from typing import Dict, Optional

from litellm._logging import verbose_router_logger
from litellm.secret_managers.main import get_secret_str
from litellm.types.llms.vertex_ai import VERTEX_CREDENTIALS_TYPES
from litellm.types.passthrough_endpoints.vertex_ai import VertexPassThroughCredentials


class PassthroughEndpointRouter:
    """
    Use this class to Set/Get credentials for pass-through endpoints
    """

    def __init__(self):
        self.credentials: Dict[str, str] = {}
        self.deployment_key_to_vertex_credentials: Dict[
            str, VertexPassThroughCredentials
        ] = {}
        self.default_vertex_config: Optional[VertexPassThroughCredentials] = None

    def set_pass_through_credentials(
        self,
        custom_llm_provider: str,
        api_base: Optional[str],
        api_key: Optional[str],
    ):
        """
        Set credentials for a pass-through endpoint. Used when a user adds a pass-through LLM endpoint on the UI.

        Args:
            custom_llm_provider: The provider of the pass-through endpoint
            api_base: The base URL of the pass-through endpoint
            api_key: The API key for the pass-through endpoint
        """
        credential_name = self._get_credential_name_for_provider(
            custom_llm_provider=custom_llm_provider,
            region_name=self._get_region_name_from_api_base(
                api_base=api_base, custom_llm_provider=custom_llm_provider
            ),
        )
        if api_key is None:
            raise ValueError("api_key is required for setting pass-through credentials")
        self.credentials[credential_name] = api_key

    def get_credentials(
        self,
        custom_llm_provider: str,
        region_name: Optional[str],
    ) -> Optional[str]:
        credential_name = self._get_credential_name_for_provider(
            custom_llm_provider=custom_llm_provider,
            region_name=region_name,
        )
        verbose_router_logger.debug(
            f"Pass-through llm endpoints router, looking for credentials for {credential_name}"
        )
        if credential_name in self.credentials:
            verbose_router_logger.debug(f"Found credentials for {credential_name}")
            return self.credentials[credential_name]
        else:
            verbose_router_logger.debug(
                f"No credentials found for {credential_name}, looking for env variable"
            )
            _env_variable_name = (
                self._get_default_env_variable_name_passthrough_endpoint(
                    custom_llm_provider=custom_llm_provider,
                )
            )
            return get_secret_str(_env_variable_name)

    def _get_vertex_env_vars(self) -> VertexPassThroughCredentials:
        """
        Helper to get vertex pass through config from environment variables

        The following environment variables are used:
        - DEFAULT_VERTEXAI_PROJECT (project id)
        - DEFAULT_VERTEXAI_LOCATION (location)
        - DEFAULT_GOOGLE_APPLICATION_CREDENTIALS (path to credentials file)
        """
        return VertexPassThroughCredentials(
            vertex_project=get_secret_str("DEFAULT_VERTEXAI_PROJECT"),
            vertex_location=get_secret_str("DEFAULT_VERTEXAI_LOCATION"),
            vertex_credentials=get_secret_str("DEFAULT_GOOGLE_APPLICATION_CREDENTIALS"),
        )

    def set_default_vertex_config(self, config: Optional[dict] = None):
        """Sets vertex configuration from provided config and/or environment variables

        Args:
            config (Optional[dict]): Configuration dictionary
            Example: {
                "vertex_project": "my-project-123",
                "vertex_location": "us-central1",
                "vertex_credentials": "os.environ/GOOGLE_CREDS"
            }
        """
        # Initialize config dictionary if None
        if config is None:
            self.default_vertex_config = self._get_vertex_env_vars()
            return

        if isinstance(config, dict):
            for key, value in config.items():
                if isinstance(value, str) and value.startswith("os.environ/"):
                    config[key] = get_secret_str(value)

        self.default_vertex_config = VertexPassThroughCredentials(**config)

    def add_vertex_credentials(
        self,
        project_id: str,
        location: str,
        vertex_credentials: VERTEX_CREDENTIALS_TYPES,
    ):
        """
        Add the vertex credentials for the given project-id, location
        """

        deployment_key = self._get_deployment_key(
            project_id=project_id,
            location=location,
        )
        if deployment_key is None:
            verbose_router_logger.debug(
                "No deployment key found for project-id, location"
            )
            return
        vertex_pass_through_credentials = VertexPassThroughCredentials(
            vertex_project=project_id,
            vertex_location=location,
            vertex_credentials=vertex_credentials,
        )
        self.deployment_key_to_vertex_credentials[deployment_key] = (
            vertex_pass_through_credentials
        )

    def _get_deployment_key(
        self, project_id: Optional[str], location: Optional[str]
    ) -> Optional[str]:
        """
        Get the deployment key for the given project-id, location
        """
        if project_id is None or location is None:
            return None
        return f"{project_id}-{location}"

    def get_vertex_credentials(
        self, project_id: Optional[str], location: Optional[str]
    ) -> Optional[VertexPassThroughCredentials]:
        """
        Get the vertex credentials for the given project-id, location
        """
        deployment_key = self._get_deployment_key(
            project_id=project_id,
            location=location,
        )

        if deployment_key is None:
            return self.default_vertex_config
        if deployment_key in self.deployment_key_to_vertex_credentials:
            return self.deployment_key_to_vertex_credentials[deployment_key]
        else:
            return self.default_vertex_config

    def _get_credential_name_for_provider(
        self,
        custom_llm_provider: str,
        region_name: Optional[str],
    ) -> str:
        if region_name is None:
            return f"{custom_llm_provider.upper()}_API_KEY"
        return f"{custom_llm_provider.upper()}_{region_name.upper()}_API_KEY"

    def _get_region_name_from_api_base(
        self,
        custom_llm_provider: str,
        api_base: Optional[str],
    ) -> Optional[str]:
        """
        Get the region name from the API base.

        Each provider might have a different way of specifying the region in the API base - this is where you can use conditional logic to handle that.
        """
        if custom_llm_provider == "assemblyai":
            if api_base and "eu" in api_base:
                return "eu"
        return None

    @staticmethod
    def _get_default_env_variable_name_passthrough_endpoint(
        custom_llm_provider: str,
    ) -> str:
        return f"{custom_llm_provider.upper()}_API_KEY"