"""LLM configuration for Graphiti MCP Server."""

import argparse
import logging
import os
from typing import TYPE_CHECKING

from openai import AsyncAzureOpenAI
from pydantic import BaseModel
from utils import create_azure_credential_token_provider

from graphiti_core.llm_client import LLMClient
from graphiti_core.llm_client.azure_openai_client import AzureOpenAILLMClient
from graphiti_core.llm_client.config import LLMConfig
from graphiti_core.llm_client.openai_client import OpenAIClient

if TYPE_CHECKING:
    pass

logger = logging.getLogger(__name__)

DEFAULT_LLM_MODEL = 'gpt-4.1-mini'
SMALL_LLM_MODEL = 'gpt-4.1-nano'


class GraphitiLLMConfig(BaseModel):
    """Configuration for the LLM client.

    Centralizes all LLM-specific configuration parameters including API keys and model selection.
    """

    api_key: str | None = None
    model: str = DEFAULT_LLM_MODEL
    small_model: str = SMALL_LLM_MODEL
    temperature: float = 0.0
    azure_openai_endpoint: str | None = None
    azure_openai_deployment_name: str | None = None
    azure_openai_api_version: str | None = None
    azure_openai_use_managed_identity: bool = False

    @classmethod
    def from_env(cls) -> 'GraphitiLLMConfig':
        """Create LLM configuration from environment variables."""
        # Get model from environment, or use default if not set or empty
        model_env = os.environ.get('MODEL_NAME', '')
        model = model_env if model_env.strip() else DEFAULT_LLM_MODEL

        # Get small_model from environment, or use default if not set or empty
        small_model_env = os.environ.get('SMALL_MODEL_NAME', '')
        small_model = small_model_env if small_model_env.strip() else SMALL_LLM_MODEL

        azure_openai_endpoint = os.environ.get('AZURE_OPENAI_ENDPOINT', None)
        azure_openai_api_version = os.environ.get('AZURE_OPENAI_API_VERSION', None)
        azure_openai_deployment_name = os.environ.get('AZURE_OPENAI_DEPLOYMENT_NAME', None)
        azure_openai_use_managed_identity = (
            os.environ.get('AZURE_OPENAI_USE_MANAGED_IDENTITY', 'false').lower() == 'true'
        )

        if azure_openai_endpoint is None:
            # Setup for OpenAI API
            # Log if empty model was provided
            if model_env == '':
                logger.debug(
                    f'MODEL_NAME environment variable not set, using default: {DEFAULT_LLM_MODEL}'
                )
            elif not model_env.strip():
                logger.warning(
                    f'Empty MODEL_NAME environment variable, using default: {DEFAULT_LLM_MODEL}'
                )

            return cls(
                api_key=os.environ.get('OPENAI_API_KEY'),
                model=model,
                small_model=small_model,
                temperature=float(os.environ.get('LLM_TEMPERATURE', '0.0')),
            )
        else:
            # Setup for Azure OpenAI API
            # Log if empty deployment name was provided
            if azure_openai_deployment_name is None:
                logger.error('AZURE_OPENAI_DEPLOYMENT_NAME environment variable not set')
                raise ValueError('AZURE_OPENAI_DEPLOYMENT_NAME environment variable not set')

            if not azure_openai_use_managed_identity:
                # api key
                api_key = os.environ.get('OPENAI_API_KEY', None)
            else:
                # Managed identity
                api_key = None

            return cls(
                azure_openai_use_managed_identity=azure_openai_use_managed_identity,
                azure_openai_endpoint=azure_openai_endpoint,
                api_key=api_key,
                azure_openai_api_version=azure_openai_api_version,
                azure_openai_deployment_name=azure_openai_deployment_name,
                model=model,
                small_model=small_model,
                temperature=float(os.environ.get('LLM_TEMPERATURE', '0.0')),
            )

    @classmethod
    def from_cli_and_env(cls, args: argparse.Namespace) -> 'GraphitiLLMConfig':
        """Create LLM configuration from CLI arguments, falling back to environment variables."""
        # Start with environment-based config
        config = cls.from_env()

        # CLI arguments override environment variables when provided
        if hasattr(args, 'model') and args.model:
            # Only use CLI model if it's not empty
            if args.model.strip():
                config.model = args.model
            else:
                # Log that empty model was provided and default is used
                logger.warning(f'Empty model name provided, using default: {DEFAULT_LLM_MODEL}')

        if hasattr(args, 'small_model') and args.small_model:
            if args.small_model.strip():
                config.small_model = args.small_model
            else:
                logger.warning(f'Empty small_model name provided, using default: {SMALL_LLM_MODEL}')

        if hasattr(args, 'temperature') and args.temperature is not None:
            config.temperature = args.temperature

        return config

    def create_client(self) -> LLMClient:
        """Create an LLM client based on this configuration.

        Returns:
            LLMClient instance
        """
        if self.azure_openai_endpoint is not None:
            # Azure OpenAI API setup
            if self.azure_openai_use_managed_identity:
                # Use managed identity for authentication
                token_provider = create_azure_credential_token_provider()
                return AzureOpenAILLMClient(
                    azure_client=AsyncAzureOpenAI(
                        azure_endpoint=self.azure_openai_endpoint,
                        azure_deployment=self.azure_openai_deployment_name,
                        api_version=self.azure_openai_api_version,
                        azure_ad_token_provider=token_provider,
                    ),
                    config=LLMConfig(
                        api_key=self.api_key,
                        model=self.model,
                        small_model=self.small_model,
                        temperature=self.temperature,
                    ),
                )
            elif self.api_key:
                # Use API key for authentication
                return AzureOpenAILLMClient(
                    azure_client=AsyncAzureOpenAI(
                        azure_endpoint=self.azure_openai_endpoint,
                        azure_deployment=self.azure_openai_deployment_name,
                        api_version=self.azure_openai_api_version,
                        api_key=self.api_key,
                    ),
                    config=LLMConfig(
                        api_key=self.api_key,
                        model=self.model,
                        small_model=self.small_model,
                        temperature=self.temperature,
                    ),
                )
            else:
                raise ValueError('OPENAI_API_KEY must be set when using Azure OpenAI API')

        if not self.api_key:
            raise ValueError('OPENAI_API_KEY must be set when using OpenAI API')

        llm_client_config = LLMConfig(
            api_key=self.api_key, model=self.model, small_model=self.small_model
        )

        # Set temperature
        llm_client_config.temperature = self.temperature

        return OpenAIClient(config=llm_client_config)