package pickup

import (
	"bytes"
	"context"
	"encoding/csv"
	"fmt"
	"strings"
	"time"

	"hfb_jysh/backend/internal/auditlog"
	"hfb_jysh/backend/internal/timeutil"

	"gorm.io/gorm"
)

const maxAdminPickupExportRows = 50000

var adminPickupExportHeader = []string{
	"提号编号",
	"账号标题",
	"区服",
	"登录平台",
	"上架编号",
	"卖家手机号",
	"操作人",
	"账号来源",
	"来源渠道",
	"交易渠道",
	"第三方单号",
	"店铺名称",
	"提号备注",
	"下单金额(元)",
	"押金金额(元)",
	"线下利润(元)",
	"结算金额(元)",
	"提号状态",
	"结算状态",
	"创建时间",
	"完成时间",
	"取消时间",
	"完成备注",
}

// ListAdminForExport 按后台列表相同条件查询全部匹配提号，不返回账号快照。
func (r *Repository) ListAdminForExport(ctx context.Context, query AdminPickupQuery) ([]PickupDTO, error) {
	if r == nil || r.db == nil {
		return nil, ErrDependencyUnavailable
	}

	var rows []pickupRow
	db := applyAdminPickupFilters(r.adminPickupExportQuery(ctx), query)
	if err := db.Order("p.id DESC").Limit(maxAdminPickupExportRows + 1).Scan(&rows).Error; err != nil {
		return nil, err
	}
	if len(rows) > maxAdminPickupExportRows {
		return nil, ErrPickupExportTooLarge
	}

	items := make([]PickupDTO, 0, len(rows))
	for _, row := range rows {
		items = append(items, row.toDTO())
	}
	return items, nil
}

// RecordAdminPickupExport 记录敏感数据导出行为。
func (r *Repository) RecordAdminPickupExport(
	ctx context.Context,
	adminID uint64,
	meta auditlog.Meta,
	query AdminPickupQuery,
	rowCount int,
) error {
	if r == nil || r.db == nil {
		return ErrDependencyUnavailable
	}
	return auditlog.Append(r.db.WithContext(ctx), auditlog.Entry{
		ActorType: "admin",
		ActorID:   adminID,
		Action:    "pickup_export",
		BizType:   "admin_pickup",
		Meta:      meta,
		Detail: map[string]any{
			"row_count":                 rowCount,
			"keyword":                   strings.TrimSpace(query.Keyword),
			"status":                    strings.TrimSpace(query.Status),
			"shop_name":                 strings.TrimSpace(query.ShopName),
			"account_source":            strings.TrimSpace(query.AccountSource),
			"offline_settlement_status": strings.TrimSpace(query.OfflineSettlementStatus),
			"operator":                  strings.TrimSpace(query.Operator),
			"third_party_order_no":      strings.TrimSpace(query.ThirdPartyOrderNo),
			"start_time":                formatExportTimePointer(query.StartTime),
			"end_time":                  formatExportTimePointer(query.EndTime),
		},
	})
}

func (r *Repository) adminPickupExportQuery(ctx context.Context) *gorm.DB {
	return r.db.WithContext(ctx).Table("admin_pickups AS p").
		Select(`p.id, p.pickup_no, p.listing_id, p.account_id, p.owner_id, p.admin_id,
			p.operator, p.platform, p.third_party_order_no, p.shop_name, p.raw_shop_name,
			p.account_source, p.source_channel, p.settlement_mode,
			p.order_amount_cent, p.deposit_amount_cent, p.profit_amount_cent, p.settle_amount_cent,
			p.status, p.offline_settlement_status, p.remark, p.complete_remark,
			p.created_at, p.completed_at, p.cancelled_at,
			l.listing_no, a.title AS account_title, a.server_region, a.login_platform, owner.phone AS owner_phone,
			COALESCE((SELECT SUM(fa.profit_delta_cent) FROM admin_pickup_financial_adjustments AS fa WHERE fa.pickup_id = p.id), 0) AS profit_adjustment_cent,
			COALESCE((SELECT SUM(fa.settle_delta_cent) FROM admin_pickup_financial_adjustments AS fa WHERE fa.pickup_id = p.id), 0) AS settle_adjustment_cent`).
		Joins("JOIN rental_listings AS l ON l.id = p.listing_id").
		Joins("JOIN game_accounts AS a ON a.id = p.account_id").
		Joins("JOIN users AS owner ON owner.id = p.owner_id")
}

