From 550e722a533ffe66a07af8491172a6a80ab012db Mon Sep 17 00:00:00 2001
From: Gabriel Simmer <gabriel@gitgalaxy.com>
Date: Sat, 29 May 2021 10:48:32 +0100
Subject: [PATCH] Implement SendFile() and ObjectInfo() for S3.

Also removed a now useless parameter for file providers, which used to
be for writing directly to the HTTP response.
---
 files/backblaze.go    |  2 +-
 files/disk.go         |  2 +-
 files/fileprovider.go |  4 ++--
 files/s3.go           | 48 ++++++++++++++++++++++++++++++++++++++++---
 router/filerouter.go  |  2 +-
 5 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/files/backblaze.go b/files/backblaze.go
index 95b2f52..d1d2e21 100644
--- a/files/backblaze.go
+++ b/files/backblaze.go
@@ -140,7 +140,7 @@ func (bp *BackblazeProvider) GetDirectory(path string) Directory {
 	return finalDir
 }
 
-func (bp *BackblazeProvider) SendFile(path string, w io.Writer) (stream io.Reader, contenttype string, err error) {
+func (bp *BackblazeProvider) SendFile(path string) (stream io.Reader, contenttype string, err error) {
 	client := &http.Client{}
 	// Get bucket name >:(
 	bucketIdPayload := fmt.Sprintf(`{"accountId": "%s", "bucketId": "%s"}`, bp.Name, bp.Bucket)
diff --git a/files/disk.go b/files/disk.go
index 2549fca..a0c4b52 100644
--- a/files/disk.go
+++ b/files/disk.go
@@ -45,7 +45,7 @@ func (dp *DiskProvider) GetDirectory(path string) Directory {
 	}
 }
 
-func (dp *DiskProvider) SendFile(path string, writer io.Writer) (stream io.Reader, contenttype string, err error) {
+func (dp *DiskProvider) SendFile(path string) (stream io.Reader, contenttype string, err error) {
 	rp := strings.Join([]string{dp.Location,path}, "/")
 	f, err := os.Open(rp)
 	if err != nil {
diff --git a/files/fileprovider.go b/files/fileprovider.go
index f7df85c..2073417 100644
--- a/files/fileprovider.go
+++ b/files/fileprovider.go
@@ -38,7 +38,7 @@ type FileInfo struct {
 type FileProviderInterface interface {
 	Setup(args map[string]string) (ok bool)
 	GetDirectory(path string) (directory Directory)
-	SendFile(path string, writer io.Writer) (stream io.Reader, contenttype string, err error)
+	SendFile(path string) (stream io.Reader, contenttype string, err error)
 	SaveFile(file io.Reader, filename string, path string) (ok bool)
 	ObjectInfo(path string) (exists bool, isDir bool, location string)
 	CreateDirectory(path string) (ok bool)
@@ -58,7 +58,7 @@ func (f FileProvider) GetDirectory(path string) Directory {
 }
 
 // RemoteFile will bypass http.ServeContent() and instead write directly to the response.
-func (f FileProvider) SendFile(path string, writer io.Writer) (stream io.Reader, contenttype string, err error) {
+func (f FileProvider) SendFile(path string) (stream io.Reader, contenttype string, err error) {
 	return
 }
 
diff --git a/files/s3.go b/files/s3.go
index 83db84d..77b9e80 100644
--- a/files/s3.go
+++ b/files/s3.go
@@ -3,6 +3,10 @@ package files
 import (
 	"fmt"
 	"io"
+	"mime"
+	"path/filepath"
+	"net/http"
+
 	// I _really_ don't want to deal with AWS API stuff by hand.
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/session"
@@ -10,6 +14,7 @@ import (
 )
 
 var svc s3.S3
+var sess *session.Session
 
 type S3Provider struct {
 	FileProvider
@@ -40,6 +45,15 @@ func (s *S3Provider) GetDirectory(path string) Directory {
 
 	dir := Directory{}
 	for _, item := range resp.Contents {
+		ik := *item.Key
+		// Why is this here? AWS returns a complete list of files, including
+		// files within subdirectories (prefixed with the dir name). So we can
+		// ignore directories altogether -- I would prefer to display them but
+		// not sure what the best method of distinguishing them in ObjectInfo()
+		// would be.
+		if ik[len(ik)-1:] == "/" {
+			continue
+		}
 		file := FileInfo{
 			IsDirectory: false,
 			Name: *item.Key,
@@ -51,8 +65,23 @@ func (s *S3Provider) GetDirectory(path string) Directory {
 }
 
 // RemoteFile will bypass http.ServeContent() and instead write directly to the response.
-func (s *S3Provider) SendFile(path string, writer io.Writer) (stream io.Reader, contenttype string, err error) {
-	return
+func (s *S3Provider) SendFile(path string) (stream io.Reader, contenttype string, err error) {
+	req, err := svc.GetObject(&s3.GetObjectInput{
+		Bucket: &s.Bucket,
+		Key: &path,
+	})
+	if err != nil {
+		return stream, contenttype, err
+	}
+
+	contenttype = mime.TypeByExtension(filepath.Ext(path))
+	if contenttype == "" {
+		var buf [512]byte
+		n, _ := io.ReadFull(req.Body, buf[:])
+		contenttype = http.DetectContentType(buf[:n])
+	}
+
+	return req.Body, contenttype, err
 }
 
 // SaveFile will save a file with the contents of the io.Reader at the path specified.
@@ -64,7 +93,20 @@ func (s *S3Provider) SaveFile(file io.Reader, filename string, path string) bool
 // Should return whether the path exists, if the path is a directory, and if it lives on disk.
 // (see constants defined: `FILE_IS_REMOTE` and `FILE_IS_LOCAL`)
 func (s *S3Provider) ObjectInfo(path string) (bool, bool, string) {
-	return true, true, ""
+	if path == "" {
+		return true, true, ""
+	}
+
+	_, err := svc.GetObject(&s3.GetObjectInput{
+		Bucket: &s.Bucket,
+		Key: &path,
+	})
+	if err != nil {
+		fmt.Println(err)
+		return false, false, ""
+	}
+
+	return true, false, ""
 }
 
 // CreateDirectory will create a directory on services that support it.
diff --git a/router/filerouter.go b/router/filerouter.go
index 6de343e..7b38c37 100644
--- a/router/filerouter.go
+++ b/router/filerouter.go
@@ -50,7 +50,7 @@ func handleProvider() handler {
 				w.Write(data)
 				return nil
 			} else {
-				stream, contenttype, err := provider.SendFile(filename, w)
+				stream, contenttype, err := provider.SendFile(filename)
 
 				if err != nil {
 					return &httpError{