<?php

namespace Aiko;

use ReflectionClass;

class ValidationRule
{
    /**
     * @var string
     */
    public $key;

    /**
     * @var \Closure|string  
     */
    public $action;

    /**
     * @var array
     */
    public $paramBag = [];

    /**
     * @var array
     */
    public $errorBag = [];

    /**
     * @var array
     */
    public $messages = [];

    public function __construct($paramBag, $key, $action, $messages = [])
    {
        $this->key = $key;
        $this->action = $action;
        $this->paramBag = $paramBag;
        $this->messages = $messages;
    }

    public function validate()
    {
        $param = $this->getParamValue();
        if (is_callable($this->action)) {
            $fn = $this->action;
            $message = $fn($param, $this->paramBag);
            if ($message !== null) {
                $this->addError($message);
                return false;
            }
        } else if (is_string($this->action)) {
            $repo = new ValidatorRuleCollection();
            $ref = new ReflectionClass($repo);
            $method = $this->action;
            if (strpos($this->action, '|') != false) {
                $exp = explode('|', $this->action);
                $method = $exp[0];
            }
            try {
                $refMethod = $ref->getMethod($method);
                $result = $refMethod->invokeArgs(new ValidatorRuleCollection(), [$this->key, $this->action, $param, $this->paramBag]);
                if (!is_null($result)) {
                    $this->addError($result);
                    return false;
                }
                return true;
            } catch (\ReflectionException $e) {
                return false;
            }
        } else {
            // defensive action
            return false;
        }
        return true;
    }

    public function parseMessage($messageKey)
    {
        if (array_key_exists($messageKey, $this->messages)) {
            return $this->messages[$messageKey];
        }
        return $messageKey;
    }

    public function addError($message = null)
    {
        $this->errorBag = [
            'key' => $this->key,
            'message' => is_null($message) ? "{$this->key} cant be empty" : $this->parseMessage($message)
        ];
    }

    public function getParamValue()
    {
        if (array_key_exists($this->key, $this->paramBag)) {
            return $this->paramBag[$this->key];
        }
        return null;
    } 
}