"use strict";

import haversine from 'haversine-distance';

import { normalise, clamp } from '../../common/Math.mjs';

class DatasetFetcher {
	constructor({ settings, GatewayRepo, RSSIRepo, ReadingRepo }) {
		this.settings = settings;
		this.repo_gateway = GatewayRepo;
		this.repo_rssi = RSSIRepo;
		this.repo_reading = ReadingRepo;
	}
	
	normalise_latlng(lat, lng) {
		return [
			normalise(lat,
				{ min: -90, max: +90 },
				{ min: 0, max: 1 }
			),
			normalise(lng,
				{ min: -180, max: +180 },
				{ min: 0, max: 1 }
			)
		];
	}
	
	fetch_all(gateway_id) {
		let gateway_location = this.repo_gateway.get_by_id(gateway_id);
		
		let result = {
			input: [],
			output: []
		};
		for(let rssi of this.repo_rssi.iterate_gateway(gateway_id)) {
			let next_input = this.normalise_latlng(rssi.latitude, rssi.longitude);
			let distance_from_gateway = haversine(gateway_location, rssi);
			
			next_input.push(clamp(
				normalise(distance_from_gateway,
					{ min: 0, max: 20000 },
					{ min: 0, max: 1 }
				),
			0, 1))
			
			result.input.push(next_input);
			
			console.log(`Distance from gateway: ${haversine(gateway_location, rssi)}m`);
			
			result.output.push([
				clamp(normalise(rssi.rssi,
					{ min: this.settings.ai.rssi_min, max: this.settings.ai.rssi_max },
					{ min: 0, max: 1 }
				), 0, 1)
			]);
		}
		
		for(let reading of this.repo_reading.iterate_unreceived()) {
			result.input.push(this.normalise_latlng(
				reading.latitude,
				reading.longitude
			));
			
			result.output.push([ 0 ]);
		}
		
		return result;
	}
	
	*fetch_input(gateway_id) {
		for(let rssi of this.repo_rssi.iterate_gateway(gateway_id))
			yield this.normalise_latlng(rssi.latitude, rssi.longitude);
		
		for(let rssi of this.repo_reading.iterate_unreceived())
			yield this.normalise_latlng(rssi.latitude, rssi.longitude);
	}
	
	*fetch_output(gateway_id) {
		for(let rssi of this.repo_rssi.iterate_gateway(gateway_id)) {
			yield [
				clamp(normalise(rssi.rssi,
					{ min: this.settings.ai.rssi_min, max: this.settings.ai.rssi_max },
					{ min: 0, max: 1 }
				), 0, 1)
			];
		}
		// Yield 0 for every unreceived message, since we want to train it to predict a *terrible* signal where the gateway is not
		for(let rssi of this.repo_reading.iterate_unreceived()) {
			yield [ 0 ];
		}
	}
}

export default DatasetFetcher;