"""
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Interfacing with 7 Segment Display (MicroPython)         ┃
┃                                                          ┃
┃ Design and Implement a Traffic Light Controller System   ┃
┃ with the use of 7 segment display as counter given the   ┃
┃ scenario: Road Structure & State Machine and State Table ┃
┃                                                          ┃
┃ Copyright (c) 2024 CPE4B - Group 1                       ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
"""

from machine import Pin
from utime import sleep

# Pins for Traffic Signal A (East-West)
red_A = Pin(26, Pin.OUT)
yellow_A = Pin(27, Pin.OUT)
green_A = Pin(28, Pin.OUT)

# Pins for Traffic Signal B (North-South)
red_B = Pin(22, Pin.OUT)
yellow_B = Pin(21, Pin.OUT)
green_B = Pin(20, Pin.OUT)

pins = [
    Pin(2, Pin.OUT), # A
    Pin(3, Pin.OUT), # B
    Pin(4, Pin.OUT), # C
    Pin(5, Pin.OUT), # D
    Pin(6, Pin.OUT), # E
    Pin(8, Pin.OUT), # F
    Pin(7, Pin.OUT), # G
    Pin(0, Pin.OUT) # DP (optional, not used)
]

digits = [
    [0, 0, 0, 0, 0, 0, 1, 1], # 0
    [1, 0, 0, 1, 1, 1, 1, 1], # 1
    [0, 0, 1, 0, 0, 1, 0, 1], # 2 
    [0, 0, 0, 0, 1, 1, 0, 1], # 3
    [1, 0, 0, 1, 1, 0, 0, 1], # 4
    [0, 1, 0, 0, 1, 0, 0, 1], # 5
    [0, 1, 0, 0, 0, 0, 0, 1], # 6
    [0, 0, 0, 1, 1, 1, 1, 1], # 7
]

# Turns off all segments on the 7-segment display
def reset_display():
    for pin in pins:
        pin.value(1)

# Displays a number on the 7-segment display
def display_number(num):
    for i in range(7):
        pins[i].value(digits[num][i])

# Initial State 0
def state_S0():
    green_A.value(1)
    red_B.value(1)
    red_A.value(0)
    for i in range(7, 0, -1):
        display_number(i)
        sleep(1)
    green_A.value(0)

# State 1
def state_S1():
    yellow_A.value(1)
    red_B.value(1)
    for i in range(2, 0, -1):
        display_number(i)
        sleep(1)
    yellow_A.value(0)

# State 2
def state_S2():
    red_A.value(1)
    red_B.value(1)
    for i in range(2, 0, -1):
        display_number(i)
        sleep(1)

# State 3
def state_S3():
    green_B.value(1)
    red_A.value(1)
    red_B.value(0)
    for i in range(7, 0, -1):
        display_number(i)
        sleep(1)
    green_B.value(0)

# State 4
def state_S4():
    yellow_B.value(1)
    red_A.value(1)
    for i in range(2, 0, -1):
        display_number(i)
        sleep(1)
    yellow_B.value(0)

# State 5
def state_S5():
    red_B.value(1)
    red_A.value(1)
    for i in range(2, 0, -1):
        display_number(i)
        sleep(1)

while True:
    reset_display()
    state_S0()
    reset_display()
    state_S1()
    reset_display()
    state_S2()
    reset_display()
    state_S3()
    reset_display()
    state_S4()
    reset_display()
    state_S5()