<?php
// SPDX-License-Identifier: EUPL-1.2
// Authors: see README.md

use SeaCMS\Api\ApiAware;
use SeaCMS\Api\BadMethodException;
use SeaCMS\Api\Cookies;
use SeaCMS\Api\JsonResponse;
use SeaCMS\Api\LateApiAware;
use SeaCMS\Api\NotFoundRouteException;
use SeaCMS\Api\SpecialOutputException;

/**
 * An api plugin for Pico 3.
 */
class SeacmsApi extends AbstractPicoPlugin implements ApiAware
{
    /**
     * Pico API version.
     * @var int
     */
    const API_VERSION = 3;

    /**
     * api routes
     * @var array
     */
    protected $routes ;

    /**
     * cookies to send
     * @var Cookies
     */
    protected $cookies;

    /**
     * Constructs a new instance of a Pico plugin
     *
     * @param Pico $pico current instance of Pico
     */
    public function __construct(Pico $pico)
    {
        parent::__construct($pico);
        $this->routes = [];
        $this->cookies= new Cookies();
    }

    /**
     * return $cookies
     * @return Cookies
     */
    public function getCookies(): Cookies
    {
        return $this->cookies;
    }

    /**
     * return api routes
     * @return array
     */
    public function registerApiRoutes():array
    {
        return [
            'POST test' => 'api',
            'GET test/cookies/(.*)' => 'apiTestCookie',
            'GET test/(.*)' => 'apiWithText',
        ];
    }

    /**
     * method for api
     * @return JsonResponse
     */
    public function api(): JsonResponse
    {
        return new JsonResponse(200,['test'=>'OK']);
    }

    /**
     * method for api
     * @param string $text
     * @return JsonResponse
     */
    public function apiWithText(string $text): JsonResponse
    {
        return new JsonResponse(200,['text'=>$text]);
    }

    /**
     * method to test cookie via api
     * @param string $text
     * @return JsonResponse
     */
    public function apiTestCookie(string $text): JsonResponse
    {
        if (empty($text)){
            $text= '';
        }
        $this->cookies->addCookie(
            'Test-Cookie',
            $text,
            time()+3,
            !empty($_SERVER['SCRIPT_NAME']) ? dirname($_SERVER['SCRIPT_NAME']) : '/',
            !empty($_SERVER['SERVER_NAME']) ? $_SERVER['SERVER_NAME'] : ''
        );
        return new JsonResponse(200,['text'=>$text]);
    }

    /**
     * Triggered after Pico has loaded all available plugins
     *
     * This event is triggered nevertheless the plugin is enabled or not.
     * It is NOT guaranteed that plugin dependencies are fulfilled!
     *
     *
     * @param object[] $plugins loaded plugin instances
     */
    public function onPluginsLoaded(array $plugins)
    {
        $this->routes = [];
        foreach($plugins as $plugin){
            if ($plugin instanceof ApiAware){
                $routes = $plugin->registerApiRoutes();
                if (is_array($routes)){
                    foreach($routes as $route => $methodName){
                        if (is_string($methodName) && method_exists($plugin,$methodName)){
                            $this->routes[$route] = [$plugin,$methodName,false];
                        }
                    }
                }
                if ($plugin instanceof LateApiAware){
                    $routes = $plugin->registerLateApiRoutes();
                    if (is_array($routes)){
                        foreach($routes as $route => $methodName){
                            if (is_string($methodName) && method_exists($plugin,$methodName)){
                                $this->routes[$route] = [$plugin,$methodName,true];
                            }
                        }
                    }
                }
            }
        }
    }

    /**
     * trig api
     * Triggered before Pico loads its theme
     * use this event because could be reach in 15 ms instead of 60 ms after rendering
     *
     * @see Pico::loadTheme()
     * @see DummyPlugin::onThemeLoaded()
     *
     * @param string &$theme name of current theme
     */
    public function onThemeLoading(&$theme)
    {
        $output = null;
        if ($this->resolveApi($output)){
            if (!($output instanceof JsonResponse)){
                throw new Exception("Return of resolveApi should be JsonResponse at this point", 1);
            } else {
                throw new SpecialOutputException($output);
            }
        }
    }
    /**
     * send cookies of not already sent.
     *
     * Triggered after Pico has rendered the page
     *
     * @param  string &$output contents which will be sent to the user
     * @return void
     */
    public function onPageRendered(&$output)
    {
        if ($this->resolveApi($output,true)){
            $output = $output->send();
        }
        if (JsonResponse::canSendHeaders()){
            $this->getCookies()->sendCookiesOnce();
        }
    }

