# P4H Traffic Light solution Template
from machine import Pin
#import utime
import time
time.sleep(0.1) # Wait for USB to become ready


# Button-controlled LED example
from machine import Pin, PWM
#import utime
import time
time.sleep(0.1) # Wait for USB to become ready

# Set up the button on GP16 with an internal pull-up resistor
button = Pin(16, Pin.IN, Pin.PULL_UP)

#Set up the Traffic lights LEDs  (separate LEDs)
Green_led = Pin(15, Pin.OUT)
Yellow_led = Pin(14, Pin.OUT)
Red_led = Pin(17, Pin.OUT)


# Set up RGB LED pins for pedestrian signal
RGB_red_pin = 12
RGB_green_pin = 11
RGB_blue_pin = 10


# RGB LED pins (using PWM for color control)
RGB_red = PWM(Pin(RGB_red_pin))
RGB_blue = PWM(Pin(RGB_blue_pin))
RGB_green = PWM(Pin(RGB_green_pin))

# Set PWM frequency (1000 Hz is good for LEDs)
RGB_red.freq(1000)
RGB_blue.freq(1000)
RGB_green.freq(1000)


## Timing variables (in milliseconds)
GREEN_TIME = 5000  # Green light stays on for 5 seconds
previous_time = time.ticks_ms()
 
# Print startup message
print("Smart Traffic Light System Starting...")
print("Press button during green light to trigger pedestrian cycle")

# Initialize - start with green light ON, everything else OFF
Green_led.value(1)


# Convert 0-255 values to 0-65535 for duty_u16 (16-bit PWM)
RGB_red.duty_u16(int(255  * 65535 / 255))
RGB_green.duty_u16(int(165  * 65535 / 255))
RGB_blue.duty_u16(int(0  * 65535 / 255))

# Main loop runs continuously
while True:
    # Read the button state
    button_state = button.value()
    print (f"Button state :{button_state}")
    # With a pull-up resistor, button pressed = 0 (LOW)
    # Get current time
    current_time = time.ticks_ms()
    
    # Calculate how much time has passed since last cycle
    elapsed_time = time.ticks_diff(current_time, previous_time)

    # Print status for debugging
    print("Time:", elapsed_time, " Button:", button_state)

    # Check if button was pressed OR if green time has expired
    if button_state == 0 or elapsed_time >= GREEN_TIME:
        # ========== YELLOW LIGHT ==========
        # Turn off green, turn on yellow
        Green_led.value(0)
        Yellow_led.value(1)
        time.sleep_ms(2500)  # Yellow for 2.5 seconds

        # ========== RED LIGHT ==========
        # Turn off yellow, turn on red
        Yellow_led.value(0)
        Red_led.value(1)
        # ========== PEDESTRIAN WALK SIGNAL (WHITE) ==========
        # Turn on all RGB colors to make white for 4 seconds
        RGB_red.duty_u16(int(255  * 65535 / 255))
        RGB_blue.duty_u16(int(255  * 65535 / 255))
        RGB_green.duty_u16(int(255  * 65535 / 255))
        time.sleep_ms(4000)
        # ========== FLASHING ORANGE WARNING ==========
        # Flash orange 8 times (2 seconds total: 250ms on, 250ms off)
      
        for i in range (8):
            RGB_red.duty_u16(int(255  * 65535 / 255))
            RGB_green.duty_u16(int(165 * 65535 / 255))
            RGB_blue.duty_u16(int(0 * 65535 / 255))
            time.sleep_ms(250)
            RGB_red.duty_u16(int(0 * 65535 / 255))
            RGB_green.duty_u16(int(0 * 65535 / 255))
            RGB_blue.duty_u16(int(0 * 65535 / 255))
            time.sleep_ms(250)

        
        # ========== SOLID ORANGE DON'T WALK ==========
        # Orange ON (stays on)
        RGB_red.duty_u16(int(255  * 65535 / 255))
        RGB_green.duty_u16(int(165 * 65535 / 255))
        RGB_blue.duty_u16(int(0 * 65535 / 255))
        
        # Red light stays on for remaining time
        # Total red time should be 7.5 seconds
        # We've used 6 seconds (4s white + 2s flashing)
        # So wait 1.5 more seconds
        time.sleep_ms(1500)

        # ========== RETURN TO GREEN ==========
        # Turn off red light
        # Turn off yellow, turn on red
        Red_led.value(0)
        Green_led.value(1)

        # Reset the timer for next cycle
        previous_time = time.ticks_ms()


    # Small delay to prevent excessive CPU usage
    time.sleep_ms(10)