import numpy as np
class Controller:
    def __init__(self):
        pass

    def __call__(self, gtm, *args, **kwargs):
        return None


# We control position, but the output of the controller is a set speed.
# Therefore, we have proportional, differential and second differential terms.
class PIDController(Controller):
    err_x, err_y, err_z = 0., 0., 0.
    derr_x, derr_y, derr_z = 0., 0., 0.
    d2err_x, d2err_y, d2err_z = 0., 0., 0.

    def __init__(self, p, i, d):
        super().__init__()
        self.p, self.i, self.d = p, i, d

    def __call__(self, gtm, *args, **kwargs):
        err_x_new, err_y_new, err_z_new = gtm.delta_steps
        derr_x_new, derr_y_new, derr_z_new = err_x_new - self.err_x, err_y_new - self.err_y, err_z_new - self.err_z
        d2err_x_new, d2err_y_new, d2err_z_new = derr_x_new - self.derr_x, derr_y_new - self.derr_y, derr_z_new - self.derr_z

        self.err_x, self.err_y, self.err_z = err_x_new, err_y_new, err_z_new
        self.derr_x, self.derr_y, self.derr_z = derr_x_new, derr_y_new, derr_z_new
        self.d2err_x, self.d2err_y, self.d2err_z = d2err_x_new, d2err_y_new, d2err_z_new

        speed_cmd_x = self.p * self.derr_x + self.i * self.err_x + self.d * self.d2err_x
        speed_cmd_y = self.p * self.derr_y + self.i * self.err_y + self.d * self.d2err_y
        speed_cmd_z = self.p * self.derr_z + self.i * self.err_z + self.d * self.d2err_z

        # It is the responsability of the coefficients to make sure this results in the desired feedrate
        gtm.x_throttle = gtm.target_feedrate / abs(speed_cmd_x)
        gtm.x_direction = 1 if (speed_cmd_x > 0) else 0

        gtm.y_throttle = gtm.target_feedrate / abs(speed_cmd_y)
        gtm.y_direction = 1 if (speed_cmd_y > 0) else 0

        gtm.z_throttle = gtm.target_feedrate / abs(speed_cmd_z)
        gtm.z_direction = 1 if (speed_cmd_z > 0) else 0

        if gtm.x_throttle > 65536:
            gtm.x_throttle = 0

        if gtm.y_throttle > 65536:
            gtm.y_throttle = 0

        if gtm.z_throttle > 65536:
            gtm.z_throttle = 0


class DummyController(Controller):
    last_delta = np.nan

    def __init__(self):
        super().__init__()

    def __call__(self, gtm, *args, **kwargs):

        feed = gtm.feedrate
        dx, dy, dz = gtm.delta_units
        feed_x = feed * dx/(dx**2 + dy**2 + dz**2)**0.5
        feed_y = feed * dy/(dx**2 + dy**2 + dz**2)**0.5
        feed_z = feed * dz/(dz**2 + dy**2 + dz**2)**0.5

        print("feed (m/min) : ", feed) 
        print("current : ", gtm.current_units)
        print("target : ", gtm.target_units)
        print("deltas: ", dx, dy, dz)

        gtm.x_direction = 1 if gtm.delta_steps[0] > 0 else 0
        gtm.y_direction = 1 if gtm.delta_steps[1] > 0 else 0
        gtm.z_direction = 1 if gtm.delta_steps[2] > 0 else 0

        feed_x,feed_y,feed_z = abs(feed_x), abs(feed_y), abs(feed_z)
        print("Feeds (m/min) : ", feed_x, feed_y, feed_z)
        print("dirs : ", gtm.x_direction, gtm.y_direction, gtm.z_direction)

        gtm.x_throttle = 0 if feed_x == 0. else np.floor(gtm.FAST_XY_FEEDRATE/feed_x)
        gtm.y_throttle = 0 if feed_y == 0. else np.floor(gtm.FAST_XY_FEEDRATE/feed_y)
        gtm.z_throttle = 0 if feed_z == 0. else np.floor(gtm.FAST_Z_FEEDRATE/feed_z)

        gtm.x_throttle = 0 if gtm.x_throttle >= 65536 else gtm.x_throttle
        gtm.y_throttle = 0 if gtm.y_throttle >= 65536 else gtm.y_throttle
        gtm.z_throttle = 0 if gtm.z_throttle >= 65536 else gtm.z_throttle

        print("Throttles : ", gtm.x_throttle, gtm.y_throttle, gtm.z_throttle)

        # If we are close enough, we're good
        if(gtm.x_throttle == 0 and gtm.y_throttle == 0 and gtm.z_throttle == 0):
            last_delta = np.nan
            return True

        delta = (dx**2 + dy**2 + dz**2)**.5
        if(delta > self.last_delta and self.last_delta < 2.0):
            self.last_delta = np.nan
            return True

        self.last_delta = delta

        print("Expected move (mm/call)", gtm.ctrl_step*feed*1000./60)
        print("Delta (mm) ", (dx**2 + dy**2 + dz**2)**.5) 
        return False