import pygame
import numpy as np
from scripts.utils import to_isometric_pixel

class Entity:
    def __init__(self, game, e_type, pos, size):
        self.game = game
        self.type = e_type
        self.pos = np.array(pos)
        self.size = np.array(size)
        self.velocity = np.array([0,0], dtype=np.float32)
    def update(self, tilemap, movement = np.array([0,0])):
        frame_movement = self.velocity + movement
        self.pos[0] += frame_movement[0]
        entity_rect = self.rect()
        for rect in tilemap.physics_rects_around(self.pos):
            if entity_rect.colliderect(rect):
                if frame_movement[0] > 0: #i was moving right
                    entity_rect.right = rect.left
                if frame_movement[0] < 0: #i was moving left
                    entity_rect.left = rect.right
                self.pos[0] = entity_rect.x
        self.pos[1] += frame_movement[1]
        entity_rect = self.rect()
        for rect in tilemap.physics_rects_around(self.pos):
            if entity_rect.colliderect(rect):
                if frame_movement[1] > 0: #i was moving down
                    entity_rect.bottom = rect.top
                if frame_movement[1] < 0: #i was moving up
                    entity_rect.top = rect.bottom
                self.pos[1] = entity_rect.y
    def render(self, surface, offset = np.array([0.,0.])):
        surface.blit(self.game.assets[self.type], to_isometric_pixel(self.pos-np.array([48,80]))*np.array([1,0.5])-offset)
    def rect(self):
        return pygame.Rect(self.pos, self.size)

class Partner(Entity):
    def __init__(self, game, pos, size):
        super().__init__(game, 'partner', pos, size)
        self.player = game.player  #player a cui è linkato
    def update(self):
        R = 50
        player_pos = self.player.pos
        if np.linalg.norm(player_pos-self.pos) <= R:
            return
        a = np.stack([player_pos, self.pos])
        if np.linalg.det(a) == 0:
            line_coeffs = np.append(np.linalg.lstsq(a,np.array([[0.0],[0.0]]),rcond=None)[0],0)
        else:
            line_coeffs = np.append(np.linalg.lstsq(a,np.array([[1.0],[1.0]]),rcond=None)[0],1)
        if np.abs(line_coeffs[1])<1e-7:
            P3 = np.array([self.pos[0], player_pos[1] + R])  #np.sqrt(R ** 2 - (x - player_pos[0]) ** 2)
            P4 = np.array([self.pos[0], player_pos[1] - R])
            theta = 0
            delta = 0
        else:
            m = - line_coeffs[0] / line_coeffs[1]
            theta = np.arctan(m)
            delta = R * np.array([np.cos(theta),np.sin(theta)])
            P3 = player_pos + delta
            P4 = player_pos - delta
        P = (P3 if (np.linalg.norm(P3-self.pos) < np.linalg.norm(P4-self.pos)) else P4)
        #super().update(tilemap, P - self.pos) #nice idea but sometimes gets blocked and needs to tp to the player
        self.pos = P

class GroupEntities:
    def __init__(self, game, entities):
        self.game = game
        self.entities = entities #sorted(entities, key=(lambda x: x.pos[1]))
    def add_entity(self, entity):
        self.entities.append(entity)
    #def update()
    def render(self, surface, offset=np.array([0.,0.])):
        self.entities.sort(key = (lambda x: x.pos[1]))
        for entity in self.entities:
            entity.render(surface, offset)