#! /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 colorama
from colorama import Fore, Style


import sys
from decimal import Decimal
import os
import time
import urllib2


COLOR_ERROR = Fore.RED
COLOR_DEPOSIT = Fore.GREEN + Style.BRIGHT
COLOR_TO_GO = Fore.MAGENTA + Style.BRIGHT
COLOR_WITHDRAW = Fore.RED + Style.BRIGHT

COLOR_SOME = Fore.WHITE + Style.BRIGHT
COLOR_MUCH = Fore.YELLOW + Style.BRIGHT

COLOR_RESET = Style.RESET_ALL


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


TO_GO_ONLY = 2
TO_GO_ALL = 1
TO_GO_NONE = 0
TO_GO_PREV = -1

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

	'TO GO ALL':('to_go', TO_GO_ALL),
	'TO GO NONE':('to_go', TO_GO_NONE),
	'TO GO PREV':('to_go', TO_GO_PREV),
	'TO GO ONLY':('to_go', TO_GO_ONLY),

	'DEPOSIT 0.01':('deposit', Decimal('0.01')),
	'DEPOSIT 0.05':('deposit', Decimal('0.05')),
	'DEPOSIT 0.10':('deposit', Decimal('0.10')),
	'DEPOSIT 0.50':('deposit', Decimal('0.50')),
	'DEPOSIT 1.00':('deposit', Decimal('1.00')),
	'DEPOSIT 5.00':('deposit', Decimal('5.00')),
	'DEPOSIT 10.00':('deposit', Decimal('10.00')),
	'DEPOSIT 50.00':('deposit', 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('Kontostand im Minus, bitte Geld aufladen.')


def error_page(message):
	clear()
	print(COLOR_ERROR + message + COLOR_RESET)
	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):
		def sign(amount, plus='+'):
			return '-' if amount < 0 else plus

		def color(amount):
			return COLOR_WITHDRAW if amount < 0 else COLOR_DEPOSIT

		def show_total(balance, plus=' '):
			print('%3s %-40s  %s%c %6.2f Euro%s' \
					% ('', '', color(balance), sign(balance, plus),
						abs(balance), COLOR_RESET))

		def show_item(position, diff, label, color):
			print('%2d) %-40s  %s%c %6.2f Euro%s' \
					% (position, label, color, sign(diff),
					abs(diff), COLOR_RESET))

		def show_bar():
			print('%3s %-40s  %13s' % ('', '', '============='))

		if self.logged_in():
			print('Eingeloggt als:  %s%s%s' % (COLOR_SOME, self.login_name, COLOR_RESET))
			print()
			if self.transfers:
				initial_command, initial_balance = self.transfers[0]

				print('Geplante Änderungen:')
				show_total(initial_balance)
				i = 1
				for command, dummy in self.transfers:
					if isinstance(command, BuyCommand):
						if (command.includes_commodity()):
							show_item(i, -command.commodity_value(), command.commodity_label(), COLOR_WITHDRAW)
							i += 1
						if (command.includes_deposit()):
							show_item(i, -command.deposit_value(), command.deposit_label(), COLOR_TO_GO)
							i += 1
					else:
						show_item(i, command.difference(), command.label(), COLOR_DEPOSIT)
						i += 1
				show_bar()
				if len(self.transfers) > 1:
					show_total(self.balance - initial_balance, plus='+')
					show_bar()
				show_total(self.balance)

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

				print(COLOR_SOME + 'Committen nicht vergessen.' + COLOR_RESET)
			else:
				print('Kontostand beträgt:  %s%.2f Euro%s' % (COLOR_MUCH, self.balance, COLOR_RESET))
				if self.balance < 0:
					print()
					warn_balance()
		else:
			print(COLOR_MUCH + 'Bitte einloggen.' + COLOR_RESET)
			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)
		balance = net.get_balance(user_name)

		self.auth_blob = auth_blob
		self.login_name = user_name
		self.balance = balance
		self.transfers = list()

