// rebate-backfill 为「线下提号」补发邀请返利（一次性运维脚本，可安全重复执行）。
//
// 背景：线下提号（admin_pickups）不走正常订单结账流程，历史上未接入邀请返利结算，
// 导致已完成提号单的号主邀请人拿不到分成。代码侧已在 pickup.Complete 内接入，
// 本脚本用于补齐「接入前已完成」的历史提号单；仍在进行中的提号单会在完成时自动发放。
//
// 幂等：写入 (source='pickup', order_id, trade_role='seller') 唯一键，
// 且候选集已排除已有提号返利记录的单据，重复执行不会重复发放。
//
// 口径：单边基数 = 提号利润对半（profit_amount_cent / 2），与租赁订单卖家侧一致；
// 比例阶梯按提号完成时刻距今（被邀请人实名生效）的档位计算。
//
// 用法（默认预演，不写库）：
//
//	go run ./cmd/rebate-backfill                      # 预演，只列待补发单据
//	go run ./cmd/rebate-backfill -apply               # 实际补发
//	go run ./cmd/rebate-backfill -apply -pickup-no PK20261011113459355
package main

import (
	"flag"
	"fmt"
	"log"
	"strings"
	"time"

	"hfb_sys/backend/internal/config"
	"hfb_sys/backend/internal/database"
	"hfb_sys/backend/internal/logging"
	"hfb_sys/backend/internal/model"
	"hfb_sys/backend/internal/modules/invitation"
	"hfb_sys/backend/internal/modules/pickup"
	"hfb_sys/backend/pkg/money"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

type candidate struct {
	ID               uint64
	PickupNo         string
	OwnerID          uint64
	ProfitAmountCent int64
	CompletedAt      *time.Time
	ListingSiteID    *uint64
}

func main() {
	apply := flag.Bool("apply", false, "实际执行补发（默认仅预演）")
	pickupNo := flag.String("pickup-no", "", "仅处理指定提号单号")
	limit := flag.Int("limit", 0, "最多处理条数，0 表示不限制")
	flag.Parse()

	cfg := config.Load()
	logger, err := logging.New(cfg.Log)
	if err != nil {
		log.Fatalf("初始化日志失败: %v", err)
	}
	defer func() {
		_ = logger.Sync()
	}()

	db, err := database.OpenMySQLWithOptions(cfg.MySQLDSN, cfg.Log.Level, logger, database.MySQLOptions{})
	if err != nil {
		log.Fatalf("连接数据库失败: %v", err)
	}

	rows, err := loadCandidates(db, *pickupNo, *limit)
	if err != nil {
		log.Fatalf("查询待补发提号单失败: %v", err)
	}
	if len(rows) == 0 {
		fmt.Println("没有需要补发的提号单：已完成提号单均已覆盖或不存在生效邀请关系。")
		return
	}

	mode := "预演"
	if *apply {
		mode = "实际补发"
	}
	fmt.Printf("模式=%s，候选提号单=%d\n", mode, len(rows))

	var paidCount, skippedCount int
	var paidCent int64
	for _, row := range rows {
		completedAt := time.Now()
		if row.CompletedAt != nil {
			completedAt = *row.CompletedAt
		}
		siteID := uint64(0)
		if row.ListingSiteID != nil {
			siteID = *row.ListingSiteID
		}

		if !*apply {
			fmt.Printf("[预演] %s 号主=%d 利润=%s 单边基数=%s 完成于=%s\n",
				row.PickupNo, row.OwnerID,
				money.FormatWithSymbol(row.ProfitAmountCent),
				money.FormatWithSymbol(row.ProfitAmountCent/2),
				completedAt.Format("2006-01-02 15:04:05"))
			continue
		}

		amountCent, err := backfillOne(db, row.ID, siteID, completedAt)
		if err != nil {
			log.Printf("补发失败 %s: %v", row.PickupNo, err)
			continue
		}
		if amountCent <= 0 {
			skippedCount++
			fmt.Printf("[跳过] %s 未产生返利（无生效邀请 / 邀请人未实名 / 返利已关闭 / 已存在记录）\n", row.PickupNo)
			continue
		}
		paidCount++
		paidCent += amountCent
		fmt.Printf("[补发] %s 返利 %s 已入邀请人钱包\n", row.PickupNo, money.FormatWithSymbol(amountCent))
	}

	if *apply {
		fmt.Printf("完成：补发 %d 单，合计 %s；跳过 %d 单。\n",
			paidCount, money.FormatWithSymbol(paidCent), skippedCount)
	}
}

func loadCandidates(db *gorm.DB, pickupNo string, limit int) ([]candidate, error) {
	query := db.Table("admin_pickups AS p").
		Select(`p.id, p.pickup_no, p.owner_id, p.profit_amount_cent, p.completed_at,
			l.distribution_site_id AS listing_site_id`).
		Joins("JOIN user_invitations i ON i.invitee_id = p.owner_id AND i.status = ? AND i.inviter_id <> p.owner_id", invitation.StatusActive).
		Joins("LEFT JOIN rental_listings l ON l.id = p.listing_id").
		Where("p.status = ?", pickup.StatusCompleted).
		Where("p.profit_amount_cent > 0").
		Where(`NOT EXISTS (
			SELECT 1 FROM invitation_rebate_ledgers r
			WHERE r.source = ? AND r.order_id = p.id AND r.trade_role = 'seller'
		)`, invitation.RebateSourcePickup).
		Order("p.completed_at ASC")

	if trimmed := strings.TrimSpace(pickupNo); trimmed != "" {
		query = query.Where("p.pickup_no = ?", trimmed)
	}
	if limit > 0 {
		query = query.Limit(limit)
	}

	var rows []candidate
	if err := query.Scan(&rows).Error; err != nil {
		return nil, err
	}
	return rows, nil
}

// backfillOne 在独立事务内为单张提号单补发返利并返回实际发放金额（分）。
func backfillOne(db *gorm.DB, pickupID uint64, siteID uint64, completedAt time.Time) (int64, error) {
	var amountCent int64
	err := db.Transaction(func(tx *gorm.DB) error {
		var record model.AdminPickup
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).First(&record, pickupID).Error; err != nil {
			return err
		}
		if record.Status != pickup.StatusCompleted {
			return nil
		}
		amount, err := invitation.AwardSellerSideRebateTx(tx, invitation.SellerSideRebateInput{
			Source:          invitation.RebateSourcePickup,
			SourceID:        record.ID,
			SourceNo:        record.PickupNo,
			SellerID:        record.OwnerID,
			GrossBasisCent:  record.ProfitAmountCent,
			BasisCent:       record.ProfitAmountCent / 2,
			SiteID:          siteID,
			RateReferenceAt: completedAt,
			SettledAt:       time.Now(),
			RemarkPrefix:    "邀请卖家提号返利",
		})
		if err != nil {
			return err
		}
		amountCent = amount
		return nil
	})
	return amountCent, err
}