import pygame as pg
import json
from enemy import Enemy
from world import World
from turret import Turret
from button import Button
import constants as c

#initialise pygame
pg.init()

#create clock
clock = pg.time.Clock()

#create game window
screen = pg.display.set_mode((c.SCREEN_WIDTH + c.SIDE_PANEL, c.SCREEN_HEIGHT))
pg.display.set_caption("Tower Defence")

#game variables
last_enemy_spawn = pg.time.get_ticks()
placing_turrets = False
selected_turret = None

#load images
#map
map_image = pg.image.load('levels/level.png').convert_alpha()
#turret spritesheets
turret_spritesheets = []
for x in range(1, c.TURRET_LEVELS + 1):
  turret_sheet = pg.image.load(f'assets/images/turrets/turret_{x}.png').convert_alpha()
  turret_spritesheets.append(turret_sheet)
#individual turret image for mouse cursor
cursor_turret = pg.image.load('assets/images/turrets/cursor_turret.png').convert_alpha()
#enemies
enemy_images = {
  "weak": pg.image.load('assets/images/enemies/enemy_1.png').convert_alpha(),
  "medium": pg.image.load('assets/images/enemies/enemy_2.png').convert_alpha(),
  "strong": pg.image.load('assets/images/enemies/enemy_3.png').convert_alpha(),
  "elite": pg.image.load('assets/images/enemies/enemy_4.png').convert_alpha()
}
#buttons
buy_turret_image = pg.image.load('assets/images/buttons/buy_turret.png').convert_alpha()
cancel_image = pg.image.load('assets/images/buttons/cancel.png').convert_alpha()
upgrade_turret_image = pg.image.load('assets/images/buttons/upgrade_turret.png').convert_alpha()

#load json data for level
with open('levels/level.tmj') as file:
  world_data = json.load(file)

#load fonts for displaying text on the screen
text_font = pg.font.SysFont("Consolas", 24, bold = True)
large_font = pg.font.SysFont("Consolas", 36)

#function for outputting text onto the screen
def draw_text(text, font, text_col, x, y):
  img = font.render(text, True, text_col)
  screen.blit(img, (x, y))

def create_turret(mouse_pos):
  mouse_tile_x = mouse_pos[0] // c.TILE_SIZE
  mouse_tile_y = mouse_pos[1] // c.TILE_SIZE
  #calculate the sequential number of the tile
  mouse_tile_num = (mouse_tile_y * c.COLS) + mouse_tile_x
  #check if that tile is grass
  if world.tile_map[mouse_tile_num] == 7:
    #check that there isn't already a turret there
    space_is_free = True
    for turret in turret_group:
      if (mouse_tile_x, mouse_tile_y) == (turret.tile_x, turret.tile_y):
        space_is_free = False
    #if it is a free space then create turret
    if space_is_free == True:
      new_turret = Turret(turret_spritesheets, mouse_tile_x, mouse_tile_y)
      turret_group.add(new_turret)
      #deduct cost of turret
      world.money -= c.BUY_COST

def select_turret(mouse_pos):
  mouse_tile_x = mouse_pos[0] // c.TILE_SIZE
  mouse_tile_y = mouse_pos[1] // c.TILE_SIZE
  for turret in turret_group:
    if (mouse_tile_x, mouse_tile_y) == (turret.tile_x, turret.tile_y):
      return turret

def clear_selection():
  for turret in turret_group:
    turret.selected = False

#create world
world = World(world_data, map_image)
world.process_data()
world.process_enemies()

#create groups
enemy_group = pg.sprite.Group()
turret_group = pg.sprite.Group()

#create buttons
turret_button = Button(c.SCREEN_WIDTH + 30, 120, buy_turret_image, True)
cancel_button = Button(c.SCREEN_WIDTH + 50, 180, cancel_image, True)
upgrade_button = Button(c.SCREEN_WIDTH + 5, 180, upgrade_turret_image, True)

#game loop
run = True
while run:

  clock.tick(c.FPS)

  #########################
  # UPDATING SECTION
  #########################

  #update groups
  enemy_group.update(world)
  turret_group.update(enemy_group)

  #highlight selected turret
  if selected_turret:
    selected_turret.selected = True

  #########################
  # DRAWING SECTION
  #########################

  screen.fill("grey100")

  #draw level
  world.draw(screen)

  #draw groups
  enemy_group.draw(screen)
  for turret in turret_group:
    turret.draw(screen)

  draw_text(str(world.health), text_font, "grey100", 0, 0)
  draw_text(str(world.money), text_font, "grey100", 0, 30)

  #spawn enemies
  if pg.time.get_ticks() - last_enemy_spawn > c.SPAWN_COOLDOWN:
    if world.spawned_enemies < len(world.enemy_list):
      enemy_type = world.enemy_list[world.spawned_enemies]
      enemy = Enemy(enemy_type, world.waypoints, enemy_images)
      enemy_group.add(enemy)
      world.spawned_enemies += 1
      last_enemy_spawn = pg.time.get_ticks()

  #draw buttons
  #button for placing turrets
  if turret_button.draw(screen):
    placing_turrets = True
  #if placing turrets then show the cancel button as well
  if placing_turrets == True:
    #show cursor turret
    cursor_rect = cursor_turret.get_rect()
    cursor_pos = pg.mouse.get_pos()
    cursor_rect.center = cursor_pos
    if cursor_pos[0] <= c.SCREEN_WIDTH:
      screen.blit(cursor_turret, cursor_rect)
    if cancel_button.draw(screen):
      placing_turrets = False
  #if a turret is selected then show the upgrade button
  if selected_turret:
    #if a turret can be upgraded then show the upgrade button
    if selected_turret.upgrade_level < c.TURRET_LEVELS:
      if upgrade_button.draw(screen):
        if world.money >= c.UPGRADE_COST:
          selected_turret.upgrade()
          world.money -= c.UPGRADE_COST

  #event handler
  for event in pg.event.get():
    #quit program
    if event.type == pg.QUIT:
      run = False
    #mouse click
    if event.type == pg.MOUSEBUTTONDOWN and event.button == 1:
      mouse_pos = pg.mouse.get_pos()
      #check if mouse is on the game area
      if mouse_pos[0] < c.SCREEN_WIDTH and mouse_pos[1] < c.SCREEN_HEIGHT:
        #clear selected turrets
        selected_turret = None
        clear_selection()
        if placing_turrets == True:
          #check if there is enough money for a turret
          if world.money >= c.BUY_COST:
            create_turret(mouse_pos)
        else:
          selected_turret = select_turret(mouse_pos)

  #update display
  pg.display.flip()

pg.quit()