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

namespace ___YOUR_NAMESPACE___
{
    public class GDirections
    {
        private string _key = "___ENTER_YOUR_KEY___";
        private string _output = "js";
        private string _requestFormat = "http://maps.google.com/maps/nav?key={0}&output={1}&q={2}";
        private Hashtable _data = new Hashtable();

        public bool IsValid { get; private set; }

        public decimal DrivingMeters
        {
            get { return Convert.ToDecimal(((Hashtable)Directions["Distance"])["meters"]); }
        }

        public TimeSpan DrivingTime
        {
            get { return new TimeSpan(0, 0, Convert.ToInt32(((Hashtable)Directions["Duration"])["seconds"])); }
        }

        public decimal DrivingMiles
        {
            get { return Math.Round(DrivingMeters * (decimal)0.000621371192, 2); } // according to Google.
        }

        private Hashtable Directions
        {
            get { return (Hashtable)_data["Directions"]; }
        }

        private List<Route> _routes = null;

        /// <summary>
        /// Returns a list of driving routes from the given start location to the destination.
        /// </summary>
        public List<Route> Routes
        {
            get
            {
                // Cache results
                if (_routes == null && IsValid)
                {
                    ArrayList data_routes = (ArrayList)Directions["Routes"];
                    if (data_routes.Count < 1)
                        return null;

                    // Cycle through each returned route
                    List<Route> routes = new List<Route>();
                    foreach (Hashtable data_route in data_routes)
                    {
                        Route route = new Route()
                        {
                            DrivingMeters = Convert.ToDecimal(((Hashtable)data_route["Distance"])["meters"]),
                            DrivingSeconds = Convert.ToInt32(((Hashtable)data_route["Duration"])["seconds"]),
                            DrivingDistanceHTML = (string)((Hashtable)data_route["Distance"])["html"],
                            SummaryHTML = (string)data_route["summaryHtml"]
                        };

                        // Cycle through each step in a route
                        ArrayList data_routesteps = (ArrayList)data_route["Steps"];
                        foreach (Hashtable data_routestep in data_routesteps)
                        {
                            RouteStep step = new RouteStep()
                            {
                                DrivingMeters = Convert.ToDecimal(((Hashtable)data_routestep["Distance"])["meters"]),
                                DrivingSeconds = Convert.ToInt32(((Hashtable)data_routestep["Duration"])["seconds"]),
                                DrivingDistanceHTML = (string)((Hashtable)data_routestep["Distance"])["html"],
                                DescriptionHTML = (string)data_routestep["descriptionHtml"]
                            };
                            route.Add(step);
                        }

                        routes.Add(route);
                    }

                    _routes = routes;
                }

                return _routes;
            }
        }

        /// <summary>
        /// Returns a semantic, xhtml ordered list representing driving directions.
        /// </summary>
        public List<string> RoutesHtml
        {
            get
            {
                List<string> routesHtml = new List<string>();

                foreach (Route route in Routes)
                {
                    string html = "";

                    foreach (RouteStep step in route)
                    {
                        html += "<li><span class=\"description\">" + step.DescriptionHTML + "</span>"
                              + "<span class=\"distance\">" + step.DrivingMiles.ToString("0.0") + " mi</span></li>";
                    }

                    html = "<ol>" + html + "</ol>";
                    routesHtml.Add(html);
                }

                return routesHtml;
            }
        }

        public GDirections(string startAddress, string endAddress)
            : this("From " + startAddress + " to " + endAddress)
        {
        }
        
        /// <summary>
        /// Returns a GDirections object.
        /// </summary>
        /// <param name="path">A path in the format "From {a} to {b}".  Example: "From Lexington, KY to Burkesville, KY"</param>
        public GDirections(string path)
        {
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(
                string.Format(_requestFormat, _key, _output, Uri.EscapeUriString(path)));
            request.Method = "GET";
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            StreamReader reader = new StreamReader(response.GetResponseStream());
            string json = reader.ReadToEnd();
            json = parseUnicode(json);

            _data = readJson(new JsonReader(new StringReader(json)));
            IsValid = _data.ContainsKey("Directions");

        }

        private Hashtable readJson(JsonReader jreader)
        {
            Hashtable data = new Hashtable();
            while (jreader.Read() && jreader.TokenType != JsonToken.EndObject)
            {
                string key = null;
                object value = null;

                if (jreader.TokenType == JsonToken.PropertyName)
                {
                    key = (string)jreader.Value;
                    jreader.Read();
                    switch (jreader.TokenType)
                    {
                        case JsonToken.StartArray:
                            value = readJsonArray(jreader);
                            break;
                        case JsonToken.StartObject:
                            value = readJson(jreader);
                            break;
                        case JsonToken.Null:
                        case JsonToken.Undefined:
                            value = null;
                            break;
                        default:
                            value = jreader.Value;
                            break;
                    }
                }

                if (key != null)
                    data.Add(key, value);
            }
            return data;
        }

        private ArrayList readJsonArray(JsonReader jreader)
        {
            ArrayList value = new ArrayList();
            while (jreader.Read() && jreader.TokenType != JsonToken.EndArray)
            {
                switch (jreader.TokenType)
                {
                    case JsonToken.StartArray:
                        value.Add(readJsonArray(jreader));
                        break;
                    case JsonToken.StartObject:
                        value.Add(readJson(jreader));
                        break;
                    case JsonToken.Null:
                    case JsonToken.Undefined:
                        value.Add(null);
                        break;
                    default:
                        value.Add(jreader.Value);
                        break;
                }
            }
            return value;
        }

        private string parseUnicode(string s)
        {
            string t = s;
            Match match = Regex.Match(s, "[^\\\\]\\\\u([0-9abcdef]{4})", RegexOptions.IgnoreCase);
            while(match != null && match.Success)
            {
                int charCode = Convert.ToInt32(match.Groups[1].Value, 16);
                t = t.Replace(match.Value.Substring(1), Convert.ToChar(charCode).ToString());
                match = match.NextMatch();
            }
            return t;
        }
    }

    public class RouteStep
    {        
        // Core data properties
        public string DescriptionHTML { get; set; }
        public string DrivingDistanceHTML { get; set; }
        public decimal DrivingMeters { get; set; }
        public int DrivingSeconds { get; set; }

        // Convenience properties
        public decimal DrivingMiles
        {
            get { return Math.Round(DrivingMeters * (decimal)0.000621371192, 2); }
        }
        
        public TimeSpan DrivingTime 
        {
            get
            {
                return new TimeSpan(0, 0, DrivingSeconds);
            }
        }        
    }

    public class Route : List<RouteStep>
    {
        public string SummaryHTML { get; set; }
        public string DrivingDistanceHTML { get; set; }
        public decimal DrivingMeters { get; set; }
        public int DrivingSeconds { get; set; }

        public decimal DrivingMiles
        {
            get { return Math.Round(DrivingMeters * (decimal)0.000621371192, 2); }
        }

        public TimeSpan DrivingTime
        {
            get
            {
                return new TimeSpan(0, 0, DrivingSeconds);
            }
        } 

        public Route() : base() { }
        public Route(int capacity) : base(capacity) { }
        public Route(IEnumerable<RouteStep> collection) : base(collection) { }
    }
}