#!/usr/bin/env python
# -*- coding: latin-1 -*-
#
# $Id: lcd_class.py,v 1.28 2016/07/23 13:21:28 bob Exp $
# Raspberry Pi Internet Radio
# using an HD44780 LCD display
#
# Author : Bob Rathbone
# Site   : http://www.bobrathbone.com
#
# From original LCD routines : Matt Hawkins
# Site   : http://www.raspberrypi-spy.co.uk
# Timing improvements fromobert Coward/Paul Carpenter
# Site   : http://www.raspberrypi-spy.co.uk
#          http://www.pcserviceslectronics.co.uk
#
# Expanded to use 4 x 20  display
#
# This program uses  Music Player Daemon 'mpd'and it's client 'mpc'
# See http://mpd.wikia.com/wiki/Music_Player_Daemon_Wiki
#
# License: GNU V3, See https://www.gnu.org/copyleft/gpl.html
#
# Disclaimer: Software is provided as is and absolutly no warranties are implied or given.
#             The authors shall not be liable for any loss or damage however caused.
#

import os
import time
import RPi.GPIO as GPIO
from translate_class import Translate
from config_class import Configuration

# The wiring for the LCD is as follows:
# 1 : GND
# 2 : 5V
# 3 : Contrast (0-5V)*
# 4 : RS (Register Select)
# 5 : R/W (Read Write)       - GROUND THIS PIN
# 6 : Enable or Strobe
# 7 : Data Bit 0             - NOT USED
# 8 : Data Bit 1             - NOT USED
# 9 : Data Bit 2             - NOT USED
# 10: Data Bit 3             - NOT USED
# 11: Data Bit 4
# 12: Data Bit 5
# 13: Data Bit 6
# 14: Data Bit 7
# 15: LCD Backlight +5V**
# 16: LCD Backlight GND

# Define GPIO to LCD mapping
lcd_select = 7
lcd_enable  = 8
LCD_D4_21 = 21    # Rev 1 Board
LCD_D4_27 = 27    # Rev 2 Board
lcd_data4 = LCD_D4_27
lcd_data5 = 22
lcd_data6 = 23
lcd_data7 = 24
lcd_bri = 10	# Brightness control (Pecus)

# Define LCD device constants
LCD_WIDTH = 16    # Default characters per line
LCD_CHR = True
LCD_CMD = False

LCD_LINE_1 = 0x80 # LCD RAM address for the 1st line
LCD_LINE_2 = 0xC0 # LCD RAM address for the 2nd line
LCD_LINE_3 = 0x94 # LCD RAM address for the 3rd line
LCD_LINE_4 = 0xD4 # LCD RAM address for the 4th line

# Some LCDs use different addresses (16 x 4 line LCDs)
# Comment out the above two lines and uncomment the two lines below
# LCD_LINE_3 = 0x90 # LCD RAM address for the 3rd line
# LCD_LINE_4 = 0xD0 # LCD RAM address for the 4th line

# If using a 4 x 16 display also amend the lcd.setWidth(<width>) statement in rradio4.py

# Timing constants
E_PULSE = 0.00001	# Pulse width of enable
E_DELAY = 0.00001	# Delay between writes
E_POSTCLEAR = 0.05	# Delay after clearing display

translate = Translate()
config = Configuration()

# Temporary files for displayed text. /tmp is a tempfs in RAM (Pecus)
# Remember! If you don't want to kill your SD card, add line in /etc/fstab : (Pecus)
# 'tmpfs     /tmp      /tmpfs    size=10M,noatime   0  0'  (Pecus)
Line1File = "/tmp/radiod/line1.txt"  # (Pecus)
Line1sFile = "/tmp/radiod/line1s.txt"  # (Pecus)
Line2File = "/tmp/radiod/line2.txt"  # (Pecus)
Line2sFile = "/tmp/radiod/line2s.txt"  # (Pecus)
Line3File = "/tmp/radiod/line3.txt"  # (Pecus)
Line3sFile = "/tmp/radiod/line3s.txt"  # (Pecus)
Line4File = "/tmp/radiod/line4.txt"  # (Pecus)
Line4sFile = "/tmp/radiod/line4s.txt"  # (Pecus)


# Lcd Class 
class Lcd:
	global lcd_enable, lcd_select, lcd_data4, lcd_data5, lcd_data6, lcd_data7
	width = LCD_WIDTH
	# If display can support umlauts set to True else False
        RawMode = False         # Test only
        ScrollSpeed = 0.3       # Default scroll speed
	lcd_data4 = LCD_D4_27	# Default for revision 2 boards 

	def __init__(self):
		# Create files for displayed texts (Pecus)
		if not os.path.isdir("/tmp/radiod/"): # (Pecus)
			os.mkdir ("/tmp/radiod/") # (Pecus)
		self.writeToFile (Line1File,"1") # (Pecus)
		self.writeToFile (Line2File,"2") # (Pecus)
		self.writeToFile (Line3File,"3") # (Pecus)
		self.writeToFile (Line4File,"4") # (Pecus)
		return

