"""
LLM Configuration Management API.
[AC-ASA-14, AC-ASA-15, AC-ASA-16, AC-ASA-17, AC-ASA-18] LLM provider management endpoints.
"""

import logging
from typing import Any

from fastapi import APIRouter, Depends, Header, HTTPException

from app.services.llm.factory import (
    LLMProviderFactory,
    get_llm_config_manager,
)

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/admin/llm", tags=["LLM Management"])


def get_tenant_id(x_tenant_id: str = Header(..., alias="X-Tenant-Id")) -> str:
    """Extract tenant ID from header."""
    if not x_tenant_id:
        raise HTTPException(status_code=400, detail="X-Tenant-Id header is required")
    return x_tenant_id


@router.get("/providers")
async def list_providers(
    tenant_id: str = Depends(get_tenant_id),
) -> dict[str, Any]:
    """
    List all available LLM providers.
    [AC-ASA-15] Returns provider list with configuration schemas.
    """
    logger.info(f"[AC-ASA-15] Listing LLM providers for tenant={tenant_id}")

    providers = LLMProviderFactory.get_providers()
    return {
        "providers": [
            {
                "name": p.name,
                "display_name": p.display_name,
                "description": p.description,
                "config_schema": p.config_schema,
            }
            for p in providers
        ],
    }


@router.get("/config")
async def get_config(
    tenant_id: str = Depends(get_tenant_id),
) -> dict[str, Any]:
    """
    Get current LLM configuration.
    [AC-ASA-14] Returns current provider and config.
    """
    logger.info(f"[AC-ASA-14] Getting LLM config for tenant={tenant_id}")

    manager = get_llm_config_manager()
    config = manager.get_current_config()

    masked_config = _mask_secrets(config.get("config", {}))

    return {
        "provider": config["provider"],
        "config": masked_config,
    }


@router.put("/config")
async def update_config(
    body: dict[str, Any],
    tenant_id: str = Depends(get_tenant_id),
) -> dict[str, Any]:
    """
    Update LLM configuration.
    [AC-ASA-16] Updates provider and config with validation.
    """
    provider = body.get("provider")
    config = body.get("config", {})

    logger.info(f"[AC-ASA-16] Updating LLM config for tenant={tenant_id}, provider={provider}")

    if not provider:
        return {
            "success": False,
            "message": "Provider is required",
        }

    try:
        manager = get_llm_config_manager()
        await manager.update_config(provider, config)

        return {
            "success": True,
            "message": f"LLM configuration updated to {provider}",
        }

    except ValueError as e:
        logger.error(f"[AC-ASA-16] Invalid LLM config: {e}")
        return {
            "success": False,
            "message": str(e),
        }


@router.post("/test")
async def test_connection(
    body: dict[str, Any] | None = None,
    tenant_id: str = Depends(get_tenant_id),
) -> dict[str, Any]:
    """
    Test LLM connection.
    [AC-ASA-17, AC-ASA-18] Tests connection and returns response.
    """
    body = body or {}

    test_prompt = body.get("test_prompt", "你好，请简单介绍一下自己。")
    provider = body.get("provider")
    config = body.get("config")

    logger.info(
        f"[AC-ASA-17] Testing LLM connection for tenant={tenant_id}, "
        f"provider={provider or 'current'}"
    )

    manager = get_llm_config_manager()
    result = await manager.test_connection(
        test_prompt=test_prompt,
        provider=provider,
        config=config,
    )

    return result


def _mask_secrets(config: dict[str, Any]) -> dict[str, Any]:
    """Mask secret fields in config for display."""
    masked = {}
    for key, value in config.items():
        if key in ("api_key", "password", "secret"):
            if value:
                masked[key] = f"{str(value)[:4]}***"
            else:
                masked[key] = ""
        else:
            masked[key] = value
    return masked