def load_save():
    f = open('data/save_file.txt','r')
    dat = f.read()
    f.close()
    dat = dat.split('\n')
    while len(dat) < 6:
        dat.append('0000000000')
    return dat

def save(dat):
    s = ''
    for line in dat:
        s += line + '\n'
    s = s[:-1]
    f = open('data/save_file.txt','w')
    f.write(s)
    f.close()

def get_progress(dat):
    world = 1
    for line in dat:
        if '0' not in line:
            world += 1
        else:
            break
    return world

def level_select():
    global right_key, left_key, up_key, down_key, select_key
    bg = menu_background()

    tips = ['Jump Off The Sides of a Wall to Prevent Falling',
            'Use WASD or Arrow Key to Move',
            'Use Space-bar or Enter Key to Shoot',
            'Collect Hidden Gems to Gain a Higher Score',
            'Avoid Enemy Projectiles by Jumping']
    tip = random.choice(tips)

    #images
    arrow_img = load_img('arrow')
    level_line_img = load_img('line')
    lock_img = load_img('lock')

    #save file
    save_dat = load_save()
    level_progress = get_progress(save_dat)

    #other stuff
    selected_level = None
    level_target = 0
    level_target = 1
    arrow_timer = 0
    start_level = False

    level_scroll = 300
    white_bar_width = 200
    level_img_fade = [900,'u',1]

    level_count = 2 #Extend to X amount for more levels
    level_amount = 2 #Extend to X amount for more levels
    level_images = []
    for i in range(level_amount):
        level_images.append(load_img('levels/' + str(i+1)))

    #loop
    in_play = True
    while in_play:

        display.fill((0,0,0))
        bg.render(display)
        text_to_show = 'Level ' + str(level_target)
        if selected_level != None:
            text_to_show += '-' + str(level_target+1)
        text.show_text(text_to_show,198-int(get_text_width(text_to_show,1)/2),50,1,9999,font,display)

        arrow_timer += 1
        if arrow_timer == 60:
            arrow_timer = 0
        if selected_level == None:
            display.blit(arrow_img,(195,115+int(arrow_timer/45)))
        text.show_text('Tip: ' + tip,5,240,1,9999,font,display)

        #world stuff
        world_surf = pygame.Surface((400,9))
        for i in range(level_amount-1):
            world_surf.blit(level_line_img,(round(level_scroll,0)+i*50,0))

        world_surf_base = pygame.Surface((400,9))
        world_surf_base.fill((188,183,197))
        pygame.draw.rect(world_surf_base,(248,248,248),pygame.Rect(0,0,white_bar_width,9))
        world_surf.set_colorkey((248,248,248))
        world_surf_base.blit(world_surf,(0,0))
        world_surf_base.set_colorkey((0,0,0))
        display.blit(world_surf_base,(0,100))
        change_rate = ((195-(level_target-1)*50)-level_scroll)/5
        level_scroll += change_rate

        if abs(change_rate) > 1.2:
            white_bar_width += change_rate
        elif white_bar_width < 204:
            white_bar_width += 4
            if white_bar_width > 204:
                white_bar_width = 204
        elif white_bar_width > 204:
            white_bar_width -= 4
            if white_bar_width < 204:
                white_bar_width = 204
        world_img = level_images[level_img_fade[2]-1].copy()
        world_img.set_alpha(level_img_fade[0])

        if level_img_fade[1] == 'u':
            level_img_fade[0] += 25
            if level_img_fade[0] > 255:
                level_img_fade[0] = 255
        else:
            level_img_fade[0] -= 25
            if level_img_fade[0] < 0:
                level_img_fade[0] = 0
                level_img_fade[1] = 'u'
                level_img_fade[2] = level_target
        display.blit(world_img,(186,66))
        if level_target > level_progress:
            display.blit(lock_img,(194,70))

        if start_level == False:
            for event in pygame.event.get():
                if event.type == QUIT:
                    pygame.quit()
                    sys.exit()
                if event.type == KEYDOWN:
                    if event.key == right_key:
                        if selected_level == None:
                            level_target += 1
                            if level_target > level_count:
                                level_target = 1
                            level_img_fade[1] = 'd'
                        else:
                            level_target += 1
                            if level_target > levels[selected_level]-1:
                                level_target = 0
                    if event.key == left_key:
                        if selected_level == None:
                            level_target -= 1
                            if level_target <= 0:
                                level_target = level_count
                            level_img_fade[1] = 'd'
                        else:
                            level_target -= 1
                            if level_target < 0:
                                level_target = levels[selected_level]-1
                    if (event.key == down_key) or (event.key == select_key):
                        if selected_level == None:
                            if event.key == up_key:
                                if start_level == False:
                                    selected_level = None
                    if event.key == K_ESCAPE:
                        in_play = False
            save_dat = load_save()
            level_progress = get_progress(save_dat)


        screen.blit(pygame.transform.scale(display,(WINDOWWIDTH,WINDOWHEIGHT)),(0,0))
        pygame.display.update()
        fps.tick(60)