	# Initialise for either revision 1 or 2 boards
	def init(self,revision=2):
        # LCD outputs
		global lcd_enable, lcd_select, lcd_bri
		global lcd_data4, lcd_data5, lcd_data6, lcd_data7

		if revision == 1:
			lcd_data4 = LCD_D4_21

		# Get LCD configuration connects including lcd_data4
		lcd_select = config.getLcdGpio("lcd_select")
		lcd_enable  = config.getLcdGpio("lcd_enable")

		if revision != 1:
			lcd_data4 = config.getLcdGpio("lcd_data4")

		lcd_data5 = config.getLcdGpio("lcd_data5")
		lcd_data6 = config.getLcdGpio("lcd_data6")
		lcd_data7 = config.getLcdGpio("lcd_data7")
		lcd_bri = config.getLcdGpio("lcd_bri")

		GPIO.setwarnings(False)	     # Disable warnings
		GPIO.setmode(GPIO.BCM)       # Use BCM GPIO numbers
		GPIO.setup(lcd_enable, GPIO.OUT)  # E
		GPIO.setup(lcd_select, GPIO.OUT) # RS
		GPIO.setup(lcd_data4, GPIO.OUT) # DB4
		GPIO.setup(lcd_data5, GPIO.OUT) # DB5
		GPIO.setup(lcd_data6, GPIO.OUT) # DB6
		GPIO.setup(lcd_data7, GPIO.OUT) # DB7
		GPIO.setup(lcd_bri, GPIO.OUT) # brightness (Pecus)
		self.lcd_init()
		return

	# Initialise the display
	def lcd_init(self):
		self._byte_out(0x00,LCD_CMD) # 000000 Initialise OLED?
		self._byte_out(0x02,LCD_CMD) # 000010 Initialise OLED?
		self._byte_out(0x33,LCD_CMD) # 110011 Initialise LCD?
		self._byte_out(0x32,LCD_CMD) # 110010 Initialise LCD?
		# Problem with OLED display after reboot ?? (Pecus)
		self._byte_out(0x28,LCD_CMD) # 101000 Data length, number of lines, font size (Pecus)
		time.sleep(E_POSTCLEAR)      # waiting for longer delay (Pecus)
		self._byte_out(0x08,LCD_CMD) # display OFF, cursor/blink off - required for OLED (Pecus)
		time.sleep(E_POSTCLEAR)      # waiting for longer delay (Pecus)
		self._byte_out(0x01,LCD_CMD) # 000001 Clear display (Pecus)
		time.sleep(E_POSTCLEAR)      # waiting for longer delay (Pecus)
		self._byte_out(0x06,LCD_CMD) # 000110 Cursor move direction
		self._byte_out(0x17,LCD_CMD) # character mode, power on
		self._byte_out(0x0C,LCD_CMD) # 001100 Display On,Cursor Off, Blink Off
		time.sleep(0.3)		     # Allow to settle before using
		self.setBright(False)
		return
	 
	# Output byte to Led  mode = Command or Data
	def _byte_out(self,bits, mode):
		global lcd_enable, lcd_select 
		global lcd_data4, lcd_data5, lcd_data6, lcd_data7
		# Send byte to data pins
		# bits = data
		# mode = True  for character
		#        False for command
		GPIO.output(lcd_select, mode) # RS

		# High bits
		GPIO.output(lcd_data4, False)
		GPIO.output(lcd_data5, False)
		GPIO.output(lcd_data6, False)
		GPIO.output(lcd_data7, False)
		if bits&0x10==0x10:
			GPIO.output(lcd_data4, True)
		if bits&0x20==0x20:
			GPIO.output(lcd_data5, True)
		if bits&0x40==0x40:
			GPIO.output(lcd_data6, True)
		if bits&0x80==0x80:
			GPIO.output(lcd_data7, True)

		# Toggle 'Enable' pin
		time.sleep(E_DELAY)
		GPIO.output(lcd_enable, True)
		time.sleep(E_PULSE)
		GPIO.output(lcd_enable, False)
		time.sleep(E_DELAY)

		# Low bits
		GPIO.output(lcd_data4, False)
		GPIO.output(lcd_data5, False)
		GPIO.output(lcd_data6, False)
		GPIO.output(lcd_data7, False)
		if bits&0x01==0x01:
			GPIO.output(lcd_data4, True)
		if bits&0x02==0x02:
			GPIO.output(lcd_data5, True)
		if bits&0x04==0x04:
			GPIO.output(lcd_data6, True)
		if bits&0x08==0x08:
			GPIO.output(lcd_data7, True)

