<?php

/**
 * @package     MokoSuiteBackup
 * @subpackage  com_mokosuitebackup
 * @author      Moko Consulting <hello@mokoconsulting.tech>
 * @copyright   Copyright (C) 2026 Moko Consulting. All rights reserved.
 * @license     GNU General Public License version 3 or later; see LICENSE
 *
 * REST API controller for content snapshot operations.
 *
 * Endpoints:
 *   GET    /api/index.php/v1/mokosuitebackup/snapshots              — List snapshots
 *   POST   /api/index.php/v1/mokosuitebackup/snapshot               — Create snapshot
 *   POST   /api/index.php/v1/mokosuitebackup/snapshot/:id/restore   — Restore snapshot
 *   DELETE /api/index.php/v1/mokosuitebackup/snapshot/:id            — Delete snapshot
 *   GET    /api/index.php/v1/mokosuitebackup/snapshot/:id/download   — Download snapshot JSON
 */

namespace Joomla\Component\MokoSuiteBackup\Api\Controller;

defined('_JEXEC') or die;

use Joomla\CMS\Factory;
use Joomla\CMS\MVC\Controller\ApiController;
use Joomla\Component\MokoSuiteBackup\Administrator\Engine\SnapshotEngine;
use Joomla\Component\MokoSuiteBackup\Administrator\Engine\SnapshotRestoreEngine;

class SnapshotsController extends ApiController
{
	protected $contentType = 'snapshots';
	protected $default_view = 'snapshots';

	/**
	 * List all snapshots with pagination (GET /api/index.php/v1/mokosuitebackup/snapshots)
	 */
	public function displayList(): static
	{
		if (!$this->app->getIdentity()->authorise('core.manage', 'com_mokosuitebackup')) {
			$this->app->setHeader('status', 403);
			echo json_encode(['errors' => [['title' => 'Access denied']]]);
			$this->app->close();

			return $this;
		}

		$db = Factory::getDbo();

		$limit  = $this->input->getInt('limit', 20);
		$offset = $this->input->getInt('offset', 0);

		// Clamp limits
		$limit = max(1, min($limit, 100));
		$offset = max(0, $offset);

		// Get total count
		$countQuery = $db->getQuery(true)
			->select('COUNT(*)')
			->from($db->quoteName('#__mokosuitebackup_snapshots'));
		$db->setQuery($countQuery);
		$total = (int) $db->loadResult();

		// Get paginated results
		$query = $db->getQuery(true)
			->select('*')
			->from($db->quoteName('#__mokosuitebackup_snapshots'))
			->order($db->quoteName('created') . ' DESC');
		$db->setQuery($query, $offset, $limit);
		$items = $db->loadObjectList() ?: [];

		$data = [];

		foreach ($items as $item) {
			$data[] = [
				'type'       => 'snapshots',
				'id'         => $item->id,
				'attributes' => $item,
			];
		}

		$this->app->setHeader('status', 200);
		echo json_encode([
			'data' => $data,
			'meta' => [
				'total'  => $total,
				'limit'  => $limit,
				'offset' => $offset,
			],
		]);
		$this->app->close();

		return $this;
	}

	/**
	 * Create a new content snapshot (POST /api/index.php/v1/mokosuitebackup/snapshot)
	 */
	public function create(): static
	{
		if (!$this->app->getIdentity()->authorise('mokosuitebackup.snapshot.manage', 'com_mokosuitebackup')) {
			$this->app->setHeader('status', 403);
			echo json_encode(['errors' => [['title' => 'Access denied']]]);
			$this->app->close();

			return $this;
		}

		$data = json_decode($this->input->json->getRaw(), true) ?: [];

		$contentTypes = $data['content_types'] ?? [];
		$description  = $data['description'] ?? '';

		if (empty($contentTypes) || !is_array($contentTypes)) {
			$this->app->setHeader('status', 400);
			echo json_encode(['errors' => [['title' => 'content_types array is required']]]);
			$this->app->close();

			return $this;
		}

		$engine = new SnapshotEngine();
		$result = $engine->create($contentTypes, $description);

		if ($result['success']) {
			$this->app->setHeader('status', 200);
			echo json_encode(['data' => $result]);
		} else {
			$this->app->setHeader('status', 500);
			echo json_encode(['errors' => [['title' => $result['message']]]]);
		}

