From d5d80944d6ad6480fd0eff28fbb6ab15cbc9aa3a Mon Sep 17 00:00:00 2001
From: Unbewohnte <Unbewohnte@gmail.com>
Date: Tue, 22 Jun 2021 13:37:28 +0300
Subject: [PATCH] Minimal ID3v1.1 support ?

---
 README.md          |   5 +-
 id3v1.1.go         | 125 +++++++++++++++++++++++++++++++++++++++++++++
 id3v1_test.go      |  17 ++++++
 testData/id3v1.txt | Bin 0 -> 165 bytes
 4 files changed, 145 insertions(+), 2 deletions(-)
 create mode 100644 id3v1.1.go
 create mode 100644 id3v1_test.go
 create mode 100644 testData/id3v1.txt

diff --git a/README.md b/README.md
index 810ab49..36ef5ea 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,5 @@
-# ID3ED (ID3- Encoder - Decoder)
+# ID3ED (ID3 - Encoder - Decoder)
 ## Library for encoding/decoding ID3 tags
 
-# Under construction !
\ No newline at end of file
+# Under construction !
+## Bugs are a possibility rn in this state
\ No newline at end of file
diff --git a/id3v1.1.go b/id3v1.1.go
new file mode 100644
index 0000000..72b5d41
--- /dev/null
+++ b/id3v1.1.go
@@ -0,0 +1,125 @@
+package id3ed
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strconv"
+)
+
+type ID3v11Tags struct {
+	SongName string
+	Artist   string
+	Album    string
+	Year     int
+	Comment  string
+	Track    int
+	Genre    int
+}
+
+// Retrieves ID3v1.1 field values of provided io.ReadSeeker (usually a file)
+func GetID3v11Tags(rs io.ReadSeeker) (*ID3v11Tags, error) {
+	// set reader to the last 128 bytes
+	_, err := rs.Seek(-int64(ID3V1SIZE), io.SeekEnd)
+	if err != nil {
+		return nil, fmt.Errorf("could not seek: %s", err)
+	}
+
+	tag, err := read(rs, 3)
+	if err != nil {
+		return nil, err
+	}
+
+	if !bytes.Equal(tag, []byte("TAG")) {
+		// no TAG, given file does not use ID3v1
+		return nil, fmt.Errorf("does not use ID3v1")
+	}
+
+	songname, err := read(rs, 30)
+	if err != nil {
+		return nil, err
+	}
+
+	artist, err := read(rs, 30)
+	if err != nil {
+		return nil, err
+	}
+
+	album, err := read(rs, 30)
+	if err != nil {
+		return nil, err
+	}
+
+	yearBytes, err := read(rs, 4)
+	if err != nil {
+		return nil, err
+	}
+	year, err := strconv.Atoi(string(yearBytes))
+	if err != nil {
+		return nil, fmt.Errorf("could not convert yearbytes into int: %s", err)
+	}
+
+	comment, err := read(rs, 28)
+	if err != nil {
+		return nil, err
+	}
+
+	// skip 1 null byte
+	_, err = read(rs, 1)
+	if err != nil {
+		return nil, err
+	}
+
+	trackByte, err := read(rs, 1)
+	if err != nil {
+		return nil, err
+	}
+
+	// track is one byte by specification
+	track := int(trackByte[0])
+
+	genreByte, err := read(rs, 1)
+	if err != nil {
+		return nil, err
+	}
+	// genre is one byte by specification
+	genre := int(genreByte[0])
+
+	return &ID3v11Tags{
+		SongName: string(songname),
+		Artist:   string(artist),
+		Album:    string(album),
+		Year:     year,
+		Comment:  string(comment),
+		Track:    track,
+		Genre:    genre,
+	}, nil
+}
+
+func (t *ID3v11Tags) GetSongName() string {
+	return t.SongName
+}
+
+func (t *ID3v11Tags) GetArtist() string {
+	return t.Artist
+}
+
+func (t *ID3v11Tags) GetAlbum() string {
+	return t.Album
+}
+
+func (t *ID3v11Tags) GetYear() int {
+	return t.Year
+}
+
+func (t *ID3v11Tags) GetComment() string {
+	return t.Comment
+}
+
+func (t *ID3v11Tags) GetTrack() int {
+	return t.Track
+}
+
+func (t *ID3v11Tags) GetGenre() int {
+	return t.Genre
+}
diff --git a/id3v1_test.go b/id3v1_test.go
new file mode 100644
index 0000000..962ad32
--- /dev/null
+++ b/id3v1_test.go
@@ -0,0 +1,17 @@
+package id3ed
+
+import (
+	"os"
+	"testing"
+)
+
+func TestGetID3v1Tags(t *testing.T) {
+	testfile, err := os.Open("./testData/id3v1.txt")
+	if err != nil {
+		t.Errorf("could not open file for testing: %s", err)
+	}
+	_, err = GetID3v1Tags(testfile)
+	if err != nil {
+		t.Errorf("GetID3v1Tags failed: %s", err)
+	}
+}
diff --git a/testData/id3v1.txt b/testData/id3v1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..c70ca6464c5b7bf38d419dcb60341ffad0927d21
GIT binary patch
literal 165
zcmWH}&rMZGNi0cJ$Ve?p<toWYEKw-W&r2v#NJ>>GN=;1R0)h}n_mIqzoKyx}z_F+#
tv$zD8Y=~=ch=QY!Q>d?khii~4nldAEBXj5c+}zZ>60jQ-(Bv67Bml1P8uS1F

literal 0
HcmV?d00001