package main

import (
	"fmt"
	"log"

	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

const (
	DbDSN = "root:bindbox2025kdy@tcp(150.158.78.154:3306)/dev_game?charset=utf8mb4&parseTime=True&loc=Local"
)

func main() {
	db, err := gorm.Open(mysql.Open(DbDSN), &gorm.Config{})
	if err != nil {
		log.Fatalf("DB connection failed: %v", err)
	}

	fmt.Println("--- Activity-Based Coupon Data Repair Auditor (Cloud DB) ---")

	var records []struct {
		ID            int64
		UserID        int64
		CouponID      int64
		BalanceAmount int64
		Status        int32
		ValidEnd      string
		OriginalValue int64
		DiscountType  int32
	}

	// Fetch all coupons joined with system data
	db.Raw(`
		SELECT uc.id, uc.user_id, uc.coupon_id, uc.balance_amount, uc.status, uc.valid_end, sc.discount_value as original_value, sc.discount_type
		FROM user_coupons uc
		JOIN system_coupons sc ON uc.coupon_id = sc.id
	`).Scan(&records)

	for _, r := range records {
		// Calculate total usage from order_coupons
		var orderUsage int64
		db.Raw("SELECT SUM(applied_amount) FROM order_coupons WHERE user_coupon_id = ?", r.ID).Scan(&orderUsage)

		// Calculate total usage from ledger
		var ledgerUsage int64
		db.Raw("SELECT ABS(SUM(change_amount)) FROM user_coupon_ledger WHERE user_coupon_id = ? AND action = 'apply'", r.ID).Scan(&ledgerUsage)

		// Max usage between sources
		finalUsage := orderUsage
		if ledgerUsage > finalUsage {
			finalUsage = ledgerUsage
		}

		expectedBalance := r.OriginalValue - finalUsage
		if expectedBalance < 0 {
			expectedBalance = 0
		}

		// Determine Correct Status
		// 1: Unused (or Partially Used but still valid)
		// 2: Used (Exhausted)
		// 3: Expired (Unused/Partially Used and time past)

		expectedStatus := r.Status
		if expectedBalance == 0 {
			expectedStatus = 2
		} else {
			// Logic for expired vs unused would go here if needed,
			// but we prioritize "Used" if balance is 0.
			// Currently if balance > 0 and Status is 2, it's definitely an error.
			if r.Status == 2 {
				expectedStatus = 1 // Revert to unused/partial if balance > 0
			}
		}

		if expectedBalance != r.BalanceAmount || expectedStatus != r.Status {
			fmt.Printf("-- Coupon %d (User %d): Bal %d->%d, Status %v->%v, Usage %d/%d\n",
				r.ID, r.UserID, r.BalanceAmount, expectedBalance, r.Status, expectedStatus, finalUsage, r.OriginalValue)
			fmt.Printf("UPDATE user_coupons SET balance_amount = %d, status = %v, updated_at = NOW() WHERE id = %d;\n",
				expectedBalance, expectedStatus, r.ID)
		}
	}
}