package repository

import (
	"time"

	"gorm.io/gorm"

	"filestoragesystem/internal/model"
)

// FileListFilter 文件列表过滤条件
type FileListFilter struct {
	UserID     uint
	ProjectID  uint
	Filename   string // 模糊匹配
	Prefix     string // 虚拟目录前缀
	Trashed    bool   // 查询回收站
	Visibility int8   // 0为不过滤
	Page       int
	PageSize   int
}

// FileRepo 文件数据访问
type FileRepo struct{ DB *gorm.DB }

func (r *FileRepo) Create(f *model.File) error { return r.DB.Create(f).Error }

func (r *FileRepo) FindByID(id uint) (*model.File, error) {
	var f model.File
	err := r.DB.First(&f, id).Error
	return &f, err
}

// List 分页查询文件
func (r *FileRepo) List(filter FileListFilter) ([]model.File, int64, error) {
	q := r.DB.Model(&model.File{})
	if filter.UserID > 0 {
		q = q.Where("user_id = ?", filter.UserID)
	}
	if filter.ProjectID > 0 {
		q = q.Where("project_id = ?", filter.ProjectID)
	}
	if filter.Filename != "" {
		q = q.Where("filename LIKE ?", "%"+filter.Filename+"%")
	}
	if filter.Prefix != "" {
		q = q.Where("(filename = ? OR filename LIKE ?)", filter.Prefix, filter.Prefix+"/%")
	}
	if filter.Trashed {
		q = q.Where("status = 0")
	} else {
		q = q.Where("status = 1")
	}
	if filter.Visibility > 0 {
		q = q.Where("visibility = ?", filter.Visibility)
	}
	var total int64
	if err := q.Count(&total).Error; err != nil {
		return nil, 0, err
	}
	var files []model.File
	err := q.Preload("Project").Order("id DESC").
		Offset((filter.Page - 1) * filter.PageSize).Limit(filter.PageSize).Find(&files).Error
	return files, total, err
}

func (r *FileRepo) Update(f *model.File) error { return r.DB.Save(f).Error }

// SoftDelete 软删除(进入回收站)
func (r *FileRepo) SoftDelete(id uint) error {
	now := time.Now()
	return r.DB.Model(&model.File{}).Where("id = ?", id).
		Updates(map[string]interface{}{"status": 0, "deleted_at": now}).Error
}

// Restore 从回收站恢复
func (r *FileRepo) Restore(id uint) error {
	return r.DB.Model(&model.File{}).Where("id = ?", id).
		Updates(map[string]interface{}{"status": 1, "deleted_at": nil}).Error
}

func (r *FileRepo) Delete(id uint) error { return r.DB.Delete(&model.File{}, id).Error }

// CountByStoredPath 统计引用同一物理文件的记录数(用于去重删除)
func (r *FileRepo) CountByStoredPath(storedPath string) (int64, error) {
	var n int64
	err := r.DB.Model(&model.File{}).Where("stored_path = ?", storedPath).Count(&n).Error
	return n, err
}

// FindByMD5AndPath 基于MD5查找可复用的物理文件记录
func (r *FileRepo) FindByMD5AndPath(md5 string) (*model.File, error) {
	var f model.File
	err := r.DB.Where("md5 = ? AND stored_path != ''", md5).Order("id ASC").First(&f).Error
	return &f, err
}

// ListByProject 项目下所有文件(用于项目删除级联)
func (r *FileRepo) ListByProject(projectID uint) ([]model.File, error) {
	var files []model.File
	err := r.DB.Where("project_id = ?", projectID).Find(&files).Error
	return files, err
}

// ListByUser 用户所有文件(用于用户删除级联)
func (r *FileRepo) ListByUser(userID uint) ([]model.File, error) {
	var files []model.File
	err := r.DB.Where("user_id = ?", userID).Find(&files).Error
	return files, err
}

