moredoc/model/download.go

package model

import (
	"fmt"
	v1 "moredoc/api/v1"
	"time"

	"go.uber.org/zap"
	"gorm.io/gorm"
)

type Download struct {
	Id         int64      `form:"id" json:"id,omitempty" gorm:"primaryKey;autoIncrement;column:id;comment:;"`
	UserId     int64      `form:"user_id" json:"user_id,omitempty" gorm:"column:user_id;type:bigint(20);size:20;default:0;index:idx_user_id;comment:下载文档的用户ID;"`
	DocumentId int64      `form:"document_id" json:"document_id,omitempty" gorm:"column:document_id;type:bigint(20);size:20;index:idx_document_id;default:0;comment:被下载的文档ID;"`
	Ip         string     `form:"ip" json:"ip,omitempty" gorm:"column:ip;type:varchar(64);size:64;index:idx_ip;comment:下载文档的用户IP;"`
	IsPay      bool       `form:"is_pay" json:"is_pay,omitempty" gorm:"column:is_pay;type:tinyint(1);size:1;default:0;comment:是否付费下载;"`
	CreatedAt  *time.Time `form:"created_at" json:"created_at,omitempty" gorm:"column:created_at;type:datetime;comment:创建时间;index:idx_created_at"`
	UpdatedAt  *time.Time `form:"updated_at" json:"updated_at,omitempty" gorm:"column:updated_at;type:datetime;comment:更新时间;"`
}

func (Download) TableName() string {
	return tablePrefix + "download"
}

// CreateDownload 创建Download
func (m *DBModel) CreateDownload(download *Download) (err error) {
	tx := m.db.Begin()
	defer func() {
		if err != nil {
			tx.Rollback()
		} else {
			tx.Commit()
		}
	}()

	err = tx.Create(download).Error
	if err != nil {
		m.logger.Error("CreateDownload", zap.Error(err))
		return
	}

	err = tx.Model(&Document{}).Where("id = ?", download.DocumentId).Update("download_count", gorm.Expr("download_count + ?", 1)).Error
	if err != nil {
		m.logger.Error("CreateDownload", zap.Error(err))
		return
	}

	doc, _ := m.GetDocument(download.DocumentId, "id", "user_id", "price")
	if download.IsPay && doc.Price > 0 && download.UserId > 0 {
		// 下载该文档的用户扣除积分
		err = tx.Model(&User{}).Where("id = ?", download.UserId).Update("credit_count", gorm.Expr("credit_count - ?", doc.Price)).Error
		if err != nil {
			m.logger.Error("CreateDownload", zap.Error(err))
			return
		}

		// 文档的作者增加积分
		err = tx.Model(&User{}).Where("id = ?", doc.UserId).Update("credit_count", gorm.Expr("credit_count + ?", doc.Price)).Error
		if err != nil {
			m.logger.Error("CreateDownload", zap.Error(err))
			return
		}
	}
	return
}

// GetDownload 根据id获取Download
func (m *DBModel) GetDownload(id interface{}, fields ...string) (download Download, err error) {
	db := m.db

	fields = m.FilterValidFields(Download{}.TableName(), fields...)
	if len(fields) > 0 {
		db = db.Select(fields)
	}

	err = db.Where("id = ?", id).First(&download).Error
	return
}

type OptionGetDownloadList struct {
	Page      int
	Size      int
	WithCount bool                     // 是否返回总数
	Ids       []interface{}            // id列表
	QueryIn   map[string][]interface{} // map[field][]{value1,value2,...}
}

// GetDownloadList 获取Download列表
func (m *DBModel) GetDownloadList(opt *OptionGetDownloadList) (downloadList []*v1.Download, total int64, err error) {
	var (
		tableDownload = Download{}.TableName()
		tableDocument = Document{}.TableName()
	)

	db := m.db.Model(&Download{})
	db = m.generateQueryIn(db, tableDownload+" "+tableDownload /* 加上表别名，防止字段冲突 */, opt.QueryIn)
	if len(opt.Ids) > 0 {
		db = db.Where(fmt.Sprintf("%s.id in (?)", tableDownload), opt.Ids)
	}

	db = db.Joins(
		fmt.Sprintf(
			"left join %s on %s.document_id = %s.id",
			tableDocument, tableDownload, tableDocument,
		)).
		Where(fmt.Sprintf("%s.id > ?", tableDocument), 0)

	if opt.WithCount {
		err = db.Count(&total).Error
		if err != nil {
			m.logger.Error("GetDownloadList", zap.Error(err))
			return
		}
	}

	// size 为了避免字段冲突，加上了后缀_，即 size_
	db = db.Select(fmt.Sprintf("%s.*, %s.*, %s.size as size_", tableDocument, tableDownload, tableDocument))
	db = db.Order(fmt.Sprintf("%s.id desc", tableDownload))
	db = db.Offset((opt.Page - 1) * opt.Size).Limit(opt.Size)

	err = db.Find(&downloadList).Error
	if err != nil && err != gorm.ErrRecordNotFound {
		m.logger.Error("GetDownloadList", zap.Error(err))
	}
	return
}

// CanIFreeDownload 判断用户是否可以免费下载
// 最后一次付费下载时间 + 免费下载时长 > 当前时间
func (m *DBModel) CanIFreeDownload(userId, documentId int64) bool {
	var download Download
	m.db.Where("user_id = ? and document_id = ? and is_pay = ?", userId, documentId, 1).Last(&download)
	m.logger.Debug("CanIFreeDownload", zap.Any("Last Download", download))
	if download.Id == 0 {
		return false
	}

	cfg := m.GetConfigOfDownload(ConfigDownloadFreeDownloadDuration)
	m.logger.Debug("CanIFreeDownload", zap.Int32("FreeDownloadDuration", cfg.FreeDownloadDuration))
	if cfg.FreeDownloadDuration <= 0 {
		return true
	}
	m.logger.Debug("CanIFreeDownload", zap.Any("CreatedAt", download.CreatedAt), zap.Time("Now", time.Now()), zap.Time("After", download.CreatedAt.Add(time.Duration(cfg.FreeDownloadDuration)*time.Hour*24)))
	return download.CreatedAt.Add(time.Duration(cfg.FreeDownloadDuration) * time.Hour * 24).After(time.Now())
}

// CountDownloadToday 统计用户今日下载次数
func (m *DBModel) CountDownloadTodayForUser(userId int64) (total int64) {
	if userId == 0 {
		return
	}
	err := m.db.Model(&Download{}).Where("user_id = ?", userId).Where("created_at >= ?", time.Now().Format("2006-01-02")).Count(&total).Error
	if err != nil {
		m.logger.Error("CountDownloadToday", zap.Error(err))
	}
	return
}

// CountDownloadToday 统计IP今日下载次数
func (m *DBModel) CountDownloadTodayForIP(ip string) (total int64) {
	if ip == "" {
		return
	}
	err := m.db.Model(&Download{}).Where("ip = ?", ip).Where("created_at >= ?", time.Now().Format("2006-01-02")).Count(&total).Error
	if err != nil {
		m.logger.Error("CountDownloadTodayForIP", zap.Error(err))
	}
	return
}