/* Copyright 2012-2013, Sebastian Reichel <sre@ring0.de>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

[DBus (name = "io.mainframe.shopsystem.ScannerSession")]
public class ScannerSessionImplementation {
	private int user = 0;
	private string name = "Guest";
	private bool logged_in = false;
	private bool disabled = false;
	private string theme = "beep";

	private Database db;
	private AudioPlayer audio;
	private SerialDevice dev;

	public signal void msg(MessageType type, string message);

	public ScannerSessionImplementation() {
		try {
			db    = Bus.get_proxy_sync(BusType.SESSION, "io.mainframe.shopsystem.Database", "/io/mainframe/shopsystem/database");
			dev   = Bus.get_proxy_sync(BusType.SESSION, "io.mainframe.shopsystem.SerialDevice", "/io/mainframe/shopsystem/device");
			audio = Bus.get_proxy_sync(BusType.SESSION, "io.mainframe.shopsystem.AudioPlayer", "/io/mainframe/shopsystem/audio");

			dev.received_barcode.connect(handle_barcode);
		} catch(IOError e) {
			error("IOError: %s\n", e.message);
		}
	}

	private void send_message(MessageType type, string format, ...) {
		var arguments = va_list();
		var message = format.vprintf(arguments);

		msg(type, message);
	}

	private void logout() {
		logged_in = false;
	}

	private bool login(int user) throws IOError {
		this.user      = user;
		try {
			this.name      = db.get_username(user);
			this.disabled  = db.get_user_auth(user).disabled;
		} catch(DatabaseError e) {
			send_message(MessageType.ERROR, "Error (user=%d): %s", user, e.message);
			return false;
		}
		this.logged_in = true;

		try {
			this.theme = audio.get_random_user_theme();
		} catch(IOError e) {
			this.theme = "beep";
		}

		return true;
	}

	private void handle_barcode(string scannerdata) {
		try {
			stdout.printf("scannerdata: %s\n", scannerdata);
			if(interpret(scannerdata))
				dev.blink(1000);
		} catch(IOError e) {
			send_message(MessageType.ERROR, "IOError: %s", e.message);
		} catch(DatabaseError e) {
			send_message(MessageType.ERROR, "DatabaseError: %s", e.message);
		}
	}

	private bool interpret(string scannerdata) throws DatabaseError, IOError {
		if(scannerdata.has_prefix("USER ")) {
			string str_id = scannerdata.substring(5);
			int32 id = int.parse(str_id);

			/* check if scannerdata has valid format */
			if(scannerdata != "USER %d".printf(id)) {
				audio.play_system("error.ogg");
				send_message(MessageType.ERROR, "Invalid User ID: %s", scannerdata);
				return false;
			}

			if(logged_in) {
				send_message(MessageType.WARNING, "Last user forgot to logout");
				logout();
			}

			if(login(id)) {
				audio.play_user(theme, "login");
				send_message(MessageType.INFO, "Login: %s (%d)", name, user);
				return true;
			} else {
				audio.play_system("error.ogg");
				send_message(MessageType.ERROR, "Login failed (User ID = %d)", id);
				return false;
			}
		} else if(scannerdata == "GUEST") {
			if(logged_in) {
				send_message(MessageType.WARNING, "Last user forgot to logout");
				logout();
			}

			if(login(0)) {
				audio.play_user(theme, "login");
				send_message(MessageType.INFO, "Login: %s (%d)", name, user);
				return true;
			} else {
				audio.play_system("error.ogg");
				send_message(MessageType.ERROR, "Login failed (User ID = 0)");
				return false;
			}
		} else if(scannerdata == "UNDO") {
			if(!logged_in) {
				audio.play_system("error.ogg");
				send_message(MessageType.ERROR, "Can't undo if not logged in!");
				return false;
			} else {
				if(db.undo(user)) {
					audio.play_user(theme, "purchase");
					return true;
				} else {
					audio.play_user(theme, "error");
					send_message(MessageType.ERROR, "Couldn't undo last purchase!");
					return false;
				}
			}
		} else if(scannerdata == "LOGOUT") {
			if(logged_in) {
				audio.play_user(theme, "logout");
				send_message(MessageType.INFO, "Logout!");
				logout();
				return true;
			}

			return false;
		} else {
			uint64 id = 0;
			scannerdata.scanf("%llu", out id);

			/* check if scannerdata has valid format */
			if(scannerdata != "%llu".printf(id) && scannerdata != "%08llu".printf(id) && scannerdata != "%013llu".printf(id)) {
				audio.play_user(theme, "error");
				send_message(MessageType.ERROR, "invalid product: %s", scannerdata);
				return false;
			}

			var name  = db.get_product_name(id);

			if(!logged_in) {
				var mprice = db.get_product_price(1, id);
				var gprice = db.get_product_price(0, id);

				audio.play_system("error.ogg");
				send_message(MessageType.INFO, @"article info: $name (Member: $mprice €, Guest: $gprice €)");
				send_message(MessageType.ERROR, "Login required for purchase!");
				return false;
			}

			if(db.buy(user, id)) {
				var price = db.get_product_price(user, id);
				audio.play_user(theme, "purchase");
				send_message(MessageType.INFO, @"article bought: $name ($price €)");
				return true;
			} else {
				audio.play_user(theme, "error");
				send_message(MessageType.ERROR, "purchase failed!");
				return false;
			}
		}
	}
}