import { Component, Host, Input, Output, EventEmitter, Optional, QueryList, OnInit, AfterViewInit, OnChanges, SimpleChanges, SkipSelf, forwardRef, Inject, InjectionToken } from '@angular/core';
import { HttpClient } from "@angular/common/http";
import { LayerVectorComponent, LayerTileComponent, LayerGroupComponent, MapComponent } from 'ngx-openlayers';
import { ItemService } from '@farmmaps/common';
import { AppConfig } from '@farmmaps/common';
import { IItemLayer, ILayerData, IRenderoutputTiles, IRenderoutputImage, IGradientstop, ILayer, IHistogram } from '../../../models';

import {Extent} from 'ol/extent';
import Projection from 'ol/proj/Projection';
import * as proj from 'ol/proj';
import * as loadingstrategy from 'ol/loadingstrategy';
import * as style from 'ol/style';
import {Tile,Layer,Image} from 'ol/layer';
import {XYZ,ImageStatic,OSM,BingMaps,TileWMS,TileArcGISRest} from 'ol/source';
import {Vector as VectorSource} from 'ol/source';
import { Vector as VectorLayer } from 'ol/layer';
import VectorTileSource from 'ol/source/VectorTile';
import VectorTileLayer from 'ol/layer/VectorTile';
import {GeoJSON,MVT} from 'ol/format';
import { from } from 'rxjs';

@Component({
  selector: 'item-layers',
  template: `<ng-content></ng-content>`,
  providers: [
    { provide: LayerGroupComponent, useExisting: forwardRef(() => ItemLayersComponent) }
  ]
})

export class ItemLayersComponent extends LayerGroupComponent implements OnChanges, OnInit {
  @Input() itemLayers: IItemLayer[];
  @Input() itemLayer: IItemLayer;
  private _apiEndPoint: string;

  constructor(private itemService: ItemService, @Host() private map: MapComponent, public appConfig: AppConfig) {
    super(map);
    this._apiEndPoint = appConfig.getConfig("apiEndPoint");
  }

  private styleCache = {}

  componentToHex(c) {
    var hex = c.toString(16);
    return hex.length == 1 ? "0" + hex : hex;
  }

   rgbaToHex(r, g, b,a) {
     return "#" + this.componentToHex(r) + this.componentToHex(g) + this.componentToHex(b) + this.componentToHex(a);
  }

  getColorFromGradient(layer: ILayer,  feature): style.Style {
    var value = feature.get(layer.name);
    var gradient: IGradientstop[] = layer.renderer.colorMap.gradient;
    var histogram: IHistogram = layer.renderer.band.histogram;
    var index = (value - histogram.min) / histogram.max;
    var min = gradient[0];
    var max = gradient[gradient.length - 1];
    for (var n = 0; n < gradient.length; n++) {
      var s = gradient[n];
      if (s.relativestop <= index && min.relativestop < s.relativestop && n < gradient.length - 1) min = s;
      if (s.relativestop >= index && max.relativestop > s.relativestop && n > 0) max = s;
    }
    var i = index - min.relativestop;
    var size = max.relativestop - min.relativestop;
    var alpha = Math.round( min.color.alpha + ((max.color.alpha - min.color.alpha) * i / size));
    var red = Math.round(min.color.red + ((max.color.red - min.color.red) * i / size));
    var green = Math.round(min.color.green + ((max.color.green - min.color.green) * i / size));
    var blue = Math.round(min.color.blue + ((max.color.blue - min.color.blue) * i / size));

    return new style.Style(
      {
        image: new style.Circle({
          fill: new style.Fill({
            color: this.rgbaToHex(red,green,blue,alpha)
          }),
          radius: 3
        }),
        fill: new style.Fill({
          color: this.rgbaToHex(red, green, blue, alpha)
        }),
        stroke: new style.Stroke({
          color: this.rgbaToHex(red, green, blue, alpha),
          width: 1.25
        }),
      });
  }

