package eirb.pg203;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URL;

import org.json.JSONArray;
import org.json.JSONObject;

import eirb.pg203.utils.Coords;

public class City {
	private String cityName;
	private Coords cityCoords;

	/**
	 * Fetch data from adresse.data.gouv.fr
	 * @throws IOException if the request fails
	 */
	private static JSONObject getDataFromName(String cityName) throws IOException {
		StringBuilder result = new StringBuilder();
		URL url = URI.create(
			String.format("https://api-adresse.data.gouv.fr/search/?q=%s&autocomplete=0&limit=1",
				cityName
			)
		).toURL();

		HttpURLConnection conn = (HttpURLConnection) url.openConnection();
		conn.setRequestMethod("GET");

		try (BufferedReader reader = new BufferedReader(
				new InputStreamReader(conn.getInputStream()))) {
			for (String line; (line = reader.readLine()) != null; ) {
				result.append(line);
			}
		}

		return new JSONObject(result.toString());
	}

	private static Coords getCoordsFromName(String cityName) throws IOException {
		JSONObject data = getDataFromName(cityName);
		JSONArray rawCoords = data.getJSONArray("features")
			.getJSONObject(0)
			.getJSONObject("geometry")
			.getJSONArray("coordinates");

		final float lon = rawCoords.getFloat(0);
		final float lat = rawCoords.getFloat(1);

		return new Coords(lat, lon);
	}

	City (String cityName) {
		this.cityName = cityName;
	}

	public String getCityName() {
		return cityName;
	}

	/**
	 * Returns the city coords using adresse.data.gouv.fr, cache the result
	 * @return the city Coords
	 * @throws IOException if the request to adresse.data.gouv.fr fails
	 *
	 */
	public Coords getCityCoords() throws IOException {
		if (this.cityCoords == null) {
			this.cityCoords = getCoordsFromName(cityName);
		}

		return cityCoords;
	}

	@Override
	public String toString() {
		try {
			Coords coords = this.getCityCoords();
			return String.format(
					"City(%s, lat: %f, lon: %f)",
					this.cityName,
					coords.getLat(),
					coords.getLon()
				);
		}
		catch (IOException e) {
			return String.format(
					"City(%s, lat: Request failed, lon: Request Failed)",
					this.cityName
				);
		}
	}
}