from typing import Any

from pipelex.cogt.exceptions import CogtError
from pipelex.system.configuration.config_model import ConfigModel
from pipelex.system.exceptions import CredentialsError, MissingDependencyError
from pipelex.tools.misc.json_utils import load_json_dict_from_path
from pipelex.tools.misc.placeholder import value_is_placeholder
from pipelex.types import StrEnum


class VertexAIConfigError(CogtError):
    pass


class VertexAICredentialsError(CredentialsError):
    pass


class VertexAIExtraField(StrEnum):
    GCP_PROJECT_ID = "gcp_project_id"
    GCP_LOCATION = "gcp_location"
    GCP_CREDENTIALS_FILE_PATH = "gcp_credentials_file_path"


class VertexAIFactory(ConfigModel):
    @classmethod
    def make_endpoint_and_api_key(
        cls,
        extra_config: dict[str, Any],
    ) -> tuple[str, str]:
        """Configure and return endpoint, and API key."""
        gcp_project_id = extra_config.get(VertexAIExtraField.GCP_PROJECT_ID)
        if not gcp_project_id:
            msg = "GCP project ID is not set in VertexAI config"
            raise VertexAIConfigError(msg)

        gcp_location = extra_config.get(VertexAIExtraField.GCP_LOCATION)
        if not gcp_location:
            msg = "GCP location is not set in VertexAI config"
            raise VertexAIConfigError(msg)

        endpoint = cls._make_endpoint(gcp_project_id=gcp_project_id, gcp_location=gcp_location)

        gcp_credentials_file_path = extra_config.get(VertexAIExtraField.GCP_CREDENTIALS_FILE_PATH)
        if not gcp_credentials_file_path or value_is_placeholder(gcp_credentials_file_path):
            msg = "GCP credentials file path is not properly set for VertexAI."
            raise VertexAIConfigError(msg)

        api_key = cls._make_api_key(gcp_credentials_file_path=gcp_credentials_file_path)

        return endpoint, api_key

    @classmethod
    def _make_endpoint(cls, gcp_project_id: str, gcp_location: str) -> str:
        return f"https://{gcp_location}-aiplatform.googleapis.com/v1beta1/projects/{gcp_project_id}/locations/{gcp_location}/endpoints/openapi"

    @classmethod
    def _make_api_key(cls, gcp_credentials_file_path: str) -> str:
        """Get GCP credentials and return access token."""
        try:
            from google.auth.transport.requests import Request  # noqa: PLC0415
            from google.oauth2.service_account import Credentials  # noqa: PLC0415
        except ImportError as exc:
            lib_name = "google-auth-oauthlib"
            lib_extra_name = "google"
            msg = (
                "The google-auth-oauthlib SDK is required in order to use Google connection. "
                "You can install it with 'uv pip install \"pipelex[google]\"', or use this model via another provider "
                "(such as Azure OpenAI, OpenAI, anthropic or bedrock)."
            )
            raise MissingDependencyError(lib_name, lib_extra_name, msg) from exc

        try:
            credentials_dict: dict[str, Any] = load_json_dict_from_path(path=gcp_credentials_file_path)
        except FileNotFoundError as exc:
            msg = f"Could not get VertexAI credentials from GCP credentials file: File not found: {gcp_credentials_file_path}"
            raise VertexAICredentialsError(msg) from exc

        credentials = Credentials.from_service_account_info(  # pyright: ignore[reportUnknownMemberType]
            credentials_dict,
            scopes=["https://www.googleapis.com/auth/cloud-platform"],
        )
        auth_req = Request()
        credentials.refresh(auth_req)  # pyright: ignore[reportUnknownMemberType]
        if not isinstance(credentials.token, str):  # pyright: ignore[reportUnknownMemberType]
            msg = "Token is not a string"
            raise VertexAICredentialsError(msg)
        return credentials.token
