From 1ff4d5997848df7a8373d7ff93adabe28eb787bd Mon Sep 17 00:00:00 2001
From: HFO4 <912394456@qq.com>
Date: Tue, 28 Jan 2020 13:40:19 +0800
Subject: [PATCH] Feat: preview shared file

---
 routers/controllers/share.go | 24 +++++++++++++++++
 routers/controllers/user.go  |  6 +++++
 routers/router.go            |  7 ++++-
 service/explorer/file.go     |  5 ++++
 service/share/visit.go       | 51 +++++++++++++++++++++++++++++++-----
 5 files changed, 85 insertions(+), 8 deletions(-)

diff --git a/routers/controllers/share.go b/routers/controllers/share.go
index 6845f5a..6d18bf8 100644
--- a/routers/controllers/share.go
+++ b/routers/controllers/share.go
@@ -1,6 +1,7 @@
 package controllers
 
 import (
+	"context"
 	"github.com/HFO4/cloudreve/service/share"
 	"github.com/gin-gonic/gin"
 )
@@ -37,3 +38,26 @@ func GetShareDownload(c *gin.Context) {
 		c.JSON(200, ErrorResponse(err))
 	}
 }
+
+// PreviewShare 预览分享文件内容
+func PreviewShare(c *gin.Context) {
+	// 创建上下文
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	var service share.SingleFileService
+	if err := c.ShouldBindUri(&service); err == nil {
+		res := service.PreviewContent(ctx, c, false)
+		// 是否需要重定向
+		if res.Code == -301 {
+			c.Redirect(301, res.Data.(string))
+			return
+		}
+		// 是否有错误发生
+		if res.Code != 0 {
+			c.JSON(200, res)
+		}
+	} else {
+		c.JSON(200, ErrorResponse(err))
+	}
+}
diff --git a/routers/controllers/user.go b/routers/controllers/user.go
index 268b296..0e75ffe 100644
--- a/routers/controllers/user.go
+++ b/routers/controllers/user.go
@@ -116,6 +116,12 @@ func UserLogin(c *gin.Context) {
 
 }
 
+// UserSignOut 用户退出登录
+func UserSignOut(c *gin.Context) {
+	util.DeleteSession(c, "user_id")
+	c.JSON(200, serializer.Response{})
+}
+
 // UserMe 获取当前登录的用户
 func UserMe(c *gin.Context) {
 	currUser := CurrentUser(c)
diff --git a/routers/router.go b/routers/router.go
index a2c1d1e..00aa1bd 100644
--- a/routers/router.go
+++ b/routers/router.go
@@ -171,9 +171,11 @@ func InitMasterRouter() *gin.Engine {
 		share := v3.Group("share")
 		{
 			// 获取分享
-			share.GET(":id", controllers.GetShare)
+			share.GET("info/:id", controllers.GetShare)
 			// 创建文件下载会话
 			share.POST("download/:id", controllers.GetShareDownload)
+			// 预览分享文件
+			share.GET("preview/:id", controllers.PreviewShare)
 		}
 
 		// 需要登录保护的
@@ -185,7 +187,10 @@ func InitMasterRouter() *gin.Engine {
 			{
 				// 当前登录用户信息
 				user.GET("me", controllers.UserMe)
+				// 存储信息
 				user.GET("storage", controllers.UserStorage)
+				// 退出登录
+				user.DELETE("session", controllers.UserSignOut)
 
 				// WebAuthn 注册相关
 				authn := user.Group("authn")
diff --git a/service/explorer/file.go b/service/explorer/file.go
index 40c00d0..065950d 100644
--- a/service/explorer/file.go
+++ b/service/explorer/file.go
@@ -218,6 +218,11 @@ func (service *SingleFileService) PreviewContent(ctx context.Context, c *gin.Con
 	}
 	defer fs.Recycle()
 
+	// 如果上下文中已有File对象，则重设目标
+	if file, ok := ctx.Value(fsctx.FileModelCtx).(*model.File); ok {
+		fs.SetTargetFile(&[]model.File{*file})
+	}
+
 	// 获取文件预览响应
 	resp, err := fs.Preview(ctx, service.Path, isText)
 	if err != nil {
diff --git a/service/share/visit.go b/service/share/visit.go
index e622fb6..b8612e9 100644
--- a/service/share/visit.go
+++ b/service/share/visit.go
@@ -5,8 +5,10 @@ import (
 	"fmt"
 	model "github.com/HFO4/cloudreve/models"
 	"github.com/HFO4/cloudreve/pkg/filesystem"
+	"github.com/HFO4/cloudreve/pkg/filesystem/fsctx"
 	"github.com/HFO4/cloudreve/pkg/serializer"
 	"github.com/HFO4/cloudreve/pkg/util"
+	"github.com/HFO4/cloudreve/service/explorer"
 	"github.com/gin-gonic/gin"
 )
 
@@ -66,13 +68,7 @@ func (service *SingleFileService) CreateDownloadSession(c *gin.Context) serializ
 	}
 
 	// 检查用户是否可以下载此分享的文件
-	err := share.CanBeDownloadBy(user)
-	if err != nil {
-		return serializer.Err(serializer.CodeNoPermissionErr, err.Error(), nil)
-	}
-
-	// 对积分、下载次数进行更新
-	err = share.DownloadBy(user)
+	err := CheckBeforeGetShare(share, user)
 	if err != nil {
 		return serializer.Err(serializer.CodeNoPermissionErr, err.Error(), nil)
 	}
@@ -101,3 +97,44 @@ func (service *SingleFileService) CreateDownloadSession(c *gin.Context) serializ
 		Data: downloadURL,
 	}
 }
+
+// PreviewContent 预览文件，需要登录会话, isText - 是否为文本文件，文本文件会
+// 强制经由服务端中转
+func (service *SingleFileService) PreviewContent(ctx context.Context, c *gin.Context, isText bool) serializer.Response {
+	user := currentUser(c)
+	share := model.GetShareByHashID(c.Param("id"))
+	if share == nil || !share.IsAvailable() {
+		return serializer.Err(serializer.CodeNotFound, "分享不存在或已被取消", nil)
+	}
+
+	// 检查用户是否可以下载此分享的文件
+	err := CheckBeforeGetShare(share, user)
+	if err != nil {
+		return serializer.Err(serializer.CodeNoPermissionErr, err.Error(), nil)
+	}
+
+	// 用于调用子service
+	ctx = context.WithValue(ctx, fsctx.FileModelCtx, share.GetSource())
+	subService := explorer.SingleFileService{
+		Path: "",
+	}
+
+	return subService.PreviewContent(ctx, c, isText)
+}
+
+// CheckBeforeGetShare 获取分享内容/下载前进行的一系列检查
+func CheckBeforeGetShare(share *model.Share, user *model.User) error {
+	// 检查用户是否可以下载此分享的文件
+	err := share.CanBeDownloadBy(user)
+	if err != nil {
+		return err
+	}
+
+	// 对积分、下载次数进行更新
+	err = share.DownloadBy(user)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}