using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class GetElevationFromGeoServerTMS : MonoBehaviour {

    public static string url =
        "[[geoserver link]]/{0}/{1}/{2}.png";

    private OnlineMapsTileSetControl control;
    public int resolution = 32;
    public int elevationScale = 1;
    bool getTiles = false;
    List<TileRequest> tileRequests;

    private void Start()
    {
        tileRequests = new List<TileRequest>();

        // Get Tileset control.
        control = OnlineMapsControlBase.instance as OnlineMapsTileSetControl;
        control.elevationResolution = resolution;
        if (control == null)
        {
            Debug.LogError("You must use the Tileset control.");
            return;
        }
        OnlineMaps.instance.OnStartDownloadTile += OnStartDownloadTile;
        control.OnGetElevation += OnGetElevation;
    }

    private void OnGetElevation(Vector2 topLeftCoords, Vector2 bottomRightCoords)
    {
        if (!getTiles)
            getTiles = true;

    }


    private void OnStartDownloadTile(OnlineMapsTile tile)
    {
        if (!getTiles)
            return;

        tileRequests.Add(new TileRequest(tile));
        OnlineMaps.instance.StartDownloadTile(tile);

    }


    private void CheckDownloadComplete()
    {
        bool hasComplete = false;
        foreach (TileRequest request in tileRequests)
        {
            if (request.www != null)
            {
                try { while (!request.www.isDone) { } } catch (Exception) { }
            }
            if (request.www.isDone)
            {
                if (string.IsNullOrEmpty(request.www.error))
                {
                    //default resize to 32x32
                    Texture2D tex = ResizeTexture2D.ResizeTexture
                        (request.GetTexture2D(),
                        ResizeTexture2D.ImageFilterMode.Average,
                        resolution, resolution);

                    Color[] colors = tex.GetPixels();
                    control.SetElevationData(GetElevation(colors, (int)Mathf.Sqrt(colors.Length)));
                }
                request.Dispose();
                hasComplete = true;
            }
        }

        if (hasComplete)
            tileRequests.RemoveAll(d => d.tile == null);
    }

    private void Update()
    {
        CheckDownloadComplete();
        OnlineMapsTileSetControl.instance.elevationScale = elevationScale;
    }


    short[,] GetElevation(Color[] colors, int resolution)
    {
        short[,] elevation = new short[resolution, resolution];
        for (int i = 0; i < resolution; i++)
        {
            for (int j = 0; j < resolution; j++)
                elevation[i, j] = (short)(colors[i * resolution + j].grayscale * 1000);
        }
        return elevation;
    }


    internal class TileRequest
    {
        public OnlineMapsWWW www;
        public OnlineMapsTile tile;
        int y = -999;

        public TileRequest(OnlineMapsTile _tile)
        {
            int z = _tile.zoom;
            int ymax = 1 << z;
            y = ymax - _tile.y - 1;

            string urlFormatted = string.Format(url, _tile.zoom, _tile.x, y);
            www = new OnlineMapsWWW(urlFormatted);
            tile = _tile;
        }

        public Texture2D GetTexture2D()
        {
            Texture2D tex = new Texture2D(256, 256, TextureFormat.ARGB32, false);
            www.LoadImageIntoTexture(tex);
            return (tex);
        }

        public string GenerateImage(string path)
        {
            if (y != -999)
            {
                path += tile.zoom + "-" + tile.x + "-" + y + ".png";
                System.IO.File.WriteAllBytes(path, www.bytes);
                return path;
            }
            return null;
        }

        public void Dispose()
        {
            www.Dispose();
            www = null;
            tile = null;
        }
    }

}