#! /usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright (C) 2011 Sebastian Pipping <sebastian@pipping.org>
# Licensed under GPL v3 or later

from __future__ import print_function
import freitagslib.network as net
from freitagslib.commands import BuyCommand, DepositCommand

import sys
import decimal
import os
import time


def clear():
	os.system('clear')


CODES = {
	'UNDO':('undo',),
	'COMMIT':('commit',),

	'DEPOSIT 0.01':('deposit', decimal.Decimal('0.01')),
	'DEPOSIT 0.05':('deposit', decimal.Decimal('0.05')),
	'DEPOSIT 0.10':('deposit', decimal.Decimal('0.10')),
	'DEPOSIT 0.50':('deposit', decimal.Decimal('0.50')),
	'DEPOSIT 1.00':('deposit', decimal.Decimal('1.00')),
	'DEPOSIT 5.00':('deposit', decimal.Decimal('5.00')),
	'DEPOSIT 10.00':('deposit', decimal.Decimal('10.00')),
	'DEPOSIT 50.00':('deposit', decimal.Decimal('50.00')),
}


def delay(what, seconds):
	for i in xrange(seconds, 0, -1):
		if i < seconds:
			sys.stdout.write('\r')
		sys.stdout.write('%s in %d Sekunden... ' % (what, i))
		sys.stdout.flush()
		time.sleep(1)


def warn_balance():
	print('Kontostrand im Minus, NICHT cool!')


def error_page(message):
	clear()
	print(message)
	print()
	delay('Weiter', 3)


class Status:
	def __init__(self):
		self._reset()
		self.item_cache = dict()

	def _reset(self):
		self.auth_blob = None
		self.login_name = None
		self.balance = None
		self.transfers = None

	def dump(self):
		if self.logged_in():
			print('Eingeloggt als:  %s' % (self.login_name))
			print()
			if self.transfers:
				print('Geplante Änderungen:')
				initial_command, initial_balance = self.transfers[0]
				print(('%3s %-40s  %c %6.2f Euro') % ('', '', ' ' if initial_balance > 0 else '-', abs(initial_balance)))
				for i, (command, balance_backup) in enumerate(self.transfers):
					difference = command.difference()
					label = command.label()
					print(('%2d) %-40s  %c %6.2f Euro') % (i + 1, label, '+' if difference > 0 else '-', abs(difference)))
				print(('%3s %-40s  %8s') % ('', '', '============='))
				print(('%3s %-40s  %c %6.2f Euro') % ('', '', ' ' if self.balance > 0 else '-', abs(self.balance)))

				if self.balance < 0:
					warn_balance()
					print()

				print('Committen nicht vergessen!')
			else:
				print('Kontostand beträgt:  %.2f Euro' % (self.balance))
				if self.balance < 0:
					print()
					warn_balance()
		else:
			print('Bitte einloggen.')
			print()
			print('Scanne dazu deine ID-Karte mit dem Barcode-Leser.')
		print()

	def logged_in(self):
		return self.auth_blob is not None

	def login(self, auth_blob):
		assert(not self.logged_in())
		user_name = net.get_user_name_from_auth_blob(auth_blob)
		self.auth_blob = auth_blob
		self.login_name = user_name
		self.balance = net.get_balance(user_name)
		self.transfers = list()

	def commit(self):
		assert(self.logged_in())

		# Process command queue
		for (command, balance_backup) in self.transfers:
			command.run(self.login_name)
		self.transfers = None

		# Show final balance for some time
		clear()
		self.dump()
		delay('Logout', 3)

		# Logout
		self._reset()

	def find(self, item_id):
		try:
			return self.item_cache[item_id]
		except KeyError:
			item = net.get_item(item_id)
			self.item_cache[item_id] = item
			return item

	def buy(self, item):
		assert(self.logged_in())
		log_entry = (BuyCommand(item), self.balance)
		self.transfers.append(log_entry)
		self.balance = self.balance - item.price

	def deposit(self, amount):
		assert(self.logged_in())
		log_entry = (DepositCommand(amount), self.balance)
		self.transfers.append(log_entry)
		self.balance = self.balance + amount

	def undo(self):
		assert(self.logged_in())
		if self.transfers:
			(command, balance_backup) = self.transfers[-1]
			self.transfers.pop()
			self.balance = balance_backup
		else:
			error_page('FEHLER: Nichts da, was ich rückgängig machen könnte.')


def print_prompt():
	sys.stdout.write(">>> ")


def handle(line, status):
	if line == 'exit':
		clear()
		sys.exit(0)

	if status.logged_in():
		if line in CODES:
			call = CODES[line]
			method = call[0]
			params = call[1:]
			getattr(status, method)(*params)
		else:
			item_id = int(line)  # TODO
			try:
				item = status.find(item_id)
			except:  # TODO
				error_page('FEHLER: Aktion oder Ware "%s" nicht bekannt' % line)
			else:
				status.buy(item)
	else:
		status.login(line)


def main():
	status = Status()

	while True:
		clear()
		status.dump()
		print_prompt()
		l = sys.stdin.readline()
		if not l:
			break
		line = l.rstrip()
		handle(line, status)


if __name__ == '__main__':
	main()