class Semver

class Semver {
    const SORT_ASC = 1;
    const SORT_DESC = -1;
    
    /** @var VersionParser */
    private static $versionParser;
    
    /**
     * Determine if given version satisfies given constraints.
     *
     * @param string $version
     * @param string $constraints
     *
     * @return bool
     */
    public static function satisfies($version, $constraints) {
        if (null === self::$versionParser) {
            self::$versionParser = new VersionParser();
        }
        $versionParser = self::$versionParser;
        $provider = new Constraint('==', $versionParser->normalize($version));
        $parsedConstraints = $versionParser->parseConstraints($constraints);
        return $parsedConstraints->matches($provider);
    }
    
    /**
     * Return all versions that satisfy given constraints.
     *
     * @param string[] $versions
     * @param string   $constraints
     *
     * @return string[]
     */
    public static function satisfiedBy(array $versions, $constraints) {
        $versions = array_filter($versions, function ($version) use ($constraints) {
            return Semver::satisfies($version, $constraints);
        });
        return array_values($versions);
    }
    
    /**
     * Sort given array of versions.
     *
     * @param string[] $versions
     *
     * @return string[]
     */
    public static function sort(array $versions) {
        return self::usort($versions, self::SORT_ASC);
    }
    
    /**
     * Sort given array of versions in reverse.
     *
     * @param string[] $versions
     *
     * @return string[]
     */
    public static function rsort(array $versions) {
        return self::usort($versions, self::SORT_DESC);
    }
    
    /**
     * @param string[] $versions
     * @param int      $direction
     *
     * @return string[]
     */
    private static function usort(array $versions, $direction) {
        if (null === self::$versionParser) {
            self::$versionParser = new VersionParser();
        }
        $versionParser = self::$versionParser;
        $normalized = array();
        // Normalize outside of usort() scope for minor performance increase.
        // Creates an array of arrays: [[normalized, key], ...]
        foreach ($versions as $key => $version) {
            $normalizedVersion = $versionParser->normalize($version);
            $normalizedVersion = $versionParser->normalizeDefaultBranch($normalizedVersion);
            $normalized[] = array(
                $normalizedVersion,
                $key,
            );
        }
        usort($normalized, function (array $left, array $right) use ($direction) {
            if ($left[0] === $right[0]) {
                return 0;
            }
            if (Comparator::lessThan($left[0], $right[0])) {
                return -$direction;
            }
            return $direction;
        });
        // Recreate input array, using the original indexes which are now in sorted order.
        $sorted = array();
        foreach ($normalized as $item) {
            $sorted[] = $versions[$item[1]];
        }
        return $sorted;
    }

}