from abc import ABC, abstractmethod
import pigpio
import time

class GPIOInterface(ABC):
    """
    Interface for handling communication to the GPIO pins.
    out_pins are set low when program is aborted.
    """
    def __init__(self, in_pins: list=[], out_pins: list=[]):
        self.out_pins = out_pins
        self.in_pins = in_pins

    @abstractmethod
    def set_pin(self, pin: int, value: int) -> None:
        pass
    
    @abstractmethod
    def get_pin(self, pin: int) -> int:
        pass

    @abstractmethod
    def set_servo_angle(self, pin: int, angle: float) -> None:
        """
        Set the servo connected to 'pin' to the specified angle.
        """
        pass

    @abstractmethod
    def set_servo_angle_smooth(self, pin: int, target_angle: float, duration_ms: float) -> None:
        """
        Move the servo to 'target_angle' at the specified speed (duration in ms).
        """
        pass

    def do_step(self, dir_pin: int, step_pin: int, steps: int = 100, step_delay_us: int = 200, direction: bool = True):
        """
        Perform a step operation on a stepper motor.
        """
        pass
    
    def cleanup(self):
        pass

class PiGPIO(GPIOInterface):
    def __init__(self, in_pins: list=[], out_pins: list=[]):
        super().__init__(in_pins, out_pins)
        self.pi = pigpio.pi()
        if not self.pi.connected:
            raise RuntimeError("Could not connect to pigpiod. Is it running? Try: 'sudo systemctl start pigpiod'")
        for pin in out_pins:
            self.pi.set_mode(pin, pigpio.OUTPUT)
            self.pi.write(pin, 0)  # Ensure output pins are off initially
        for pin in in_pins:
            self.pi.set_mode(pin, pigpio.INPUT)

    def set_pin(self, pin: int, value: int) -> None:
        if pin < 0 or pin > 27:
            return
        if pin not in self.out_pins:
            self.pi.set_mode(pin, pigpio.OUTPUT)
            self.out_pins.append(pin)
        self.pi.write(pin, value)

    def get_pin(self, pin: int) -> int:
        if pin < 0 or pin > 27:
            return -1
        if pin not in self.in_pins:
            self.pi.set_mode(pin, pigpio.INPUT)
            self.in_pins.append(pin)
        return self.pi.read(pin)  

    def set_servo_angle(self, pin: int, angle_deg: float) -> None:
        """
        Set servo to a specific angle (0-180 degrees).
        MG90 typical pulse width: 0 deg = 500us, 180 deg = 2500us.
        """
        if pin not in self.out_pins:
            self.pi.set_mode(pin, pigpio.OUTPUT)
            self.out_pins.append(pin)
        # Clamp angle
        angle_deg = max(0, min(180, angle_deg))
        # Map angle to pulse width
        pulsewidth = int(500 + (angle_deg / 180.0) * 2000)
        self.pi.set_servo_pulsewidth(pin, pulsewidth)

    def set_servo_angle_smooth(self, pin: int, target_angle_deg: float, duration_ms: float) -> None:
        """
        Move servo to target_angle at given speed (duration in ms).
        """
        if pin < 0 or pin > 27 or duration_ms <= 0:
            return
        # Read current angle by assuming last set value (no feedback)
        # For simplicity, we store last angle in an instance dict
        if not hasattr(self, "_servo_angles"):
            self._servo_angles:dict[int, float] = {}

        if pin not in self._servo_angles:
            self.set_servo_angle(pin, target_angle_deg)
            return

        current_angle = self._servo_angles[pin]

        target_angle_deg = max(0, min(180, target_angle_deg))
        step = 1 if target_angle_deg > current_angle else -1
        delay = duration_ms / int(abs(target_angle_deg-current_angle)) / 1000
        for angle in range(int(current_angle), int(target_angle_deg), step):
            self.set_servo_angle(pin, angle)
            time.sleep(delay)
        self.set_servo_angle(pin, target_angle_deg)
        self._servo_angles[pin] = target_angle_deg

    def do_step(self, dir_pin: int, step_pin: int, steps: int = 100, step_delay_us: int = 200, direction: bool = True):
        """
        Perform a step operation on a stepper motor.
        dir_pin: Direction pin
        step_pin: Step pin to trigger steps
        steps: Number of steps to perform
        step_delay_us: Delay between steps in microseconds
        direction: True for forward, False for reverse
        """
        # Set direction
        self.set_pin(dir_pin, 1 if direction else 0)

        # Create pulse waveform
        pulses = []
        for _ in range(steps):
            pulses.append(pigpio.pulse(1 << step_pin, 0, step_delay_us))   # STEP high
            pulses.append(pigpio.pulse(0, 1 << step_pin, step_delay_us))   # STEP low

        self.pi.wave_clear()
        self.pi.wave_add_generic(pulses)
        wave_id = self.pi.wave_create()

        if wave_id >= 0:
            self.pi.wave_send_once(wave_id)
            while self.pi.wave_tx_busy():
                time.sleep(0.1)

            self.pi.wave_delete(wave_id)

        self.set_pin(dir_pin, 0)

    def cleanup(self):
        if self.pi.connected:
            for pin in self.out_pins:
                self.set_pin(pin, 0)
        self.pi.stop()

class MockGPIO(GPIOInterface):
    def set_pin(self, pin: int, value: int) -> None:
        pass

    def get_pin(self, pin: int) -> int:      
        return 0
    
    def set_servo_angle(self, pin: int, angle: float) -> None:
        pass

    def set_servo_angle_smooth(self, pin: int, target_angle: float, duration_ms: float) -> None:
        pass