From 437bdf46d4ded73981e1e1c9e0fe8ca530668e35 Mon Sep 17 00:00:00 2001
From: HFO4 <912394456@qq.com>
Date: Sat, 1 Feb 2020 10:34:23 +0800
Subject: [PATCH] Feat: thumb for shared folder

---
 pkg/filesystem/file.go       |  7 +++++
 routers/controllers/share.go | 13 +++++++++
 routers/router.go            |  6 ++++
 service/share/visit.go       | 55 ++++++++++++++++++++++++++++++++++++
 4 files changed, 81 insertions(+)

diff --git a/pkg/filesystem/file.go b/pkg/filesystem/file.go
index 8ec5fd0..f17d2a7 100644
--- a/pkg/filesystem/file.go
+++ b/pkg/filesystem/file.go
@@ -311,6 +311,13 @@ func (fs *FileSystem) resetFileIDIfNotExist(ctx context.Context, id uint) error
 		fs.FileTarget = []model.File{file[0]}
 	}
 
+	// 如果上下文限制了父目录，则进行检查
+	if parent, ok := ctx.Value(fsctx.LimitParentCtx).(*model.Folder); ok {
+		if parent.ID != fs.FileTarget[0].FolderID {
+			return ErrObjectNotExist
+		}
+	}
+
 	// 将当前存储策略重设为文件使用的
 	return fs.resetPolicyToFirstFile(ctx)
 }
diff --git a/routers/controllers/share.go b/routers/controllers/share.go
index 326067b..09612f1 100644
--- a/routers/controllers/share.go
+++ b/routers/controllers/share.go
@@ -160,3 +160,16 @@ func ArchiveShare(c *gin.Context) {
 		c.JSON(200, ErrorResponse(err))
 	}
 }
+
+// ShareThumb 获取分享目录下文件的缩略图
+func ShareThumb(c *gin.Context) {
+	var service share.Service
+	if err := c.ShouldBindQuery(&service); err == nil {
+		res := service.Thumb(c)
+		if res.Code >= 0 {
+			c.JSON(200, res)
+		}
+	} else {
+		c.JSON(200, ErrorResponse(err))
+	}
+}
diff --git a/routers/router.go b/routers/router.go
index a6616d8..324f99c 100644
--- a/routers/router.go
+++ b/routers/router.go
@@ -214,6 +214,12 @@ func InitMasterRouter() *gin.Engine {
 				middleware.CheckShareUnlocked(),
 				controllers.PreviewShareReadme,
 			)
+			// 获取缩略图
+			share.GET("thumb/:id/:file",
+				middleware.CheckShareUnlocked(),
+				middleware.ShareCanPreview(),
+				controllers.ShareThumb,
+			)
 		}
 
 		// 需要登录保护的
diff --git a/service/share/visit.go b/service/share/visit.go
index f6a9b31..db1164f 100644
--- a/service/share/visit.go
+++ b/service/share/visit.go
@@ -11,7 +11,9 @@ import (
 	"github.com/HFO4/cloudreve/pkg/util"
 	"github.com/HFO4/cloudreve/service/explorer"
 	"github.com/gin-gonic/gin"
+	"net/http"
 	"path"
+	"strconv"
 )
 
 // ShareGetService 获取分享服务
@@ -219,6 +221,58 @@ func (service *Service) List(c *gin.Context) serializer.Response {
 	}
 }
 
+// Thumb 获取被分享文件的缩略图
+func (service *Service) Thumb(c *gin.Context) serializer.Response {
+	shareCtx, _ := c.Get("share")
+	share := shareCtx.(*model.Share)
+
+	if !share.IsDir {
+		return serializer.ParamErr("此分享无缩略图", nil)
+	}
+
+	// 创建文件系统
+	fs, err := filesystem.NewFileSystem(share.GetCreator())
+	if err != nil {
+		return serializer.Err(serializer.CodePolicyNotAllowed, err.Error(), err)
+	}
+	defer fs.Recycle()
+
+	// 重设根目录
+	fs.Root = share.GetSource().(*model.Folder)
+
+	// 找到缩略图的父目录
+	exist, parent := fs.IsPathExist(service.Path)
+	if !exist {
+		return serializer.Err(serializer.CodeNotFound, "路径不存在", nil)
+	}
+
+	ctx := context.WithValue(context.Background(), fsctx.LimitParentCtx, parent)
+
+	// 获取文件ID
+	fileID, err := strconv.ParseUint(c.Param("file"), 10, 32)
+	if err != nil {
+		return serializer.ParamErr("无法解析文件ID", err)
+	}
+
+	// 获取缩略图
+	resp, err := fs.GetThumb(ctx, uint(fileID))
+	if err != nil {
+		return serializer.Err(serializer.CodeNotSet, "无法获取缩略图", err)
+	}
+
+	if resp.Redirect {
+		c.Header("Cache-Control", fmt.Sprintf("max-age=%d", resp.MaxAge))
+		c.Redirect(http.StatusMovedPermanently, resp.URL)
+		return serializer.Response{Code: -1}
+	}
+
+	defer resp.Content.Close()
+	http.ServeContent(c.Writer, c.Request, "thumb.png", fs.FileTarget[0].UpdatedAt, resp.Content)
+
+	return serializer.Response{Code: -1}
+
+}
+
 // Archive 创建批量下载归档
 func (service *ArchiveService) Archive(c *gin.Context) serializer.Response {
 	shareCtx, _ := c.Get("share")
@@ -251,6 +305,7 @@ func (service *ArchiveService) Archive(c *gin.Context) serializer.Response {
 		return serializer.Err(serializer.CodeNotFound, "路径不存在", nil)
 	}
 
+	// 限制操作范围为父目录下
 	ctx := context.WithValue(context.Background(), fsctx.LimitParentCtx, parent)
 
 	// 用于调下层service