Initial commit

.gitignore

@@ -0,0 +1 @@
+videos/

cmd/video_server_backend/main.go

@@ -0,0 +1,200 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"slices"
+	"strconv"
+	"strings"
+
+	"github.com/google/uuid"
+	"github.com/gorilla/websocket"
+)
+
+var upgrader = websocket.Upgrader{
+	ReadBufferSize:  1024,
+	WriteBufferSize: 1024,
+	CheckOrigin: func(r *http.Request) bool {
+		return true
+	},
+}
+
+var tasks = []string{}
+
+const VIDEOS_DIR = "./videos"
+
+type Video struct {
+	Filename string `json:"filename"`
+}
+
+func notFound(w http.ResponseWriter, r *http.Request) {
+	http.Error(w, "Endpoint not found", http.StatusNotFound)
+}
+
+func searchVideo(w http.ResponseWriter, r *http.Request) {
+	query := r.URL.Query().Get("q")
+	if query == "" {
+		http.Error(w, "Query is required.", http.StatusBadRequest)
+		return
+	}
+
+	task := uuid.New().String()
+	tasks = append(tasks, task)
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	w.Write([]byte(task))
+
+	fmt.Printf("Task %s created\n", task)
+}
+
+func connectSearchSocket(w http.ResponseWriter, r *http.Request) {
+	taskId := r.URL.Query().Get("task")
+	if !slices.Contains(tasks, taskId) {
+		http.Error(w, "Task not found.", http.StatusNotFound)
+		return
+	}
+
+	fmt.Printf("Task %s started\n", taskId)
+
+	conn, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		fmt.Println(err)
+		http.Error(w, "Could not upgrade to websocket.", http.StatusInternalServerError)
+		return
+	}
+
+	defer func() {
+		err := conn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
+		if err != nil {
+			log.Println("Error during websocket close: ", err)
+		}
+		conn.Close()
+	}()
+
+	files := []string{}
+	err = filepath.Walk(VIDEOS_DIR, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		files = append(files, path)
+		return nil
+	})
+
+	if err != nil {
+		// http.Error(w, "Could not read video directory.", http.StatusInternalServerError)
+		return
+	}
+
+	for _, file := range files {
+		if strings.Contains(file, ".mp4") {
+			jsonMsg, err := json.Marshal(Video{Filename: file})
+			if err != nil {
+				log.Println(err)
+			}
+
+			err = conn.WriteMessage(websocket.TextMessage, jsonMsg)
+			if err != nil {
+				log.Println(err)
+			}
+		}
+	}
+
+	tasks = slices.DeleteFunc(tasks, func(task string) bool { return task == taskId })
+	fmt.Printf("Task %s finished\n", taskId)
+}
+
+func streamVideo(w http.ResponseWriter, r *http.Request) {
+	videoPath := r.URL.Query().Get("v")
+	videoFile, err := os.Open(videoPath)
+	if err != nil {
+		http.Error(w, "Video file not found.", http.StatusNotFound)
+		return
+	}
+	defer videoFile.Close()
+
+	fileInfo, err := videoFile.Stat()
+	if err != nil {
+		http.Error(w, "Could not obtain file info.", http.StatusInternalServerError)
+		return
+	}
+
+	fileSize := fileInfo.Size()
+	rangeHeader := r.Header.Get("Range")
+	if rangeHeader == "" {
+		http.ServeFile(w, r, videoPath)
+		return
+	}
+
+	start, end, err := getStartEndRange(rangeHeader, fileSize)
+	if err != nil || start > end || end >= fileSize {
+		http.Error(w, "Invalid range.", http.StatusBadRequest)
+		return
+	}
+
+	w.Header().Set("Content-Type", "video/mp4")
+	w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", start, end, fileSize))
+	w.Header().Set("Accept-Ranges", "bytes")
+	w.WriteHeader(http.StatusPartialContent)
+
+	videoFile.Seek(start, 0)
+	buf := make([]byte, end-start+1)
+	videoFile.Read(buf)
+	w.Write(buf)
+}
+
+func getStartEndRange(rangeHeader string, fileSize int64) (int64, int64, error) {
+	rangeParts := strings.Split(rangeHeader, "=")
+	if len(rangeParts) != 2 || rangeParts[0] != "bytes" {
+		return 0, 0, fmt.Errorf("invalid range header")
+	}
+
+	rangeSpec := strings.Split(rangeParts[1], "-")
+	start, err := strconv.ParseInt(rangeSpec[0], 10, 64)
+	if err != nil {
+		return 0, 0, fmt.Errorf("invalid range start")
+	}
+
+	var end int64
+	if len(rangeSpec) == 2 && rangeSpec[1] != "" {
+		end, err = strconv.ParseInt(rangeSpec[1], 10, 64)
+		if err != nil {
+			return 0, 0, fmt.Errorf("invalid range end")
+		}
+	} else {
+		end = fileSize - 1
+	}
+
+	return start, end, nil
+}
+
+func addCORSHeaders(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
+		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")
+		if r.Method == "OPTIONS" {
+			w.WriteHeader(http.StatusOK)
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
+func createMux() *http.ServeMux {
+	var mux *http.ServeMux = http.NewServeMux()
+	mux.HandleFunc("/video", streamVideo)
+	mux.HandleFunc("/search", searchVideo)
+	mux.HandleFunc("/search_socket", connectSearchSocket)
+	mux.HandleFunc("/", notFound)
+
+	return mux
+}
+
+func main() {
+	log.Fatal(http.ListenAndServe(":8080", addCORSHeaders(createMux())))
+}

go.mod

@@ -0,0 +1,8 @@
+module video_server_backend
+
+go 1.22.6
+
+require (
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/gorilla/websocket v1.5.3 // indirect
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
+github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=