"""Default providers when no model backend is configured — AI features are off.

They fail loudly (rather than silently doing nothing) so a caller that reaches
for an unconfigured capability gets a clear, actionable error.
"""

from app.integrations.models.base import (
    EmbeddingProvider,
    LLMProvider,
    ModelProviderNotConfigured,
)

_MSG = (
    "No model provider configured. Set MODEL_PROVIDER (e.g. 'anthropic') and the "
    "provider's credentials to enable AI features."
)


class NullLLMProvider(LLMProvider):
    async def complete(self, *, prompt: str, system: str | None = None) -> str:
        raise ModelProviderNotConfigured(_MSG)


class NullEmbeddingProvider(EmbeddingProvider):
    dimensions = 0

    async def embed(self, texts: list[str]) -> list[list[float]]:
        raise ModelProviderNotConfigured(
            "No embedding provider configured. Set EMBEDDING_PROVIDER and its "
            "credentials to enable match ranking."
        )