  createLayer(itemLayer: IItemLayer): Layer {
    var layer: Layer = null;    
    if (itemLayer.item.itemType == 'vnd.farmmaps.itemtype.geotiff.processed') {
      let source = new XYZ({ maxZoom: 19, minZoom: 1, url: `${this._apiEndPoint}/api/v1/items/${itemLayer.item.code}/tiles/{z}/{x}/{y}.png?v=${itemLayer.item.updated.getTime()}` });
      layer = new Tile({ source: source });
      var data = itemLayer.item.data;
      var l = (data && data.layers && data.layers.length > 0) ? data.layers[0] : null;
      if (l && l.rendering && l.rendering.renderoutputType == "Tiles") {
        var rt = l.rendering as IRenderoutputTiles;
        let source = new XYZ({ maxZoom: rt.maxzoom, minZoom: rt.minzoom, url: `${this._apiEndPoint}/api/v1/items/${itemLayer.item.code}/tiles/{z}/{x}/{y}.png?v=${itemLayer.item.updated.getTime()}` });
        layer = new Tile({ source: source });
      }
      if (l && l.rendering && l.rendering.renderoutputType == "Image") {
        var ri = l.rendering as IRenderoutputImage;
        let projection = new Projection({
          code: 'image',
          units: 'pixels',
          extent: ri.extent
        });
        let source = new ImageStatic({ imageExtent: ri.extent, projection: projection, url: `${this._apiEndPoint}/api/v1/items/${itemLayer.item.code}/mapimage?v=${itemLayer.item.updated.getTime()}` });
        layer = new Image({ source: source });
      }
    } else if (itemLayer.item.itemType == 'vnd.farmmaps.itemtype.shape.processed') {
      var data = itemLayer.item.data;
      var layerIndex = itemLayer.layerIndex != -1 ? itemLayer.layerIndex : itemLayer.item.data.layers[0].index;
      var l = itemLayer.item.data.layers[layerIndex];
      if (l && l.rendering && l.rendering.renderoutputType == "VectorTiles") {
        var rt = itemLayer.item.data.layers[layerIndex].rendering as IRenderoutputTiles;
        layer = new VectorTileLayer({
          declutter: true,
          source: new VectorTileSource({
            maxZoom: rt.maxzoom,
            minZoom: rt.minzoom,
            format: new MVT(),
            url: `${this._apiEndPoint}/api/v1/items/${itemLayer.item.code}/vectortiles/{z}/{x}/{y}.pbf?v=${itemLayer.item.updated.getTime()}`
          }),
          style: (feature) => {
            return this.getColorFromGradient(l, feature);           
          }
        })
      } if (l && l.rendering && l.rendering.renderoutputType == "Tiles") {
        var rt = l.rendering as IRenderoutputTiles;
        layer = new Tile({
          source: new XYZ({
            maxZoom: rt.maxzoom,
            minZoom: rt.minzoom,
            url: `${this._apiEndPoint}/api/v1/items/${itemLayer.item.code}/vectortiles/image_tiles/${layerIndex}/{z}/{x}/{y}.png?v=${itemLayer.item.updated.getTime()}`
          })
        });
      } else {
        let __this = this;
        let format = new GeoJSON();
        let source = new VectorSource({
          strategy: loadingstrategy.bbox,
          loader: function (extent: Extent, resolution: number, projection: Projection) {
            var source = this as VectorSource;
            __this.itemService.getItemFeatures(itemLayer.item.code, extent, projection.getCode(), layerIndex).subscribe(function (data) {
              var features = format.readFeatures(data);
              for (let f of features) {
                if (f.get("code")) {
                  f.setId(f.get("code"));
                }
              }
              source.addFeatures(features);
            });
          }
        });
        layer = new VectorLayer({
          source: source,
          style: (feature) => {
            var key = feature.get("color");
            if (!this.styleCache[key]) {
              var color = feature.get("color");
              this.styleCache[key] = new style.Style(
                {
                  fill: new style.Fill({
                    color: color
                  }),
                  stroke: new style.Stroke({
                    color: color,
                    width: 1.25
                  }),
                  image: new style.Circle({
                    fill: new style.Fill({
                      color: color
                    }),
                    stroke: new style.Stroke({
                      color: color,
                      width: 1.25
                    }),
                    radius: 5
                  }),
                }
              )
            }
            return this.styleCache[key];
          }
        });
      }      
    } else if (itemLayer.item.itemType == 'vnd.farmmaps.itemtype.layer') {
      let data = itemLayer.item.data as ILayerData;
      switch (data.interfaceType) {
        case 'OSM': {
          let source = new OSM();
          layer = new Tile({ source: source });
          break;
        }
        case 'BingMaps': {
          let source = new BingMaps(data.options);
          layer = new Tile({ source: source });
          break;
        }
        case 'TileWMS': {
          let source = new TileWMS(data.options);
          layer = new Tile({ source: source });
          break;
        }
        case 'TileArcGISRest': {
          let source = new TileArcGISRest(data.options);
          layer = new Tile({ source: source });
          break;
        }
        default: {
          break;
        }
      }
    }
    if (layer) {
      let geometry = new GeoJSON().readGeometry(itemLayer.item.geometry);
      let extent = geometry ? proj.transformExtent(geometry.getExtent(), 'EPSG:4326', 'EPSG:3857') : null;
      if (extent) layer.setExtent(extent);
    }

    return layer;
  }

  ngOnInit() {
    super.ngOnInit();
    this.updateLayers(this.itemLayers);
  }

  updateLayers(itemLayers: IItemLayer[]) {
    if (itemLayers) {
      var olLayers = this.instance.getLayers();
      itemLayers.forEach((itemLayer, index) => {

        var layer = itemLayer.layer;
        let olIndex = olLayers.getArray().indexOf(layer);
        if (olIndex < 0) {
          // New layer: we add it to the map
          layer = this.createLayer(itemLayer);
          if (layer) {
            itemLayer.layer = layer;
          }
          olLayers.insertAt(index, layer);
        } else if (index !== olIndex) {
          // layer has moved inside the layers list
          olLayers.removeAt(olIndex);
          olLayers.insertAt(index, layer);
        }
        layer.setOpacity(itemLayer.opacity);
        layer.setVisible(itemLayer.visible);
      });
      // Remove the layers that have disapeared from childrenLayers
      if (olLayers.getLength() > itemLayers.length) {
        for (let i = itemLayers.length; i < olLayers.getLength(); i++) {
          olLayers.removeAt(i);
        }
      }
    }   
  }

  ngOnChanges(changes: SimpleChanges) {
    if (this.instance) {
      if (changes['itemLayers']) {
        var itemLayers = changes['itemLayers'].currentValue as IItemLayer[];
        this.updateLayers(itemLayers);
      }
      if (changes['itemLayer']) {
        var itemLayer = changes['itemLayer'].currentValue as IItemLayer;
        if(itemLayer) {
          this.updateLayers([itemLayer]);
        } else {
          this.updateLayers([]);
        }
      }
    }
  }
}