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

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 SourceFileUrl = @"https://bytescout-com.s3.amazonaws.com/files/demo-files/cloud-api/pdf-to-image/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 = "";

        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);

            try
            {
                // Prepare URL for `PDF To PNG` API call
                string url = "https://api.pdf.co/v1/pdf/convert/to/png";

                // Prepare requests params as JSON
                Dictionary<string, object> parameters = new Dictionary<string, object>();
                parameters.Add("password", Password);
                parameters.Add("pages", Pages);
                parameters.Add("url", SourceFileUrl);

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

                // 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)
                {
                    // Download generated PNG files
                    int page = 1;
                    foreach (JToken token in json["urls"])
                    {
                        string resultFileUrl = token.ToString();
                        string localFileName = String.Format(@".\page{0}.png", page);

                        webClient.DownloadFile(resultFileUrl, localFileName);

                        Console.WriteLine("Downloaded \"{0}\".", localFileName);
                        page++;
                    }
                }
                else
                {
                    Console.WriteLine(json["message"].ToString());
                }
            }
            catch (WebException e)
            {
                Console.WriteLine(e.ToString());
            }

            webClient.Dispose();

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