<?php
namespace Kant\Routing;

use Kant\Kant;
use ReflectionMethod;
use ReflectionParameter;
use Kant\Support\Arr;
use ReflectionFunctionAbstract;

trait RouteDependencyResolverTrait
{

    /**
     * Resolve the object method's type-hinted dependencies.
     *
     * @param array $parameters            
     * @param object $instance            
     * @param string $method            
     * @return array
     */
    protected function resolveClassMethodDependencies(array $parameters, $instance, $method)
    {
        if (!method_exists($instance, $method)) {
            return $parameters;
        }
        
        return $this->resolveMethodDependencies($parameters, new ReflectionMethod($instance, $method));
    }

    /**
     * Resolve the given method's type-hinted dependencies.
     *
     * @param array $parameters            
     * @param \ReflectionFunctionAbstract $reflector            
     * @return array
     */
    public function resolveMethodDependencies(array $parameters, ReflectionFunctionAbstract $reflector)
    {
        $originalParameters = $parameters;
        foreach ($reflector->getParameters() as $key => $parameter) {
            $instance = $this->transformDependency($parameter, $parameters, $originalParameters);
            if (!is_null($instance)) {
                $this->spliceIntoParameters($parameters, $key, $instance);
            }
        }
        
        return $parameters;
    }

    /**
     * Attempt to transform the given parameter into a class instance.
     *
     * @param \ReflectionParameter $parameter            
     * @param array $parameters            
     * @param array $originalParameters            
     * @return mixed
     */
    protected function transformDependency(ReflectionParameter $parameter, $parameters, $originalParameters)
    {
        $class = $parameter->getClass();
        
        // If the parameter has a type-hinted class, we will check to see if it is already in
        // the list of parameters. If it is we will just skip it as it is probably a model
        // binding and we do not want to mess with those; otherwise, we resolve it here.
        if ($class && ! $this->alreadyInParameters($class->name, $parameters)) {
            return Kant::createObject($class->name);
        }
    }

    /**
     * Determine if an object of the given class is in a list of parameters.
     *
     * @param string $class            
     * @param array $parameters            
     * @return bool
     */
    protected function alreadyInParameters($class, array $parameters)
    {
        return ! is_null(Arr::first($parameters, function ($value) use($class) {
            return $value instanceof $class;
        }));
    }

    /**
     * Splice the given value into the parameter list.
     *
     * @param array $parameters            
     * @param string $key            
     * @param mixed $instance            
     * @return void
     */
    protected function spliceIntoParameters(array &$parameters, $key, $instance)
    {
        array_splice($parameters, $key, 0, [
            $instance
        ]);
    }
}
