// CSE 142 Lecture 15
// Files
// Plots cities with population greater than or equal to
// a city specified by the user.

import java.awt.*; // For Graphics
import java.io.*; // For File, FileNotFoundException
import java.util.*; // For Scanner

public class CitiesChained {
	// The width and height of the overall DrawingPanel
	public static final int WIDTH = 800;
	public static final int HEIGHT = 515;
	// The thickness of the gray border
	public static final int BORDER = 100;
	
	// The minimum and maximum latitude and longitude.
	// I wrote code to find these in the input file rather than
	// manually checking.
	public static final int MIN_LAT = 24562841;
	public static final int MAX_LAT = 48996136;
	public static final int MIN_LON = -124610967;
	public static final int MAX_LON = -67012040;

	public static void main(String[] args) throws FileNotFoundException {
		System.out.println("This program allows you to search through");
		System.out.println("United States census data from the year 2009");
		System.out.println("and plot cities depending on their population");
		System.out.println();
		
		Scanner console = new Scanner(System.in);
		getCity(console);
	}
	
	// Gets the minimum population city from the user
	public static void getCity(Scanner console) throws FileNotFoundException {
		System.out.print("Plot all cities as large as which city? ");
		String city = console.next();
		findPopulation(city);
	}
	
	// Finds the population of the given city
	public static void findPopulation(String city) throws FileNotFoundException {
		Scanner cityScan = new Scanner(new File("cities.txt"));
		boolean foundPopulation = false;
		while (cityScan.hasNextLine() && !foundPopulation) {
			String line = cityScan.nextLine();
			Scanner lineScan = new Scanner(line);
			String lineCity = lineScan.next();
			lineScan.next();
			int population = lineScan.nextInt();
			if (lineCity.equalsIgnoreCase(city)) {
				foundPopulation = true;
				graphCities(population);
			}
		}
		if (!foundPopulation) {
			System.out.println("\"" + city + "\" not found");
		}
	}
	
	// Graphs each city with population at least minPop
	public static void graphCities(int minPop) throws FileNotFoundException {
		DrawingPanel panel = new DrawingPanel(WIDTH, HEIGHT);
		Graphics g = panel.getGraphics();
		Scanner cityScan = new Scanner(new File("cities.txt"));
		int cities = 0;
		while (cityScan.hasNextLine()) {
			String line = cityScan.nextLine();
			Scanner lineScan = new Scanner(line);
			lineScan.next();
			String state = lineScan.next();
			int population = lineScan.nextInt();
			if (population >= minPop) {
				int lat = lineScan.nextInt();
				int lon = lineScan.nextInt();
				
				int y = HEIGHT - BORDER - convertRange(lat, MIN_LAT, MAX_LAT, HEIGHT - 2 * BORDER);
				int x = BORDER + convertRange(lon, MIN_LON, MAX_LON, WIDTH - 2 * BORDER);
				g.fillOval(x, y, 2, 2);
				
				cities++;
			}
		}
		graphStatic(g, minPop, cities);
	}
	
	// Graphs the static parts of the plot
	public static void graphStatic(Graphics g, int minPop, int cities) {
		g.setColor(Color.LIGHT_GRAY);
		g.fillRect(0, 0, WIDTH, BORDER);
		g.fillRect(0, HEIGHT - BORDER, WIDTH, BORDER);
		g.fillRect(0, 0, BORDER, HEIGHT);
		g.fillRect(WIDTH - BORDER, 0, BORDER, HEIGHT);
		
		g.setColor(Color.BLACK);
		g.drawString("Cities with at least " + minPop + " people", 10, 20);
		g.drawString(cities + " cities plotted", 10, HEIGHT - 10);
	}
	
	// Convert a lat-long to a screen coordinate
	public static int convertRange(int value, int rangeMin, int rangeMax, int newRange) {
		return (int)((value - rangeMin) * 1.0 / (rangeMax - rangeMin) * newRange);
	}
}