using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Net;

using System.IO;

using System.Collections.ObjectModel;



namespace WiFiChannelSpread.GoogleApi

{

    public static class GeolocationApi

    {

        private const int HttpRequestTimeoutMilliseconds = 5000;

        private const string GeolocationApiUrl = "http://www.google.com/loc/json";

        private const string ApplicationHost = "WiFiChannelSpread.CodePlex.com";

        private const string GeolocationApiVersion = "1.1.0";



        public static Location GetGeolocation(Collection<WiFiTower> listOfWiFiTowers, bool includeAddress)

        {

            GeolocationRequest request = CreateGeolocationRequest(includeAddress);

            request.wifi_towers = listOfWiFiTowers;



            string jsonResponse = PostHttpJson(GeolocationApiUrl, Newtonsoft.Json.JsonConvert.SerializeObject(request));

            GeolocationResponse response = Newtonsoft.Json.JsonConvert.DeserializeObject<GeolocationResponse>(jsonResponse);

            if (response == null)

            {

                throw new InvalidOperationException("No response from Google.");

            }



            return response.location;

        }



        public static Location GetGeolocationOfWiFiTower(string macAddress, string ssid, bool includeAddress)

        {

            GeolocationRequest request = CreateGeolocationRequest(includeAddress);

            request.wifi_towers.Add(new WiFiTower { mac_address = macAddress, ssid = ssid });



            string jsonResponse = PostHttpJson(GeolocationApiUrl, Newtonsoft.Json.JsonConvert.SerializeObject(request));

            GeolocationResponse response = Newtonsoft.Json.JsonConvert.DeserializeObject<GeolocationResponse>(jsonResponse);

            if (response == null)

            {

                throw new InvalidOperationException("No response from Google.");

            }



            return response.location;

        }



        private static GeolocationRequest CreateGeolocationRequest(bool includeAddress)

        {

            return new GeolocationRequest

                {

                    host = ApplicationHost,

                    version = GeolocationApiVersion,

                    request_address = includeAddress,

                    wifi_towers = new Collection<WiFiTower>()

                };

        }



        private static string PostHttpJson(string url, string data)

        {

            byte[] postData = Encoding.ASCII.GetBytes(data);



            HttpWebRequest request = CreateWebRequest(url);

            request.Method = "POST";

            request.ContentType = "application/json; charset=utf-8";

            request.Accept = "application/json, text/javascript, */*";

            request.ContentLength = postData.Length;



            using (Stream requestStream = request.GetRequestStream())

            {

                requestStream.Write(postData, 0, postData.Length);

            }



            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())

            using (Stream responseStream = response.GetResponseStream())

            using (StreamReader reader = new StreamReader(responseStream))

            {

                return reader.ReadToEnd();

            }

        }



        private static HttpWebRequest CreateWebRequest(string url)

        {

            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);

            request.Timeout = HttpRequestTimeoutMilliseconds;

            return request;

        }



    }

}