories(string $sort = 'newest'): array

{

    $order = REPO_SORTS[$sort] ?? REPO_SORTS['newest'];

    $stmt = db()->query('SELECT * FROM repositories ORDER BY ' . $order);

    return $stmt->fetchAll();

}

function get_repository_by_slug(string $slug): ?array

{

    $stmt = db()->prepare('SELECT * FROM repositories WHERE slug = ? LIMIT 1');

    $stmt->execute([$slug]);

    $row = $stmt->fetch();

    return $row ?: null;

}

function get_repository(int $id): ?array

{

    $stmt = db()->prepare('SELECT * FROM repositories WHERE id = ? LIMIT 1');

    $stmt->execute([$id]);

    $row = $stmt->fetch();

    return $row ?: null;

}

function create_repository(string $slug, string $name, string $desc, string $lang): int

{

    $stmt = db()->prepare(

        'INSERT INTO repositories (slug, name, description, language) VALUES (?, ?, ?, ?)'

    );

    $stmt->execute([$slug, $name, $desc, $lang]);

    return (int) db()->lastInsertId();

}

function update_repository(int $id, string $name, string $desc, string $lang): void

{

    $stmt = db()->prepare(

        'UPDATE repositories SET name = ?, description = ?, language = ? WHERE id = ?'

    );

    $stmt->execute([$name, $desc, $lang, $id]);

}

/**

 * Rename a repository's slug. Updates the repositories row and rewrites the

 * stored slug prefix on every file's `filepath` (which is "slug/rel-path").

 * Runs in a transaction so both tables stay consistent. The caller is

 * responsible for renaming the on-disk uploads/<slug> directory.

 */

function rename_repository(int $id, string $oldSlug, string $newSlug): void

{

    $pdo = db();

    $pdo->beginTransaction();

    try {

        $stmt = $pdo->prepare('UPDATE repositories SET slug = ? WHERE id = ?');

        $stmt->execute([$newSlug, $id]);

        // filepath looks like "oldslug/dir/file.ext" — swap the leading segment.

        $stmt = $pdo->prepare(

            'UPDATE files SET filepath = CONCAT(?, SUBSTRING(filepath, ?)) WHERE repo_id = ?'

        );

        $stmt->execute([$newSlug, strlen($oldSlug) + 1, $id]);

        $pdo->commit();

    } catch (Throwable $e) {

        $pdo->rollBack();

        throw $e;

    }

}

function delete_repository(int $id): void

{

    // Files rows are removed automatically via ON DELETE CASCADE.

    $stmt = db()->prepare('DELETE FROM repositories WHERE id = ?');

    $stmt->execute([$id]);

}

// ---- Files ------------------------------------------------------------------

function get_files_by_repo(int $repoId): array

{

    $stmt = db()->prepare('SELECT * FROM files WHERE repo_id = ? ORDER BY filename ASC');

    $stmt->execute([$repoId]);

    return $stmt->fetchAll();

}

function get_file_by_name(int $repoId, string $filename): ?array

{

    $stmt = db()->prepare('SELECT * FROM files WHERE repo_id = ? AND filename = ? LIMIT 1');

    $stmt->execute([$repoId, $filename]);

    $row = $stmt->fetch();

    return $row ?: null;

}

function get_file(int $id): ?array

{

    $stmt = db()->prepare('SELECT * FROM files WHERE id = ? LIMIT 1');

    $stmt->execute([$id]);

    $row = $stmt->fetch();

    return $row ?: null;

}

function create_file(int $repoId, string $filename, string $filepath, int $size): int

{

    // Replace an existing same-named file record for this repo (re-upload).

    $stmt = db()->prepare(

        'INSERT INTO files (repo_id, filename, filepath, filesize)

         VALUES (?, ?, ?, ?)

         ON DUPLICATE KEY UPDATE filepath = VALUES(filepath), filesize = VALUES(filesize)'

    );

    $stmt->execute([$repoId, $filename, $filepath, $size]);

    return (int) db()->lastInsertId();

}

function delete_file(int $id): void

{

    $stmt = db()->prepare('DELETE FROM files WHERE id = ?');

    $stmt->execute([$id]);

}

// ---- Folders ----------------------------------------------------------------

function get_folders_by_repo(int $repoId): array

{

    $stmt = db()->prepare('SELECT * FROM folders WHERE repo_id = ? ORDER BY path ASC');

    $stmt->execute([$repoId]);

    return $stmt->fetchAll();

}

function get_folder(int $id): ?array

{

    $stmt = db()->prepare('SELECT * FROM folders WHERE id = ? LIMIT 1');

    $stmt->execute([$id]);

    $row = $stmt->fetch();

    return $row ?: null;

}

/**

 * Register a folder path and all of its ancestors. For "a/b/c" this inserts

 * "a", "a/b" and "a/b/c". Existing rows are ignored (INSERT IGNORE).

 */

function create_folder(int $repoId, string $path): void

{

    $stmt  = db()->prepare('INSERT IGNORE INTO folders (repo_id, path) VALUES (?, ?)');

    $accum = [];

    foreach (explode('/', trim($path, '/')) as $seg) {

        if ($seg === '') {

            continue;

        }

        $accum[] = $seg;

        $stmt->execute([$repoId, implode('/', $accum)]);

    }

}

/**

 * Delete a folder plus every sub-folder and file beneath it. Returns the

 * deleted folder's path (so the caller can remove it from disk), or null.

 */

function delete_folder(int $id): ?string

{

    $folder = get_folder($id);

    if (!$folder) {

        return null;

    }

    $repoId = (int) $folder['repo_id'];

    $path   = $folder['path'];

    // Escape LIKE wildcards in the stored path (safe_relpath permits "_").

    $prefix = str_replace(['\\', '%', '_'], ['\\\\', '\\%', '\\_'], $path) . '/%';

    // Files that live inside the folder.

    $stmt = db()->prepare('DELETE FROM files WHERE repo_id = ? AND filename LIKE ?');

    $stmt->execute([$repoId, $prefix]);

    // The folder row itself and all descendant folder rows.

    $stmt = db()->prepare('DELETE FROM folders WHERE repo_id = ? AND (path = ? OR path LIKE ?)');

    $stmt->execute([$repoId, $path, $prefix]);

    return $path;

}