SCREEN_SIZE = (640, 480)
NEST_POSITION = (320, 240)
ANT_COUNT = 20
NEST_SIZE = 100.

import pygame
from pygame.locals import *

from random import randint, choice
from gameobjects.vector2 import Vector2

class State(object):
    
    def __init__(self, name):        
        self.name = name
        
    def do_actions(self):
        pass
        
    def check_conditions(self):        
        pass    
    
    def entry_actions(self):        
        pass    
    
    def exit_actions(self):        
        pass
        
        
class StateMachine(object):
    
    def __init__(self):
        
        self.states = {}
        self.active_state = None
    
    
    def add_state(self, state):
        
        self.states[state.name] = state
        
        
    def think(self):
        
        if self.active_state is None:
            return
        
        self.active_state.do_actions()        

        new_state_name = self.active_state.check_conditions()
        if new_state_name is not None:
            self.set_state(new_state_name)
        
    
    def set_state(self, new_state_name):
        
        if self.active_state is not None:
            self.active_state.exit_actions()
            
        self.active_state = self.states[new_state_name]        
        self.active_state.entry_actions()
        
      
    
class World(object):
    
    def __init__(self):
        
        self.entities = {}
        self.entity_id = 0        
        self.background = pygame.surface.Surface(SCREEN_SIZE).convert()
        self.background.fill((255, 255, 255))
        pygame.draw.circle(self.background, (200, 255, 200), NEST_POSITION, int(NEST_SIZE))
        
    def add_entity(self, entity):
        
        self.entities[self.entity_id] = entity
        entity.id = self.entity_id
        self.entity_id += 1
        
    def remove_entity(self, entity):
        
        del self.entities[entity.id]
                
    def get(self, entity_id):
        
        if entity_id in self.entities:
            return self.entities[entity_id]
        else:
            return None
        
    def process(self, time_passed):
                
        time_passed_seconds = time_passed / 1000.0        
        for entity in self.entities.values():
            entity.process(time_passed_seconds)
            
    def render(self, surface):
        
        surface.blit(self.background, (0, 0))
        for entity in self.entities.itervalues():
            entity.render(surface)
            
            
    def get_close_entity(self, name, location, range=100.):
        
        location = Vector2(*location)        
        
        for entity in self.entities.itervalues():            
            if entity.name == name:                
                distance = location.get_distance_to(entity.location)
                if distance < range:
                    return entity        
        return None
  

class GameEntity(object):
    
    def __init__(self, world, name, image):
        
        self.world = world
        self.name = name
        self.image = image
        self.location = Vector2(0, 0)
        self.destination = Vector2(0, 0)
        self.speed = 0.
        
        self.brain = StateMachine()
        
        self.id = 0
        
    def render(self, surface):
        
        x, y = self.location
        w, h = self.image.get_size()
        surface.blit(self.image, (x-w/2, y-h/2))   
        
    def process(self, time_passed):
        
        self.brain.think()
        
        if self.speed > 0. and self.location != self.destination:
            
            vec_to_destination = self.destination - self.location        
            distance_to_destination = vec_to_destination.get_length()
            heading = vec_to_destination.get_normalized()
            travel_distance = min(distance_to_destination, time_passed * self.speed)
            self.location += travel_distance * heading
        

class Leaf(GameEntity):
    
    def __init__(self, world, image):
        GameEntity.__init__(self, world, "leaf", image)
        
        
class Spider(GameEntity):
    
    def __init__(self, world, image):
        GameEntity.__init__(self, world, "spider", image)
        self.dead_image = pygame.transform.flip(image, 0, 1)
        self.health = 25
        self.speed = 50. + randint(-20, 20)
        
    def bitten(self):
        
        self.health -= 1
        if self.health <= 0:
            self.speed = 0.
            self.image = self.dead_image
        self.speed = 140.
        
    def render(self, surface):
        
        GameEntity.render(self, surface)
                
        x, y = self.location
        w, h = self.image.get_size()
        bar_x = x - 12
        bar_y = y + h/2
        surface.fill( (255, 0, 0), (bar_x, bar_y, 25, 4))
        surface.fill( (0, 255, 0), (bar_x, bar_y, self.health, 4))
        
    def process(self, time_passed):
        
        x, y = self.location
        if x > SCREEN_SIZE[0] + 2:
            self.world.remove_entity(self)
            return
        
        GameEntity.process(self, time_passed)
        
    
class Ant(GameEntity):
    
    def __init__(self, world, image):
        
        GameEntity.__init__(self, world, "ant", image)
        
        exploring_state = AntStateExploring(self)
        seeking_state = AntStateSeeking(self)
        delivering_state = AntStateDelivering(self)
        hunting_state = AntStateHunting(self)
        
        self.brain.add_state(exploring_state)
        self.brain.add_state(seeking_state)
        self.brain.add_state(delivering_state)
        self.brain.add_state(hunting_state)
        
        self.carry_image = None
        
    def carry(self, image):
        
        self.carry_image = image
        
    def drop(self, surface):
        
        if self.carry_image:
            x, y = self.location
            w, h = self.carry_image.get_size()
            surface.blit(self.carry_image, (x-w, y-h/2))
            self.carry_image = None
        
    def render(self, surface):
        
