<?php

namespace Kirby\Cms;

use Kirby\Exception\InvalidArgumentException;
use Kirby\Exception\NotFoundException;
use Kirby\Toolkit\Str;

/**
 * The Find class is used in the API and
 * the Panel to find models and parents
 * based on request paths
 *
 * @package   Kirby Cms
 * @author    Bastian Allgeier <bastian@getkirby.com>
 * @link      https://getkirby.com
 * @copyright Bastian Allgeier GmbH
 * @license   https://getkirby.com/license
 */
class Find
{
    /**
     * Returns the file object for the given
     * parent path and filename
     *
     * @param string|null $path Path to file's parent model
     * @param string $filename Filename
     * @return \Kirby\Cms\File|null
     * @throws \Kirby\Exception\NotFoundException if the file cannot be found
     */
    public static function file(string $path = null, string $filename)
    {
        $filename = urldecode($filename);
        $file     = static::parent($path)->file($filename);

        if ($file && $file->isReadable() === true) {
            return $file;
        }

        throw new NotFoundException([
            'key'  => 'file.notFound',
            'data' => [
                'filename' => $filename
            ]
        ]);
    }

    /**
     * Returns the language object for the given code
     *
     * @param string $code Language code
     * @return \Kirby\Cms\Language|null
     * @throws \Kirby\Exception\NotFoundException if the language cannot be found
     */
    public static function language(string $code)
    {
        if ($language = App::instance()->language($code)) {
            return $language;
        }

        throw new NotFoundException([
            'key'  => 'language.notFound',
            'data' => [
                'code' => $code
            ]
        ]);
    }

    /**
     * Returns the page object for the given id
     *
     * @param string $id Page's id
     * @return \Kirby\Cms\Page|null
     * @throws \Kirby\Exception\NotFoundException if the page cannot be found
     */
    public static function page(string $id)
    {
        $id   = str_replace(['+', ' '], '/', $id);
        $page = App::instance()->page($id);

        if ($page && $page->isReadable() === true) {
            return $page;
        }

        throw new NotFoundException([
            'key'  => 'page.notFound',
            'data' => [
                'slug' => $id
            ]
        ]);
    }

    /**
     * Returns the model's object for the given path
     *
     * @param string $path Path to parent model
     * @return \Kirby\Cms\Model|null
     * @throws \Kirby\Exception\InvalidArgumentException if the model type is invalid
     * @throws \Kirby\Exception\NotFoundException if the model cannot be found
     */
    public static function parent(string $path)
    {
        $path       = trim($path, '/');
        $modelType  = in_array($path, ['site', 'account']) ? $path : trim(dirname($path), '/');
        $modelTypes = [
            'site'    => 'site',
            'users'   => 'user',
            'pages'   => 'page',
            'account' => 'account'
        ];

        $modelName = $modelTypes[$modelType] ?? null;

        if (Str::endsWith($modelType, '/files') === true) {
            $modelName = 'file';
        }

        $kirby = App::instance();

        switch ($modelName) {
            case 'site':
                $model = $kirby->site();
                break;
            case 'account':
                $model = static::user();
                break;
            case 'page':
                $model = static::page(basename($path));
                break;
            case 'file':
                $model = static::file(...explode('/files/', $path));
                break;
            case 'user':
                $model = $kirby->user(basename($path));
                break;
            default:
                throw new InvalidArgumentException('Invalid model type: ' . $modelType);
        }

        if ($model) {
            return $model;
        }

        throw new NotFoundException([
            'key' => $modelName . '.undefined'
        ]);
    }

    /**
     * Returns the user object for the given id or
     * returns the current authenticated user if no
     * id is passed
     *
     * @param string|null $id User's id
     * @return \Kirby\Cms\User|null
     * @throws \Kirby\Exception\NotFoundException if the user for the given id cannot be found
     */
    public static function user(string $id = null)
    {
        // account is a reserved word to find the current
        // user. It's used in various API and area routes.
        if ($id === 'account') {
            $id = null;
        }

        $kirby = App::instance();

        // get the authenticated user
        if ($id === null) {
            if ($user = $kirby->user(null, $kirby->option('api.allowImpersonation', false))) {
                return $user;
            }

            throw new NotFoundException([
                'key' => 'user.undefined'
            ]);
        }

        // get a specific user by id
        if ($user = $kirby->user($id)) {
            return $user;
        }

        throw new NotFoundException([
            'key'  => 'user.notFound',
            'data' => [
                'name' => $id
            ]
        ]);
    }
}