# -*- coding: utf-8 -*-
"""
Created on Fri Nov 27 10:34:13 2020

@author: Studente


Write a function that takes as an input an image with black background and several segmented lines together with a point of the image and returns the number of turns made by the segmented line the point belongs to
"""
black = (0,0,0)
white = (255,255,255)


class Position:
    def __init__(self,row,pix):
        self.row = row
        self.pix = pix
        
    def __add__(self, p):
        return Position(self.row+p.row, self.pix+p.pix)
    
    def __repr__(self):
        return f'({self.row},{self.pix})'
    
    def __eq__(self, p):
        return p.row==self.row and p.pix==self.pix
    
di = {'d':Position(1,0),
      'u':Position(-1,0),
      'r':Position(0,1),
      'l':Position(0,-1)
              }

class Turtle:
    def __init__(self, initial_point, image):
        self.pos = initial_point
        self.imm = image
        
        
    def check_pos(self, p):
        return 0 <= p.row < len(self.imm) and 0 <= p.pix < len(self.imm[0])
    
    
    def color(self, p=None):
        ''' if p is None we return the color of the pixel where we are '''
        if not p:
            return self.imm[self.pos.row][self.pos.pix]
        if self.check_pos(p):
            return self.imm[p.row][p.pix]
        return None
    
        
    def directions(self, p=None):
        if not p:
            p=self.pos
        ret = []
        if self.color() == black:
            return []
        elif self.color() == white:
            for direction in di.values():
                if self.color(p+direction) == white:
                    ret.append(direction)
        return ret
            
    
    def move(self, direction):
        self.pos+=direction
        
        
    def go_to(self, p):
        self.pos = p
        
    
    def check_corner(self, p=None):
        if not p:
            p=self.pos
        movements = self.directions(p)
        if len(movements) == 2:
            pos = movements[0]+movements[1]
            return pos.row + pos.pix
        return False
        
        
    def explore(self, pos, direction):
        self.pos = pos
        corners = 0
        while self.color() != black:
            self.move(direction)
            if self.check_corner():
                corners+=1
                ## CHANGE DIRECTION
                movements = self.directions()
                if movements[0] == Position(-direction.row, -direction.pix):
                    direction = movements[1]
                else:
                    direction = movements[0]
#            if len(self.directions()) == 1:
#                return corners
        return corners
                
                
        
    def count_corners(self):
        movements = self.directions()
        corners = 0
        if not movements:
            return 0
        initial_pos = self.pos
        if len(movements) == 2:
            if self.check_corner():
                corners+=1
            corners += self.explore(initial_pos, movements[0]) + self.explore(initial_pos, movements[1])
        return corners
            
            
            
#        
#        first_direction = 
#        second_direction = 
        
    
#
#def count_turns(imm, row, pixel):
#    ''' returns the number of turns made by the line the point imm[row][pixel] belongs to (if any) '''
#    
#