using packt.FoodyGO.Utils;
using packt.FoodyGO.Mapping;
using System.Collections;
using UnityEngine;

namespace packt.FoodyGO.Services {
  [AddComponentMenu("Services/GPSLocationService")]
  public class GPSLocationService : MonoBehaviour {
    // Redraw Event
    public delegate void OnRedrawEvent(GameObject g);
    public event OnRedrawEvent OnMapRedraw;
    [Header("GPS Accuracy")]
    public float DesiredAccuracyInMeters = 10f;
    public float UpdateAccuracyInMeters = 10f;

    [Header("Map Tile Parameters")]
    public int MapTileScale;
    public int MapTileSizePixels;
    public int MapTileZoomLevel;

    [Header("GPS Simulation Settings")]
    public bool Simulating;
    public MapLocation StartCoordinates;
    public float Rate = 1f;
    public Vector2[] SimulationOffsets;
    private int simulationIndex;

    [Header("Exposed for GPS Debugging Purposes Only")]
    public bool IsServiceStarted;
    public float Latitude;
    public float Longitude;
    public float Altitude;
    public float Accuracy;
    public double Timestamp;
    public double PlayerTimestamp;
    public MapLocation mapCenter;
    public MapEnvelope mapEnvelope;
    public Vector3 mapWorldCenter;
    public Vector2 mapScale;

    void Start() {
      print("Starting GPSLocationService");
      #if !UNITY_EDITOR
      StartCoroutine(StartService());
      Simulating = false;
      #else
      StartCoroutine(StartSimulationService());
      Latitude = StartCoordinates.Latitude;
      Longitude = StartCoordinates.Longitude;
      Accuracy = 10;
      Timestamp = 0;
      CenterMap();
      #endif
    }
        
    IEnumerator StartSimulationService() {
      while (Simulating) {
        IsServiceStarted = true;
        if (simulationIndex++ >= SimulationOffsets.Length-1) {
          simulationIndex = 0;
        }

        Longitude += SimulationOffsets[simulationIndex].x;
        Latitude += SimulationOffsets[simulationIndex].y;

        PlayerTimestamp = Epoch.Now;

        yield return new WaitForSeconds(Rate);
      }
      IsServiceStarted = false;
    }

    IEnumerator StartService() {
      // First, check if user has location service enabled
      if (!Input.location.isEnabledByUser) {
        print("location not enabled by user, existing");
        yield break;
      }

      // Start service before querying location
      Input.location.Start(DesiredAccuracyInMeters, UpdateAccuracyInMeters);

      // Wait until service initializes
      int maxWait = 20;
      while (Input.location.status == LocationServiceStatus.Initializing && maxWait > 0) {
        yield return new WaitForSeconds(1);
        maxWait--;
      }

      // Service didn't initialize in 20 seconds
      if (maxWait < 1) {
        print("Timed out");
        yield break;
      }

      // Connection has failed
      if (Input.location.status == LocationServiceStatus.Failed) {
        print("Unable to determine device location.");
        yield break;
      } else {
        Simulating = false;
        print("GSPLocationService started");
        // Access granted and location value could be retrieved
        print("Location initialized at: " + Input.location.lastData.latitude + " " + Input.location.lastData.longitude + " " + Input.location.lastData.altitude + " " + Input.location.lastData.horizontalAccuracy + " " + Input.location.lastData.timestamp);
        Timestamp = Input.location.lastData.timestamp; // added by nitta Oct/21/2019
        CenterMap();
        IsServiceStarted = true;
      }
           
    }

    void Update() {
      if(Input.location.status == LocationServiceStatus.Running && IsServiceStarted) {
        Latitude = Input.location.lastData.latitude;
        Longitude = Input.location.lastData.longitude;
        Altitude = Input.location.lastData.altitude;
        Accuracy = Input.location.lastData.horizontalAccuracy;
        PlayerTimestamp = Input.location.lastData.timestamp;
        MapLocation loc = new MapLocation(Input.location.lastData.longitude, Input.location.lastData.latitude);
        if (mapEnvelope.Contains(loc) == false) {
          Timestamp = Input.location.lastData.timestamp;
          CenterMap();
        }
      } else if (Simulating && IsServiceStarted) {
        MapLocation loc = new MapLocation(Longitude, Latitude);
        if (mapEnvelope.Contains(loc) == false) {
          Timestamp = PlayerTimestamp;
          CenterMap();
        }
      }
    }

    public void MapRedrawn() {
      if (OnMapRedraw != null) {
        OnMapRedraw(this.gameObject);
      }
    }

    private void CenterMap() {
      mapCenter.Latitude = Latitude;
      mapCenter.Longitude = Longitude;
      mapWorldCenter.x = GoogleMapUtils.LonToX(mapCenter.Longitude);
      mapWorldCenter.y = GoogleMapUtils.LatToY(mapCenter.Latitude);
            
      mapScale.x = GoogleMapUtils.CalculateScaleX(Longitude, MapTileSizePixels, MapTileScale, MapTileZoomLevel);
      mapScale.y = GoogleMapUtils.CalculateScaleY(Latitude, MapTileSizePixels, MapTileScale, MapTileZoomLevel);
            
      var lon1 = GoogleMapUtils.adjustLonByPixels(Longitude, -MapTileSizePixels/2, MapTileZoomLevel);
      var lat1 = GoogleMapUtils.adjustLatByPixels(Latitude, MapTileSizePixels/2, MapTileZoomLevel);
            
      var lon2 = GoogleMapUtils.adjustLonByPixels(Longitude, MapTileSizePixels/2, MapTileZoomLevel);
      var lat2 = GoogleMapUtils.adjustLatByPixels(Latitude, -MapTileSizePixels/2, MapTileZoomLevel);
            
      mapEnvelope = new MapEnvelope(lon1, lat1, lon2, lat2);
    }

    void OnDestroy() {
      if (IsServiceStarted)
        Input.location.Stop();
    }
  }
}