class Version

class Version {
    
    /** @var string */
    private $originalVersionString;
    
    /** @var VersionNumber */
    private $major;
    
    /** @var VersionNumber */
    private $minor;
    
    /** @var VersionNumber */
    private $patch;
    
    /** @var null|PreReleaseSuffix */
    private $preReleaseSuffix;
    
    /** @var null|BuildMetaData */
    private $buildMetadata;
    public function __construct(string $versionString) {
        $this->ensureVersionStringIsValid($versionString);
        $this->originalVersionString = $versionString;
    }
    
    /**
     * @throws NoPreReleaseSuffixException
     */
    public function getPreReleaseSuffix() : PreReleaseSuffix {
        if ($this->preReleaseSuffix === null) {
            throw new NoPreReleaseSuffixException('No pre-release suffix set');
        }
        return $this->preReleaseSuffix;
    }
    public function getOriginalString() : string {
        return $this->originalVersionString;
    }
    public function getVersionString() : string {
        $str = \sprintf('%d.%d.%d', $this->getMajor()
            ->getValue() ?? 0, $this->getMinor()
            ->getValue() ?? 0, $this->getPatch()
            ->getValue() ?? 0);
        if (!$this->hasPreReleaseSuffix()) {
            return $str;
        }
        return $str . '-' . $this->getPreReleaseSuffix()
            ->asString();
    }
    public function hasPreReleaseSuffix() : bool {
        return $this->preReleaseSuffix !== null;
    }
    public function equals(Version $other) : bool {
        if ($this->getVersionString() !== $other->getVersionString()) {
            return false;
        }
        if ($this->hasBuildMetaData() !== $other->hasBuildMetaData()) {
            return false;
        }
        if ($this->hasBuildMetaData() && $other->hasBuildMetaData() && !$this->getBuildMetaData()
            ->equals($other->getBuildMetaData())) {
            return false;
        }
        return true;
    }
    public function isGreaterThan(Version $version) : bool {
        if ($version->getMajor()
            ->getValue() > $this->getMajor()
            ->getValue()) {
            return false;
        }
        if ($version->getMajor()
            ->getValue() < $this->getMajor()
            ->getValue()) {
            return true;
        }
        if ($version->getMinor()
            ->getValue() > $this->getMinor()
            ->getValue()) {
            return false;
        }
        if ($version->getMinor()
            ->getValue() < $this->getMinor()
            ->getValue()) {
            return true;
        }
        if ($version->getPatch()
            ->getValue() > $this->getPatch()
            ->getValue()) {
            return false;
        }
        if ($version->getPatch()
            ->getValue() < $this->getPatch()
            ->getValue()) {
            return true;
        }
        if (!$version->hasPreReleaseSuffix() && !$this->hasPreReleaseSuffix()) {
            return false;
        }
        if ($version->hasPreReleaseSuffix() && !$this->hasPreReleaseSuffix()) {
            return true;
        }
        if (!$version->hasPreReleaseSuffix() && $this->hasPreReleaseSuffix()) {
            return false;
        }
        return $this->getPreReleaseSuffix()
            ->isGreaterThan($version->getPreReleaseSuffix());
    }
    public function getMajor() : VersionNumber {
        return $this->major;
    }
    public function getMinor() : VersionNumber {
        return $this->minor;
    }
    public function getPatch() : VersionNumber {
        return $this->patch;
    }
    
    /**
     * @psalm-assert-if-true BuildMetaData $this->buildMetadata
     * @psalm-assert-if-true BuildMetaData $this->getBuildMetaData()
     */
    public function hasBuildMetaData() : bool {
        return $this->buildMetadata !== null;
    }
    
    /**
     * @throws NoBuildMetaDataException
     */
    public function getBuildMetaData() : BuildMetaData {
        if (!$this->hasBuildMetaData()) {
            throw new NoBuildMetaDataException('No build metadata set');
        }
        return $this->buildMetadata;
    }
    
    /**
     * @param string[] $matches
     *
     * @throws InvalidPreReleaseSuffixException
     */
    private function parseVersion(array $matches) : void {
        $this->major = new VersionNumber((int) $matches['Major']);
        $this->minor = new VersionNumber((int) $matches['Minor']);
        $this->patch = isset($matches['Patch']) ? new VersionNumber((int) $matches['Patch']) : new VersionNumber(0);
        if (isset($matches['PreReleaseSuffix']) && $matches['PreReleaseSuffix'] !== '') {
            $this->preReleaseSuffix = new PreReleaseSuffix($matches['PreReleaseSuffix']);
        }
        if (isset($matches['BuildMetadata'])) {
            $this->buildMetadata = new BuildMetaData($matches['BuildMetadata']);
        }
    }
    
    /**
     * @param string $version
     *
     * @throws InvalidVersionException
     */
    private function ensureVersionStringIsValid($version) : void {
        $regex = '/^v?
            (?P<Major>0|[1-9]\\d*)
            \\.
            (?P<Minor>0|[1-9]\\d*)
            (\\.
                (?P<Patch>0|[1-9]\\d*)
            )?
            (?:
                -
                (?<PreReleaseSuffix>(?:(dev|beta|b|rc|alpha|a|patch|p|pl)\\.?\\d*))
            )?
            (?:
                \\+
                (?P<BuildMetadata>[0-9a-zA-Z-]+(?:\\.[0-9a-zA-Z-@]+)*)
            )?
        $/xi';
        if (\preg_match($regex, $version, $matches) !== 1) {
            throw new InvalidVersionException(\sprintf("Version string '%s' does not follow SemVer semantics", $version));
        }
        $this->parseVersion($matches);
    }

}