func buildAdminPickupCSV(items []PickupDTO) ([]byte, error) {
	var buf bytes.Buffer
	buf.WriteString("\xEF\xBB\xBF")

	writer := csv.NewWriter(&buf)
	writer.UseCRLF = true
	if err := writer.Write(adminPickupExportHeader); err != nil {
		return nil, err
	}

	for _, item := range items {
		settleAmount := ""
		if item.Status == StatusCompleted {
			settleAmount = formatExportAmount(item.EffectiveSettleAmountCent)
		}
		record := []string{
			exportCSVText(item.PickupNo),
			exportCSVText(item.AccountTitle),
			exportCSVText(item.ServerRegion),
			exportCSVText(item.LoginPlatform),
			exportCSVText(item.ListingNo),
			exportCSVText(item.OwnerPhone),
			exportCSVText(item.Operator),
			exportAccountSourceLabel(item.AccountSource),
			exportCSVText(item.SourceChannel),
			exportCSVText(item.Platform),
			exportCSVText(item.ThirdPartyOrderNo),
			exportCSVText(item.ShopName),
			exportCSVText(item.Remark),
			formatExportAmount(item.OrderAmountCent),
			formatExportAmount(item.DepositAmountCent),
			formatExportAmount(item.EffectiveProfitAmountCent),
			settleAmount,
			exportPickupStatusLabel(item.Status),
			exportSettlementStatusLabel(item),
			formatExportTime(item.CreatedAt),
			formatExportTimePointer(item.CompletedAt),
			formatExportTimePointer(item.CancelledAt),
			exportCSVText(item.CompleteRemark),
		}
		if err := writer.Write(record); err != nil {
			return nil, err
		}
	}

	writer.Flush()
	if err := writer.Error(); err != nil {
		return nil, err
	}
	return buf.Bytes(), nil
}

func exportCSVText(value string) string {
	if value == "" {
		return ""
	}
	trimmed := strings.TrimLeft(value, " \t\r")
	if trimmed == "" {
		return value
	}
	switch trimmed[0] {
	case '=', '+', '-', '@', '\t', '\r':
		return "'" + value
	default:
		return value
	}
}

func exportPickupStatusLabel(status string) string {
	switch status {
	case StatusPickingUp:
		return "提号中"
	case StatusCompleted:
		return "已完成"
	case StatusCancelled:
		return "已取消"
	default:
		return status
	}
}

func exportAccountSourceLabel(source string) string {
	switch source {
	case AccountSourceExternalPlatformManaged:
		return "外部上传 · 平台代管"
	case AccountSourceInternal:
		return "站内上传"
	default:
		return source
	}
}

func exportSettlementStatusLabel(item PickupDTO) string {
	if item.SettlementMode != SettlementModePlatformManaged {
		return "钱包已结算"
	}
	switch item.OfflineSettlementStatus {
	case OfflineSettlementStatusPending:
		return "待线下结算"
	case OfflineSettlementStatusSettled:
		return "已线下结算"
	default:
		return "待完成提号"
	}
}

func formatExportAmount(cent int64) string {
	if cent < 0 {
		return "-" + formatExportAmount(-cent)
	}
	return fmt.Sprintf("%d.%02d", cent/100, cent%100)
}

func formatExportTime(value time.Time) string {
	if value.IsZero() {
		return ""
	}
	return value.In(timeutil.ShanghaiLocation()).Format("2006-01-02 15:04:05")
}

func formatExportTimePointer(value *time.Time) string {
	if value == nil {
		return ""
	}
	return formatExportTime(*value)
}

func encodeExportFilename(filename string) string {
	var builder strings.Builder
	for _, value := range []byte(filename) {
		if (value >= 'a' && value <= 'z') ||
			(value >= 'A' && value <= 'Z') ||
			(value >= '0' && value <= '9') ||
			value == '-' || value == '_' || value == '.' || value == '~' {
			builder.WriteByte(value)
			continue
		}
		builder.WriteByte('%')
		builder.WriteString(strings.ToUpper(fmt.Sprintf("%02X", value)))
	}
	return builder.String()
}