// gencode — 平台方批量生成兑换券（激活码）并写入码池 license_codes。
//
// 用法（在 backend/ 目录下执行，读 config/env 取数据库 DSN）：
//
//	go run ./cmd/gencode -type annual -days 365 -count 100 -batch 2026-summer
//	go run ./cmd/gencode -days 30 -count 10 -note "试用补偿"
//	go run ./cmd/gencode -type lifetime -days 0 -count 1        # 永久授权码
//
// 生成的码以 JIUKU-XXXX-XXXX 格式打印（status=unused），分发给用户在 App 内兑换。
package main

import (
	"flag"
	"fmt"
	stdlog "log"
	"os"
	"time"

	"gorm.io/driver/mysql"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"github.com/wangjia/jiu/backend/config"
	"github.com/wangjia/jiu/backend/internal/model"
	"github.com/wangjia/jiu/backend/internal/util"
)

func main() {
	licType := flag.String("type", "annual", "计费/时长标签：trial|monthly|annual|lifetime")
	tier := flag.String("tier", "standard", "档位（当前仅 standard）")
	days := flag.Int("days", 365, "授予时长（天）；0 = 永久")
	devices := flag.Int("devices", 0, "授予设备上限；0 = 兑换时不改变门店现值")
	count := flag.Int("count", 1, "生成数量")
	batch := flag.String("batch", "", "发放批次/活动名（便于追踪）")
	note := flag.String("note", "", "备注")
	flag.Parse()

	if *count < 1 {
		fmt.Fprintln(os.Stderr, "error: -count 必须 >= 1")
		os.Exit(1)
	}

	config.Load()
	db, err := gorm.Open(mysql.Open(config.C.Database.DSN), &gorm.Config{
		Logger: logger.New(
			stdlog.New(os.Stdout, "\r\n", stdlog.LstdFlags),
			logger.Config{LogLevel: logger.Warn, IgnoreRecordNotFoundError: true},
		),
	})
	if err != nil {
		stdlog.Fatalf("连接数据库失败: %v", err)
	}
	if err := db.AutoMigrate(&model.LicenseCode{}); err != nil {
		stdlog.Fatalf("迁移 license_codes 失败: %v", err)
	}

	display := make([]string, 0, *count)
	for i := 0; i < *count; i++ {
		// 重试避免极小概率的唯一冲突
		var shown string
		for attempt := 0; attempt < 5; attempt++ {
			shown = util.GenerateRedeemCode()
			lc := model.LicenseCode{
				Code:         util.NormalizeCode(shown),
				Type:         *licType,
				Tier:         *tier,
				DurationDays: *days,
				MaxDevices:   *devices,
				Status:       "unused",
				Batch:        *batch,
				Note:         *note,
			}
			err := db.Create(&lc).Error
			if err == nil {
				break
			}
			if attempt == 4 {
				stdlog.Fatalf("写入兑换码失败（连续冲突）: %v", err)
			}
		}
		display = append(display, shown)
	}

	fmt.Printf("\n✅ 已生成 %d 个兑换码（type=%s tier=%s 时长=%d天 设备=%d batch=%q）于 %s：\n\n",
		*count, *licType, *tier, *days, *devices, *batch, time.Now().Format("2006-01-02 15:04:05"))
	for _, c := range display {
		fmt.Println("   " + c)
	}
	fmt.Println()
}