import os
from .clip_encoder import CLIPVisionTower


def build_vision_tower(vision_tower_cfg, **kwargs):
    vision_tower = getattr(vision_tower_cfg, 'mm_vision_tower', getattr(vision_tower_cfg, 'vision_tower', None))

    if vision_tower == 'biovil':
        vision_tower_cfg.mm_hidden_size = 512
        return None
    else:
        is_absolute_path_exists = os.path.exists(vision_tower)
        if is_absolute_path_exists or vision_tower.startswith("openai") or vision_tower.startswith("laion"):
            return CLIPVisionTower(vision_tower, args=vision_tower_cfg, **kwargs)

        raise ValueError(f'Unknown vision tower: {vision_tower}')