commit 811a8bf5faf2c4318e4597d4e50ebae35653b4a1
Author: milarin <milaring@proton.me>
Date:   Tue Feb 14 21:59:56 2023 +0100

    initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..6eab256
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+.env
+music-library
\ No newline at end of file
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..c6a67c1
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,9 @@
+module git.milar.in/milarin/music-library
+
+go 1.20
+
+require (
+	git.milar.in/milarin/envvars/v2 v2.0.0
+	git.milar.in/milarin/slices v0.0.6
+	github.com/gorilla/mux v1.8.0
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..d57bc8a
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,6 @@
+git.milar.in/milarin/envvars/v2 v2.0.0 h1:DWRQCWaHqzDD8NGpSgv5tYLuF9A/dVFPAtTvz3oiIqE=
+git.milar.in/milarin/envvars/v2 v2.0.0/go.mod h1:HkdEi+gG2lJSmVq547bTlQV4qQ0hO333bE8IrE0B9yY=
+git.milar.in/milarin/slices v0.0.6 h1:AQoSarZ58WHYol9c6woWJSe8wFpPC2RC4cvIlZpfg9s=
+git.milar.in/milarin/slices v0.0.6/go.mod h1:NOr53AOeur/qscu/FBj3lsFR262PNYBccLYSTCAXRk4=
+github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
+github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
diff --git a/library.go b/library.go
new file mode 100644
index 0000000..7d74ee4
--- /dev/null
+++ b/library.go
@@ -0,0 +1,55 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+
+	"git.milar.in/milarin/slices"
+)
+
+type Playlist struct {
+	Name  string   `json:"name"`
+	Songs []string `json:"songs"`
+}
+
+func GetAll() ([]Playlist, error) {
+	playlistNames, err := GetPlaylists()
+	if err != nil {
+		return nil, err
+	}
+
+	playlists := make([]Playlist, 0, len(playlistNames))
+	for _, playlistName := range playlistNames {
+		songs, err := GetSongs(playlistName)
+		if err != nil {
+			return nil, err
+		}
+
+		playlists = append(playlists, Playlist{
+			Name:  playlistName,
+			Songs: songs,
+		})
+	}
+
+	return playlists, nil
+}
+
+func GetPlaylists() ([]string, error) {
+	entries, err := os.ReadDir(LibraryPath)
+	if err != nil {
+		return nil, err
+	}
+
+	directories := slices.Filter(entries, And(IsDir, Not(IsHidden)))
+	return slices.Map(directories, FsEntry2Name), nil
+}
+
+func GetSongs(playlist string) ([]string, error) {
+	entries, err := os.ReadDir(filepath.Join(LibraryPath, playlist))
+	if err != nil {
+		return nil, err
+	}
+
+	directories := slices.Filter(entries, Not(IsDir))
+	return slices.Map(directories, FsEntry2Name), nil
+}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..129be78
--- /dev/null
+++ b/main.go
@@ -0,0 +1,107 @@
+package main
+
+import (
+	"bytes"
+	"crypto/sha512"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"path/filepath"
+
+	"git.milar.in/milarin/envvars/v2"
+	"github.com/gorilla/mux"
+)
+
+var (
+	HttpIntf    = envvars.String("HTTP_INTERFACE", "")
+	HttpPort    = envvars.Uint16("HTTP_PORT", 80)
+	LibraryPath = envvars.String("LIBRARY_PATH", "/music")
+)
+
+func main() {
+	r := mux.NewRouter()
+
+	r.HandleFunc("/all/", GetAllHandler).Methods("GET")
+	r.HandleFunc("/all/hash/", GetAllHashHandler).Methods("GET")
+	r.HandleFunc("/playlist/", GetPlaylistsHandler).Methods("GET")
+	r.HandleFunc("/playlist/{playlist}/", GetPlaylistHandler).Methods("GET")
+	r.HandleFunc("/playlist/{playlist}/song/{song}/", GetSongHandler).Methods("GET")
+
+	fmt.Printf("Starting music server on port %d\n", HttpPort)
+	if err := http.ListenAndServe(fmt.Sprintf("%s:%d", HttpIntf, HttpPort), r); err != nil {
+		panic(err)
+	}
+}
+
+func GetAllHashHandler(w http.ResponseWriter, r *http.Request) {
+	playlists, err := GetAll()
+	if err != nil {
+		InternalServerError(w, err)
+		return
+	}
+
+	b := &bytes.Buffer{}
+	if err := json.NewEncoder(b).Encode(playlists); err != nil {
+		InternalServerError(w, err)
+		return
+	}
+
+	hash := sha512.Sum512(b.Bytes())
+	if _, err := fmt.Fprint(w, hex.EncodeToString(hash[:])); err != nil {
+		InternalServerError(w, err)
+		return
+	}
+}
+
+func GetAllHandler(w http.ResponseWriter, r *http.Request) {
+	playlists, err := GetAll()
+	if err != nil {
+		InternalServerError(w, err)
+		return
+	}
+
+	w.Header().Add("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(playlists); err != nil {
+		InternalServerError(w, err)
+		return
+	}
+}
+
+func GetSongHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	playlist := vars["playlist"]
+	song := vars["song"]
+
+	http.ServeFile(w, r, filepath.Join(LibraryPath, playlist, song))
+}
+
+func GetPlaylistHandler(w http.ResponseWriter, r *http.Request) {
+	playlist := mux.Vars(r)["playlist"]
+
+	songs, err := GetSongs(playlist)
+	if err != nil {
+		InternalServerError(w, err)
+		return
+	}
+
+	w.Header().Add("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(songs); err != nil {
+		InternalServerError(w, err)
+		return
+	}
+}
+
+func GetPlaylistsHandler(w http.ResponseWriter, r *http.Request) {
+	playlists, err := GetPlaylists()
+	if err != nil {
+		InternalServerError(w, err)
+		return
+	}
+
+	w.Header().Add("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(playlists); err != nil {
+		InternalServerError(w, err)
+		return
+	}
+}
diff --git a/utils.go b/utils.go
new file mode 100644
index 0000000..d3dc645
--- /dev/null
+++ b/utils.go
@@ -0,0 +1,50 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"os"
+	"strings"
+)
+
+func MethodNotAllowed(w http.ResponseWriter, allowedMethods ...string) {
+	for _, method := range allowedMethods {
+		w.Header().Add("Allow", strings.ToUpper(method))
+	}
+	w.WriteHeader(http.StatusMethodNotAllowed)
+}
+
+func InternalServerError(w http.ResponseWriter, err error) {
+	log.Println(err)
+	w.WriteHeader(http.StatusInternalServerError)
+}
+
+func And[T any](f1, f2 func(T) bool) func(T) bool {
+	return func(v T) bool {
+		return f1(v) && f2(v)
+	}
+}
+
+func Or[T any](f1, f2 func(T) bool) func(T) bool {
+	return func(v T) bool {
+		return f1(v) || f2(v)
+	}
+}
+
+func Not[T any](f func(T) bool) func(T) bool {
+	return func(v T) bool {
+		return !f(v)
+	}
+}
+
+func IsDir(entry os.DirEntry) bool {
+	return entry.IsDir()
+}
+
+func IsHidden(entry os.DirEntry) bool {
+	return strings.HasPrefix(entry.Name(), ".")
+}
+
+func FsEntry2Name(entry os.DirEntry) string {
+	return entry.Name()
+}