"use strict";

import path from 'path';

import L from 'leaflet';
import * as tf from '@tensorflow/tfjs';
import chroma from 'chroma-js';

import GetFromUrl from './Helpers/GetFromUrl.mjs';
import Config from './ClientConfig.mjs';
import { normalise } from '../../common/Math.mjs';

class LayerAI {
	get gateway_bounds() {
		let result = {
			east: Infinity,
			west: -Infinity,
			north: Infinity,
			south: -Infinity
		};
		for(let gateway of this.index) {
			result.east = Math.min(gateway.longitude, result.east);
			result.west = Math.max(gateway.longitude, result.west);
			
			result.north = Math.min(gateway.latitude, result.north);
			result.south = Math.max(gateway.latitude, result.south);
		}
		
		return result;
	}
	constructor(map) {
		this.map = map;
		this.gateways = new Map();
	}
	
	async setup() {
		this.index = JSON.parse(
			await GetFromUrl(Config.ai_index_file)
		);
		console.log(this.index);
		
		for(let gateway of this.index.index) {
			this.gateways.set(
				gateway.id,
				await tf.loadModel(`${window.location.href}/${path.dirname(Config.ai_index_file)}/${gateway.id}`)
			);
		}
		
		this.layer = this.generate_layer();
		this.layer.addTo(this.map);
	}
	
	generate_layer() {
		return L.geoJSON(this.render_map(), {
			style: (feature) => { return {
				fillColor: feature.properties.colour,
				fillOpacity: 0.4
			} }
		});
	}
	
	render_map() {
		// FUTURE: Do this in a web worker?
		let map_bounds = this.gateway_bounds;
		map_bounds.north += Config.border;
		map_bounds.south -= Config.border;
		
		map_bounds.east += Config.border;
		map_bounds.west -= Config.border;
		
		let coverage = [],
			colour_scale = chroma.scale(
				Config.colour_scale.min,
				Config.colour_scale.max
			).domain(
				this.index.properties.rssi_min,
				this.index.properties.rssi_max
			);
		
		for(let lat = map_bounds.west; lat < map_bounds.east; lat += Config.step) {
			for(let lng = map_bounds.south; lng < map_bounds.north; lng += Config.step) {
				let max_predicted_rssi = -Infinity;
				
				for(let [, ai] of this.gateways) {
					max_predicted_rssi = Math.max(
						max_predicted_rssi,
						ai.predict(
							tf.tensor1d([ lat, lng ])
						)
					);
				}
				
				max_predicted_rssi = normalise(max_predicted_rssi,
					{ min: 0, max: 1 },
					{
						min: this.index.properties.rssi_min,
						max: this.index.properties.rssi_max
					}
				);
				
				coverage.push({
					type: "Feature",
					geometry: {
						type: "Polygon",
						coordinates: [
							[lat, lng],
							[lat + Config.step, lng],
							[lat + Config.step, lng + Config.step],
							[lat, lng + Config.step]
						]
					},
					properties: {
						colour: colour_scale(max_predicted_rssi)
					}
				})
			}
		}
		
		return coverage;
	}
}

export default LayerAI;