from fastapi import FastAPI, HTTPException, BackgroundTasks
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel
from typing import Optional, Dict
from supabase import create_client, Client
import os
import requests
import uuid
import json
import base64
import hashlib
import hmac
import time
import asyncio
import urllib.parse

app = FastAPI(title="Cié Cié Backend API")

# 🌟 解決 CORS (跨域) 問題
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"], 
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# 讀取環境變數 
SUPABASE_URL = os.getenv("SUPABASE_URL", "")
SUPABASE_KEY = os.getenv("SUPABASE_KEY", "") # 必須使用 service_role key
LINE_ACCESS_TOKEN = os.getenv("LINE_ACCESS_TOKEN", "")
BOSS_LINE_ID = os.getenv("BOSS_LINE_ID", "")

# 🌟 LINE Pay 金鑰設定 🌟
LINE_PAY_CHANNEL_ID = os.getenv("LINE_PAY_CHANNEL_ID", "")
LINE_PAY_CHANNEL_SECRET = os.getenv("LINE_PAY_CHANNEL_SECRET", "")
LINE_PAY_BASE_URL = "https://sandbox-api-pay.line.me" 

# 設定結帳後要跳回前端哪裡？ (指向您的 GitHub Pages booking.html)
RETURN_URL = "https://ciecietaipei.github.io/booking.html" 

supabase: Client = create_client(SUPABASE_URL, SUPABASE_KEY) if SUPABASE_URL else None

# --- 資料結構定義 ---
class OrderPayload(BaseModel):
    service_type: str
    name: str
    tel: str
    date: str
    time: str
    line_id: Optional[str] = ""
    pax: int = 2
    cart: Dict[str, int] = {}
    deposit_required: int = 0
    total_amount: int = 0

class ConfirmPayload(BaseModel):
    transaction_id: str
    order_id: str
    amount: int

class RepayPayload(BaseModel):
    order_id: str

# ==========================================
# 🌟 背景自動救援掉單機器人 🌟
# ==========================================
async def auto_rescue_dropped_order(order_id: str, amount: int):
    # 讓程式在背景默默等待 3 分鐘 (180秒)
    await asyncio.sleep(180)
    
    if not supabase: return
    try:
        # 3 分鐘後醒來，去資料庫看這筆訂單的狀態
        res = supabase.table("bookings").select("*").ilike("remarks", f"%{order_id}%").execute()
        if not res.data: return
        
        booking = res.data[0]
        # 如果狀態已經是「已付」或「確認」，代表客人有乖乖跳轉回來，不需要救援
        if "已付" in booking.get("status", "") or "確認" in booking.get("status", ""):
            return
            
        # 🚨 如果還是「待付款」，立刻去敲 LINE Pay 總部的門查帳
        uri = "/v3/payments"
        query_string = urllib.parse.urlencode({"orderId": order_id})
        nonce = str(uuid.uuid4())
        message = LINE_PAY_CHANNEL_SECRET + uri + query_string + nonce
        signature = base64.b64encode(hmac.new(LINE_PAY_CHANNEL_SECRET.encode(), message.encode(), hashlib.sha256).digest()).decode()

        headers = {
            "Content-Type": "application/json", "X-LINE-ChannelId": LINE_PAY_CHANNEL_ID,
            "X-LINE-Authorization-Nonce": nonce, "X-LINE-Authorization": signature
        }
        
        r = requests.get(f"{LINE_PAY_BASE_URL}{uri}?{query_string}", headers=headers)
        res_data = r.json()
        
        if res_data.get("returnCode") == "0000" and res_data.get("info"):
            tx = res_data["info"][0]
            # 🚨 發現掉單！客人付了錢但沒跳轉回來 (卡在 AUTHORIZATION 授權中)
            if tx.get("transactionType") == "AUTHORIZATION":
                transaction_id = tx.get("transactionId")
                
