# imports
import machine
import math
import time

########################################
# Pin and constant definitions
########################################
# ADC pin
ADC_PIN = 26

# Segment pins (a-g): GPIO 0, 1, 2, 3, 4, 5, 6
SEGMENT_PINS = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]

# Digit select pins (DIG1 to DIG4): GPIO 18, 19, 20, 21
DIGIT_PINS = [18, 19, 20, 21]

# Button pin
BUTTON_PIN = 16

# Segment bit patterns for digits 0-9, and blank (COMMON CATHODE)
DIGIT_ENCODING = {
    '0': [1, 1, 1, 1, 1, 1, 0],
    '1': [0, 1, 1, 0, 0, 0, 0],
    '2': [1, 1, 0, 1, 1, 0, 1],
    '3': [1, 1, 1, 1, 0, 0, 1],
    '4': [0, 1, 1, 0, 0, 1, 1],
    '5': [1, 0, 1, 1, 0, 1, 1],
    '6': [1, 0, 1, 1, 1, 1, 1],
    '7': [1, 1, 1, 0, 0, 0, 0],
    '8': [1, 1, 1, 1, 1, 1, 1],
    '9': [1, 1, 1, 1, 0, 1, 1],
    ' ': [0, 0, 0, 0, 0, 0, 0],
    '.': [0, 0, 0, 0, 0, 0, 1]
}

########################################
# Global variables
########################################
display_value = 0
segment_outputs = [machine.Pin(pin, machine.Pin.OUT) for pin in SEGMENT_PINS]
digit_outputs = [machine.Pin(pin, machine.Pin.OUT) for pin in DIGIT_PINS]
adc = machine.ADC(ADC_PIN)
button = machine.Pin(BUTTON_PIN, machine.Pin.IN, machine.Pin.PULL_UP)
display_digits = [' ', ' ', ' ', ' ']
current_digit_index = 0
display_timer = None
button_pressed = False
last_button_time = 0
display_enabled = False

########################################
# 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):
    raw = adc.read_u16()
    voltage = (raw * 3.3) / 65535
    global display_value
    display_value = voltage

# Function to disable timer that triggers scanning 7 segment displays
def disable_display_timer():
    global display_timer
    if display_timer:
        display_timer.deinit()
        display_timer = None

# Function to enable timer that triggers scanning 7 segment displays
def enable_display_timer():
    global display_timer
    display_timer = machine.Timer()
    display_timer.init(freq=500, mode=machine.Timer.PERIODIC, callback=scan_display)

# 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 current_digit_index, display_digits

    # إيقاف تشغيل جميع الأرقام مؤقتًا قبل عرض الرقم التالي
    for pin in digit_outputs:
        pin.value(1)

    digit_value = display_digits[current_digit_index]
    display_digit(digit_value, current_digit_index)
    current_digit_index = (current_digit_index + 1) % 4

# 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):
    pattern = DIGIT_ENCODING.get(digit_value, DIGIT_ENCODING[' '])
    offset = digit_index * 7  # حساب بداية أطراف أجزاء الرقم الحالي

    # إيقاف تشغيل جميع الأرقام
    for pin in digit_outputs:
        pin.value(1)

    # تعيين أطراف الأجزاء للرقم الحالي
    for i in range(7):
        if offset + i < len(segment_outputs):
            segment_outputs[offset + i].value(pattern[i])

    # تفعيل الرقم الحالي
    if 0 <= digit_index < len(digit_outputs):
        digit_outputs[digit_index].value(0)
    else:
        print("Error: digit_index out of range:", digit_index)

# Function to test available 7-segment displays
def display_value_test():
    while True:
        for i in range(10):
            display_digits = list("{:4d}".format(i * 111))
            time.sleep(1)
        display_digits = [' ', ' ', ' ', ' ']
        time.sleep(1)

def update_display_digits(voltage):
    voltage_str = "{:.2f}".format(voltage)
    digits = []
    count = 0
    for char in voltage_str:
        if count < 4:
            if char.isdigit() or char == '.':
                digits.append(char)
                count += 1
    while len(digits) < 4:
        digits.insert(0, ' ')
    global display_digits
    display_digits = digits[:4]

# Button interrupt handler
def button_handler(pin):
    global last_button_time, button_pressed, display_enabled
    now = time.ticks_ms()
    if time.ticks_diff(now, last_button_time) > 300:  # debounce
        button_pressed = True
        display_enabled = not display_enabled
        if display_enabled:
            enable_display_timer()
        else:
            disable_display_timer()
            for pin in digit_outputs:
                pin.value(1) # Turn off all digits
        last_button_time = now

# Function to setup GPIO/ADC pins, timers and interrupts
def setup():
    button.irq(trigger=machine.Pin.IRQ_FALLING, handler=button_handler)

if __name__ == '__main__':
    setup()
    while True:
        if display_enabled:
            read_analogue_voltage(ADC_PIN)
            update_display_digits(display_value)
        time.sleep(0.1)
    #display_value_test()