<?php

namespace App\Services;

use Illuminate\Support\Facades\Log;

class DropboxService
{
    /**
     * @var string
     */
    private $accessToken;

    /**
     * Configuration related to the Backblaze B2 service.
     * @var \Illuminate\Config\Repository|mixed
     */
    private $config;

    public function __construct()
    {
        $this->config = config('services.dropbox');
    }

    public function downloadFile($pathOnStorage)
    {
        $dropboxArgs = ['path' => $pathOnStorage];

        return $this->sendRequest(
            $this->config['download_url'],
            'POST',
            null,
            [
                'http_headers' => [
                    sprintf('Dropbox-API-Arg: %s', json_encode($dropboxArgs)),
                    'Content-Type: application/octet-stream'
                ],
                'post_body_is_json' => false,
                'response_body_is_json' => false
            ]
        );
    }

    /**
     * @param string $accessToken
     */
    public function setAccessToken(string $accessToken)
    {
        $this->accessToken = $accessToken;
    }

    public function uploadFile($pathToFileToUpload, $pathToStorage)
    {
        $dropboxArgs = [
            'path' => $pathToStorage,
            'mode' => 'add',
            'mute' => true
        ];

        $uploadResult = $this->sendRequest(
            $this->config['upload_url'],
            'POST',
            file_get_contents($pathToFileToUpload),
            [
                'http_headers' => [
                    sprintf('Dropbox-API-Arg: %s', json_encode($dropboxArgs)),
                    'Content-Type: application/octet-stream'
                ],
                'post_body_is_json' => false
            ]
        );
    }

    private function getBasicHttpClient($url, $method = 'GET', array $httpHeaders = [])
    {
        $httpHeaders = array_merge(
            [
                'Accept: application/json',
                sprintf('Authorization: Bearer %s', $this->accessToken)
            ],
            $httpHeaders
        );

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $httpHeaders);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

        switch (strtoupper($method))
        {
            case 'GET':
                curl_setopt($ch, CURLOPT_HTTPGET, true);
                break;

            case 'POST':
                curl_setopt($ch, CURLOPT_POST, true);
                break;
        }

        return $ch;
    }

    private function sendRequest($url, $method = 'GET', $postData = null, array $postOptions = [])
    {
        $postOptions = array_merge(
            [
                'http_headers' => [],
                'post_body_is_json' => true,
                'response_body_is_json' => true
            ],
            $postOptions
        );
        $httpHeaders = $postOptions['http_headers'];

        $ch = $this->getBasicHttpClient($url, $method, $httpHeaders);

        if (!is_null($postData))
        {
            if ($postOptions['post_body_is_json'])
            {
                $postData = json_encode($postData);
            }

            curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);
        }

        Log::info(sprintf('%s: %s', strtoupper($method), $url));
        Log::debug('HTTP headers:', $httpHeaders);

        // Only log a post body if we have one and it's in JSON format (i.e. not a file upload)
        if (!is_null($postData) && $postOptions['post_body_is_json'])
        {
            Log::debug($postData);
        }

        $result = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

        Log::info(sprintf('Received HTTP code %d', $httpCode));

        // Only log a result if we have one and it's in JSON format (i.e. not a file download)
        if (!is_null($result) && $result !== false && $postOptions['response_body_is_json'])
        {
            Log::debug($result);
        }

        if ($httpCode != 200 && $httpCode != 304)
        {
            throw new \Exception(sprintf('Exception from Dropbox: %s', $result));
        }

        curl_close($ch);

        return $postOptions['response_body_is_json']
            ? json_decode($result)
            : $result;
    }
}