// Fetch returns a group from the collection with the given path.
func (l *Library) Fetch(c index.Collection, path []string) (group, error) {
if len(path) == 0 {
return build(c, index.Key("Root")), nil
}
var g index.Group = c
k := index.Key(path[0])
g = c.Get(k)
if g == nil {
return group{}, fmt.Errorf("invalid path: near '%v'", path[0])
}
index.Sort(g.Tracks(), index.MultiSort(index.SortByInt("DiscNumber"), index.SortByInt("TrackNumber")))
g = index.Transform(g, index.SplitList("Artist", "AlbumArtist", "Composer"))
c = index.Collect(g, index.ByPrefix("Name"))
g = index.SubTransform(c, index.TrimEnumPrefix)
g = index.SumGroupIntAttr("TotalTime", g)
commonFields := []attr.Interface{
attr.String("Album"),
attr.Strings("Artist"),
attr.Strings("AlbumArtist"),
attr.Strings("Composer"),
attr.Int("Year"),
attr.Int("BitRate"),
attr.Int("DiscNumber"),
}
g = index.CommonGroupAttr(commonFields, g)
g = index.RemoveEmptyCollections(g)
for i, p := range path[1:] {
var ok bool
c, ok = g.(index.Collection)
if !ok {
return group{}, fmt.Errorf("retrieved Group is not a Collection")
}
k = index.Key(p)
g = c.Get(k)
if g == nil {
return group{}, fmt.Errorf("invalid path near '%v'", path[1:][i])
}
if _, ok = g.(index.Collection); !ok {
if i == len(path[1:])-1 {
break
}
return group{}, fmt.Errorf("retrieved Group isn't a Collection: %v", p)
}
}
if g == nil {
return group{}, fmt.Errorf("could not find group")
}
g = index.FirstTrackAttr(attr.String("ID"), g)
return build(g, k), nil
}
func TestFirstTrackAttr(t *testing.T) {
table := []struct {
in Group
field attr.Interface
out interface{}
}{
// One group with no tracks
{
in: group{
name: "Group One",
},
field: attr.String("Name"),
out: nil,
},
{
in: group{
name: "Group One",
},
field: attr.Strings("Artist"),
out: nil,
},
// One group with one track
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Track One",
},
},
},
field: attr.String("Name"),
out: "Track One",
},
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Artist: "Track One",
},
},
},
field: attr.Strings("Artist"),
out: []string{"Track One"},
},
// One group with two tracks, empty first field
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{},
testTrack{
Name: "Track Two",
Artist: "Artist One",
},
},
},
field: attr.String("Artist"),
out: nil,
},
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{},
testTrack{
Name: "Track Two",
Artist: "Artist One",
},
},
},
field: attr.Strings("Artist"),
out: nil,
},
// One collection, one group, one track
{
in: testCol{
name: "Group One (collection)",
keys: []Key{"Group-One-One"},
grps: map[Key]Group{
"Group-One-One": group{
name: "Group One (One)",
tracks: []Track{
testTrack{
Name: "Track One",
},
},
},
},
},
field: attr.String("Name"),
out: "Track One",
},
// One group with one track
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Duration: 1234,
},
},
},
field: attr.Int("Duration"),
out: 1234,
},
// One group with two tracks, empty first field
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{},
testTrack{
Duration: 1234,
Artist: "Artist One",
},
},
},
field: attr.Int("Duration"),
out: nil,
},
// One collection, one group, one track
{
in: testCol{
name: "Group One (collection)",
keys: []Key{"Group-One-One"},
grps: map[Key]Group{
"Group-One-One": group{
name: "Group One (One)",
tracks: []Track{
testTrack{
Duration: 1234,
},
},
},
},
},
field: attr.Int("Duration"),
out: 1234,
},
}
for ii, tt := range table {
g := FirstTrackAttr(tt.field, tt.in)
got := g.Field(tt.field.Name())
if !reflect.DeepEqual(got, tt.out) {
t.Errorf("[%d] got %#v, expected %#v", ii, got, tt.out)
}
}
}
func TestCommonGroupAttr(t *testing.T) {
table := []struct {
in Group
fields []attr.Interface
out []interface{}
}{
// One group with one track, unset common field
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Track One",
},
},
},
fields: []attr.Interface{attr.String("Artist")},
out: []interface{}{nil},
},
// One group with one track, unset common int field
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Empty common field",
},
},
},
fields: []attr.Interface{attr.Int("Year")},
out: []interface{}{nil},
},
