# imports
from machine import Pin, ADC
import math
import time

#######################################
# Pin and constant definitions
#######################################
button_pin = Pin(16, Pin.IN, Pin.PULL_UP)
reader_pin = 26
start_7seg_pin = 0
digit_count = 4

digit_list = [
    [0,0,0,0,0,0,1], # 0
    [1,0,0,1,1,1,1], # 1
    [0,0,1,0,0,1,0], # 2
    [0,0,0,0,1,1,0], # 3
    [1,0,0,1,1,0,0], # 4
    [0,1,0,0,1,0,0], # 5
    [0,1,0,0,0,0,0], # 6
    [0,0,0,1,1,1,1], # 7
    [0,0,0,0,0,0,0], # 8
    [0,0,0,0,1,0,0]  # 9
]

digit_list_test = [ #This should show you "HI ('')" ← this is a face
    [1,1,0,0,1,0,1,1],
    [1,0,1,0,0,1,1,0],
    [1,1,1,1,0,0,1,1],
    [1,0,0,1,0,0,0,1],
]

#######################################
# Global variables
#######################################
display_value = 0
digit_pins = []
seg_pins = []

#######################################
# Function definitions
#######################################

# Function to read the ADC pin and
# to convert the digital value to a voltage level in the 0-3.3V range
# This function updates the value of the display_value global variable
def read_analogue_voltage(pin):  # We can use the pin parameter if needed
    global display_value

    display_value = ADC(pin).read_u16()*3.3/65535
    pass

# Function to disable timer that triggers scanning 7 segment displays
def disable_display_timer():
    pass

# Function to enable timer that triggers scanning 7 segment displays
def enable_display_timer():
    pass

# Function to handle scanning 7 segment displays
# Display the value stored in the display_value global variable
# on available 7-segment displays
def scan_display(timer_int):
    global display_value

    while True:
        if button_pin.value() == 0:
            read_analogue_voltage(reader_pin)
        for i in range(0, digit_count):
            voltage = str((display_value * pow(10, 2 - i) - int(display_value * pow(10, 2 - i))) * 10)
            display_digit(int(voltage[0:1]), i)
        time.sleep(.05)
    pass

# Function display the given value on the display with the specified index
# dp_enable specifies if the decimal pooint should be on or off
def display_digit(digit_value, digit_index, dp_enable = False):
    digit_pins[digit_index].value(1)
    for s in range(7):
        seg_pins[s].value(digit_list[int(digit_value)][s])

    seg_pins[7].value(dp_enable if digit_index == 3 else 1)

    digit_pins[digit_index].value(0)
    for s in range(8):
        seg_pins[s].value(1)
    pass    

# Function to test avaiable 7-segment displays
def display_value_test():
    global digit_list_test

    while True:
        for i in range(digit_count):
            digit_pins[i].value(1)
            for s in range(7):
                seg_pins[s].value(digit_list_test[i][s])
            digit_pins[i].value(0)

            for s in range(7):
                seg_pins[s].value(1)
            time.sleep(.01)
    pass

# Function to setup GPIO/ADC pins, timers and interrupts
def setup():
    for i in range(start_7seg_pin, start_7seg_pin + 8):
        pin = Pin(i, Pin.OUT, value=1)
        seg_pins.append(pin)
    
    for i in range(start_7seg_pin + 8, start_7seg_pin + 8 + digit_count):
        pin = Pin(i, Pin.OUT)
        digit_pins.append(pin)
    pass

if __name__ == '__main__':
    setup()

    button_pin.irq(trigger=Pin.IRQ_FALLING, handler=scan_display)

    #display_value_test()