package services

import (
	"fmt"
	"net/url"
	"path/filepath"
	"strings"
	"time"

	"server/models"
)

// FileUploadParams 创建文件记录所需参数
type FileUploadParams struct {
	Source    string // backend / platform
	Scope     string // tenant / user
	Tid       uint64
	Tuid      uint64 // 归属用户，0 表示租户共享
	Uid       uint64 // 上传者
	Name      string
	Ext       string
	Cate      uint64
	Size      uint64
	Src       string
	ObjectKey string
	Storage   string
	MD5       string
}

// FindDuplicate 按「来源端 + 归属范围 + 租户 + 归属用户 + MD5」精确查重。
//
// 规则：
//   - 租户共享文件：同一 tid 内 MD5 相同才算重复（tuid 为 NULL）
//   - 用户个人文件：同一 tid + 同一 tuid 内 MD5 相同才算重复
//   - 因此「租户已有 a 文件」与「用户 c 上传同样文件」互不冲突，可并存
//
// 未命中时返回 (nil, nil)，调用方按 err == nil && file == nil 处理即可。
func FindDuplicate(source, scope string, tid, tuid uint64, md5Str string) (*models.SystemFile, error) {
	if md5Str == "" {
		return nil, nil
	}
	models.EnsureSystemFileStorageColumns()

	qs := models.Orm.QueryTable(new(models.SystemFile)).
		Filter("source", source).
		Filter("scope", scope).
		Filter("tid", tid).
		Filter("md5", md5Str).
		Filter("delete_time__isnull", true)

	if scope == ScopeUser {
		qs = qs.Filter("tuid", tuid)
	} else {
		qs = qs.Filter("tuid__isnull", true)
	}

	var f models.SystemFile
	if err := qs.OrderBy("-id").One(&f); err != nil {
		return nil, nil
	}
	return &f, nil
}

// CreateFileRecord 写入文件记录（同步写入归属与存储字段）
func CreateFileRecord(p FileUploadParams) (uint64, error) {
	models.EnsureSystemFileStorageColumns()

	uid := p.Uid
	row := &models.SystemFile{
		Tid:       p.Tid,
		Uid:       &uid,
		Name:      p.Name,
		Type:      DetectFileType(p.Ext),
		Cate:      p.Cate,
		Size:      p.Size,
		Src:       p.Src,
		Uploader:  p.Uid,
		Md5:       p.MD5,
		Source:    p.Source,
		Scope:     p.Scope,
		Storage:   p.Storage,
		ObjectKey: p.ObjectKey,
	}
	if p.Tuid > 0 {
		tuid := p.Tuid
		row.Tuid = &tuid
	}
	if row.Source == "" {
		row.Source = SourceBackend
	}
	if row.Scope == "" {
		row.Scope = ScopeTenant
	}

	id, err := models.Orm.Insert(row)
	if err != nil {
		return 0, err
	}
	return uint64(id), nil
}

// RemovePhysical 删除物理文件。优先用 object_key，老数据则从 src 反推。
func RemovePhysical(svc StorageService, objectKey, src string) error {
	if svc == nil {
		return fmt.Errorf("存储服务未初始化")
	}
	key := strings.TrimSpace(objectKey)
	if key == "" {
		key = KeyFromSrc(src, svc)
	}
	if key == "" {
		return fmt.Errorf("无法解析文件路径: %s", src)
	}
	return svc.Delete(key)
}

// KeyFromSrc 从访问 URL/相对路径中解析出存储 key（object_key）
func KeyFromSrc(src string, svc StorageService) string {
	src = strings.TrimSpace(src)
	if src == "" {
		return ""
	}
	switch s := svc.(type) {
	case *LocalStorage:
		base := filepath.ToSlash(s.BaseDir)
		rel := src
		if i := strings.Index(rel, base+"/"); i >= 0 {
			rel = rel[i+len(base)+1:]
		}
		rel = strings.TrimPrefix(rel, "/")
		// 去掉可能的查询串
		if i := strings.IndexAny(rel, "?#"); i >= 0 {
			rel = rel[:i]
		}
		return rel
	case *QiniuStorage:
		domain := strings.TrimRight(s.Domain, "/")
		rel := src
		if domain != "" && strings.HasPrefix(rel, domain) {
			rel = strings.TrimPrefix(strings.TrimPrefix(rel, domain), "/")
		} else if u, err := url.Parse(rel); err == nil && u.Host != "" {
			rel = strings.TrimPrefix(u.Path, "/")
		}
		rel = strings.TrimPrefix(rel, "/")
		if i := strings.IndexAny(rel, "?#"); i >= 0 {
			rel = rel[:i]
		}
		return rel
	}
	return ""
}

// 文件类型与扩展名白名单（两端共用同一套规则）
var fileTypeByCategory = map[string]uint8{
	"image":       1,
	"document":    2,
	"video":       3,
	"audio":       4,
	"appsupgrade": 2,
}

var allowedExtByCategory = map[string][]string{
	"image":       {"jpg", "jpeg", "png", "gif", "bmp", "webp"},
	"document":    {"pdf", "doc", "docx", "xls", "xlsx", "ppt", "pptx", "txt"},
	"video":       {"mp4", "webm", "mov"},
	"audio":       {"mp3", "wav", "ogg"},
	"appsupgrade": {"zip", "exe", "dmg", "msi", "msix", "apk", "deb", "rpm", "7z", "tar", "gz", "pkg"},
}

// FileExt 取小写扩展名（不含点）
func FileExt(name string) string {
	name = strings.TrimSpace(name)
	if i := strings.LastIndex(name, "."); i >= 0 && i < len(name)-1 {
		return strings.ToLower(name[i+1:])
	}
	return ""
}

// DetectFileType 根据扩展名推断文件类型：1图片 2文档 3视频 4音频，未匹配返回 2（文档/其他）
func DetectFileType(ext string) uint8 {
	ext = strings.ToLower(strings.TrimPrefix(ext, "."))
	for cat, exts := range allowedExtByCategory {
		for _, e := range exts {
			if e == ext {
				if t, ok := fileTypeByCategory[cat]; ok {
					return t
				}
				return 2
			}
		}
	}
	return 2
}

// SoftDeleteFiles 软删除（标记 delete_time）
func SoftDeleteFiles(ids []uint64) (int64, error) {
	if len(ids) == 0 {
		return 0, nil
	}
	models.EnsureSystemFileStorageColumns()
	return models.Orm.QueryTable(new(models.SystemFile)).
		Filter("id__in", ids).
		Filter("delete_time__isnull", true).
		Update(map[string]interface{}{"delete_time": time.Now()})
}

// DeleteFilesPermanently 彻底删除数据库记录（物理文件由调用方先删）
func DeleteFilesPermanently(ids []uint64) (int64, error) {
	if len(ids) == 0 {
		return 0, nil
	}
	models.EnsureSystemFileStorageColumns()
	return models.Orm.QueryTable(new(models.SystemFile)).
		Filter("id__in", ids).
		Delete()
}