class Deprecation

class Deprecation {
    private const TYPE_NONE = 0;
    private const TYPE_TRACK_DEPRECATIONS = 1;
    private const TYPE_TRIGGER_ERROR = 2;
    private const TYPE_PSR_LOGGER = 4;
    
    /** @var int-mask-of<self::TYPE_*>|null */
    private static $type;
    
    /** @var LoggerInterface|null */
    private static $logger;
    
    /** @var array<string,bool> */
    private static $ignoredPackages = [];
    
    /** @var array<string,int> */
    private static $triggeredDeprecations = [];
    
    /** @var array<string,bool> */
    private static $ignoredLinks = [];
    
    /** @var bool */
    private static $deduplication = true;
    
    /**
     * Trigger a deprecation for the given package and identfier.
     *
     * The link should point to a Github issue or Wiki entry detailing the
     * deprecation. It is additionally used to de-duplicate the trigger of the
     * same deprecation during a request.
     *
     * @param float|int|string $args
     */
    public static function trigger(string $package, string $link, string $message, ...$args) : void {
        $type = self::$type ?? self::getTypeFromEnv();
        if ($type === self::TYPE_NONE) {
            return;
        }
        if (isset(self::$ignoredLinks[$link])) {
            return;
        }
        if (array_key_exists($link, self::$triggeredDeprecations)) {
            self::$triggeredDeprecations[$link]++;
        }
        else {
            self::$triggeredDeprecations[$link] = 1;
        }
        if (self::$deduplication === true && self::$triggeredDeprecations[$link] > 1) {
            return;
        }
        if (isset(self::$ignoredPackages[$package])) {
            return;
        }
        $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
        $message = sprintf($message, ...$args);
        self::delegateTriggerToBackend($message, $backtrace, $link, $package);
    }
    
    /**
     * Trigger a deprecation for the given package and identifier when called from outside.
     *
     * "Outside" means we assume that $package is currently installed as a
     * dependency and the caller is not a file in that package. When $package
     * is installed as a root package then deprecations triggered from the
     * tests folder are also considered "outside".
     *
     * This deprecation method assumes that you are using Composer to install
     * the dependency and are using the default /vendor/ folder and not a
     * Composer plugin to change the install location. The assumption is also
     * that $package is the exact composer packge name.
     *
     * Compared to {@link trigger()} this method causes some overhead when
     * deprecation tracking is enabled even during deduplication, because it
     * needs to call {@link debug_backtrace()}
     *
     * @param float|int|string $args
     */
    public static function triggerIfCalledFromOutside(string $package, string $link, string $message, ...$args) : void {
        $type = self::$type ?? self::getTypeFromEnv();
        if ($type === self::TYPE_NONE) {
            return;
        }
        $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
        // first check that the caller is not from a tests folder, in which case we always let deprecations pass
        if (isset($backtrace[1]['file'], $backtrace[0]['file']) && strpos($backtrace[1]['file'], DIRECTORY_SEPARATOR . 'tests' . DIRECTORY_SEPARATOR) === false) {
            $path = DIRECTORY_SEPARATOR . 'vendor' . DIRECTORY_SEPARATOR . str_replace('/', DIRECTORY_SEPARATOR, $package) . DIRECTORY_SEPARATOR;
            if (strpos($backtrace[0]['file'], $path) === false) {
                return;
            }
            if (strpos($backtrace[1]['file'], $path) !== false) {
                return;
            }
        }
        if (isset(self::$ignoredLinks[$link])) {
            return;
        }
        if (array_key_exists($link, self::$triggeredDeprecations)) {
            self::$triggeredDeprecations[$link]++;
        }
        else {
            self::$triggeredDeprecations[$link] = 1;
        }
        if (self::$deduplication === true && self::$triggeredDeprecations[$link] > 1) {
            return;
        }
        if (isset(self::$ignoredPackages[$package])) {
            return;
        }
        $message = sprintf($message, ...$args);
        self::delegateTriggerToBackend($message, $backtrace, $link, $package);
    }
    
    /**
     * @param list<array{function: string, line?: int, file?: string, class?: class-string, type?: string, args?: mixed[], object?: object}> $backtrace
     */
    private static function delegateTriggerToBackend(string $message, array $backtrace, string $link, string $package) : void {
        $type = self::$type ?? self::getTypeFromEnv();
        if (($type & self::TYPE_PSR_LOGGER) > 0) {
            $context = [
                'file' => $backtrace[0]['file'] ?? null,
                'line' => $backtrace[0]['line'] ?? null,
                'package' => $package,
                'link' => $link,
            ];
            assert(self::$logger !== null);
            self::$logger->notice($message, $context);
        }
        if (!(($type & self::TYPE_TRIGGER_ERROR) > 0)) {
            return;
        }
        $message .= sprintf(' (%s:%d called by %s:%d, %s, package %s)', self::basename($backtrace[0]['file'] ?? 'native code'), $backtrace[0]['line'] ?? 0, self::basename($backtrace[1]['file'] ?? 'native code'), $backtrace[1]['line'] ?? 0, $link, $package);
        @trigger_error($message, E_USER_DEPRECATED);
    }
    
    /**
     * A non-local-aware version of PHPs basename function.
     */
    private static function basename(string $filename) : string {
        $pos = strrpos($filename, DIRECTORY_SEPARATOR);
        if ($pos === false) {
            return $filename;
        }
        return substr($filename, $pos + 1);
    }
    public static function enableTrackingDeprecations() : void {
        self::$type = self::$type ?? 0;
        self::$type |= self::TYPE_TRACK_DEPRECATIONS;
    }
    public static function enableWithTriggerError() : void {
        self::$type = self::$type ?? 0;
        self::$type |= self::TYPE_TRIGGER_ERROR;
    }
    public static function enableWithPsrLogger(LoggerInterface $logger) : void {
        self::$type = self::$type ?? 0;
        self::$type |= self::TYPE_PSR_LOGGER;
        self::$logger = $logger;
    }
    public static function withoutDeduplication() : void {
        self::$deduplication = false;
    }
    public static function disable() : void {
        self::$type = self::TYPE_NONE;
        self::$logger = null;
        self::$deduplication = true;
        self::$ignoredLinks = [];
        foreach (self::$triggeredDeprecations as $link => $count) {
            self::$triggeredDeprecations[$link] = 0;
        }
    }
    public static function ignorePackage(string $packageName) : void {
        self::$ignoredPackages[$packageName] = true;
    }
    public static function ignoreDeprecations(string ...$links) : void {
        foreach ($links as $link) {
            self::$ignoredLinks[$link] = true;
        }
    }
    public static function getUniqueTriggeredDeprecationsCount() : int {
        return array_reduce(self::$triggeredDeprecations, static function (int $carry, int $count) {
            return $carry + $count;
        }, 0);
    }
    
    /**
     * Returns each triggered deprecation link identifier and the amount of occurrences.
     *
     * @return array<string,int>
     */
    public static function getTriggeredDeprecations() : array {
        return self::$triggeredDeprecations;
    }
    
    /**
     * @return int-mask-of<self::TYPE_*>
     */
    private static function getTypeFromEnv() : int {
        switch ($_SERVER['DOCTRINE_DEPRECATIONS'] ?? $_ENV['DOCTRINE_DEPRECATIONS'] ?? null) {
            case 'trigger':
                self::$type = self::TYPE_TRIGGER_ERROR;
                break;
            case 'track':
                self::$type = self::TYPE_TRACK_DEPRECATIONS;
                break;
            default:
                self::$type = self::TYPE_NONE;
                break;
        }
        return self::$type;
    }

}