package exporter

import (
	"context"
	"strconv"

	"gorm.io/gorm"

	"github.com/break/junhong_cmp_fiber/internal/model"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
)

// DeviceDataSource 设备导出数据源。
type DeviceDataSource struct {
	db *gorm.DB
}

// NewDeviceDataSource 创建设备导出数据源。
func NewDeviceDataSource(db *gorm.DB) *DeviceDataSource {
	return &DeviceDataSource{db: db}
}

// Scene 返回导出场景编码。
func (s *DeviceDataSource) Scene() string {
	return constants.ExportTaskSceneDevice
}

// Count 统计设备导出行数。
func (s *DeviceDataSource) Count(ctx context.Context, params ExportParams) (int, error) {
	var total int64
	query := s.applyFilters(s.db.WithContext(ctx).Model(&model.Device{}), params)
	if err := query.Count(&total).Error; err != nil {
		return 0, err
	}
	return int(total), nil
}

// Headers 返回设备导出表头。
func (s *DeviceDataSource) Headers(ctx context.Context, params ExportParams) ([]string, error) {
	return []string{"ID", "设备虚拟号", "设备名称", "设备型号", "设备类型", "状态", "店铺ID", "创建时间"}, nil
}

// Fetch 按 offset/limit 查询设备导出数据。
func (s *DeviceDataSource) Fetch(ctx context.Context, params ExportParams, offset, limit int) ([][]string, error) {
	if limit <= 0 {
		return [][]string{}, nil
	}

	var devices []model.Device
	query := s.applyFilters(s.db.WithContext(ctx).Model(&model.Device{}), params).
		Order("id ASC").
		Limit(limit).
		Offset(offset)
	if err := query.Find(&devices).Error; err != nil {
		return nil, err
	}

	rows := make([][]string, 0, len(devices))
	for _, item := range devices {
		rows = append(rows, []string{
			strconv.FormatUint(uint64(item.ID), 10),
			item.VirtualNo,
			item.DeviceName,
			item.DeviceModel,
			item.DeviceType,
			strconv.Itoa(item.Status),
			formatOptionalUint(item.ShopID),
			item.CreatedAt.Format(exportTimeLayout),
		})
	}
	return rows, nil
}

func (s *DeviceDataSource) applyFilters(query *gorm.DB, params ExportParams) *gorm.DB {
	query = applyExportShopScope(query, params, "shop_id")

	if status, ok := filterInt(params.Filters, "status"); ok {
		query = query.Where("status = ?", status)
	}
	if shopID, ok := filterUint(params.Filters, "shop_id"); ok {
		query = query.Where("shop_id = ?", shopID)
	}
	if start, ok := filterTime(params.Filters, "created_at_start"); ok {
		query = query.Where("created_at >= ?", start)
	}
	if end, ok := filterTime(params.Filters, "created_at_end"); ok {
		query = query.Where("created_at <= ?", end)
	}
	return query
}