using Adrenak.Unex;
using System.Text;
using System.Threading.Tasks;
using System;
using UnityEngine;
using RestSharp;

namespace Adrenak.UniMap {
	public class StreetViewMetaRequest {
		/// <summary>
		/// The base URL of the Street View API
		/// </summary>
		const string k_BaseURL = "https://maps.googleapis.com/maps/api/streetview/metadata?";

		/// <summary>
		/// The options for the meta data request
		/// </summary>
		public StreetView.Options options = new StreetView.Options();

		/// <summary>
		/// Gets the request URL for the given face given the API parameters.
		/// </summary>
		/// <param name="face">The <see cref="Face"/> whose texture is to be downloaded.</param>
		/// <returns>The URL for downloading the texture of this <see cref="Face"/></returns>
		public string GetURL() {
			var sb = new StringBuilder(k_BaseURL).Append("key=").Append(options.key);

			switch (options.mode) {
				case StreetView.Mode.Coordinates:
					sb.Append("&location=").Append(options.location.lat).Append(",").Append(options.location.lng);
					break;
				case StreetView.Mode.PanoID:
					sb.Append("&pano=").Append(options.panoID);
					break;
				case StreetView.Mode.Location:
					sb.Append("&location=").Append(options.place);
					break;
			}

			sb.Append("&radius=").Append(options.radius)
			.Append("&source=").Append(EnumToString.From(options.source));

			return sb.ToString();
		}

		/// <summary>
		/// Send the API request and returns the response or exception
		/// </summary>
		/// <param name="onResponse">Action that returns the response as a C# object</param>
		/// <param name="onException">Action that returns the exception encountered in case of an error</param>
		public void Send(Action<StreetViewMetaResponse> onResponse, Action<Exception> onException) {
			string url = string.Empty;
			try {
				url = GetURL();
			}
			catch (Exception e) {
				onException(e);
			}

            var client = new RestClient();
            var request = new RestRequest(url, Method.GET);
            client.ExecuteAsync(request, response => { 
                Dispatcher.Enqueue(() => {
                    if (response.IsSuccessful()) {
                        try {
                            var result = JsonUtility.FromJson<StreetViewMetaResponse>(response.Content);
                            onResponse?.Invoke(result);
                        }
                        catch (Exception e) {
                            onException?.Invoke(e);
                        }
                    }
                    else
                        onException?.Invoke(response.GetException());
                });
            });
        }

        /// <summary>
        /// Send the API request and return a task for the response
        /// </summary>
        public Task<StreetViewMetaResponse> Send() {
            var source = new TaskCompletionSource<StreetViewMetaResponse>();
            Send(
                response => source.SetResult(response),
                exception => source.SetException(exception)
            );
            return source.Task;
        }
    }
}