<?php

namespace App\Lib\CafelApi\Transport;

use App\Enums\ApiStatus;
use App\Exceptions\CafelApiException;
use Psr\Http\Message\ResponseInterface;

/**
 * @property int $httpCode The http response code
 * @property string $message The api message
 * @property array $headers The http reponse headers
 * @property array $body The http response body, this is parsed json
 * @property ?array $data The reponse data
 *
 */
class Response
{
    /**
     * The response http code
     *
     * @var integer
     */
    private $httpCode = 0;

    /**
     * The response headers
     *
     * @var string
     */
    private $headers;

    /**
     * The response body
     *
     * @var string
     */
    private $body;

    /**
     * The interface message
     *
     * @var string
     */
    private $message;

    /**
     * PSR response
     *
     * @var \Psr\Http\Message\ResponseInterface
     */
    private $response;

    /**
     * Response
     *
     * @param \App\Enums\ApiStatus                $status
     * @param \Psr\Http\Message\ResponseInterface $response
     * @param \App\Lib\CafelApi\Transport\Request $request
     * @throws \App\Exceptions\CafelApiException If HTTP response body in not JSON.
     */
    public function __construct(ApiStatus $status, ResponseInterface $response, Request $request)
    {
        $this->response = $response;
        $this->status   = $status;
        $this->httpCode = $response->getStatusCode();
        $this->headers  = $response->getHeaders();
        /** @var \GuzzleHttp\Psr7\Stream */
        $this->body = $response->getBody();

        if (!in_array($response->getStatusCode(), [200, 201])) {
            $this->message = $response->getReasonPhrase();
        }

        // * Body should be json data.
        if (($decodedJson = $this->tryDecodeJson($this->body->getContents())) === false) {
            if (in_array(config('app.env'), ['testing', 'local'])) {
                dump(
                    'should have been json',
                    $this->httpCode,
                    $this->status,
                    $this->headers,
                    $request->uri,
                    (string)$this->body
                );
            }
            throw new CafelApiException(
                "The Api should have returned JSON data '{$request->uri}'"
            );
        }
        $this->body = $decodedJson;

        // * If Api Error.
        if ($this->status->equals(ApiStatus::KO())) {
            new CafelApiException("CAfel Api responded http code $this->httpCode");
        }

        return $this;
    }

    /**
     * Generic accessor
     *
     * @param string $field
     * @return mixed|null
     */
    public function __get(string $field)
    {
        if (
            \in_array($field, [
                'status', 'httpCode', 'headers',
            'body', 'message', 'response'
            ])
        ) {
            return $this->{$field};
        }
        if ($field === 'data' and isset($this->body[$field])) {
            return $this->body[$field];
        }
        return null;
    }

    /**
     * Try to decode json and return false if it is
     * not a valid json
     *
     * @param string $string
     * @return array|false Returns an associative data array or false if failed to parse.
     */
    private function tryDecodeJson(string $string)
    {
        /** @var array|null */
        $data = json_decode($string, true);
        return (json_last_error() == JSON_ERROR_NONE) ? $data : false;
    }
}