                # 系統自動代客執行 Confirm 請款！
                confirm_uri = f"/v3/payments/{transaction_id}/confirm"
                confirm_nonce = str(uuid.uuid4())
                confirm_body = json.dumps({"amount": amount, "currency": "TWD"})
                confirm_msg = LINE_PAY_CHANNEL_SECRET + confirm_uri + confirm_body + confirm_nonce
                confirm_sig = base64.b64encode(hmac.new(LINE_PAY_CHANNEL_SECRET.encode(), confirm_msg.encode(), hashlib.sha256).digest()).decode()
                
                confirm_headers = {
                    "Content-Type": "application/json", "X-LINE-ChannelId": LINE_PAY_CHANNEL_ID,
                    "X-LINE-Authorization-Nonce": confirm_nonce, "X-LINE-Authorization": confirm_sig
                }
                
                confirm_res = requests.post(f"{LINE_PAY_BASE_URL}{confirm_uri}", headers=confirm_headers, data=confirm_body).json()
                
                if confirm_res.get("returnCode") == "0000":
                    # 救援請款成功！強制更新資料庫狀態
                    supabase.table("bookings").update({"status": "待處理 (已付訂金)"}).eq("id", booking['id']).execute()
                    
                    # 發送【特殊救援通知】給老闆
                    if LINE_ACCESS_TOKEN and BOSS_LINE_ID:
                        msg = f"🌟 【防掉單自動救援成功】🌟\n系統發現客人付完款但提早關閉網頁，已自動完成請款並建立訂單！\n\n👤 姓名：{booking['name']}\n📞 電話：{booking['tel']}\n⏰ 取餐：{booking['date']} {booking['time']}\n💰 成功收回：${amount}\n📝 備註：請至後台查看餐點明細。"
                        headers_line = {"Authorization": f"Bearer {LINE_ACCESS_TOKEN}"}
                        payload_line = {"to": BOSS_LINE_ID, "messages": [{"type": "text", "text": msg}]}
                        requests.post("https://api.line.me/v2/bot/message/push", headers=headers_line, json=payload_line)
    except Exception as e:
        print(f"Auto rescue failed: {e}")


# --- API 端點定義 ---

@app.get("/")
def read_root():
    return {"status": "online", "message": "Cié Cié FastAPI is running."}

@app.post("/api/submit_booking")
async def submit_booking(payload: OrderPayload, background_tasks: BackgroundTasks):
    if not supabase:
        raise HTTPException(status_code=500, detail="資料庫未設定")

    is_noshow = False
    try:
        res = supabase.table("bookings").select("id").eq("tel", payload.tel).eq("status", "No-Show").execute()
        is_noshow = len(res.data) > 0
    except: pass

    final_deposit = payload.deposit_required
    if is_noshow and final_deposit == 0:
        final_deposit = 1000

    if final_deposit > 0:
        order_id = f"ORDER-{uuid.uuid4().hex[:8].upper()}"
        
        request_body = {
            "amount": final_deposit,
            "currency": "TWD",
            "orderId": order_id,
            "packages": [{
                "id": "pkg_1", "amount": final_deposit, "name": "Cié Cié Taipei 預付金",
                "products": [{"name": "餐飲訂金與預付金", "quantity": 1, "price": final_deposit}]
            }],
            "redirectUrls": {
                "confirmUrl": f"{RETURN_URL}?action=payment_confirm&amount={final_deposit}&orderId={order_id}", 
                "cancelUrl": f"{RETURN_URL}?action=payment_cancel"
            }
        }
        
        uri = "/v3/payments/request"
        nonce = str(uuid.uuid4())
        body_str = json.dumps(request_body)
        message = LINE_PAY_CHANNEL_SECRET + uri + body_str + nonce
        signature = base64.b64encode(hmac.new(LINE_PAY_CHANNEL_SECRET.encode(), message.encode(), hashlib.sha256).digest()).decode()

        headers = {
            "Content-Type": "application/json",
            "X-LINE-ChannelId": LINE_PAY_CHANNEL_ID,
            "X-LINE-Authorization-Nonce": nonce,
            "X-LINE-Authorization": signature
        }
        
        try:
            line_pay_res = requests.post(f"{LINE_PAY_BASE_URL}{uri}", headers=headers, data=body_str)
            res_data = line_pay_res.json()
            
            if res_data.get("returnCode") == "0000":
                payment_url = res_data["info"]["paymentUrl"]["web"]
                booking_data = {
                    "name": payload.name, "tel": payload.tel, "date": payload.date, 
                    "time": payload.time, "pax": payload.pax, "user_id": payload.line_id,
                    "status": "待付款", 
                    "remarks": f"類型: {'外帶' if payload.service_type == 'takeout' else '內用'}\n餐點: {payload.cart}\n訂單號: {order_id}"
                }
                supabase.table("bookings").insert(booking_data).execute()

