# Copyright (C) 2020 by ÿnérant, eichhornchen, nicomarg, charlse
# SPDX-License-Identifier: GPL-3.0-or-later

from functools import reduce
from queue import PriorityQueue
from random import randint
from typing import Dict, Tuple

from ..interfaces import FightingEntity, InventoryHolder


class Player(InventoryHolder, FightingEntity):
    """
    The class of the player.
    """
    current_xp: int = 0
    max_xp: int = 10
    paths: Dict[Tuple[int, int], Tuple[int, int]]

    def __init__(self, name: str = "player", maxhealth: int = 20,
                 strength: int = 5, intelligence: int = 1, charisma: int = 1,
                 dexterity: int = 1, constitution: int = 1, level: int = 1,
                 current_xp: int = 0, max_xp: int = 10, inventory: list = None,
                 hazel: int = 42, *args, **kwargs) \
            -> None:
        super().__init__(name=name, maxhealth=maxhealth, strength=strength,
                         intelligence=intelligence, charisma=charisma,
                         dexterity=dexterity, constitution=constitution,
                         level=level, *args, **kwargs)
        self.current_xp = current_xp
        self.max_xp = max_xp
        self.inventory = self.translate_inventory(inventory or [])
        self.paths = dict()
        self.hazel = hazel

    def move(self, y: int, x: int) -> None:
        """
        Moves the view of the map (the point on which the camera is centered)
        according to the moves of the player.
        """
        super().move(y, x)
        self.map.currenty = y
        self.map.currentx = x
        self.recalculate_paths()

    def level_up(self) -> None:
        """
        Add as many levels as possible to the player.
        """
        while self.current_xp > self.max_xp:
            self.level += 1
            self.current_xp -= self.max_xp
            self.max_xp = self.level * 10
            self.health = self.maxhealth
            self.strength = self.strength + 1
            # TODO Remove it, that's only fun
            self.map.spawn_random_entities(randint(3 * self.level,
                                                   10 * self.level))

    def add_xp(self, xp: int) -> None:
        """
        Adds some experience to the player.
        If the required amount is reached, the player levels up.
        """
        self.current_xp += xp
        self.level_up()

    # noinspection PyTypeChecker,PyUnresolvedReferences
    def check_move(self, y: int, x: int, move_if_possible: bool = False) \
            -> bool:
        """
        If the player tries to move but a fighting entity is there,
        the player fights this entity.
        If the entity dies, the player is rewarded with some XP
        """
        # Don't move if we are dead
        if self.dead:
            return False
        for entity in self.map.entities:
            if entity.y == y and entity.x == x:
                if entity.is_fighting_entity():
                    self.map.logs.add_message(self.hit(entity))
                    if entity.dead:
                        self.add_xp(randint(3, 7))
                    return True
                elif entity.is_item():
                    entity.hold(self)
        return super().check_move(y, x, move_if_possible)

    def recalculate_paths(self, max_distance: int = 8) -> None:
        """
        Uses Dijkstra algorithm to calculate best paths for monsters to go to
        the player.
        """
        distances = []
        predecessors = []
        # four Dijkstras, one for each adjacent tile
        for dir_y, dir_x in [(1, 0), (-1, 0), (0, 1), (0, -1)]:
            queue = PriorityQueue()
            new_y, new_x = self.y + dir_y, self.x + dir_x
            if not 0 <= new_y < self.map.height or \
                    not 0 <= new_x < self.map.width or \
                    not self.map.tiles[new_y][new_x].can_walk():
                continue
            queue.put(((1, 0), (new_y, new_x)))
            visited = [(self.y, self.x)]
            distances.append({(self.y, self.x): (0, 0), (new_y, new_x): (1, 0)})
            predecessors.append({(new_y, new_x): (self.y, self.x)})
            while not queue.empty():
                dist, (y, x) = queue.get()
                if dist[0] >= max_distance or (y, x) in visited:
                    continue
                visited.append((y, x))
                for diff_y, diff_x in [(1, 0), (-1, 0), (0, 1), (0, -1)]:
                    new_y, new_x = y + diff_y, x + diff_x
                    if not 0 <= new_y < self.map.height or \
                            not 0 <= new_x < self.map.width or \
                            not self.map.tiles[new_y][new_x].can_walk():
                        continue
                    new_distance = (dist[0] + 1,
                                    dist[1] + (not self.map.is_free(y, x)))
                    if not (new_y, new_x) in distances[-1] or \
                            distances[-1][(new_y, new_x)] > new_distance:
                        predecessors[-1][(new_y, new_x)] = (y, x)
                        distances[-1][(new_y, new_x)] = new_distance
                        queue.put((new_distance, (new_y, new_x)))
        # For each tile that is reached by at least one Dijkstra, sort the
        # different paths by distance to the player. For the technical bits :
        # The reduce function is a fold starting on the first element of the
        # iterable, and we associate the points to their distance, sort
        # along the distance, then only keep the points.
        self.paths = {}
        for y, x in reduce(set.union,
                           [set(p.keys()) for p in predecessors], set()):
            self.paths[(y, x)] = [p for d, p in sorted(
                [(distances[i][(y, x)], predecessors[i][(y, x)])
                 for i in range(len(distances)) if (y, x) in predecessors[i]])]

    def save_state(self) -> dict:
        """
        Saves the state of the entity into a dictionary
        """
        d = super().save_state()
        d["current_xp"] = self.current_xp
        d["max_xp"] = self.max_xp
        return d