# Mechanicaly conforms a moving gantry to the bed with 4 Z steppers
#
# Copyright (C) 2018  Maks Zolin <mzolin@mzbot.us>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import logging
import probe

class QuadGantryLevel:
    def __init__(self, config):
        self.printer = config.get_printer()
        self.probe_helper = probe.ProbePointsHelper(config, self)
        gantry_corners = config.get('gantry_corners').split('\n')
        try:
            gantry_corners = [line.split(',', 1)
                           for line in gantry_corners if line.strip()]
            self.gantry_corners = [(float(zp[0].strip()), float(zp[1].strip()))
                                for zp in gantry_corners]
        except:
            raise config.error("Unable to parse gantry_corners in %s" % (
                config.get_name()))
        if len(self.gantry_corners) < 2:
            raise config.error("quad_gantry_level requires at least two gantry_corners")
        self.z_steppers = []
        # Register QUAD_GANTRY_LEVEL command
        self.gcode = self.printer.lookup_object('gcode')
        self.gcode.register_command(
            'QUAD_GANTRY_LEVEL', self.cmd_QUAD_GANTRY_LEVEL,
            desc=self.cmd_QUAD_GANTRY_LEVEL_help)
    def printer_state(self, state):
        if state == 'connect':
            self.handle_connect()
    def handle_connect(self):
        kin = self.printer.lookup_object('toolhead').get_kinematics()
        z_steppers = kin.get_steppers('Z')
        if len(z_steppers) != 4:
            raise self.printer.config_error("quad_gantry_level needs exactly 4 z steppers")
        self.z_steppers = z_steppers
    cmd_QUAD_GANTRY_LEVEL_help = "Conform a moving, twistable gantry to the shape of a stationary bed"
    def cmd_QUAD_GANTRY_LEVEL(self, params):
        self.probe_helper.start_probe()
    def get_probed_position(self):
        kin = self.printer.lookup_object('toolhead').get_kinematics()
        return kin.calc_position()
    def squash_positions(self,positions):
        # Group multi-probe data and average out the Z readings
        # Assumes samples come in sequentially
        grouped_pos = []
        for position in positions:
            if len(grouped_pos) > 0 and grouped_pos[-1][0] == position[0] and grouped_pos[-1][1] == position[1]:
                grouped_pos[-1][2].append(position[2])
            else:
                grouped_pos.append(position)
                grouped_pos[-1][2] = [grouped_pos[-1][2]]
        for id,pos in enumerate(grouped_pos):
            grouped_pos[id][2] = sum(grouped_pos[id][2]) / len(grouped_pos[id][2])
        return grouped_pos
    def finalize(self, offsets, positions):
        if len(positions) > 4:
            positions = self.squash_positions(positions)
        logging.info("quad_gantry_level Calculating gantry geometry with: %s", positions)
        p1 = [positions[0][0] + offsets[0],positions[0][2]]
        p2 = [positions[1][0] + offsets[0],positions[1][2]]
        p3 = [positions[2][0] + offsets[0],positions[2][2]]
        p4 = [positions[3][0] + offsets[0],positions[3][2]]
        f1 = self.linefit(p1,p4)
        f2 = self.linefit(p2,p3)
        logging.info("quad_gantry_level f1: %s, f2: %s" % (f1,f2))
        a1 = [positions[0][1] + offsets[1], self.plot(f1,self.gantry_corners[0][0])]
        a2 = [positions[1][1] + offsets[1], self.plot(f2,self.gantry_corners[0][0])]
        b1 = [positions[0][1] + offsets[1], self.plot(f1,self.gantry_corners[1][0])]
        b2 = [positions[1][1] + offsets[1], self.plot(f2,self.gantry_corners[1][0])]
        logging.info("quad_gantry_level a1: %s a2: %s b1: %s b2: %s\n" % (a1,a2,b1,b2))
        af = self.linefit(a1,a2)
        bf = self.linefit(b1,b2)
        logging.info("quad_gantry_level af: %s, bf: %s" % (af,bf))
        z_adjust = [0,0,0,0]
        z_adjust[0] = self.plot(af,self.gantry_corners[0][1])
        z_adjust[1] = self.plot(af,self.gantry_corners[1][1])
        z_adjust[2] = self.plot(bf,self.gantry_corners[1][1])
        z_adjust[3] = self.plot(bf,self.gantry_corners[0][1])
        z_avg = sum(z_adjust)/len(z_adjust)
        for z_id in range(4):
            z_adjust[z_id] = z_avg - z_adjust[z_id]
        try:
            self.adjust_steppers(z_adjust)
        except:
            logging.exception("quad_gantry_level adjust_steppers")
            for s in self.z_steppers:
                z.set_ignore_move(False)
            raise
    def linefit(self,p1,p2):
        if p1[1] == p2[1]:
            # Straight line
            return 0,p1[1]
        m = (p2[1] - p1[1])/(p2[0] - p1[0])
        b = p1[1] - m * p1[0]
        return m,b
    def plot(self,f,x):
        return f[0]*x + f[1]
    def adjust_steppers(self, z_adjust):
        msg = "Making the following gantry adjustments:\n%s\n" % (
            "\n".join(["%s = %.6f" % (
                self.z_steppers[z_id].get_name(), z_adjust[z_id]
                ) for z_id in range(4)]))
        self.gcode.respond_info(msg)
        toolhead = self.printer.lookup_object('toolhead')
        cur_pos = toolhead.get_position()
        speed = self.probe_helper.get_lift_speed() / 2
        for s in self.z_steppers:
            s.set_ignore_move(True)
        for z_id in range(len(z_adjust)):
            stepper = self.z_steppers[z_id]
            stepper.set_ignore_move(False)
            cur_pos[2] = cur_pos[2] - z_adjust[z_id]
            toolhead.move(cur_pos, speed)
            toolhead.set_position(cur_pos)
            stepper.set_ignore_move(True)
        for s in self.z_steppers:
            s.set_ignore_move(False)
        self.gcode.reset_last_position()

def load_config(config):
    return QuadGantryLevel(config)
