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

namespace SeaCMS\Api;

use JsonSerializable;
use SeaCMS\Api\Cookies;
use Throwable;

/**
 * Response for http response
 */
class JsonResponse implements JsonSerializable
{

    /**
     * HTTP Codes
     * @var array
     */
    const HTTP_CODES = [
        200 => 'OK',
        301 => 'Moved Permanently',
        302 => 'Found',
        304 => 'Not Modified',
        307 => 'Temporary Redirect',
        308 => 'Permanent Redirect',
        400 => 'Bad Request',
        401 => 'Unauthorized',
        403 => 'Forbidden',
        404 => 'Not Found',
        405 => 'Method Not Allowed',
        406 => 'Not Acceptable',
        408 => 'Request Timeout',
        500 => 'Internal Server Error',
        501 => 'Not Implemented',
        503 => 'Service Unavailable',
    ];

    
    /**
     * cookies to send
     * @var null|Cookies
     */
    protected $cookies;
    /**
     * HTTP CODE
     * @var int
     */
    protected $code;
    /**
     * content as array
     * @var array
     */
    protected $content;
    /**
     * headers
     * @var array
     */
    protected $headers;


    public function __construct(int $code, array $content, array $headers = [],?Cookies $cookies = null){
        $this->code = array_key_exists($code, self::HTTP_CODES) ? $code : 501; // default
        $this->content = $content;
        $this->headers = array_merge([
            'Content-Type' => 'application/json',
            'Access-Control-Allow-Origin' => '*',
            'Access-Control-Allow-Credentials' => 'true',
            'Access-Control-Allow-Headers' => 'X-Requested-With, Location, Slug, Accept, Content-Type',
            'Access-Control-Expose-Headers' => 'Location, Slug, Accept, Content-Type',
            'Access-Control-Allow-Methods' => 'POST, GET, OPTIONS, DELETE, PUT, PATCH',
            'Access-Control-Max-Age' => '86400'
        ], $headers);
        $this->cookies = $cookies;
    }

    /**
     * set Cookies instance
     * @param Cookies $cookies
     */
    public function setCookies(Cookies $cookies)
    {
        $this->cookies = $cookies;
    }

    /**
     * merge in content
     * @param array $newContent
     * @return $this
     */
    public function mergeInContent(array $newContent){
        $this->content = array_merge(
            $this->content,
            $newContent
        );
    }
    /**
     * prepend in content
     * @param array $newContent
     * @return $this
     */
    protected function prependInContent(array $newContent){
        $this->content = array_merge(
            $newContent,
            $this->content
        );
    }
    
    /**
     * set code
     * @param int
     */
    public function setCode(int $code)
    {
        $this->code = $code;
    }

    /* === Getters === */
    /**
     * return code
     * @return int
     */
    public function getCode(): int
    {
        return $this->code;
    }
    /**
     * return content
     * @return array
     */
    public function getContent(): array
    {
        return $this->content;
    }

    /* ===         === */

    /**
     * Sends HTTP headers.
     *
     * @return $this
     */
    public function sendHeaders(): JsonResponse 
    {        
        // headers have already been sent by the developer
        if (JsonResponse::canSendHeaders()) {

            // headers
            foreach ($this->headers as $name => $value) {
                header($name.': '.$value);
            }

            // cookies
            if (!is_null($this->cookies)){
                $this->cookies->sendCookiesOnce();
            }

            // status
            $statusText = self::HTTP_CODES[$this->code];
            $protocol = !empty($_SERVER['SERVER_PROTOCOL']) ? $_SERVER['SERVER_PROTOCOL'] : 'HTTP/1.1';
            header("$protocol {$this->code} $statusText");
        }

        return $this;

    }

    /**
     * test if headers can be sent
     * @return bool
     */
    public static function canSendHeaders(): bool
    {
        return !headers_sent() && !in_array(php_sapi_name(), ['cli', 'cli-server',' phpdbg'], true);
    }

    /**
     * send headers and return output
     * @return string
     */
    public function send(): string
    {
        return $this->preparedOutput()->prepareStatusText()->sendHeaders()->returnContent();
    }

    /**
     * check if output is JSONSerializable
     * @return JsonResponse $this
     */
    protected function preparedOutput(): JsonResponse
    {
        try {
            if (!empty($GLOBALS['errorMessages'])){
                $this->mergeInContent(['errorMessages'=>$GLOBALS['errorMessages']]);
            }
            json_encode($this->content);
        } catch (Throwable $th) {
            $this->code = 500;
            $this->content = ['code' => 500, 'reason' =>"Not possible to JSONSerialize content"];
        }
        return $this;
    }

    /**
     * prepare statusText
     * @return JsonResponse $this
     */
    protected function prepareStatusText(): JsonResponse
    {
        if (!array_key_exists($this->code,self::HTTP_CODES)){
            $previousCode = intval($this->code);
            $this->code = 501;
            $this->prependInContent(['code' => 501, 'reason' =>"Wanted code ($previousCode) is not implemented !"]);
        }
        return $this;
    }

    /**
     * return content as String
     * @return string
     */
    protected function returnContent(): string
    {
        return json_encode($this->getContent());
    }

    /**
     * export class as array
     * @return array
     */
    public function jsonSerialize(): mixed
    {
        return [
            'code' => $this->getCode(),
            'content' => $this->getContent(),
            'headers' => $this->headers,
        ];
    }
}