try:
    import langchain

    if langchain.__version__.startswith("1"):
        # Langchain v1 — all imports below are from langchain_core
        from langchain_core.agents import AgentAction, AgentFinish
        from langchain_core.callbacks import (
            BaseCallbackHandler as LangchainBaseCallbackHandler,
        )
        from langchain_core.documents import Document
        from langchain_core.messages import (
            AIMessage, BaseMessage, ChatMessage, FunctionMessage,
            HumanMessage, SystemMessage, ToolMessage,
        )
        from langchain_core.outputs import ChatGeneration, LLMResult
    else:
        # Langchain v0 — uses some langchain.* imports
        ...
except ImportError:
    raise ModuleNotFoundError(
        "Please install langchain to use the Langfuse langchain integration: 'pip install langchain'"
    )

import langchain_core

if langchain_core.__version__.startswith("1"):
    # langchain v1 imports
    from langchain_core.agents import AgentAction, AgentFinish
    from langchain_core.callbacks import (
        BaseCallbackHandler as LangchainBaseCallbackHandler,
    )
    # ... etc, all from langchain_core
else:
    # langchain v0 imports — still need the umbrella package
    try:
        from langchain.callbacks.base import (
            BaseCallbackHandler as LangchainBaseCallbackHandler,
        )
        from langchain.schema.agent import AgentAction, AgentFinish
        from langchain.schema.document import Document
        # ...
    except ImportError:
        raise ModuleNotFoundError(
            "Please install langchain<1.0 to use the legacy Langfuse "
            "langchain integration"
        )