From 8fa048d078f86197c45d4ea1ff62da38826a2fe1 Mon Sep 17 00:00:00 2001
From: Soukron <soukron@gmbros.net>
Date: Mon, 26 Mar 2018 08:17:10 +0200
Subject: [PATCH] Include support to parse tags

* Ignore tags to calculate length

* Parse tags

* Added trim to strings and removing double quotes in some values

* Added test case to read tag name and tag value
---
 m3u.go                | 25 ++++++++++++++++++++-----
 m3u_test.go           |  8 ++++++++
 testdata/playlist.m3u | 10 +++++-----
 3 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/m3u.go b/m3u.go
index 9faff09..9aac8c0 100644
--- a/m3u.go
+++ b/m3u.go
@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"errors"
 	"os"
+	"regexp"
 	"strconv"
 	"strings"
 )
@@ -13,11 +14,18 @@ type Playlist struct {
 	Tracks []Track
 }
 
-// Track represents an m3u track
+// A Tag is a simple key/value pair
+type Tag struct {
+	Name string
+	Value string
+}
+
+// Track represents an m3u track with a Name, Lengh, URI and a set of tags
 type Track struct {
 	Name   string
 	Length int
 	URI    string
+	Tags   []Tag
 }
 
 // Parse parses an m3u playlist with the given file name and returns a Playlist
@@ -31,7 +39,8 @@ func Parse(fileName string) (playlist Playlist, err error) {
 
 	onFirstLine := true
 	scanner := bufio.NewScanner(f)
-
+	tagsRegExp, _ := regexp.Compile("([a-zA-Z0-9-]+?)=\"([^\"]+)\"")
+	
 	for scanner.Scan() {
 		line := scanner.Text()
 		if onFirstLine && !strings.HasPrefix(line, "#EXTM3U") {
@@ -48,12 +57,18 @@ func Parse(fileName string) (playlist Playlist, err error) {
 				err = errors.New("Invalid m3u file format. Expected EXTINF metadata to contain track length and name data")
 				return
 			}
-			length, parseErr := strconv.Atoi(trackInfo[0])
+			length, parseErr := strconv.Atoi(strings.Split(trackInfo[0], " ")[0])
 			if parseErr != nil {
 				err = errors.New("Unable to parse length")
 				return
 			}
-			track := &Track{trackInfo[1], length, ""}
+			track := &Track{strings.Trim(trackInfo[1], " "), length, "", nil}
+			tagList := tagsRegExp.FindAllString(line, -1)
+			for i := range tagList {
+				tagInfo := strings.Split(tagList[i], "=")
+				tag := &Tag{tagInfo[0], strings.Replace(tagInfo[1], "\"", "", -1)}
+				track.Tags = append(track.Tags, *tag)
+			}
 			playlist.Tracks = append(playlist.Tracks, *track)
 		} else if strings.HasPrefix(line, "#") || line == "" {
 			continue
@@ -61,7 +76,7 @@ func Parse(fileName string) (playlist Playlist, err error) {
 			err = errors.New("URI provided for playlist with no tracks")
 			return
 		} else {
-			playlist.Tracks[len(playlist.Tracks)-1].URI = line
+			playlist.Tracks[len(playlist.Tracks)-1].URI = strings.Trim(line, " ")
 		}
 	}
 
diff --git a/m3u_test.go b/m3u_test.go
index 66057d3..36d8ef8 100644
--- a/m3u_test.go
+++ b/m3u_test.go
@@ -24,6 +24,14 @@ func TestPlaylist(t *testing.T) {
 		if playlist.Tracks[i].URI != fmt.Sprintf("Track%d.mp4", i+1) {
 			t.Fatalf("Expected track URI to be Track%d.mp4 but was '%s'", i+1, playlist.Tracks[i].URI)
 		}
+
+                if playlist.Tracks[i].Tags[0].Name != "group-title" {
+			t.Fatalf("Expected tag to be group-title but was '%s'", playlist.Tracks[i].Tags[0].Name)
+                }
+
+                if playlist.Tracks[i].Tags[0].Value != "Album1" {
+			t.Fatalf("Expected group-title tag value to be Album1 but was '%s'", playlist.Tracks[i].Tags[0].Value)
+                }
 	}
 }
 
diff --git a/testdata/playlist.m3u b/testdata/playlist.m3u
index 936c18c..7323f41 100644
--- a/testdata/playlist.m3u
+++ b/testdata/playlist.m3u
@@ -1,11 +1,11 @@
 #EXTM3U
-#EXTINF:1,Track 1
+#EXTINF:1 group-title="Album1", Track 1
 Track1.mp4
-#EXTINF:2,Track 2
+#EXTINF:2 group-title="Album1", Track 2
 Track2.mp4
-#EXTINF:3,Track 3
+#EXTINF:3 group-title="Album1", Track 3
 Track3.mp4
-#EXTINF:4,Track 4
+#EXTINF:4 group-title="Album1", Track 4
 Track4.mp4
-#EXTINF:5,Track 5
+#EXTINF:5 group-title="Album1", Track 5
 Track5.mp4