From 30cb171612a26c1f34b0331f0e9c07eeae2dc1ca Mon Sep 17 00:00:00 2001
From: Zoe Roux <zoe.roux@zoriya.dev>
Date: Wed, 17 Jan 2024 18:17:06 +0100
Subject: [PATCH] Add basic extraction methods

---
 transcoder/main.go        | 43 +++++++++++++++++++++++++++++++++++++++
 transcoder/src/extract.go | 42 ++++++++++++++++++++++++++++++++++++++
 transcoder/utils.go       |  7 +++++++
 3 files changed, 92 insertions(+)
 create mode 100644 transcoder/src/extract.go

diff --git a/transcoder/main.go b/transcoder/main.go
index b1953f87..7ff1b6d8 100644
--- a/transcoder/main.go
+++ b/transcoder/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"net/http"
 	"strconv"
 
@@ -208,6 +209,46 @@ func GetInfo(c echo.Context) error {
 	return c.JSON(http.StatusOK, ret)
 }
 
+// Get attachments
+//
+// Get a specific attachment
+//
+// Path: /:sha/attachment/:name
+func GetAttachment(c echo.Context) error {
+	sha := c.Param("sha")
+	name := c.Param("name")
+
+	if err := SanitizePath(sha); err != nil {
+		return err
+	}
+	if err := SanitizePath(name); err != nil {
+		return err
+	}
+
+	path := fmt.Sprintf("%s/%s/att/%s", src.GetMetadataPath(), sha, name)
+	return c.File(path)
+}
+
+// Get subtitle
+//
+// Get a specific subtitle
+//
+// Path: /:sha/sub/:name
+func GetSubtitle(c echo.Context) error {
+	sha := c.Param("sha")
+	name := c.Param("name")
+
+	if err := SanitizePath(sha); err != nil {
+		return err
+	}
+	if err := SanitizePath(name); err != nil {
+		return err
+	}
+
+	path := fmt.Sprintf("%s/%s/sub/%s", src.GetMetadataPath(), sha, name)
+	return c.File(path)
+}
+
 type Handler struct {
 	transcoder *src.Transcoder
 }
@@ -231,6 +272,8 @@ func main() {
 	e.GET("/:resource/:slug/:quality/:chunk", h.GetVideoSegment)
 	e.GET("/:resource/:slug/audio/:audio/:chunk", h.GetAudioSegment)
 	e.GET("/:resource/:slug/info", GetInfo)
+	e.GET("/:sha/attachment/:name", GetAttachment)
+	e.GET("/:sha/sub/:name", GetSubtitle)
 
 	e.Logger.Fatal(e.Start(":7666"))
 }
diff --git a/transcoder/src/extract.go b/transcoder/src/extract.go
new file mode 100644
index 00000000..0ec4d24e
--- /dev/null
+++ b/transcoder/src/extract.go
@@ -0,0 +1,42 @@
+package src
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+func GetMetadataPath() string {
+	out := os.Getenv("GOCODER_METADATA_ROOT")
+	if out == "" {
+		return "/metadata"
+	}
+	return out
+}
+
+func extract(path string, sha string, subs *[]Subtitle) {
+	fmt.Printf("Extract subs and fonts for %s", path)
+	cmd := exec.Command(
+		"ffmpeg",
+		"-dump_attachment:t", "",
+		"-i", path,
+	)
+	cmd.Dir = fmt.Sprintf("/%s/%s/att/", GetMetadataPath(), sha)
+
+	for _, sub := range *subs {
+		if ext := sub.Extension; ext != nil {
+			cmd.Args = append(
+				cmd.Args,
+				"-map", fmt.Sprintf("0:s:%d", sub.Index),
+				"-c:s", "copy",
+				fmt.Sprintf("/%s/%s/sub/%d.%s", GetMetadataPath(), sha, sub.Index, *ext),
+			)
+		}
+	}
+	fmt.Printf("Starting extraction with the command: %s", cmd)
+	cmd.Stdout = nil
+	err := cmd.Run()
+	if err != nil {
+		fmt.Println("Error starting ffmpeg extract:", err)
+	}
+}
diff --git a/transcoder/utils.go b/transcoder/utils.go
index c1c6e1aa..bc3f3901 100644
--- a/transcoder/utils.go
+++ b/transcoder/utils.go
@@ -56,6 +56,13 @@ func GetPath(resource string, slug string) (string, error) {
 	return ret.Path, nil
 }
 
+func SanitizePath(path string) error {
+	if strings.Contains(path, "/") || strings.Contains(path, "..") {
+		return echo.NewHTTPError(http.StatusBadRequest, "Invalid parameter. Can't contains path delimiters or ..")
+	}
+	return nil
+}
+
 func GetClientId(c echo.Context) (string, error) {
 	key := c.Request().Header.Get("X-CLIENT-ID")
 	if key == "" {