import os
import sys

matformer_root = os.getenv("MATFORMER_ROOT")
if matformer_root:
    matformer_root = os.path.abspath(os.path.expanduser(matformer_root))
    if matformer_root not in sys.path:
        sys.path.insert(0, matformer_root)

try:
    from matformer.modelling_matformer import (
        MatformerForCausalLM,
        MatformerForSequenceClassification,
        MatformerModel,
        MatformerConfig,
        register_matformer
    )
    register_matformer()
except ImportError as e:
    raise ImportError(
        "To use this model, please install the Matformer library: "
        "`pip install matformer`\\n"
        "Alternatively, set the `MATFORMER_ROOT` environment variable to a local clone:\\n"
        "  export MATFORMER_ROOT=/path/to/matformer"
    ) from e