#!/bin/env python3

import abc
import dataclasses
import math
import random
import sys
from typing import List

import pygame


# TODO replace with pygame.Rect
@dataclasses.dataclass
class Entity:
    pos: pygame.Vector2
    size: int

    @property
    def top(self) -> int:
        return self.pos.y

    @property
    def bottom(self) -> int:
        return self.pos.y + self.size

    @property
    def left(self) -> int:
        return self.pos.x

    @property
    def right(self) -> int:
        return self.pos.x + self.size

    @abc.abstractmethod
    def draw(self, screen: pygame.Surface) -> None:
        pass


@dataclasses.dataclass
class Food(Entity):
    color: str = "white"
    growth: int = 5
    size: int = 10

    @classmethod
    def new(cls):
        return cls(
            pos=pygame.Vector2(random.randint(0, sw), random.randint(0, sh)),
        )

    def draw(self, screen: pygame.Surface) -> None:
        p = pygame.Vector2(self.pos.x + self.size / 2, self.pos.y + self.size / 2)
        pygame.draw.circle(screen, self.color, p, self.size / 2)


@dataclasses.dataclass
class Man(Entity):
    name: str = None
    speed: float = 500
    color: str = "yellow"
    alive: bool = True
    size: int = 40
    enabled: bool = True

    key_up: int = pygame.K_w
    key_down: int = pygame.K_s
    key_left: int = pygame.K_a
    key_right: int = pygame.K_d

    def handle_input(self, inputs: pygame.key.ScancodeWrapper, dt: float) -> None:
        if self.enabled:
            horz, vert = 0, 0
            if keys[self.key_up]:
                vert = -1
            if keys[self.key_down]:
                vert = 1
            if keys[self.key_left]:
                horz = -1
            if keys[self.key_right]:
                horz = 1
            self.walk(horz, vert)

    def walk(self, horizontal, vertical):
        horizontal = horizontal / abs(horizontal) if horizontal else 0
        vertical = vertical / abs(vertical) if vertical else 0
        mov = self.speed * dt
        if horizontal != 0 and vertical != 0:
            mov = math.sqrt(2 * mov**2) / 2

        self.move(mov * horizontal, mov * vertical)

    def move(self, dx: int, dy: int) -> None:
        self.pos.x += dx
        self.pos.y += dy

    def draw(self, screen: pygame.Surface) -> None:
        p = pygame.Vector2(self.pos.x + self.size / 2, self.pos.y + self.size / 2)
        pygame.draw.circle(screen, self.color, p, self.size / 2)

    def can_eat(self, other: Entity) -> bool:
        overlaps_x = self.left <= other.left and self.right >= other.right
        overlaps_y = self.top <= other.top and self.bottom >= other.bottom
        return overlaps_x and overlaps_y and self.size >= other.size


@dataclasses.dataclass
class AI:
    man: Man = None
    enemies: List[Man] = None
    target = None

    def decide(self):
        if self.man is None:
            return

        target = self.target
        if random.random() * 100 < 10:
            target = None

        if target is None:
            if targets := [e for e in self.enemies or [] if e.size < self.man.size]:
                target = random.choice(targets)

        if target is None:
            target = food

        self.target = target

        horz = (target.pos.x + target.size / 2) - (self.man.pos.x + self.man.size / 2)
        vert = (target.pos.y + target.size / 2) - (self.man.pos.y + self.man.size / 2)
        self.man.walk(horz, vert)

    def hook(self, player):
        player.enabled = False
        self.man = player
        self.target = None
        self.enemies = [p for p in players if p != player]

    def release(self):
        self.man.enabled = True
        self.man = None
        self.target = None
        self.enemies = players


# set up pygame
pygame.init()
pygame.display.set_caption("Maxman")
screen = pygame.display.set_mode([1000, 1000])
clock = pygame.time.Clock()
running = True
paused = True
font = pygame.font.Font("freesansbold.ttf", 32)
space_was_pressed = False
dt = 0

# set up board
sw, sh = screen.get_width(), screen.get_height()
ai = AI()
maxman = Man(pygame.Vector2(sw / 4, sh / 4), name="Maxman")
blackman = Man(
    pygame.Vector2(sw * 0.75, sh * 0.25),
    name="Blackman",
    color="black",
    key_up=pygame.K_i,
    key_down=pygame.K_k,
    key_left=pygame.K_j,
    key_right=pygame.K_l,
)
chrisman = Man(
    pygame.Vector2(sw * 0.25, sh * 0.75),
    name="Chrisman",
    color="red",
    key_up=pygame.K_UP,
    key_down=pygame.K_DOWN,
    key_left=pygame.K_LEFT,
    key_right=pygame.K_RIGHT,
)
manman = Man(
    pygame.Vector2(sw * 0.75, sh * 0.75),
    name="Manman",
    color="green",
    key_up=pygame.K_KP_8,
    key_down=pygame.K_KP_2,
    key_left=pygame.K_KP_4,
    key_right=pygame.K_KP_6,
)
players = [maxman, blackman, chrisman, manman]
food = Food.new()

if any([arg in ["--ai", "-a"] for arg in sys.argv]):
    ai.hook(blackman)

while running:
    # check recent events
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # draw players in order of size
    screen.fill("purple")
    food.draw(screen)
    for p in sorted(players, key=lambda p: p.size):
        p.draw(screen)

    keys = pygame.key.get_pressed()
    if len(players) == 1:
        text = font.render(
            f"{players[0].name} wins",
            True,
            "black",
        )
        text_rect = text.get_rect()
        screen.blit(
            text,
            pygame.Vector2((sw - text_rect.width) / 2, (sh - text_rect.height) / 2),
        )

        if keys[pygame.K_SPACE]:
            running = False

    else:
        for p in players:
            for op in players:
                if p != op and p.can_eat(op):
                    players.remove(op)

            if p.can_eat(food):
                p.size += food.growth
                food = food.new()

        # handle inputs
        if paused:
            text = font.render("Pause", True, "black")
            text_rect = text.get_rect()
            screen.blit(
                text,
                pygame.Vector2((sw - text_rect.width) / 2, (sh - text_rect.height) / 2),
            )

        else:
            ai.decide()
            for p in players:
                p.handle_input(keys, dt)

        if keys[pygame.K_SPACE]:
            if not space_was_pressed:
                paused = not paused
            space_was_pressed = True
        else:
            space_was_pressed = False

    pygame.display.flip()
    dt = clock.tick(100) / 1000

pygame.quit()