"""
API 轉接層 - 偽裝 OpenAI API，將請求轉為人工回覆隊列
"""

from fastapi import FastAPI
from pydantic import BaseModel
import asyncpg
import asyncio
import time
import uuid
import os
from typing import Optional
from datetime import datetime

app = FastAPI()

# 資料庫連接池
db_pool = None

# 資料庫設定
DB_CONFIG = {
    "host": os.getenv("DB_HOST", "postgres"),
    "port": int(os.getenv("DB_PORT", 5432)),
    "database": os.getenv("DB_NAME", "tobiichi"),
    "user": os.getenv("DB_USER", "tobiichi"),
    "password": os.getenv("DB_PASSWORD", "tobiichi_password")
}


class Message(BaseModel):
    role: str
    content: str


class ChatRequest(BaseModel):
    model: str
    messages: list[Message]
    stream: Optional[bool] = False


async def init_db():
    """初始化資料庫連接池和表格"""
    global db_pool
    db_pool = await asyncpg.create_pool(**DB_CONFIG, min_size=2, max_size=10)
    
    # 建立對話隊列表格
    async with db_pool.acquire() as conn:
        await conn.execute("""
            CREATE TABLE IF NOT EXISTS reply_queue (
                id SERIAL PRIMARY KEY,
                conversation_id VARCHAR(50) UNIQUE NOT NULL,
                user_message TEXT NOT NULL,
                admin_reply TEXT,
                status VARCHAR(20) DEFAULT 'pending',
                created_at TIMESTAMP DEFAULT NOW(),
                replied_at TIMESTAMP
            )
        """)
        
        # 建立索引
        await conn.execute("""
            CREATE INDEX IF NOT EXISTS idx_status ON reply_queue(status);
            CREATE INDEX IF NOT EXISTS idx_conversation_id ON reply_queue(conversation_id);
        """)


@app.on_event("startup")
async def startup():
    await init_db()
    print("✅ 資料庫連接成功")


@app.on_event("shutdown")
async def shutdown():
    if db_pool:
        await db_pool.close()


@app.get("/")
async def root():
    return {
        "status": "TobiichiGPT API Running",
        "database": "Connected" if db_pool else "Disconnected"
    }


@app.get("/v1/models")
async def list_models():
    """模擬 OpenAI 模型列表"""
    return {
        "object": "list",
        "data": [{
            "id": "human-admin",
            "object": "model",
            "created": int(time.time()),
            "owned_by": "tobiichi"
        }]
    }


@app.post("/v1/chat/completions")
async def chat_completions(request: ChatRequest):
    """接收用戶訊息，等待管理員回覆"""
    
    # 生成對話 ID
    conv_id = str(uuid.uuid4())[:12]
    
    # 提取用戶訊息
    user_message = ""
    for msg in reversed(request.messages):
        if msg.role == "user":
            user_message = msg.content
            break
    
    if not user_message:
        return {
            "id": f"chatcmpl-{conv_id}",
            "object": "chat.completion",
            "created": int(time.time()),
            "model": request.model,
            "choices": [{
                "index": 0,
                "message": {
                    "role": "assistant",
                    "content": "無法識別您的訊息，請重新輸入。"
                },
                "finish_reason": "stop"
            }]
        }
    
    # 寫入資料庫
    async with db_pool.acquire() as conn:
        await conn.execute("""
            INSERT INTO reply_queue (conversation_id, user_message, status)
            VALUES ($1, $2, 'pending')
        """, conv_id, user_message)
    
    print(f"[新對話 {conv_id}] {user_message[:50]}...")
    
    # 等待管理員回覆（最多 15 分鐘）
    timeout = 900
    start_time = time.time()
    reply_content = None
    
    while time.time() - start_time < timeout:
        async with db_pool.acquire() as conn:
            row = await conn.fetchrow("""
                SELECT admin_reply, status 
                FROM reply_queue 
                WHERE conversation_id = $1
            """, conv_id)
            
            if row and row['status'] == 'replied' and row['admin_reply']:
                reply_content = row['admin_reply']
                print(f"[已回覆 {conv_id}] {reply_content[:50]}...")
                break
        
        await asyncio.sleep(3)  # 每 3 秒檢查一次
    
    # 如果超時
    if not reply_content:
        reply_content = "抱歉，管理員暫時無法回覆，請稍後再試。"
        async with db_pool.acquire() as conn:
            await conn.execute("""
                UPDATE reply_queue 
                SET status = 'timeout' 
                WHERE conversation_id = $1
            """, conv_id)
    
    return {
        "id": f"chatcmpl-{conv_id}",
        "object": "chat.completion",
        "created": int(time.time()),
        "model": request.model,
        "choices": [{
            "index": 0,
            "message": {
                "role": "assistant",
                "content": reply_content
            },
            "finish_reason": "stop"
        }],
        "usage": {
            "prompt_tokens": len(user_message),
            "completion_tokens": len(reply_content) if reply_content else 0,
            "total_tokens": len(user_message) + (len(reply_content) if reply_content else 0)
        }
    }


@app.get("/health")
async def health():
    """健康檢查"""
    db_ok = db_pool is not None
    return {"status": "healthy" if db_ok else "unhealthy", "database": db_ok}


if __name__ == "__main__":
    import uvicorn
    print("=" * 60)
    print("🚀 TobiichiGPT API 啟動中...")
    print("=" * 60)
    print(f"📊 資料庫: {DB_CONFIG['host']}:{DB_CONFIG['port']}/{DB_CONFIG['database']}")
    print(f"🌐 API 端點: http://0.0.0.0:8000/v1")
    print("=" * 60)
    
    uvicorn.run(app, host="0.0.0.0", port=8000)