        GameEntity.render(self, surface)
        
        if self.carry_image:
            x, y = self.location
            w, h = self.carry_image.get_size()
            surface.blit(self.carry_image, (x-w, y-h/2))
        

class AntStateExploring(State):
    
    def __init__(self, ant):
        
        State.__init__(self, "exploring")
        self.ant = ant
        
    def random_destination(self):
        
        w, h = SCREEN_SIZE
        self.ant.destination = Vector2(randint(0, w), randint(0, h))    
    
    def do_actions(self):
        
        if randint(1, 20) == 1:
            self.random_destination()
            
    def check_conditions(self):
                        
        leaf = self.ant.world.get_close_entity("leaf", self.ant.location)        
        if leaf is not None:
            self.ant.leaf_id = leaf.id
            return "seeking"        
                
        spider = self.ant.world.get_close_entity("spider", NEST_POSITION, NEST_SIZE)        
        if spider is not None:
            if self.ant.location.get_distance_to(spider.location) < 100.:
                self.ant.spider_id = spider.id
                return "hunting"
        
        return None
    
    def entry_actions(self):
        
        self.ant.speed = 120. + randint(-30, 30)
        self.random_destination()
        
        
class AntStateSeeking(State):
    
    def __init__(self, ant):
        
        State.__init__(self, "seeking")
        self.ant = ant
        self.leaf_id = None
    
    def check_conditions(self):
        
        leaf = self.ant.world.get(self.ant.leaf_id)
        if leaf is None:
            return "exploring"
        
        if self.ant.location.get_distance_to(leaf.location) < 5.0:
        
            self.ant.carry(leaf.image)
            self.ant.world.remove_entity(leaf)
            return "delivering"
        
        return None
    
    def entry_actions(self):
    
        leaf = self.ant.world.get(self.ant.leaf_id)
        if leaf is not None:                        
            self.ant.destination = leaf.location
            self.ant.speed = 160. + randint(-20, 20)
        
        
class AntStateDelivering(State):
    
    def __init__(self, ant):
        
        State.__init__(self, "delivering")
        self.ant = ant
        
        
    def check_conditions(self):
                
        if Vector2(*NEST_POSITION).get_distance_to(self.ant.location) < NEST_SIZE:
            if (randint(1, 10) == 1):
                self.ant.drop(self.ant.world.background)
                return "exploring"
            
        return None
        
        
    def entry_actions(self):
        
        self.ant.speed = 60.        
        random_offset = Vector2(randint(-20, 20), randint(-20, 20))
        self.ant.destination = Vector2(*NEST_POSITION) + random_offset       
       
        
class AntStateHunting(State):
    
    def __init__(self, ant):
        
        State.__init__(self, "hunting")
        self.ant = ant
        self.got_kill = False
        
    def do_actions(self):
        
        spider = self.ant.world.get(self.ant.spider_id)
        
        if spider is None:
            return
            
        self.ant.destination = spider.location
            
        if self.ant.location.get_distance_to(spider.location) < 15.:
            
            if randint(1, 5) == 1:
                spider.bitten()
                
                if spider.health <= 0:
                    self.ant.carry(spider.image)                
                    self.ant.world.remove_entity(spider)
                    self.got_kill = True
                            
        
    def check_conditions(self):
        
        if self.got_kill:
            return "delivering"
        
        spider = self.ant.world.get(self.ant.spider_id)
                        
        if spider is None:
            return "exploring"
        
        if spider.location.get_distance_to(NEST_POSITION) > NEST_SIZE * 3:
            return "exploring"
        
        return None

    def entry_actions(self):
        
        self.speed = 160. + randint(0, 50)

    def exit_actions(self):
        
        self.got_kill = False


    
def run():
    
    pygame.init()
    screen = pygame.display.set_mode(SCREEN_SIZE, 0, 32)
    
    world = World()
    
    w, h = SCREEN_SIZE
    
    clock = pygame.time.Clock()
    
    ant_image = pygame.image.load("ant.png").convert_alpha()
    leaf_image = pygame.image.load("leaf.png").convert_alpha()
    spider_image = pygame.image.load("spider.png").convert_alpha()
    
    for ant_no in xrange(ANT_COUNT):
        
        ant = Ant(world, ant_image)
        ant.location = Vector2(randint(0, w), randint(0, h))
        ant.brain.set_state("exploring")
        world.add_entity(ant)
    
    
    while True:
        
        for event in pygame.event.get():
            if event.type == QUIT:
                return        
        
        time_passed = clock.tick(30)
        
        if randint(1, 10) == 1:
            leaf = Leaf(world, leaf_image)
            leaf.location = Vector2(randint(0, w), randint(0, h))
            world.add_entity(leaf)
            
        if randint(1, 100) == 1:
            spider = Spider(world, spider_image)
            spider.location = Vector2(-50, randint(0, h))
            spider.destination = Vector2(w+50, randint(0, h))            
            world.add_entity(spider)
        
        world.process(time_passed)
        world.render(screen)
        
        pygame.display.update()
    
if __name__ == "__main__":    
    run()