import os
from fastapi import FastAPI, Request, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from linebot import LineBotApi, WebhookHandler
from linebot.exceptions import InvalidSignatureError
from linebot.models import MessageEvent, TextMessage, TextSendMessage
import logging
from backend.services.nlp_service import NLPService
from backend.services.database_service import DatabaseService
from backend.services.message_router import MessageRouter
from backend.config import settings
from backend.database.connection import test_database_connection

# 設定日誌
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = FastAPI(title="LINE Bot API", version="1.0.0")

# CORS 設定
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# LINE Bot 初始化
line_bot_api = LineBotApi(settings.LINE_CHANNEL_ACCESS_TOKEN)
handler = WebhookHandler(settings.LINE_CHANNEL_SECRET)

# 服務初始化
nlp_service = NLPService()
db_service = DatabaseService()
message_router = MessageRouter()

@app.get("/")
def greet_json():
    return {"Hello": "LINE Bot API is running!"}

@app.get("/health")
def health_check():
    # 檢查資料庫連線
    db_status = "connected" if test_database_connection() else "disconnected"
    
    return {
        "status": "healthy", 
        "message": "LINE Bot API is operational",
        "database": db_status,
        "database_url": f"postgresql://{settings.DB_HOST}:{settings.DB_PORT}/{settings.DB_NAME}"
    }

@app.post("/webhook")
async def callback(request: Request):
    """LINE Bot Webhook 端點"""
    signature = request.headers.get('X-Line-Signature', '')
    body = await request.body()
    
    try:
        handler.handle(body.decode('utf-8'), signature)
    except InvalidSignatureError:
        logger.error("Invalid signature")
        raise HTTPException(status_code=400, detail="Invalid signature")
    
    return {"status": "ok"}

@handler.add(MessageEvent, message=TextMessage)
def handle_message(event):
    """處理 LINE 訊息 - 使用新的路由系統"""
    try:
        user_message = event.message.text
        user_id = event.source.user_id
        
        logger.info(f"收到訊息: {user_message} from {user_id}")
        
        # 使用訊息路由器處理
        response_data = message_router.route_message(user_message, user_id)
        
        # 回覆訊息
        line_bot_api.reply_message(
            event.reply_token,
            TextSendMessage(text=response_data["text"])
        )
        
    except Exception as e:
        logger.error(f"處理訊息時發生錯誤: {str(e)}")
        line_bot_api.reply_message(
            event.reply_token,
            TextSendMessage(text="抱歉，處理您的訊息時發生錯誤，請稍後再試。")
        )

# 新增直接 API 端點
@app.post("/chat")
async def direct_chat(request: dict):
    """直接聊天 API"""
    try:
        message = request.get("message", "")
        user_id = request.get("user_id", "api_user")
        
        if not message:
            return {
                "success": False,
                "error": "訊息內容不能為空"
            }
        
        # 強制使用聊天模式
        result = message_router._handle_chat_mode(message, user_id)
        return result
        
    except Exception as e:
        logger.error(f"直接聊天 API 錯誤: {str(e)}")
        return {
            "success": False,
            "error": str(e),
            "text": "聊天服務暫時無法使用"
        }

@app.post("/search") 
async def direct_search(request: dict):
    """直接搜尋 API"""
    try:
        message = request.get("message", "")
        user_id = request.get("user_id", "api_user")
        
        if not message:
            return {
                "success": False,
                "error": "查詢內容不能為空"
            }
        
        # 強制使用搜尋模式
        result = message_router._handle_search_mode(message, user_id)
        return result
        
    except Exception as e:
        logger.error(f"直接搜尋 API 錯誤: {str(e)}")
        return {
            "success": False,
            "error": str(e),
            "text": "搜尋服務暫時無法使用"
        }

@app.post("/route")
async def smart_route(request: dict):
    """智能路由 API"""
    try:
        message = request.get("message", "")
        user_id = request.get("user_id", "api_user")

        if not message:
            return {
                "success": False,
                "error": "訊息內容不能為空"
            }

        # 使用智能路由
        result = message_router.route_message(message, user_id)
        return result

    except Exception as e:
        logger.error(f"智能路由 API 錯誤: {str(e)}")
        return {
            "success": False,
            "error": str(e),
            "text": "路由服務暫時無法使用"
        }

@app.post("/product-query")
async def product_query(request: dict):
    """專門的商品查詢 API - 使用 Pydantic AI"""
    try:
        message = request.get("message", "")
        user_id = request.get("user_id", "api_user")

        if not message:
            return {
                "success": False,
                "error": "查詢內容不能為空"
            }

        # 直接使用商品查詢服務
        from backend.services.pydantic_ai_service import ProductQueryService
        product_service = ProductQueryService()

        if not product_service.is_available():
            return {
                "success": False,
                "error": "商品查詢服務不可用，請檢查 GROQ_API_KEY 設定",
                "text": "商品查詢服務暫時無法使用"
            }

        result = product_service.process_product_query_sync(message, user_id)
        return result

    except Exception as e:
        logger.error(f"商品查詢 API 錯誤: {str(e)}")
        return {
            "success": False,
            "error": str(e),
            "text": "商品查詢服務暫時無法使用"
        }

@app.get("/stats")
async def get_stats():
    """取得路由統計"""
    try:
        stats = message_router.get_route_statistics()
        return {
            "success": True,
            "data": stats
        }
    except Exception as e:
        logger.error(f"統計 API 錯誤: {str(e)}")
        return {
            "success": False,
            "error": str(e)
        }

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=7860)