from machine import ADC, Pin, PWM, I2C, SPI, Timer
from ssd1306 import SSD1306_I2C
from time import sleep, ticks_ms

# ================= INPUT SUBROUTINES =================

# Initialize hardware components
BUZZER = PWM(Pin(15))  # Buzzer for feedback when button is pressed
BUZZER.freq(2000)  # Set buzzer frequency to 2000Hz
BUZZER.duty(0)  # Start with buzzer off

LED = PWM(Pin(2))  # LED with PWM for brightness control
LED.freq(1000)  # Set PWM frequency for LED to ensure smooth dimming

BUTTON = Pin(12, Pin.IN, Pin.PULL_DOWN)  # Button with pull-down resistor
POT = ADC(Pin(34))  # Potentiometer for manual brightness control
LIGHT_SENSOR = ADC(Pin(14))  # Light sensor for ambient light measurement

i2c = I2C(0, scl=Pin(22), sda=Pin(21))  # I2C communication for OLED display

# Setup OLED display
spi = SPI(1, baudrate=5000000, polarity=0, phase=0)
oled_width = 128
oled_height = 64
oled = SSD1306_I2C(oled_width, oled_height, i2c)

# Define lamp operating modes
modes = ["off", "on", "auto"]  # Modes: Off, Manual On, Auto (sensor-based)
mode = [0]  # Start in "off" mode
last_press_time = [0]  # Track last button press time for debouncing

# Function to debounce and toggle lamp mode when button is pressed
def debounce_toggle_lamp(pin):
    current_time = ticks_ms()  # Get current time in milliseconds
    if current_time - last_press_time[0] > 300:  # Check if 300ms has passed since last press
        last_press_time[0] = current_time  # Update last press time
        mode[0] = (mode[0] + 1) % len(modes)  # Cycle through modes
        BUZZER.duty(512)  # Activate buzzer for feedback
        sleep(0.01)  # Short delay for beep
        BUZZER.duty(0)  # Turn off buzzer

# Function to read light sensor value and convert it to 0-99 range
def read_light():
    raw_adc = LIGHT_SENSOR.read()  # Read ADC value (0-4095)
    lux = 100 - (raw_adc / 4095) * 100  # Invert the mapping
    return int(lux)  # Return scaled lux value

# Function to read potentiometer value and scale it to 0-1023 range
def read_pot():
    return POT.read() // 4  # Scale ADC (0-4095) to 0-1023

# ================= OUTPUT SUBROUTINES =================

# Function to update OLED display periodically
def update_display(timer):
    oled.fill(0)  # Clear display
    oled.text(f"Light: {read_light()} lux", 0, 0)  # Display light level
    oled.text(f"Lamp: {modes[mode[0]]}", 0, 10)  # Display current mode
    oled.show()  # Refresh display

# Configure button interrupt to switch modes with debounce
BUTTON.irq(trigger=Pin.IRQ_FALLING, handler=debounce_toggle_lamp)

# Setup periodic OLED display update
timer = Timer(0)
timer.init(period=500, mode=Timer.PERIODIC, callback=update_display)

# Define brightness levels for different light sensor values
lux_levels = [0, 10, 25, 40, 60, 80, 99]  # ADC lux values from 0 to 99
brightness_levels = [1023, 900, 700, 300, 100, 50, 0]  # Corresponding brightness levels (0-1023)

# Function to interpolate brightness based on measured lux
def interpolate_brightness(lux):
    for i in range(len(lux_levels) - 1):  # Iterate through defined brightness levels
        if lux_levels[i] <= lux <= lux_levels[i + 1]:  # Find range where lux fits
            ratio = (lux - lux_levels[i]) / (lux_levels[i + 1] - lux_levels[i])  # Compute ratio
            return int(brightness_levels[i] + ratio * (brightness_levels[i + 1] - brightness_levels[i]))  # Linear interpolation
    return brightness_levels[-1]  # Default to max brightness if out of range

# Define LED brightness functions for different modes
def mode_off():
    return 0  # LED off in "off" mode

def mode_on(pot_value):
    return pot_value  # Use potentiometer value in "on" mode

def mode_auto(lux):
    return interpolate_brightness(lux)  # Adjust brightness based on ambient light in "auto" mode

# ================= MAIN ROUTINE =================

# Main loop
while True:
    pot_value = read_pot() * (mode[0] == 1)  # Read potentiometer only in "on" mode
    lux = read_light() * (mode[0] == 2)  # Read light sensor only in "auto" mode
    brightness = [mode_off(), mode_on(pot_value), mode_auto(lux)][mode[0]]  # Select brightness based on mode

    print(f"Mode: {modes[mode[0]]}, Lux: {lux}, Potentiometer: {pot_value}, Brightness: {brightness}")  # Debug output

    LED.duty(brightness)  # Set LED brightness
    sleep(0.1)  # Small delay to prevent flickering