#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sat Jan 25 20:54:34 2020

@author: suwako
"""

import sys, pygame, time, random
import numpy as np


pygame.init()
black=(0,0,0)
size = width, height = 1366, 720
TICK_RATE=60
camera=np.array([0.,0.])
origin=camera=np.array([0.,0.])
follow=1
screen = pygame.display.set_mode(size)

class satellite(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("assets/ship.png").convert_alpha()
        self.image = pygame.transform.scale(self.image, (self.image.get_rect().width*5, self.image.get_rect().height*5))
        self.position = self.image.get_rect()
        self.speed=np.array([0.,0.])
        self.pos = np.array([0.,0.])
        self.mass=1
        self.G=0.0000001
    def tick(self, camera=np.array([0.,0.]), origin=np.array([0.,0.])):
        self.pos += self.speed
    def apply(self, camera=np.array([0.,0.]), origin=np.array([0.,0.])):
        self.position.x, self.position.y = map(int, self.pos-camera-origin)
    def apply_gravity(self, elements):
        for element in elements:
            if element != self:
                d=(element.pos - self.pos )
                u=d/np.linalg.norm(d)
                norm = self.G * element.mass*(d[0]**2+d[1]**2)
                self.speed+=norm*u
premier = satellite()
#premier.position.center = (width/2, height/2)
tick=(time.time(), time.time(), 0)
def clip(val, minval, maxval):
    return min(max(val, minval), maxval)
elements=[satellite() for _ in range(3)]
"""for element in elements:
    element.pos=np.array([random.randint(0,width), random.randint(0,height)], dtype='float64')
    element.speed=np.array([random.randint(0,50), random.randint(0,50)], dtype='float64')"""
elements[1].pos= np.array([-500.,0.])
elements[0].pos= np.array([-100.,0.])
elements[0].speed[1]=20
elements[1].mass=300
elements[2].mass=30
elements[2].speed[1]=100
keys=set()
while 1:
    dtick=tick
    tick=(tick[0], time.time(), int((time.time() - tick[0])*TICK_RATE))
    dtick=tick[2] - dtick[2]
    if dtick>2:
        print(dtick)
    for _ in range(dtick):
        for event in pygame.event.get():
            #print(event.type)
            if event.type == pygame.QUIT: sys.exit()
            if event.type == pygame.KEYDOWN:
                keys.update({event.key})
                print(event.key)
                if event.key == 102:
                    follow = (follow + 1)%len(elements)
            if event.type == pygame.KEYUP:
                if event.key in keys:
                    keys.remove(event.key)
        screen.fill(black)
        for key in keys:
            if key in [275,276,273,274]:    
                exec("camera" + ("[0]+","[0]-","[1]-","[1]+")[[275,276,273,274].index(key)] + "=30")
        for element in elements:
            element.apply_gravity(elements)
            element.tick(camera=camera)
        ori = elements[-1].pos
        ori_spe = elements[-1].speed
        for element in elements:
            element.pos = element.pos - ori
            element.speed = element.speed - ori_spe
        origin=elements[follow].pos
        for element in elements:
            element.apply(camera=camera, origin=origin)
            screen.blit(element.image, element.position)
        pygame.display.flip()
    time.sleep(0.001)
    if tick[2]%60 == 0 : print(elements[follow].pos)