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

		# Process command queue
		for (command, balance_backup) in list(self.transfers):
			try:
				command.run(self.login_name)
			except urllib2.HTTPError as e:
				error_page('FEHLER bei Kommunikation mit Server "%s"' % str(e))
				break
			else:
				self.transfers.pop(0)

		if not self.transfers:
			# Show final balance for some time
			clear()
			self.dump()
			delay('Logout', 3)

			# Logout
			self._reset()

	def find(self, barcode):
		try:
			return self.item_cache[barcode]
		except KeyError:
			item = net.get_item(barcode)
			self.item_cache[barcode] = 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 to_go(self, scope):
		_PRODUCT_FIRST = 'FEHLER: Bitte zuerst den betreffenden Artikel scannen.'
		if not self.transfers:
			error_page(_PRODUCT_FIRST)
			return

		if scope == TO_GO_ALL:
			"""
			Makes all BuyCommands with deposit > 0 include deposit
			...and updates future balance accordingly.
			"""
			dummy, initial_balance = self.transfers[0]
			balance_before = initial_balance

			for command, dummy in self.transfers:
				if isinstance(command, BuyCommand) \
						and not command.includes_deposit() \
						and command.deposit_value() > 0:
					command.include_deposit(True)
				balance_before += command.difference()

			self.balance = balance_before
		elif scope == TO_GO_NONE:
			"""
			Makes all BuyCommands that include commodity
			not include deposit any more
			...and updates future balance accordingly.
			"""
			first_command, initial_balance = self.transfers[0]
			balance_before = initial_balance

			for command, dummy in self.transfers:
				if isinstance(command, BuyCommand) \
						and command.includes_commodity():
					command.include_deposit(False)
				balance_before += command.difference()

			self.balance = balance_before
		elif scope == TO_GO_PREV:
			"""
			Makes the last BuyCommand include deposit
			...and updates future balance accordingly.
			"""
			prev, balance_backup = self.transfers[-1]
			if not isinstance(prev, BuyCommand):
				error_page(_PRODUCT_FIRST)
				return
			if prev.includes_deposit():
				error_page('FEHLER: Pfand für Produkt "%s" bereits aktiviert' % prev.item_name())
				return
			if prev.deposit_value() <= 0:
				error_page('FEHLER: Produkt "%s" hat kein Pfand' % prev.item_name())
				return
			before = prev.difference()
			prev.include_deposit(True)
			after = prev.difference()
			self.balance += (after - before)
		elif scope == TO_GO_ONLY:
			"""
			Makes all BuyCommand that include commodity
			be deposit only
			...and updates future balance accordingly.
			"""
			dummy, initial_balance = self.transfers[0]
			balance_before = initial_balance

			for command, dummy in self.transfers:
				if isinstance(command, BuyCommand) \
						and command.deposit_value() > 0 \
						and command.includes_commodity():
					command.include_commodity(False)
					command.include_deposit(True)
				balance_before += command.difference()

			self.balance = balance_before

	def undo(self):
		assert(self.logged_in())
		if self.transfers:
			dummy, 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:
			try:
				item = status.find(line)
			except urllib2.HTTPError as e:
				if e.code == 404:  # URL not found == item not found with REST
					error_page('FEHLER: Aktion oder Ware "%s" nicht bekannt' % line)
				else:
					error_page('FEHLER bei Kommunikation mit Server "%s"' % str(e))
			else:
				status.buy(item)
	else:
		try:
			status.login(line)
		except urllib2.HTTPError as e:
			if e.code == 404:  # URL not found == user unknown
				error_page('FEHLER: Benutzer "%s" nicht bekannt' % line)
			else:
				error_page('FEHLER bei Kommunikation mit Server "%s"' % str(e))
		except urllib2.URLError as e:
			error_page('FEHLER bei Kommunikation mit Server "%s"' % str(e))


def main():
	colorama.init()
	status = Status()

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


if __name__ == '__main__':
	try:
		main()
	except KeyboardInterrupt:
		pass