<?php

namespace Picea\Ui\Method;

use Psr\Http\Message\ServerRequestInterface,
    Psr\Http\Message\ResponseInterface;

class FormContext implements FormContextInterface
{
    public string $formContextMethod;

    public bool $formSent = false;

    public bool $formExecuted = false;

    public mixed $formExecutionStatus = null;

    protected string $formContextValuesRoot;

    public array $formContextValues = [];

    public array $formContextFiles = [];

    public array $formContextMessages = [];

    public bool $formSkipCsrf = false;

    protected array $formContextDefinedProperties = [];

    protected array $formContextCatchedMethods = [ 'POST', 'PUT', 'PATCH', 'DELETE', ];

    protected array $formConstructorProperties = [];

    public ? ResponseInterface $formContextResponse = null;

    public function __construct(
        public ServerRequestInterface $formContextRequest,
        public readonly ? string $formName = null
    ) {
        # From constructor
        $reflection = new \ReflectionClass($this);

        $this->formConstructorProperties = array_map(fn($e) => strtolower($e->getName()), array_filter($reflection->getConstructor()->getParameters(), fn($e) => $e->isPromoted()));

        $this->formContextValues = $formContextRequest->getParsedBody() ?: [];

        if ( ! $this->formContextValues ) {
            $content = mb_convert_encoding((string) $formContextRequest->getBody(), 'UTF-8');

            if ( $content && ( $json = json_decode($content, true) ) ) {
                $this->formContextValues = $json;
            }
        }

        if ($this->formContextValuesRoot ?? false) {
            $this->formContextValues = $this->formContextValues[$this->formContextValuesRoot] ?? [];
        }

        $this->fillValues();

        $this->formContextFiles = $formContextRequest->getUploadedFiles() ?: [];

        $this->initialize();
    }

    public function initialize() : void {}
    
    public function valid() : bool
    {
        foreach($this->formContextMessages as $message) {
            if ( $message->isError() ) {
                return false;
            }
        }
        
        return true;
    }

    public function executed() : bool
    {
        return $this->formExecutionStatus === false ? false : $this->formExecuted;
    }

    public function formSent() : bool
    {
        $valid = in_array($this->requestMethod(), $this->formContextCatchedMethods);

        if ( (! $this->formSkipCsrf) && ! empty($this->formName) ) {
            $token = $this->get('picea-ui-form')[$this->formName] ?? false;

            if ( $token ) {
                if (! $this->formSkipCsrf) {
                    $valid = in_array($token, $_SESSION["picea-ui.form:{$this->formName}"] ?? []);
                }
                else {
                    $valid = (bool) $token;
                }
            }
            else {
                $valid = false;
            }
        }

        return $this->formSent = $valid;
    }

    public function getExecutionStatus() : mixed
    {
        return $this->formExecutionStatus;
    }

    public function getRequest() : ServerRequestInterface
    {
        return $this->formContextRequest;
    }

    public function requestMethod() : string
    {
        return $this->formContextRequest->getMethod();
    }

    public function __set($key, $value)
    {
        return $this->set($key, $value);
    }

    public function __get($key)
    {
        return $this->get($key);
    }

    public function __isset($key)
    {
        return array_key_exists($key, $this->formContextValues);
    }

    public function __unset($key)
    {
        $this->delete($key);
    }   
    
    public function get(string $key, mixed $default = null)
    {
        return $this->has($key) ? $this->formContextValues[$key] : $default;
    }

    public function set(string $key, mixed $value)
    {

        if ($this->canWriteProperty($key)) {
            $this->$key = $this->castValue($key, $value);
        }

        return $this->formContextValues[$key] = $value;
    }

    public function sets(array $values) : static
    {
        foreach($values as $key =>$value) {
            $this->set($key, $value);
        }

        return $this;
    }


    public function delete(string $key) : void
    {
        unset($this->formContextValues[$key]);
    }

    public function has(string $key) : bool
    {
        return array_key_exists($key, $this->formContextValues);
    }

    public function pushMessage(FormMessage $message) : void
    {
        if ($message->isError() /* && $message->isSuccess() @TODO next major v. */ ) {
            $this->formContextMessages = array_merge([ $message ], $this->formContextMessages);
        }
        else {
            $this->formContextMessages[] = $message;
        }
    }

    public function messages() : array
    {
        return $this->formContextMessages;
    }

    protected function fillValues() : void
    {
        foreach($this->formContextValues as $property => $value) {
            if ($this->canWriteProperty($property)) {
                $this->$property = $this->castValue($property, $value);
                $this->formContextDefinedProperties[$property] = true;
            }
        }
    }

    protected function canWriteProperty(string $property) : bool
    {
        # Skipping overrides of this particular class vars as a security measure
        static $skipping = array_keys(array_change_key_case(get_class_vars(FormContext::class), CASE_LOWER));

        return ! in_array(strtolower($property), array_merge($skipping, $this->formConstructorProperties)) && property_exists($this, $property);
    }

    protected function definedProperty(string $property) : bool
    {
        return $this->formContextDefinedProperties[$property] ?? false;
    }

    protected function castValue(string $property, mixed $value) : mixed
    {
        $cast = fn($e) => match(true) {
            is_a($e, Context\FormContextCastableInterface::class, true) => $e::instance($value),
            $e === "array" => (function(array|string $value) use ($property) {
                if (is_string($value)) {
                    return json_validate($value) ? json_decode($value, true) ?? [] : throw new \InvalidArgumentException("Field '$property' is awaiting JSON encoded content.");
                }

                return $value;
            })($value),
            is_null($value) => null,
            enum_exists($e) => ( $value instanceof \BackedEnum ? $value : $e::tryFrom($value) ) ?? throw new \InvalidArgumentException(sprintf("Field '\$$property' awaiting values : '%s'.", implode("', '", array_map(fn($e) => $e->value, $e::cases())))),
            function_exists($e) => $e($value),
            class_exists($e) => new $e(...$value),
            interface_exists($e) => throw new \InvalidArgumentException("There is no way provided to match an interface object yet."),
            default => $value
        };

        $types = ( new \ReflectionProperty($this, $property) )->getType();

        if ($types instanceof \ReflectionNamedType) {
            $value = $cast($types->getName());
        }
        elseif ($types instanceof \ReflectionIntersectionType || $types instanceof \ReflectionUnionType) {
            foreach($types->getTypes() as $type) {
                return $cast($type->getName());
            }
        }
        elseif ($types->isBuiltin()) {
            return $cast($types->getName());
        }

        return $value;
    }
}