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"""VLM modality token-index constants.

Split from the former ``components/utils/constants.py`` in stage 6
(05 §15.10 step 3). These sentinel indexes mark multimodal input/output
positions in VLM label sequences.
"""


# input index
IMAGE_INPUT_INDEX = -200
VIDEO_INPUT_INDEX = -300
AUDIO_INPUT_INDEX = -400
# output index
IMAGE_OUTPUT_INDEX = -201
VIDEO_OUTPUT_INDEX = -301
AUDIO_OUTPUT_INDEX = -401


TYPE2INDEX = {
    "input": {
        "image": IMAGE_INPUT_INDEX,
        "video": VIDEO_INPUT_INDEX,
        "audio": AUDIO_INPUT_INDEX,
    },
    "output": {
        "image": IMAGE_OUTPUT_INDEX,
        "video": VIDEO_OUTPUT_INDEX,
        "audio": AUDIO_OUTPUT_INDEX,
    },
}


MODALITY = TYPE2INDEX["input"].keys() | TYPE2INDEX["output"].keys()