# Tip of the hat to https://github.com/johnlr/raspberrypi-tm1637 for
# this code.  This has been very slightly modified, but is mostly his
# work.

from time import sleep
from wiringpi import pinMode, digitalRead, digitalWrite, GPIO

"""
      A
     ---
  F |   | B
     -G-
  E |   | C
     ---
      D

"""


class TM1637:
    I2C_COMM1 = 0x40
    I2C_COMM2 = 0xC0
    I2C_COMM3 = 0x80
    digit_to_segment = [
        0b0111111, # 0
        0b0000110, # 1
        0b1011011, # 2
        0b1001111, # 3
        0b1100110, # 4
        0b1101101, # 5
        0b1111101, # 6
        0b0000111, # 7
        0b1111111, # 8
        0b1101111, # 9
        0b1110111, # A
        0b1111100, # b
        0b0111001, # C
        0b1011110, # d
        0b1111001, # E
        0b1110001, # F
        0b1000000, # Minus Sign
        ]

    def __init__(self, clk, dio, brightness):
        self.clk = clk
        self.dio = dio
        self.brightness = brightness

        pinMode(self.clk, GPIO.INPUT)
        pinMode(self.dio, GPIO.INPUT)
        digitalWrite(self.clk, GPIO.LOW)
        digitalWrite(self.dio, GPIO.LOW)

    def bit_delay(self):
        sleep(0.001)
        return

    def set_segments(self, segments, pos=0):
        # Write COMM1
        self.start()
        self.write_byte(self.I2C_COMM1)
        self.stop()

        # Write COMM2 + first digit address
        self.start()
        self.write_byte(self.I2C_COMM2 + pos)

        for seg in segments:
            self.write_byte(seg)
        self.stop()

        # Write COMM3 + brightness
        self.start()
        self.write_byte(self.I2C_COMM3 + self.brightness)
        self.stop()

    def start(self):
        pinMode(self.dio, GPIO.OUTPUT)
        self.bit_delay()

    def stop(self):
        pinMode(self.dio, GPIO.OUTPUT)
        self.bit_delay()
        pinMode(self.clk, GPIO.INPUT)
        self.bit_delay()
        pinMode(self.dio, GPIO.INPUT)
        self.bit_delay()

    def write_byte(self, b):
      # 8 Data Bits
        for i in range(8):

            # CLK low
            pinMode(self.clk, GPIO.OUTPUT)
            self.bit_delay()

            pinMode(self.dio, GPIO.INPUT if b & 1 else GPIO.OUTPUT)

            self.bit_delay()

            pinMode(self.clk, GPIO.INPUT)
            self.bit_delay()
            b >>= 1

        pinMode(self.clk, GPIO.OUTPUT)
        self.bit_delay()
        pinMode(self.clk, GPIO.INPUT)
        self.bit_delay()
        pinMode(self.clk, GPIO.OUTPUT)
        self.bit_delay()

        return

# End of class 'TM1637'