<?php
// Simple container
// Простая реализация контейнера.

namespace System\Container;

use Psr\Container\ContainerInterface;
use ReflectionClass;
use ReflectionException;

/**
 * Class Container
 * @package System\Container
 */
class Container implements ContainerInterface
{
    /**
     * @var array
     */
    private $instances = [];

    /**
     * @var array
     */
    private $bindings = [];

    /**
     * @var Container
     */
    private static $instance;

    /**
     * Container constructor.
     */
    private function __construct()
    {
    }

    /**
     * Get container instance
     *
     * @return Container
     */
    public static function getInstance()
    {
        if (static::$instance === null) {
            static::$instance = new static();
        }

        return static::$instance;
    }

    /**
     * Added bind with the name
     *
     * @param string $name
     * @param mixed $source
     * @param mixed $params
     * @return $this
     */
    public function bind($name, $source, $params = [])
    {
        if (($source instanceof \Closure) || is_string($source)) {
            $this->bindings[$name] = [$source, $params];
        } else {
            $this->instances[$name] = $source;
        }

        return $this;
    }

    /**
     * @param string $name
     * @return mixed
     * @throws NotFoundException
     * @throws ReflectionException
     */
    public function get($name)
    {
        if ($this->has($name)) {
            if ($this->hasInstance($name)) {
                $instance = $this->instances[$name];
            } else {
                $instance = $this->binding($name);
                $this->instances[$name] = $instance;
            }
            return $instance;
        }

        throw new NotFoundException();
    }

    /**
     * Binding instance to the name
     *
     * @param string $name
     * @return mixed
     * @throws NotFoundException
     * @throws ReflectionException
     */
    private function binding($name)
    {
        list($source, $params) = $this->bindings[$name];

        if (is_string($source) || class_exists($source)) {
            $reflector = new ReflectionClass($source);
            return $reflector->newInstanceArgs($params);
        } elseif ($source instanceof \Closure) {
            return call_user_func_array($source, $params);
        }

        throw new NotFoundException();
    }

    /**
     * Check exist instance with the name
     *
     * @param string $name
     * @return bool
     */
    private function hasInstance($name)
    {
        return isset($this->instances[$name]);
    }

    /**
     * Check exist bind with the name
     *
     * @param string $name
     * @return bool
     */
    private function hasBinding($name)
    {
        return isset($this->bindings[$name]);
    }

    /**
     * @param string $name
     * @return bool
     */
    public function has($name)
    {
        return $this->hasBinding($name) || $this->hasInstance($name);
    }
}