#!/usr/bin/env python

import time
import smbus
import socket
import fcntl
import struct

BUS = smbus.SMBus(1)

def write_word(addr, data):
        global BLEN
        temp = data
        if BLEN == 1:
                temp |= 0x08
        else:
                temp &= 0xF7
        BUS.write_byte(addr ,temp)

def send_command(comm):
        # Send bit7-4 firstly
        buf = comm & 0xF0
        buf |= 0x04               # RS = 0, RW = 0, EN = 1
        write_word(LCD_ADDR ,buf)
        time.sleep(0.002)
        buf &= 0xFB               # Make EN = 0
        write_word(LCD_ADDR ,buf)

        # Send bit3-0 secondly
        buf = (comm & 0x0F) << 4
        buf |= 0x04               # RS = 0, RW = 0, EN = 1
        write_word(LCD_ADDR ,buf)
        time.sleep(0.002)
        buf &= 0xFB               # Make EN = 0
        write_word(LCD_ADDR ,buf)

def send_data(data):
        # Send bit7-4 firstly
        buf = data & 0xF0
        buf |= 0x05               # RS = 1, RW = 0, EN = 1
        write_word(LCD_ADDR ,buf)
        time.sleep(0.002)
        buf &= 0xFB               # Make EN = 0
        write_word(LCD_ADDR ,buf)

        # Send bit3-0 secondly
        buf = (data & 0x0F) << 4
        buf |= 0x05               # RS = 1, RW = 0, EN = 1
        write_word(LCD_ADDR ,buf)
        time.sleep(0.002)
        buf &= 0xFB               # Make EN = 0
        write_word(LCD_ADDR ,buf)

def init(addr, bl):
#       global BUS
#       BUS = smbus.SMBus(1)
        global LCD_ADDR
        global BLEN
        LCD_ADDR = addr
        BLEN = bl
        try:
                send_command(0x33) # Must initialize to 8-line mode at first
                time.sleep(0.005)
                send_command(0x32) # Then initialize to 4-line mode
                time.sleep(0.005)
                send_command(0x28) # 2 Lines & 5*7 dots
                time.sleep(0.005)
                send_command(0x0C) # Enable display without cursor
                time.sleep(0.005)
                send_command(0x01) # Clear Screen
                BUS.write_byte(LCD_ADDR, 0x08)
        except:
                return False
        else:
                return True

def clear():
        send_command(0x01) # Clear Screen

def openlight():  # Enable the backlight
        BUS.write_byte(0x27,0x08)
        BUS.close()

def write(x, y, str):
        if x < 0:
                x = 0
        if x > 15:
                x = 15
        if y <0:
                y = 0
        if y > 1:
                y = 1

        # Move cursor
        addr = 0x80 + 0x40 * y + x
        send_command(addr)

        for chr in str:
                send_data(ord(chr))


def get_ip_address(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    return socket.inet_ntoa(fcntl.ioctl(
        s.fileno(),
        0x8915,
        struct.pack('256s', ifname[:15])
    )[20:24])


if __name__ == '__main__':
    init(0x27, 1)
    write(0, 1, 'IP: ' + get_ip_address('wlan0'))
    write(0, 0, time.strftime('%b'))    #month
    write(4, 0, time.strftime('%d'))    #day of month
    write(8, 0, time.strftime('%H:'))   #hour
    write(11, 0, time.strftime('%M:'))  #minute

    while True:
            write(14, 0, time.strftime('%S'))#second
            time.sleep(1)