                # 🌟 啟動救援精靈：指派它在背景倒數 3 分鐘後執行檢查 🌟
                background_tasks.add_task(auto_rescue_dropped_order, order_id, final_deposit)

                return {
                    "status": "require_payment", "message": "訂單需支付訂金",
                    "is_noshow_penalty": is_noshow, "deposit_amount": final_deposit,
                    "payment_url": payment_url, "order_id": order_id
                }
            else: raise HTTPException(status_code=500, detail=f"LINE Pay 錯誤: {res_data.get('returnMessage')}")
        except Exception as e: raise HTTPException(status_code=500, detail=f"金流連線失敗: {str(e)}")

    booking_data = {
        "name": payload.name, "tel": payload.tel, "date": payload.date, "time": payload.time,
        "pax": payload.pax, "email": "", "user_id": payload.line_id, "status": "待處理",
        "remarks": f"類型: {'外帶' if payload.service_type == 'takeout' else '內用'}\n餐點: {payload.cart}"
    }
    
    try:
        supabase.table("bookings").insert(booking_data).execute()
        notify_boss(payload.name, payload.tel, payload.date, payload.time, payload.pax, 0)
        return { "status": "success", "message": "訂位已成功建立！" }
    except Exception as e: raise HTTPException(status_code=500, detail=f"寫入資料庫失敗: {str(e)}")


# 確認收錢的端點 (Confirm API)
@app.post("/api/linepay/confirm")
async def confirm_payment(payload: ConfirmPayload):
    uri = f"/v3/payments/{payload.transaction_id}/confirm"
    nonce = str(uuid.uuid4())
    body_str = json.dumps({"amount": payload.amount, "currency": "TWD"})
    message = LINE_PAY_CHANNEL_SECRET + uri + body_str + nonce
    signature = base64.b64encode(hmac.new(LINE_PAY_CHANNEL_SECRET.encode(), message.encode(), hashlib.sha256).digest()).decode()

    headers = {
        "Content-Type": "application/json", "X-LINE-ChannelId": LINE_PAY_CHANNEL_ID,
        "X-LINE-Authorization-Nonce": nonce, "X-LINE-Authorization": signature
    }

    try:
        res = requests.post(f"{LINE_PAY_BASE_URL}{uri}", headers=headers, data=body_str)
        res_data = res.json()

        if res_data.get("returnCode") == "0000":
            update_res = supabase.table("bookings").update({"status": "待處理 (已付訂金)"}).ilike("remarks", f"%{payload.order_id}%").execute()
            if update_res.data:
                b = update_res.data[0]
                notify_boss(b['name'], b['tel'], b['date'], b['time'], b['pax'], payload.amount)

            return {"status": "success", "message": "付款確認成功"}
        else:
            raise HTTPException(status_code=400, detail=res_data.get('returnMessage'))
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

# 處理重新產生付款連結的 API (防呆升級版)
@app.post("/api/linepay/repay")
async def repay_payment(payload: RepayPayload):
    if not supabase: raise HTTPException(status_code=500, detail="資料庫未連線")
    
    try:
        res = supabase.table("bookings").select("*").ilike("remarks", f"%{payload.order_id}%").execute()
        if not res.data: raise HTTPException(status_code=404, detail="找不到該筆訂單")
        
        booking = res.data[0]
        if "已付" in booking.get("status", "") or "確認" in booking.get("status", ""):
            raise HTTPException(status_code=400, detail="此訂單已完成付款或確認，無需重新結帳")

