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
		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 Meta` API call
            string url = "https://api.pdf.co/v1/pdf/convert/to/json-meta";

			// 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"]);
		}
	}
}