#! /usr/bin/env python
"""
 Garbagepatch.py is a program which simply simulates
 random floating of garbage in a currentless body of water.

 Paul Eugenio
 Florida State University
 Mar 23, 2017
"""

from __future__ import division, print_function
import numpy as np
from random import randrange
import matplotlib.pyplot as plt



class Garbage():
    """ 
     Garbage is an object which simulates the random floating of trash in 
     a currentless ocean
    """

    def __init__(self, x=0, y=0):
        """ Each piece of garbage has an (x,y) position. """
        self.x, self.y = x, y
            
    def move(self, x_increment=0, y_increment=0):
        """ 
         Move the garbage according to the parameters given.
         Default behavior is to stay put
        """
        self.x, self.y =  self.x + x_increment, self.y + y_increment  

    def get_distance(self, other):
        """ 
         Calculates the distance from this piece to another piece,
         and returns that value.
        """
        return np.sqrt( (self.x - other.x)**2 + (self.y - other.y )**2 ) 
       
    def float(self):
        """ 
         random floating movement: moves one unit East, North, West, South,
         or stays put
        """
        direction = np.random.randint(5)
        dx,dy = 0,0  # default for direction == 0

        if direction == 1:
            dx = 1
        elif direction == 2:
            dy = 1
        elif direction == 3:
            dx = -1
        elif direction == 4:
            dy = -1
        
        self.move(dx,dy)


#
# main
#

# Create some trash
garbagePatch = []
for k in range(60):
    garbagePatch += [Garbage()]

# time interval 
max_t = 1000
tRange = range(max_t)

# plot the location of the trash as it randomly floats
for trash  in garbagePatch:
    x,y = [],[]
    for t in tRange:        
        trash.float()
        x += [trash.x]
        y += [trash.y]    
    plt.plot(x,y,"o")

plt.title("Random movement of a 60 element garbage patch")
plt.savefig("garbagePatch.jpg")
plt.show()