    /**
     * resolve api
     * @param null|string|JsonResponse $output
     * @param bool $isLate
     * @return bool $outputChanged
     */
    protected function resolveApi(&$output, bool $isLate = false): bool
    {
        $outputChanged = false;
        if (isset($_GET['api'])){
            $route = $this->getPico()->getUrlParameter(
                'api',
                FILTER_UNSAFE_RAW,
                [
                    'default' => ''
                ],
                [
                    FILTER_FLAG_STRIP_LOW,
                    FILTER_FLAG_STRIP_HIGH
                ]
            );
            $route = trim($route);
            if (empty($route)){
                $output = new JsonResponse(404,['code'=>404,'reason'=>'Empty api route'],[],$this->cookies);
            } elseif (!preg_match('/^[A-Za-z0-9_\-.\/]+$/',$route)) {
                $output = new JsonResponse(404,['code'=>404,'reason'=>"Route '$route' use forbidden characters !"],[],$this->cookies);
            } else {
                ob_start();
                $response = null;
                try {
                    $data = $this->searchCorrespondingRoute($route);
                    if ($data['isLate'] !== $isLate){
                        if ($isLate){
                            return new Exception('Calling an api route but catch onPageRedered whereas should be caught onThemeLoading !');
                        } else {
                            ob_end_clean();
                            return false;
                        }
                    }
                    $response = call_user_func_array([$data['plugin'],$data['methodName']],$data['params']);
                    if (!($response instanceof JsonResponse)){
                        $response = null;
                        throw new Exception("Return of '{$data['methodName']}' should be instanceof of 'JsonResponse'");
                    } else {
                        $response->setCookies($this->cookies);
                    }
                } catch (BadMethodException $th) {
                    $code = 405;
                    $content = ['reason'=>$th->getMessage()];
                } catch (NotFoundRouteException $th) {
                    $code = 404;
                    $content = ['reason'=>"Route '$route' not found !"];
                } catch (Throwable $th) {
                    $code = 500;
                    $content = ['reason'=>$th->__toString()];
                }
                $rawOutput = ob_get_contents();
                ob_end_clean();
                if (empty($response)){
                    if (!empty($rawOutput)){
                        $content['rawOutput'] = $rawOutput;
                    }
                    $content = array_merge(['code'=>$code],$content);
                    $response = (new JsonResponse($code,$content,[],$this->cookies));
                } elseif (!empty($rawOutput)) {
                    $response->mergeInContent(compact(['rawOutput']));
                }
                $output = $response;
            }
            $outputChanged = true;
        }
        return $outputChanged;
    }

    /**
     * search corresponding route 
     * @param string $route
     * @return array ['plugin'=>$plugin,'methodName'=>string,'params'=>array]
     * @throws BadMethodException
     * @throws NotFoundRouteException
     */
    protected function searchCorrespondingRoute(string $route): array
    {
        if (empty($_SERVER['REQUEST_METHOD'])){
            throw new BadMethodException('Method not defined');
        }
        $method = $_SERVER['REQUEST_METHOD'];
        if (!in_array($method,['GET','POST'],true)){
            throw new BadMethodException('Not allowed method');
        }
        $splittedRoute = explode('/',$route);
        
        $nb = count($splittedRoute);
        $badMethod = false;
        for ($i=0; $i < 2**$nb; $i++) {
            $params = [];
            $splittedRouteFiltered = [];
            foreach ($splittedRoute as $idx => $value) {
                $currentPower = $nb - $idx - 1 ;
                if ((2**$currentPower & $i) > 0){
                    $splittedRouteFiltered[] = '(.*)';
                    $params[] = $value;
                } else {
                    $splittedRouteFiltered[] = $value;
                }
            }
            $searchingRoute = implode('/',$splittedRouteFiltered);
            $data = [];
            if (array_key_exists("$method $searchingRoute",$this->routes)){
                $data = $this->routes["$method $searchingRoute"];
            } elseif (array_key_exists("$searchingRoute",$this->routes)){
                $data = $this->routes["$searchingRoute"];
            }
            if (!empty($data)){
                return [
                    'plugin' => $data[0],
                    'methodName' => $data[1],
                    'params' => $params,
                    'isLate' => $data[2]
                ];
            } elseif (!$badMethod && array_key_exists((($method == 'GET') ? 'POST' : 'GET' )." $searchingRoute",$this->routes)){
                $badMethod = true;
            }
        }
        if ($badMethod){
            throw new BadMethodException('Not allowed method');
        }
        throw new NotFoundRouteException('');
    }
}