"""파이썬(Flask) 가맹점 연동 예: 충전 신청 → 결제 팝업 → 웹훅으로 보유금 지급.
GW_URL, GW_API_KEY, GW_WEBHOOK_SECRET, GW_XPUB(B/C) 환경변수. 표는 sqlite 로 단순화."""
import os
import secrets
import sqlite3
from decimal import Decimal

import requests
from flask import Flask, abort, jsonify, request, session

from gateway_sdk import check_order, verify_webhook

GW = os.environ["GW_URL"].rstrip("/")
app = Flask(__name__)
app.secret_key = os.environ["SESSION_SECRET"]
db = sqlite3.connect("shop.db", isolation_level=None, check_same_thread=False)
db.executescript("""
CREATE TABLE IF NOT EXISTS charges(order_id TEXT PRIMARY KEY, user_id TEXT, gw_id TEXT, currency TEXT, amount TEXT,
  status TEXT DEFAULT 'pending', credit TEXT);
CREATE TABLE IF NOT EXISTS credits(event_id TEXT PRIMARY KEY, order_id TEXT, amount TEXT);
CREATE TABLE IF NOT EXISTS balances(user_id TEXT, currency TEXT, amount TEXT DEFAULT '0', PRIMARY KEY(user_id, currency));
""")


@app.post("/charge")
def charge():
    uid = session.get("user_id") or abort(401)
    b = request.get_json(silent=True) or {}
    cur = (b.get("currency") or "KRW").upper()
    oid = f"chg-{uid}-{secrets.token_hex(6)}"
    body = {"order_id": oid, "amount": str(b.get("amount")), "customer_ref": str(uid)}
    if cur != "USDT":
        body["currency"] = cur
    r = requests.post(f"{GW}/v1/orders", json=body, headers={"Authorization": "Bearer " + os.environ["GW_API_KEY"]}, timeout=15)
    if r.status_code != 201:
        return jsonify(error=r.json().get("error", "gateway")), 502
    o = check_order(r.json(), xpub=os.environ["GW_XPUB"])  # 주소가 내 키에서 나온 것인지 (서버 털림 대비)
    db.execute("INSERT INTO charges(order_id,user_id,gw_id,currency,amount) VALUES(?,?,?,?,?)",
               (oid, uid, o["id"], o["currency"], o["fiat_amount"] or o["amount"]))
    return jsonify(id=o["id"])


@app.post("/gw/webhook")
def webhook():
    raw = request.get_data()
    if not verify_webhook(os.environ["GW_WEBHOOK_SECRET"], request.headers, raw):
        abort(400)
    ev = request.get_json()
    o = ev["data"]
    # 받은 만큼 지급: 입금마다 credit_delta 를 웹훅(id)당 한 번 더함 (부족=받은 만큼, 추가=그만큼 더, 초과=넘친 만큼)
    if ev["type"] in ("order.partial", "order.paid") and Decimal(o["credit_delta"]) > 0:
        try:
            db.execute("BEGIN IMMEDIATE")
            if db.execute("INSERT OR IGNORE INTO credits(event_id,order_id,amount) VALUES(?,?,?)",
                          (ev["id"], o["order_id"], o["credit_delta"])).rowcount == 1:
                uid, cur = db.execute("SELECT user_id, currency FROM charges WHERE order_id=?", (o["order_id"],)).fetchone()
                # ponytail: 금액을 문자열로 저장, 실서비스는 정수(원·센트 단위) 열 권장
                old = db.execute("SELECT amount FROM balances WHERE user_id=? AND currency=?", (uid, cur)).fetchone()
                new = Decimal(old[0] if old else "0") + Decimal(o["credit_delta"])
                db.execute("INSERT OR REPLACE INTO balances(user_id,currency,amount) VALUES(?,?,?)", (uid, cur, str(new)))
                db.execute("UPDATE charges SET status=?, credit=? WHERE order_id=?", (o["status"], o["credit"], o["order_id"]))
            db.execute("COMMIT")
        except Exception:
            db.execute("ROLLBACK")
            raise
    elif ev["type"] == "order.expired":
        db.execute("UPDATE charges SET status='expired' WHERE order_id=?", (o["order_id"],))
    return "", 200