		# Toggle 'Enable' pin
		time.sleep(E_DELAY)
		GPIO.output(lcd_enable, True)
		time.sleep(E_PULSE)
		GPIO.output(lcd_enable, False)
		time.sleep(E_DELAY)
		return

	# Set the display width
	def setWidth(self,width):
		self.width = width
		return

	# Send string to display
	def _string(self,message):
		s = message.ljust(self.width," ")
		if not self.RawMode:
			s = translate.toLCD(s)
		for i in range(self.width):
			self._byte_out(ord(s[i]),LCD_CHR)
		return

	# Display Line 1 on LCD
	def line1(self,text):
		self.writeToFile (Line1File,text) # (Pecus)
		self.writeToFile (Line1sFile,text[0:self.width]) # (Pecus)
		self._byte_out(LCD_LINE_1, LCD_CMD)
		self._string(text)
		return

	# Display Line 2 on LCD
	def line2(self,text):
		self.writeToFile (Line2File,text) # (Pecus)
		self.writeToFile (Line2sFile,text[0:self.width]) # (Pecus)
		self._byte_out(LCD_LINE_2, LCD_CMD)
		self._string(text)
		return

	# Display Line 3 on LCD
	def line3(self,text):
		self.writeToFile (Line3File,text) # (Pecus)
		self.writeToFile (Line3sFile,text[0:self.width]) # (Pecus)
		self._byte_out(LCD_LINE_3, LCD_CMD)
		self._string(text)
		return

	# Display Line 4 on LCD
	def line4(self,text):
		self.writeToFile (Line4File,text) # (Pecus)
		self.writeToFile (Line4sFile,text[0:self.width]) # (Pecus)
		self._byte_out(LCD_LINE_4, LCD_CMD)
		self._string(text)
		return

	# Scroll message on line 1
	def scroll1(self,mytext,interrupt):
		self.writeToFile (Line1File,mytext) # (Pecus)
		self._scroll(mytext,LCD_LINE_1,Line1sFile,interrupt)
		return

	# Scroll message on line 2
	def scroll2(self,mytext,interrupt):
		self.writeToFile (Line2File,mytext) # (Pecus)
		self._scroll(mytext,LCD_LINE_2,Line2sFile,interrupt)
		return

	# Scroll message on line 3
	def scroll3(self,mytext,interrupt):
		self.writeToFile (Line3File,mytext) # (Pecus)
		self._scroll(mytext,LCD_LINE_3,Line3sFile,interrupt)
		return

	# Scroll message on line 4
	def scroll4(self,mytext,interrupt):
		self.writeToFile (Line4File,mytext) # (Pecus)
		self._scroll(mytext,LCD_LINE_4,Line4sFile,interrupt)
		return

	# Scroll line - interrupt() breaks out routine if True
	def _scroll(self,mytext,line,file,interrupt):
		ilen = len(mytext)
		skip = False

		self._byte_out(line, LCD_CMD)
		self._string(mytext[0:self.width + 1])
		self.writeToFile (file,mytext[0:self.width]) # (Pecus)
		
		if (ilen <= self.width):
			skip = True

		if not skip:
			for i in range(0, 5):
				time.sleep(0.2)
				if interrupt():
					skip = True
					break

		if not skip:
			for i in range(0, ilen - self.width + 1 ):
				self._byte_out(line, LCD_CMD)
				self._string(mytext[i:i+self.width])
				self.writeToFile (file,mytext[i:i+self.width]) # (Pecus)
				if interrupt():
					skip = True
					break
				time.sleep(self.ScrollSpeed)

		if not skip:
			for i in range(0, 5):
				time.sleep(0.2)
				if interrupt():
					break
		return

	# Set Scroll line speed - Best values are 0.2 and 0.3
	# Limit to between 0.05 and 1.0
	def setScrollSpeed(self,speed):
		if speed < 0.05:
			speed = 0.2
		elif speed > 1.0:
			speed = 0.3
		self.ScrollSpeed = speed
		return

	# Set raw mode on (No translation)
	def setRawMode(self,value):
		self.RawMode = value
		return

	# Clear display
	def clearDisplay(self):
		self.writeToFile (Line1File,"") # (Pecus)
		self.writeToFile (Line2File,"") # (Pecus)
		self.writeToFile (Line3File,"") # (Pecus)
		self.writeToFile (Line4File,"") # (Pecus)
		self._byte_out(0x01,LCD_CMD) # 000001 Clear display
		time.sleep(E_POSTCLEAR)
		return

	# Set brightness (Pecus)
	def setBright(self,value):
		GPIO.output(lcd_bri, value)
		return

	# Write text to file (Pecus)
	def writeToFile(self,fname,text): # (Pecus)
		file = open(fname, "w") # (Pecus)
		file.write(text) # (Pecus)
		file.close() # (Pecus)
		return # (Pecus)

# End of Lcd class