import math
import random
from copy import deepcopy
from random import randrange
from typing import List

import numpy as np
import numpy.typing as npt

from common import Position, get_islands, AREAS_TO_CROSS, find_neighbours, get_tiles_positions
from const import *


class Genome:
    grid: npt.NDArray
    knights_red: List[Position]
    knights_blue: List[Position]
    waters: List[Position]
    trees: List[Position]
    sands: List[Position]
    monsters: List[Position]
    fitness: int
    sand_islands: List[Position]
    tree_islands: List[Position]
    water_islands: List[Position]

    def __init__(self):
        self.grid = np.zeros((ROWS, COLUMNS), dtype=int)
        self.fitness = 0

        self.knights_red = spawn_objects_in_given_area(
            grid=self.grid,
            object_alias=MAP_ALIASES.get("KNIGHT_RED"),
            objects_count=KNIGHTS_PER_TEAM_COUNT,
            spawn_position_start=Position(row=LEFT_KNIGHTS_SPAWN_FIRST_ROW, col=LEFT_KNIGHTS_SPAWN_FIRST_COL),
            width=KNIGHTS_SPAWN_WIDTH,
            height=KNIGHTS_SPAWN_HEIGHT
        )

        self.knights_blue = spawn_objects_in_given_area(
            grid=self.grid,
            object_alias=MAP_ALIASES.get("KNIGHT_BLUE"),
            objects_count=KNIGHTS_PER_TEAM_COUNT,
            spawn_position_start=Position(row=RIGHT_KNIGHTS_SPAWN_FIRST_ROW, col=RIGHT_KNIGHTS_SPAWN_FIRST_COL),
            width=KNIGHTS_SPAWN_WIDTH,
            height=KNIGHTS_SPAWN_HEIGHT
        )

        spawn_objects_in_given_area(
            grid=self.grid,
            object_alias=MAP_ALIASES.get("CASTLE"),
            objects_count=4,
            spawn_position_start=Position(row=CASTLE_SPAWN_FIRST_ROW, col=CASTLE_SPAWN_FIRST_COL),
            width=2,
            height=2
        )

        self.waters = spawn_objects_in_given_area(grid=self.grid, object_alias=MAP_ALIASES.get("WATER"),
                                                  objects_count=WATER_COUNT)
        self.trees = spawn_objects_in_given_area(grid=self.grid, object_alias=MAP_ALIASES.get("TREE"),
                                                 objects_count=TREE_COUNT)
        self.sands = spawn_objects_in_given_area(grid=self.grid, object_alias=MAP_ALIASES.get("SAND"),
                                                 objects_count=SAND_COUNT)
        self.monsters = spawn_objects_in_given_area(grid=self.grid, object_alias=MAP_ALIASES.get("MONSTER"),
                                                    objects_count=MONSTERS_COUNT)

        self.sand_islands = get_islands(self.grid, self.sands)
        self.tree_islands = get_islands(self.grid, self.trees)
        self.water_islands = get_islands(self.grid, self.waters)

    def update_map(self):
        self.sands, self.trees, self.waters, self.monsters = get_tiles_positions(self.grid)

        self.sand_islands = get_islands(self.grid, self.sands)
        self.tree_islands = get_islands(self.grid, self.trees)
        self.water_islands = get_islands(self.grid, self.waters)

    def calc_fitness(self):
        score = SAND_COUNT + TREE_COUNT + WATER_COUNT
        score = score - len(self.sand_islands) - len(self.tree_islands) - len(self.water_islands)

        sands, trees, waters, monsters = get_tiles_positions(self.grid)

        if len(monsters) != MONSTERS_COUNT:
            self.fitness = 0
            return

        if len(sands) < SAND_COUNT or len(trees) < TREE_COUNT or len(waters) < WATER_COUNT:
            self.fitness = 5
            return

        self.fitness = score

    def crossover(self, partner):
        # replace a randomly selected part of the grid with partner's part
        child = Genome()
        child.grid = deepcopy(self.grid)
        area_to_cross = random.choice(AREAS_TO_CROSS)

        for row in range(area_to_cross.position.row, area_to_cross.position.row + area_to_cross.height):
            for col in range(area_to_cross.position.col, area_to_cross.position.col + area_to_cross.width):
                child.grid[row][col] = partner.grid[row][col]

        child.update_map()

        return child

    def mutate(self, mutation_rate: float):
        # remove 1 item from a random island and add a neighbor to another island
        if random.random() < mutation_rate:

            # select islands of the same, random type
            islands_of_same_type = random.choice([self.sand_islands, self.tree_islands, self.water_islands])
            random_index = random.randint(0, len(islands_of_same_type) - 1)
            island = islands_of_same_type[random_index]
            next_island = islands_of_same_type[(random_index + 1) % len(islands_of_same_type)]

            free_tiles_nearby = find_neighbours(self.grid, next_island.col, next_island.row)

            tile_type = self.grid[island.row][island.col]
            self.grid[island.row][island.col] = MAP_ALIASES.get('GRASS')

            # todo: if there are no free tiles around then randomize another next_island
            if len(free_tiles_nearby) > 0:
                random_free_tile = random.choice(free_tiles_nearby)
                island.row = random_free_tile.row
                island.col = random_free_tile.col
                self.grid[island.row][island.col] = tile_type

                self.update_map()


def is_empty(grid: npt.NDArray, position: Position) -> bool:
    return grid[position.row, position.col] in [MAP_ALIASES.get("GRASS"), MAP_ALIASES.get("SAND")]


def is_invalid_area(spawn_position_start, height, width) -> bool:
    return spawn_position_start.row + height - 1 < 0 or \
           spawn_position_start.row + height - 1 >= ROWS or \
           spawn_position_start.col + width - 1 < 0 or \
           spawn_position_start.col + width - 1 >= COLUMNS


def spawn_objects_in_given_area(grid: npt.NDArray,
                                object_alias: str,
                                objects_count: int = 1,
                                spawn_position_start: Position = Position(row=0, col=0),
                                width: int = COLUMNS,
                                height: int = ROWS) -> List[Position]:
    if is_invalid_area(spawn_position_start, height, width):
        raise ValueError("Invalid spawn area")

    objects_remaining = int(objects_count)
    positions = []

    while objects_remaining > 0:
        row = randrange(spawn_position_start.row, spawn_position_start.row + height)
        col = randrange(spawn_position_start.col, spawn_position_start.col + width)
        position = Position(row=row, col=col)

        if is_empty(grid=grid, position=position):
            grid[position.row, position.col] = object_alias
            positions.append(position)
            objects_remaining -= 1

    return positions