        # 🌟 修改：向 LINE Pay 查詢最初應付的正確金額，避免外帶單只收 1000 元 🌟
        amount = 1000 # 預設防護底線
        try:
            chk_uri = "/v3/payments"
            chk_query = urllib.parse.urlencode({"orderId": payload.order_id})
            chk_nonce = str(uuid.uuid4())
            chk_msg = LINE_PAY_CHANNEL_SECRET + chk_uri + chk_query + chk_nonce
            chk_sig = base64.b64encode(hmac.new(LINE_PAY_CHANNEL_SECRET.encode(), chk_msg.encode(), hashlib.sha256).digest()).decode()
            chk_headers = { "Content-Type": "application/json", "X-LINE-ChannelId": LINE_PAY_CHANNEL_ID, "X-LINE-Authorization-Nonce": chk_nonce, "X-LINE-Authorization": chk_sig }
            chk_res = requests.get(f"{LINE_PAY_BASE_URL}{chk_uri}?{chk_query}", headers=chk_headers).json()
            if chk_res.get("returnCode") == "0000" and chk_res.get("info"):
                # 成功抓出這筆訂單原本設定的金額！
                amount = chk_res["info"][0].get("payInfo", [{}])[0].get("amount", 1000)
        except Exception as e:
            print(f"無法取得原始金額，使用預設值: {e}")

        new_order_id = f"{payload.order_id}-R{int(time.time())}"
        
        request_body = {
            "amount": amount,
            "currency": "TWD",
            "orderId": new_order_id, 
            "packages": [{
                "id": "pkg_repay", "amount": amount, "name": "Cié Cié Taipei 補繳結帳",
                "products": [{"name": "餐飲訂金或外帶全額", "quantity": 1, "price": amount}]
            }],
            "redirectUrls": {
                "confirmUrl": f"{RETURN_URL}?action=payment_confirm&amount={amount}&orderId={payload.order_id}", 
                "cancelUrl": f"{RETURN_URL}?action=payment_cancel"
            }
        }
        
        uri = "/v3/payments/request"
        nonce = str(uuid.uuid4())
        body_str = json.dumps(request_body)
        message = LINE_PAY_CHANNEL_SECRET + uri + body_str + nonce
        signature = base64.b64encode(hmac.new(LINE_PAY_CHANNEL_SECRET.encode(), message.encode(), hashlib.sha256).digest()).decode()

        headers = {
            "Content-Type": "application/json", "X-LINE-ChannelId": LINE_PAY_CHANNEL_ID,
            "X-LINE-Authorization-Nonce": nonce, "X-LINE-Authorization": signature
        }
        
        line_pay_res = requests.post(f"{LINE_PAY_BASE_URL}{uri}", headers=headers, data=body_str)
        res_data = line_pay_res.json()
        
        if res_data.get("returnCode") == "0000":
            return {"payment_url": res_data["info"]["paymentUrl"]["web"]}
        else:
            raise HTTPException(status_code=500, detail=f"LINE Pay 錯誤: {res_data.get('returnMessage')}")
            
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

def notify_boss(name, tel, date, time, pax, amount):
    if not LINE_ACCESS_TOKEN or not BOSS_LINE_ID: return
    msg = f"🔔 【新訂單通知】\n姓名：{name}\n電話：{tel}\n時間：{date} {time}\n人數：{pax}位"
    if amount > 0: msg += f"\n💰 已收到線上付款：${amount}"
    
    headers = {"Authorization": f"Bearer {LINE_ACCESS_TOKEN}"}
    payload = {"to": BOSS_LINE_ID, "messages": [{"type": "text", "text": msg}]}
    try: requests.post("https://api.line.me/v2/bot/message/push", headers=headers, json=payload)
    except: pass

# ==========================================
# 🌟 計算某日庫存與銷量的 API (防護升級版) 🌟
# ==========================================
@app.get("/api/inventory/{query_date}")
async def get_inventory(query_date: str):
    if not supabase: return {}
    try:
        # 找出這天所有的訂單
        res = supabase.table("bookings").select("cart, status").eq("date", query_date).execute()
        sold_counts = {}
        if res.data:
            for b in res.data:
                # 排除已經取消或 No-Show 的訂單，把扣打還給庫存
                if "取消" in b.get("status", "") or "No-Show" in b.get("status", ""):
                    continue
                
                # 🌟 修改：加入型別檢查防護，避免 null 或 字串 引發當機
                cart = b.get("cart")
                if not cart:
                    cart = {}
                elif isinstance(cart, str):
                    try: cart = json.loads(cart)
                    except: cart = {}
                
                # 計算這筆訂單買了什麼
                for item_id, qty in cart.items():
                    try: qty = int(qty)
                    except: qty = 0
                    sold_counts[item_id] = sold_counts.get(item_id, 0) + qty
                    
        return sold_counts 
    except Exception as e:
        print(f"Inventory Error: {e}")
        return {}