class Constraint

abstract class Constraint {
    
    /**
     * The name of the group given to all constraints with no explicit group.
     */
    public const DEFAULT_GROUP = 'Default';
    
    /**
     * Marks a constraint that can be put onto classes.
     */
    public const CLASS_CONSTRAINT = 'class';
    
    /**
     * Marks a constraint that can be put onto properties.
     */
    public const PROPERTY_CONSTRAINT = 'property';
    
    /**
     * Maps error codes to the names of their constants.
     *
     * @var array<string, string>
     */
    protected const ERROR_NAMES = [];
    
    /**
     * Domain-specific data attached to a constraint.
     */
    public mixed $payload;
    
    /**
     * The groups that the constraint belongs to.
     *
     * @var string[]
     */
    public ?array $groups = null;
    
    /**
     * Returns the name of the given error code.
     *
     * @throws InvalidArgumentException If the error code does not exist
     */
    public static function getErrorName(string $errorCode) : string {
        if (isset(static::ERROR_NAMES[$errorCode])) {
            return static::ERROR_NAMES[$errorCode];
        }
        throw new InvalidArgumentException(\sprintf('The error code "%s" does not exist for constraint of type "%s".', $errorCode, static::class));
    }
    
    /**
     * Initializes the constraint with options.
     *
     * You should pass an associative array. The keys should be the names of
     * existing properties in this class. The values should be the value for these
     * properties.
     *
     * Alternatively you can override the method getDefaultOption() to return the
     * name of an existing property. If no associative array is passed, this
     * property is set instead.
     *
     * You can force that certain options are set by overriding
     * getRequiredOptions() to return the names of these options. If any
     * option is not set here, an exception is thrown.
     *
     * @param mixed    $options The options (as associative array)
     *                          or the value for the default
     *                          option (any other type)
     * @param string[] $groups  An array of validation groups
     * @param mixed    $payload Domain-specific data attached to a constraint
     *
     * @throws InvalidOptionsException       When you pass the names of non-existing
     *                                       options
     * @throws MissingOptionsException       When you don't pass any of the options
     *                                       returned by getRequiredOptions()
     * @throws ConstraintDefinitionException When you don't pass an associative
     *                                       array, but getDefaultOption() returns
     *                                       null
     */
    public function __construct(mixed $options = null, ?array $groups = null, mixed $payload = null) {
        unset($this->groups);
        // enable lazy initialization
        $options = $this->normalizeOptions($options);
        if (null !== $groups) {
            $options['groups'] = $groups;
        }
        $options['payload'] = $payload ?? $options['payload'] ?? null;
        foreach ($options as $name => $value) {
            $this->{$name} = $value;
        }
    }
    
    /**
     * @return array<string, mixed>
     */
    protected function normalizeOptions(mixed $options) : array {
        $normalizedOptions = [];
        $defaultOption = $this->getDefaultOption();
        $invalidOptions = [];
        $missingOptions = array_flip($this->getRequiredOptions());
        $knownOptions = get_class_vars(static::class);
        if (\is_array($options) && isset($options['value']) && !property_exists($this, 'value')) {
            if (null === $defaultOption) {
                throw new ConstraintDefinitionException(\sprintf('No default option is configured for constraint "%s".', static::class));
            }
            $options[$defaultOption] = $options['value'];
            unset($options['value']);
        }
        if (\is_array($options)) {
            reset($options);
        }
        if ($options && \is_array($options) && \is_string(key($options))) {
            foreach ($options as $option => $value) {
                if (\array_key_exists($option, $knownOptions)) {
                    $normalizedOptions[$option] = $value;
                    unset($missingOptions[$option]);
                }
                else {
                    $invalidOptions[] = $option;
                }
            }
        }
        elseif (null !== $options && !(\is_array($options) && 0 === \count($options))) {
            if (null === $defaultOption) {
                throw new ConstraintDefinitionException(\sprintf('No default option is configured for constraint "%s".', static::class));
            }
            if (\array_key_exists($defaultOption, $knownOptions)) {
                $normalizedOptions[$defaultOption] = $options;
                unset($missingOptions[$defaultOption]);
            }
            else {
                $invalidOptions[] = $defaultOption;
            }
        }
        if (\count($invalidOptions) > 0) {
            throw new InvalidOptionsException(\sprintf('The options "%s" do not exist in constraint "%s".', implode('", "', $invalidOptions), static::class), $invalidOptions);
        }
        if (\count($missingOptions) > 0) {
            throw new MissingOptionsException(\sprintf('The options "%s" must be set for constraint "%s".', implode('", "', array_keys($missingOptions)), static::class), array_keys($missingOptions));
        }
        return $normalizedOptions;
    }
    