// StatsByProject 项目文件统计
func (r *FileRepo) StatsByProject(projectID uint) (count int64, size int64, err error) {
	var res struct {
		Count int64 `json:"count"`
		Size  int64 `json:"size"`
	}
	err = r.DB.Model(&model.File{}).
		Where("project_id = ? AND status = 1", projectID).
		Select("COUNT(*) as count, COALESCE(SUM(size),0) as size").
		Scan(&res).Error
	return res.Count, res.Size, err
}

// StatsByUser 用户文件统计
func (r *FileRepo) StatsByUser(userID uint) (count int64, size int64, err error) {
	var res struct {
		Count int64 `json:"count"`
		Size  int64 `json:"size"`
	}
	err = r.DB.Model(&model.File{}).
		Where("user_id = ? AND status = 1", userID).
		Select("COUNT(*) as count, COALESCE(SUM(size),0) as size").
		Scan(&res).Error
	return res.Count, res.Size, err
}

// IncrDownloadCount 下载计数
func (r *FileRepo) IncrDownloadCount(id uint) error {
	return r.DB.Model(&model.File{}).Where("id = ?", id).
		UpdateColumn("download_count", gorm.Expr("download_count + 1")).Error
}

// ---- 临时链接 ----

// TempLinkRepo 临时链接数据访问
type TempLinkRepo struct{ DB *gorm.DB }

func (r *TempLinkRepo) Create(l *model.TempLink) error { return r.DB.Create(l).Error }

func (r *TempLinkRepo) FindByToken(token string) (*model.TempLink, error) {
	var l model.TempLink
	err := r.DB.Where("token = ?", token).First(&l).Error
	return &l, err
}

func (r *TempLinkRepo) IncrUsed(id uint) error {
	return r.DB.Model(&model.TempLink{}).Where("id = ?", id).
		UpdateColumn("used_count", gorm.Expr("used_count + 1")).Error
}

func (r *TempLinkRepo) DeleteByFile(fileID uint) error {
	return r.DB.Where("file_id = ?", fileID).Delete(&model.TempLink{}).Error
}

// ---- 流量日志 ----

// TrafficRepo 流量日志数据访问
type TrafficRepo struct{ DB *gorm.DB }

func (r *TrafficRepo) Create(t *model.TrafficLog) error { return r.DB.Create(t).Error }

// DailyStats 按天/类型聚合流量
func (r *TrafficRepo) DailyStats(userID uint, days int) ([]map[string]interface{}, error) {
	var rows []map[string]interface{}
	err := r.DB.Model(&model.TrafficLog{}).
		Select("date(created_at) as date, type, COALESCE(SUM(size),0) as size, COUNT(*) as count").
		Where("user_id = ? AND created_at >= date('now', ?)", userID, "-"+itoa(days)+" day").
		Group("date(created_at), type").
		Order("date DESC").
		Find(&rows).Error
	return rows, err
}

// SumByUser 汇总用户上传/下载流量
func (r *TrafficRepo) SumByUser(userID uint, days int) (upload, download int64, err error) {
	var res []struct {
		Type int64 `json:"type"`
		Size int64 `json:"size"`
	}
	q := r.DB.Model(&model.TrafficLog{}).
		Select("type, COALESCE(SUM(size),0) as size").
		Where("user_id = ?", userID)
	if days > 0 {
		q = q.Where("created_at >= date('now', ?)", "-"+itoa(days)+" day")
	}
	err = q.Group("type").Scan(&res).Error
	for _, r := range res {
		if r.Type == 1 {
			upload = r.Size
		} else if r.Type == 2 {
			download = r.Size
		}
	}
	return upload, download, err
}

func itoa(n int) string {
	if n == 0 {
		return "0"
	}
	var buf [12]byte
	i := len(buf)
	for n > 0 {
		i--
		buf[i] = byte('0' + n%10)
		n /= 10
	}
	return string(buf[i:])
}