<?php
require_once __DIR__ . "/vendor/autoload.php";

use \Aws\S3\S3Client;
use \Aws\Exception\AwsException;

class Cache_S3 extends Plugin implements Cache_Adapter {

	/** @phpstan-ignore-next-line */
	private S3Client $s3;
	private string $dir;

	const CACHE_S3_ENDPOINT = "CACHE_S3_ENDPOINT";
	const CACHE_S3_BUCKET = "CACHE_S3_BUCKET";
	const CACHE_S3_REGION = "CACHE_S3_REGION";
	const CACHE_S3_ACCESS_KEY = "CACHE_S3_ACCESS_KEY";
	const CACHE_S3_SECRET_KEY = "CACHE_S3_SECRET_KEY";

	public function remove(string $filename): bool {
		return unlink($this->get_full_path($filename));
	}

	function about() {
		return array(null,
			"File cache backend using S3 protocol (experimental)",
			"fox",
			true);
	}

	function init($host) {
		Config::add(self::CACHE_S3_ENDPOINT, "", Config::T_STRING);
		Config::add(self::CACHE_S3_BUCKET, "", Config::T_STRING);
		Config::add(self::CACHE_S3_REGION, "", Config::T_STRING);
		Config::add(self::CACHE_S3_ACCESS_KEY, "", Config::T_STRING);
		Config::add(self::CACHE_S3_SECRET_KEY, "", Config::T_STRING);

		$s3_client_props = [
			'version' => 'latest',
			'region'  => Config::get(self::CACHE_S3_REGION),
			'endpoint' => Config::get(self::CACHE_S3_ENDPOINT),
			'use_path_style_endpoint' => true,
		];

		if (Config::get(self::CACHE_S3_ACCESS_KEY) && Config::get(self::CACHE_S3_SECRET_KEY)) {
			$s3_client_props['credentials'] = [
			  'key'    => Config::get(self::CACHE_S3_ACCESS_KEY),
			  'secret' => Config::get(self::CACHE_S3_SECRET_KEY),
			];
		}

		/** @phpstan-ignore-next-line */
		$this->s3 = new Aws\S3\S3Client($s3_client_props);

		/** @phpstan-ignore-next-line */
		$this->s3->registerStreamWrapper();
	}

	public function get_mtime(string $filename) {
		return filemtime($this->get_full_path($filename));
	}

	public function set_dir(string $dir): void {
		$this->dir = $dir;
	}

	public function get_dir(): string {
		return $this->dir;
	}

	public function make_dir(): bool {
		return true;
	}

	public function is_writable(?string $filename = null): bool {
		return true;
	}

	public function exists(string $filename): bool {
		return file_exists($this->get_full_path($filename));
	}

	public function get_size(string $filename) {
		return filesize($this->get_full_path($filename));
	}

	public function put(string $filename, $data) {
		return file_put_contents($this->get_full_path($filename), $data);
	}

	public function get(string $filename): ?string {
		return file_get_contents($this->get_full_path($filename));
	}

	public function get_full_path(string $filename): string {
		return 's3://' . Config::get(self::CACHE_S3_BUCKET) . '/' . ($this->dir ? $this->dir . '/' : '') . basename(clean($filename));
	}

	public function get_mime_type(string $filename) {
		$fh = fopen($this->get_full_path($filename), 'r');

		if ($fh) {
			$mimetype =  mime_content_type($fh);

			fclose($fh);

			return $mimetype;
		}

		return false;
	}

	public function send(string $filename) {
		return readfile($this->get_full_path($filename));
	}

	public function expire_all(): void {
		$dh = opendir('s3://' . Config::get(self::CACHE_S3_BUCKET));
		$rules = [];

		if ($dh) {
			while (($file = readdir($dh)) !== false) {
				$full_path = $this->get_full_path($file);

				if (is_dir($full_path) && !file_exists("$full_path/.no-auto-expiry")) {
					array_push($rules,
						[
							'ID' => $file,
							'Expiration' => [
								'Days' => (int) Config::get(Config::CACHE_MAX_DAYS),
							],
							'Filter' => [
								'Prefix' => $file
							],
							'Status' => 'Enabled'
						]
					);
				}
			}
			closedir($dh);
		}

		try {
			/** @phpstan-ignore-next-line */
			$this->s3->putBucketLifecycleConfiguration([
				'Bucket' => Config::get(self::CACHE_S3_BUCKET),
				'LifecycleConfiguration' => [
					'Rules' => $rules
				]
			]);

			Debug::log("Set lifecycle policy on " . count($rules) . " prefixe(s).");
		} catch (Exception $e) {
			user_error($e, E_USER_WARNING);
		}
	}

	function api_version() {
		return 2;
	}

}