#! /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

from thread import start_new_thread, allocate_lock
import time


COLOR_HINT = Fore.YELLOW + Style.BRIGHT
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

display_fifo = None

scroll_line1 = None
scroll_line2 = None

idlemessage = None

offset_line1 = 0
offset_line2 = 0

brightness  = 5
screensaver = 0

SCREENSAVER_DIM     = 30
SCREENSAVER_TIMEOUT = 90
SCREENSAVER_OFF     = 300

lock = allocate_lock()

#Helper-Function, scrolls text in a specific line.
def display_scroll_text(line,text):
	global scroll_line1,scroll_line2
	global offset_line1,offset_line2
	lock.acquire()
	if (line==1): #clear the line on invocation:
		send_display("\x1f\x24\x01%c\x18" % chr(line) )
		scroll_line1 = text
		offset_line1=0
	if (line==2): #clear the line on invocation:
		send_display("\x1f\x24\x01%c\x18" % chr(line) )
		scroll_line2 = text
		offset_line2=0
	lock.release()
	

def display_handle_scroll(line,text,offset):
	if (text):
		l = len(text)
		if (l<21):
			if (offset == 0):
				send_display("\x1f\x24\x01%c%s" % (chr(line),text[offset:(20+offset)]))
				offset=1
		else:
			send_display("\x1f\x24\x01%c%s" % (chr(line),text[offset:(20+offset)]))
			missing_chars=20+offset-l
			if (missing_chars>0):
				send_display(text[:missing_chars])
			offset=((offset+1)%l)
	else:
		offset=0	#reset offset
	return offset


def display_cmd_dim(x):
	global brightness
	if (brightness!=x):
		if (x==0): #turn off:
			send_display("\x1F\x45%c" % chr(255) )
			brightness = x
			return
			
		else:
			if (brightness==0): #turn on, then set wanted brightness:
				send_display("\x1F\x45%c" % chr(0) )
			brightness = x
			send_display("\x1F\x58%c" % chr(x-1) )


def display_thread(x):
	global scroll_line1,scroll_line2
	global offset_line1,offset_line2
	global screensaver
	global idlemessage

	offset_line1=0
	offset_line2=0
	while(True):
		lock.acquire()

		offset_line1 = display_handle_scroll(1,scroll_line1,offset_line1)
		offset_line2 = display_handle_scroll(2,scroll_line2,offset_line2)

		if (screensaver <= SCREENSAVER_OFF):
			screensaver=screensaver+1

		if ((screensaver >= SCREENSAVER_DIM) and (screensaver <= (SCREENSAVER_DIM+7))): #activate first stage of screensaver:
			x = (8-( screensaver - SCREENSAVER_DIM))/2
			display_cmd_dim(1+x)

		if (screensaver == SCREENSAVER_TIMEOUT):
			now = time.localtime()
			send_display("\x0c\x1F\x54%c%c\x1f\x03" % (chr(now.tm_hour),chr(now.tm_min)));
			if (scroll_line2):
				scroll_line1=scroll_line2
			else:
				scroll_line1=idlemessage
			scroll_line2=None
			offset_line1=0
			offset_line2=0				
		
		if (screensaver == SCREENSAVER_OFF):
			display_cmd_dim(0)
			
		lock.release()
		time.sleep(.5)


def send_display(s):
	global display_fifo
	if not display_fifo:
		try:
			fd = os.open( "/tmp/display", os.O_WRONLY)
			display_fifo = os.fdopen(fd,"w")
		except OSError:
			display_fifo = None
			pass
			return
		except IOError:
			display_fifo = None
			pass
			return
	try:
		display_fifo.write(s)
		display_fifo.flush()
	except IOError:
		display_fifo = None
		pass
		return


#Front-End Funtion to display a Screen
# with heading
def display_screen(title,message):
	global scroll_line1,scroll_line2
	global offset_line1,offset_line2
	global screensaver

	offset_line1=0
	offset_line2=0
	screensaver=0
	display_cmd_dim(5)

	if (len(title)<21):
		scroll_line1=None
		send_display("\x1f\x24\x01%c\x18%s" % (chr(1),'\xdb'*20) )
		if (len(title)<20):
			pos=1+(20-len(title))/2
		else:
			pos=1
		send_display("\x1f\x24%c%c%s" % (chr(pos),chr(1),title) )
	else:
		display_scroll_text(1,title)

	display_scroll_text(2,message)


#Front-End function to send data to the display.
def print_display(s):
	global scroll_line1,scroll_line2
	global offset_line1,offset_line2
	global screensaver

	lock.acquire()
	screensaver=0
	offset_line1=0
	offset_line2=0
	scroll_line1=None
	scroll_line2=None
	display_cmd_dim(5)
	send_display(s)
	lock.release()

