import pygame


class FunctionSelector:

    def __init__(self, resources_dir, game_res, functions):
        self.font = pygame.font.Font(resources_dir + '/fonts/5Pts5.ttf', 10)
        self.functions = functions
        self.max_lines = 6  # Max number of lines to be shown on screen at a time.
        self.offset = 0
        self.game_res = game_res

        self.selected = 0
        self.max_index = len(self.functions) - 1
        self.selector = pygame.image.load(resources_dir + '/images/dev_menu/selector.png').convert_alpha()

    def draw(self, surface):
        for i in range(self.max_index + 1):
            text = self.font.render(self.functions[i], False, (0, 0, 0))
            surface.blit(text, (8, (-3 + (i * 6))))
            surface.blit(self.selector, (0, (self.selected * 6)))

    def scroll_down(self):
        self.selected += 1
        if self.selected > self.max_index:
            self.selected = self.max_index

    def scroll_up(self):
        self.selected -= 1
        if self.selected < 0:
            self.selected = 0

    def get_function(self):
        return self.functions[self.selected]