<?php
declare(strict_types=1);

namespace Container;

use Container\Exception\AlreadyExistsException;
use Container\Exception\NotFoundException;
use Psr\Container\ContainerInterface;

final class Container implements ContainerInterface
{
    /**
     * @var array
     */
    private $entries;

    /**
     * @var array
     */
    private $lazyEntries;

    public function __construct()
    {
        $this->entries = [];
        $this->lazyEntries = [];
    }

    /**
     * @inheritdoc
     */
    public function get($id)
    {
        if (!$this->has($id)) {
            throw new NotFoundException(sprintf('No entry was found for "%s" identifier.', $id));
        }

        if (array_key_exists($id, $this->lazyEntries)) {
            $factory = $this->lazyEntries[$id];
            unset($this->lazyEntries[$id]);
            $this->entries[$id] = $factory($this);
        }

        return $this->entries[$id];
    }

    /**
     * @inheritdoc
     */
    public function has($id)
    {
        return array_key_exists($id, $this->entries) || array_key_exists($id, $this->lazyEntries);
    }

    /**
     * Add entry to container
     *
     * @param string $id
     * @param mixed $entry
     *
     * @throws AlreadyExistsException Entry for **this** identifier already exists
     */
    public function add($id, $entry)
    {
        if ($this->has($id)) {
            throw new AlreadyExistsException(sprintf('Entry for "%s" identifier already exists', $id));
        }

        $this->entries[$id] = $entry;
    }

    /**
     * Add lazy entry to container
     *
     * @param string $id
     * @param callable $factory
     *
     * @throws AlreadyExistsException Entry for **this** identifier already exists
     */
    public function addLazy($id, callable $factory)
    {
        if ($this->has($id)) {
            throw new AlreadyExistsException(sprintf('Entry for "%s" identifier already exists', $id));
        }

        $this->lazyEntries[$id] = $factory;
    }

    /**
     * Remove entry
     *
     * @param string $id
     *
     * @throws NotFoundException No entry was found for **this** identifier
     */
    public function remove($id)
    {
        if (!$this->has($id)) {
            throw new NotFoundException(sprintf('No entry was found for "%s" identifier', $id));
        }

        unset($this->entries[$id], $this->lazyEntries[$id]);
    }
}