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(error_message, hint_message=None):
	clear()
	print(COLOR_ERROR + error_message + COLOR_RESET)
	print()
	delay_seconds = 3
	if hint_message is not None:
		print(COLOR_HINT + hint_message + COLOR_RESET)
		print()
		delay_seconds += 3
	delay('Weiter', delay_seconds)


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()
			print_display('\x0cHallo %-14s' % (self.login_name[:13]+"!") )
			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 isinstance(command, BuyCommand):
					mycmd = 0;
					if (command.includes_commodity()):
						mycmd+=1;
					if (command.includes_deposit()):
						mycmd+=2;
					if (mycmd==1):	
						mylabel=command.item_name()
					if (mycmd==2):	
						mylabel="Pfand "+command.commodity_label()[:9]
					if (mycmd==3):	
						mylabel=("%-13s" % (command.commodity_label()[:13]))+"+P"
					print_display('\x0b%-15s %4.2f' % (mylabel[:15],abs(command.difference())));
					print_display('\x0b\nSUMME: {%02i} %8.2f' % ((i-1),initial_balance - self.balance));
				else:
					print_display('\x0b%-15s %4.2f' % (command.label()[:15],abs(command.difference())));
					print_display('\x0b\nSUMME: {%02i} %8.2f' % ((i-1),initial_balance - self.balance));

				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_display('\x0b\nKonto: %5.2f!' % (self.balance) )
					print()

				print(COLOR_SOME + 'Committen nicht vergessen.' + COLOR_RESET)
			else:
				print('Kontostand beträgt:  %s%.2f Euro%s' % (COLOR_MUCH, self.balance, COLOR_RESET))
				display_screen("KONTOSTAND","%s: %.2f Euro" % (self.login_name,self.balance))
				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.')
			display_screen("LOGIN","Bitte scanne Deinen login-Token! *** ")
		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:
				print_display('\x0cFEHLER: Server Error%20s' % str(e)[:20])
				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()
			print_display('\x0bDanke, %-12s' % (self.login_name[:12]+"!") )
			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():
				print_display('\x0cFEHLER: schon Pfand %20s' % prev.item_name()[:20])
				error_page('FEHLER: Pfand für Produkt "%s" bereits aktiviert' % prev.item_name())
				return
			if prev.deposit_value() <= 0:
				print_display('\x0cFEHLER: Pfandfrei!  %20s' % prev.item_name()[:20])
				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):
	global idlemessage
	if line == 'exit':
		clear()
		print_display("\x0c")
		sys.exit(0)

	if status.logged_in():
		idlemessage=" Comitten nicht vergessen! ***"
		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
					print_display('\x0cERROR: %13sCode ist unbekannt' % ( line[:13]))
					error_page('FEHLER: Aktion oder Ware "%s" nicht bekannt' % line)
				else:
					print_display('\x0cERROR: Server Error%20s' % str(e)[:20])
					error_page('FEHLER bei Kommunikation mit Server "%s"' % str(e))
			else:
				status.buy(item)
	else:
		idlemessage="Mir ist langweilig!"
		try:
			status.login(line)
		except urllib2.HTTPError as e:
			if e.code == 404:  # URL not found == user unknown
				display_screen("FEHLER","Nutzer ist  unbekannt: '%s' *** " % line)

				error_page('FEHLER: Benutzer "%s" nicht bekannt' % line,
						hint_message='Ist in der WebApp unter "Einstellungen" ' \
						'für Ihren Account Plugin "BarcodePlugin" ' \
						'als erlaubt markiert?')
			else:
				print_display('\x0cFEHLER: Server Error%20s' % str(e)[:20])
				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()
	global scroll_line1,scroll_line2
	print_display("\x1b\x40\x1f\x43\x00")
	start_new_thread(display_thread,(1,))

	#display_scroll_text(1,"Line1: Text, dumm scrollend!")
	#display_scroll_text(4,"Line2: Und hier Text, auch dumm scrollend!")
	display_screen("HINWEIS","Herzlich willkommen bei der Freitagsrunde! *** ")
	while True:
		clear()
		status.dump()
		print_prompt()
		l = sys.stdin.readline()
		if not l:
			break
		line = l.rstrip()
		print_display('\x0cBarcode:\n%20s' % line[:20])
		if line:
			handle(line, status)


if __name__ == '__main__':
	try:
		main()
	except KeyboardInterrupt:
		pass
		print_display("\x1b\x40Goodbye!")