    /**
     * Sets the value of a lazily initialized option.
     *
     * Corresponding properties are added to the object on first access. Hence
     * this method will be called at most once per constraint instance and
     * option name.
     *
     * @throws InvalidOptionsException If an invalid option name is given
     */
    public function __set(string $option, mixed $value) : void {
        if ('groups' === $option) {
            $this->groups = (array) $value;
            return;
        }
        throw new InvalidOptionsException(\sprintf('The option "%s" does not exist in constraint "%s".', $option, static::class), [
            $option,
        ]);
    }
    
    /**
     * Returns the value of a lazily initialized option.
     *
     * Corresponding properties are added to the object on first access. Hence
     * this method will be called at most once per constraint instance and
     * option name.
     *
     * @throws InvalidOptionsException If an invalid option name is given
     */
    public function __get(string $option) : mixed {
        if ('groups' === $option) {
            $this->groups = [
                self::DEFAULT_GROUP,
            ];
            return $this->groups;
        }
        throw new InvalidOptionsException(\sprintf('The option "%s" does not exist in constraint "%s".', $option, static::class), [
            $option,
        ]);
    }
    public function __isset(string $option) : bool {
        return 'groups' === $option;
    }
    
    /**
     * Adds the given group if this constraint is in the Default group.
     */
    public function addImplicitGroupName(string $group) : void {
        if (null === $this->groups && \array_key_exists('groups', (array) $this)) {
            throw new \LogicException(\sprintf('"%s::$groups" is set to null. Did you forget to call "%s::__construct()"?', static::class, self::class));
        }
        if (\in_array(self::DEFAULT_GROUP, $this->groups) && !\in_array($group, $this->groups, true)) {
            $this->groups[] = $group;
        }
    }
    
    /**
     * Returns the name of the default option.
     *
     * Override this method to define a default option.
     *
     * @see __construct()
     */
    public function getDefaultOption() : ?string {
        return null;
    }
    
    /**
     * Returns the name of the required options.
     *
     * Override this method if you want to define required options.
     *
     * @return string[]
     *
     * @see __construct()
     */
    public function getRequiredOptions() : array {
        return [];
    }
    
    /**
     * Returns the name of the class that validates this constraint.
     *
     * By default, this is the fully qualified name of the constraint class
     * suffixed with "Validator". You can override this method to change that
     * behavior.
     */
    public function validatedBy() : string {
        return static::class . 'Validator';
    }
    
    /**
     * Returns whether the constraint can be put onto classes, properties or
     * both.
     *
     * @return self::CLASS_CONSTRAINT|self::PROPERTY_CONSTRAINT|array<self::CLASS_CONSTRAINT|self::PROPERTY_CONSTRAINT>
     */
    public function getTargets() : string|array {
        return self::PROPERTY_CONSTRAINT;
    }
    
    /**
     * Optimizes the serialized value to minimize storage space.
     *
     * @internal
     */
    public function __sleep() : array {
        // Initialize "groups" option if it is not set
        $this->groups;
        return array_keys(get_object_vars($this));
    }

}