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

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 TXT file name
		const string DestinationFile = @".\result.txt";

		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);

			// 1. RETRIEVE THE PRESIGNED URL TO UPLOAD THE FILE.
			// * If you already have a direct file URL, skip to the step 3.
			
			// 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)));

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

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

				if (json["error"].ToObject<bool>() == false)
				{
					// Get URL to use for the file upload
					string uploadUrl = json["presignedUrl"].ToString();
					string uploadedFileUrl = json["url"].ToString();

					// 2. UPLOAD THE FILE TO CLOUD.

					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");

					// 3. CONVERT UPLOADED PDF FILE TO TXT

					// URL for `PDF To TXT` API call
					var url = "https://api.pdf.co/v1/pdf/convert/to/text";

					// 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);

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

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

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

					if (json["error"].ToObject<bool>() == false)
					{
						// Get URL of generated TXT file
						string resultFileUrl = json["url"].ToString();

						// Download TXT file
						webClient.DownloadFile(resultFileUrl, DestinationFile);

						Console.WriteLine("Generated TXT file saved as \"{0}\" file.", DestinationFile);
					}
					else
					{
						Console.WriteLine(json["message"].ToString());
					}
				}
				else
				{
					Console.WriteLine(json["message"].ToString());
				}
			}
			catch (WebException e)
			{
				Console.WriteLine(e.ToString());
			}

			webClient.Dispose();

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