		$this->app->close();

		return $this;
	}

	/**
	 * Restore from a snapshot (POST /api/index.php/v1/mokosuitebackup/snapshot/:id/restore)
	 */
	public function restore(): static
	{
		if (!$this->app->getIdentity()->authorise('mokosuitebackup.snapshot.manage', 'com_mokosuitebackup')) {
			$this->app->setHeader('status', 403);
			echo json_encode(['errors' => [['title' => 'Access denied']]]);
			$this->app->close();

			return $this;
		}

		$id = $this->input->getInt('id', 0);

		if (!$id) {
			$this->app->setHeader('status', 400);
			echo json_encode(['errors' => [['title' => 'Snapshot ID is required']]]);
			$this->app->close();

			return $this;
		}

		$data = json_decode($this->input->json->getRaw(), true) ?: [];

		$mode         = $data['mode'] ?? 'replace';
		$contentTypes = $data['content_types'] ?? [];

		// Enforce valid restore mode
		if (!in_array($mode, ['replace', 'merge'], true)) {
			$mode = 'replace';
		}

		$engine = new SnapshotRestoreEngine();
		$result = $engine->restore($id, $mode, $contentTypes);

		if ($result['success']) {
			$this->app->setHeader('status', 200);
			echo json_encode(['data' => $result]);
		} else {
			$this->app->setHeader('status', 500);
			echo json_encode(['errors' => [['title' => $result['message']]]]);
		}

		$this->app->close();

		return $this;
	}

	/**
	 * Delete a snapshot record and its data file (DELETE /api/index.php/v1/mokosuitebackup/snapshot/:id)
	 */
	public function delete(): static
	{
		if (!$this->app->getIdentity()->authorise('mokosuitebackup.snapshot.manage', 'com_mokosuitebackup')) {
			$this->app->setHeader('status', 403);
			echo json_encode(['errors' => [['title' => 'Access denied']]]);
			$this->app->close();

			return $this;
		}

		$id = $this->input->getInt('id', 0);

		if (!$id) {
			$this->app->setHeader('status', 400);
			echo json_encode(['errors' => [['title' => 'Snapshot ID is required']]]);
			$this->app->close();

			return $this;
		}

		$db = Factory::getDbo();

		// Load record to get file path
		$query = $db->getQuery(true)
			->select('*')
			->from($db->quoteName('#__mokosuitebackup_snapshots'))
			->where($db->quoteName('id') . ' = ' . $id);
		$db->setQuery($query);
		$record = $db->loadObject();

		if (!$record) {
			$this->app->setHeader('status', 404);
			echo json_encode(['errors' => [['title' => 'Snapshot not found']]]);
			$this->app->close();

			return $this;
		}

		// Delete data file
		if ($record->data_file && is_file($record->data_file)) {
			if (!unlink($record->data_file)) {
				error_log('MokoSuiteBackup: Failed to delete snapshot file: ' . $record->data_file);
			}
		}

		// Delete record
		$query = $db->getQuery(true)
			->delete($db->quoteName('#__mokosuitebackup_snapshots'))
			->where($db->quoteName('id') . ' = ' . $id);
		$db->setQuery($query);
		$db->execute();

		$this->app->setHeader('status', 200);
		echo json_encode(['data' => ['success' => true, 'message' => 'Snapshot deleted']]);
		$this->app->close();

		return $this;
	}

	/**
	 * Stream the JSON snapshot file (GET /api/index.php/v1/mokosuitebackup/snapshot/:id/download)
	 */
	public function download(): static
	{
		if (!$this->app->getIdentity()->authorise('core.manage', 'com_mokosuitebackup')) {
			$this->app->setHeader('status', 403);
			echo json_encode(['errors' => [['title' => 'Access denied']]]);
			$this->app->close();

			return $this;
		}

		$id = $this->input->getInt('id', 0);

		if (!$id) {
			$this->app->setHeader('status', 400);
			echo json_encode(['errors' => [['title' => 'Snapshot ID is required']]]);
			$this->app->close();

			return $this;
		}

		$db = Factory::getDbo();

		$query = $db->getQuery(true)
			->select('*')
			->from($db->quoteName('#__mokosuitebackup_snapshots'))
			->where($db->quoteName('id') . ' = ' . $id);
		$db->setQuery($query);
		$record = $db->loadObject();

		if (!$record || !is_file($record->data_file) || !is_readable($record->data_file)) {
			$this->app->setHeader('status', 404);
			echo json_encode(['errors' => [['title' => 'Snapshot file not found']]]);
			$this->app->close();

			return $this;
		}

		// Stream as download
		while (@ob_end_clean()) {
			// clear all buffers
		}

		$filename = basename($record->data_file);
		$filesize = filesize($record->data_file);

		header('Content-Type: application/json');
		header("Content-Disposition: attachment; filename*=UTF-8''" . rawurlencode($filename));
		header('Content-Length: ' . $filesize);
		header('Cache-Control: no-cache, must-revalidate');

		readfile($record->data_file);

		$this->app->close();

		return $this;
	}
}