// One group with one track, unset common (string) and (int) fields
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Track One",
},
},
},
fields: []attr.Interface{attr.String("Artist"), attr.Int("Year")},
out: []interface{}{nil, nil},
},
// One group with one track, set strings field
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
stringsMap: map[string][]string{
"Artist": []string{"First Artist", "Second Artist"},
},
},
},
},
fields: []attr.Interface{attr.Strings("Artist")},
out: []interface{}{[]string{"First Artist", "Second Artist"}},
},
// One group with two tracks, check intersection of artists list
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
stringsMap: map[string][]string{
"Artist": []string{"First Artist", "Second Artist"},
},
},
testTrack{
stringsMap: map[string][]string{
"Artist": []string{"First Artist"},
},
},
},
},
fields: []attr.Interface{attr.Strings("Artist")},
out: []interface{}{[]string{"First Artist"}},
},
// One group with two tracks, empty first string & int fields
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Track One",
},
testTrack{
Name: "Track Two",
Artist: "Artist One",
Year: 1984,
},
},
},
fields: []attr.Interface{attr.String("Artist"), attr.Int("Year")},
out: []interface{}{nil, nil},
},
// One group with two tracks, empty first field
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Track One",
},
testTrack{
Name: "Track Two",
Year: 1985,
},
},
},
fields: []attr.Interface{attr.Int("Year")},
out: []interface{}{nil},
},
// One group with one track, common string/int fields
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Track One",
Artist: "Artist One",
Composer: "Composer One",
Year: 1984,
},
},
},
fields: []attr.Interface{attr.String("Artist"), attr.Int("Year")},
out: []interface{}{"Artist One", 1984},
},
// One group with one track, common string fields for Artist and Composer
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Track One",
Artist: "Artist One",
Composer: "Composer One",
},
},
},
fields: []attr.Interface{attr.String("Artist"), attr.String("Composer")},
out: []interface{}{"Artist One", "Composer One"},
},
// One group with two tracks, common fields across pairs
{
in: group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Track One",
Artist: "Artist One",
Composer: "Composer One",
},
testTrack{
Name: "Track Two",
Artist: "Artist Two",
Composer: "Composer One",
},
},
},
fields: []attr.Interface{attr.String("Artist"), attr.String("Composer")},
out: []interface{}{nil, "Composer One"},
},
// One collection, one group, one track
{
in: testCol{
name: "Group Three (collection)",
keys: []Key{"Group-Three-One"},
grps: map[Key]Group{
"Group-Three-One": group{
name: "Group One (Three)",
tracks: []Track{
testTrack{
Name: "Track One",
Artist: "Artist One",
},
},
},
},
},
fields: []attr.Interface{attr.String("Artist"), attr.String("Composer")},
out: []interface{}{"Artist One", nil},
},
// One collection, three groups, many tracks!
{
in: testCol{
name: "Root",
keys: []Key{"Group-One", "Group-Two", "Group-Three"},
grps: map[Key]Group{
"Group-One": group{
name: "Group One",
tracks: []Track{
testTrack{
Name: "Track One",
Artist: "Artist One",
Year: 1984,
},
},
},
"Group-Two": group{
name: "Group Two",
tracks: []Track{
testTrack{
Name: "Track One",
Artist: "Artist One",
Year: 1984,
},
testTrack{
Name: "Track Two",
Artist: "Artist One",
Year: 1984,
},
},
},
"Group-Three": testCol{
name: "Group Three (collection)",
keys: []Key{"Group-Three-One"},
grps: map[Key]Group{
"Group-Three-One": group{
name: "Group One (Three)",
tracks: []Track{
testTrack{
Name: "Track One",
Artist: "Artist One",
Year: 1984,
},
testTrack{
Name: "Track Two",
Artist: "Artist One",
Year: 2000,
},
testTrack{
Name: "Track One",
Artist: "Artist One",
Year: 1984,
},
},
},
},
},
},
},
fields: []attr.Interface{attr.String("Artist"), attr.Int("Year")},
out: []interface{}{"Artist One", nil},
},
}
for ii, tt := range table {
g := CommonGroupAttr(tt.fields, tt.in)
got := make([]interface{}, len(tt.out))
for i, f := range tt.fields {
got[i] = g.Field(f.Name())
}
if !reflect.DeepEqual(got, tt.out) {
t.Errorf("[%d] got %#v, expected %#v", ii, got, tt.out)
}
}
}