#!/usr/bin/env python3
# Suggestion: 	implement odometry as class that is not using the ev3dev.ev3 package
# 				establish value exchange with main driving class via getters and setters

import time
from planet import Direction
import math

'''
Documentation:
good and simple explanation on how odometry works:
https://www.youtube.com/watch?v=qsdiIZncgqo

Summary:
axis a (measure distance where wheels have most friction)
calibration factor c = diameter/ticks_per_turn
distance d = ticks wheel * c (calculate for each wheel individually)
vector_length = (d_l + d_r)/2
vector_angle ~= (d_l + d_r)/a      (only applicable for small distances)

Functionality that should be implemented in this class:
- tracking of relative distances
- track the roboters orientation
- maybe have seperate functions for vector length and orientation (only if it is beneficial)
- closest coordinate to relative distance estimation/calculation
'''


class Odometry:
    def __init__(self):  # planet
        self._wheel_axis = 11
        self._distance_per_tick = 0.0488
        self._pi = 3.141
        self.distance = 0
        self.alpha = 0


    # worked fine outside the class as function in nano, maybe we must fix it a bit :)
    def degree(self, delta_rotation_l, delta_rotation_r):  # delta_rotation_l/r should work with getmovement method

        self.alpha = ((delta_rotation_l * self._distance_per_tick - delta_rotation_r * self._distance_per_tick)/self._wheel_axis) + self.alpha
        self.distance = (delta_rotation_r * self._distance_per_tick + delta_rotation_l * self._distance_per_tick)/2 + self.distance
        if self.alpha % (2 * self._pi) >= 0 and self.alpha % (2 * self._pi) < self._pi * 0.25 or self.alpha % (2 * self._pi) >= 7 / 4 * self._pi and self.alpha % (2 * self._pi) < 2 * self._pi:
            return(Direction.NORTH, "Distance = ", self.distance)

        elif self.alpha % (2 * self._pi) >= self._pi * 0.25 and self.alpha % (2 * self._pi) < self._pi * 0.5 or self.alpha % (2 * self._pi) >= self._pi * 0.5 and self.alpha % (2 * self._pi) < self._pi * 0.75:
            return(Direction.EAST, "Distance = ", self.distance)

        elif self.alpha % (2 * self._pi) >= self._pi * 0.75 and self.alpha % (2 * self._pi) < self._pi or self.alpha % (2 * self._pi) >= self._pi and self.alpha % (2 * self._pi) < 5 / 4 * self._pi:
            return(Direction.SOUTH, "Distance = ", self.distance)

        else:
            return(Direction.WEST, "Distance = ", self.distance)

    def coordinates(self, delta_rota_l, delta_rota_r, Y_koord, X_koord):  # worked as function outside the class
        self.y = self.Y_koord
        self.x = self.X_koord
        self.wheel_center = (delta_rota_r + delta_rota_l) / 2
        self.alpha = ((self.delta_rotation_l * self._distance_per_tick - self.delta_rotation_r * self._distance_per_tick)/self._wheel_axis) + self.alpha
        self.y = self.y + self.wheel_center * math.cos(self.alpha)
        self.x = self.x + self.wheel_center * math.sin(self.alpha)
        return(self.x, self.y)