using System;
using System.IO;
using System.Net;
using Newtonsoft.Json.Linq;
using System.Threading;
using System.Collections.Generic;
using Newtonsoft.Json;


// Cloud API asynchronous "PDF To JSON" job example.
// Allows to avoid timeout errors when processing huge or scanned PDF documents.

namespace ByteScoutWebApiExample
{
    class Program
    {
        // The authentication key (API Key).
        // Get your own by registering at https://app.pdf.co/documentation/api
        const String API_KEY = "***********************************";

        // Source PDF file
        const string SourceFile = @".\sample.pdf";
        // Comma-separated list of page indices (or ranges) to process. Leave empty for all pages. Example: '0,2-5,7-'.
        const string Pages = "";
        // PDF document password. Leave empty for unprotected documents.
        const string Password = "";
        // Destination JSON file name
        const string DestinationFile = @".\result.json";
        // (!) Make asynchronous job
        const bool Async = true;


        static void Main(string[] args)
        {
            // Create standard .NET web client instance
            WebClient webClient = new WebClient();

            // Set API Key
            webClient.Headers.Add("x-api-key", API_KEY);

            // Upload file
            string uploadedFileUrl = UploadFile(webClient, SourceFile);

            // URL for `PDF To JSON` API call
            string url = "https://api.pdf.co/v1/pdf/convert/to/json";

            // Prepare requests params as JSON
            Dictionary<string, object> parameters = new Dictionary<string, object>();
            parameters.Add("name", Path.GetFileName(DestinationFile));
            parameters.Add("password", Password);
            parameters.Add("pages", Pages);
            parameters.Add("url", uploadedFileUrl);
            parameters.Add("async", Async);

            // Convert dictionary of params to JSON
            string jsonPayload = JsonConvert.SerializeObject(parameters);

            try
            {
                // Execute POST request with JSON payload
                string response = webClient.UploadString(url, jsonPayload);

                // Parse JSON response
                JObject json = JObject.Parse(response);

                if (json["error"].ToObject<bool>() == false)
                {
                    // Asynchronous job ID
                    string jobId = json["jobId"].ToString();
                    // URL of generated JSON file that will available after the job completion
                    string resultFileUrl = json["url"].ToString();

                    // Check the job status in a loop. 
                    // If you don't want to pause the main thread you can rework the code 
                    // to use a separate thread for the status checking and completion.
                    do
                    {
                        string status = CheckJobStatus(webClient, jobId); // Possible statuses: "working", "failed", "aborted", "success".

                        // Display timestamp and status (for demo purposes)
                        Console.WriteLine(DateTime.Now.ToLongTimeString() + ": " + status);

                        if (status == "success")
                        {
                            // Download JSON file
                            webClient.DownloadFile(resultFileUrl, DestinationFile);

                            Console.WriteLine("Generated JSON file saved as \"{0}\" file.", DestinationFile);
                            break;
                        }
                        else if (status == "working")
                        {
                            // Pause for a few seconds
                            Thread.Sleep(3000);
                        }
                        else
                        {
                            Console.WriteLine(status);
                            break;
                        }
                    }
                    while (true);
                }
                else
                {
                    Console.WriteLine(json["message"].ToString());
                }
            }
            catch (WebException e)
            {
                Console.WriteLine(e.ToString());
            }

            webClient.Dispose();

            Console.WriteLine();
            Console.WriteLine("Press any key...");
            Console.ReadKey();
        }

        static string UploadFile(WebClient webClient, string file)
        {
            // RETRIEVE THE PRESIGNED URL TO UPLOAD THE FILE:

            // Prepare URL for `Get Presigned URL` API call
            string query = Uri.EscapeUriString(string.Format(
                "https://api.pdf.co/v1/file/upload/get-presigned-url?contenttype=application/octet-stream&name={0}",
                Path.GetFileName(SourceFile)));

            // Execute request
            string response = webClient.DownloadString(query);

            // Parse JSON response
            JObject json = JObject.Parse(response);

            string uploadUrl = json["presignedUrl"].ToString();
            string uploadedFileUrl = json["url"].ToString();

            // UPLOAD FILE:

            webClient.Headers.Add("content-type", "application/octet-stream");
            webClient.UploadFile(uploadUrl, "PUT", SourceFile); // You can use UploadData() instead if your file is byte[] or Stream
            webClient.Headers.Remove("content-type");

            return uploadedFileUrl;
        }

        static string CheckJobStatus(WebClient webClient, string jobId)
        {
            string url = "https://api.pdf.co/v1/job/check?jobid=" + jobId;

            string response = webClient.DownloadString(url);
            JObject json = JObject.Parse(response);

            return Convert.ToString(json["status"]);
        }
    }
}