package musicbrainz

import (
	"testing"
)

func TestParseReleaseGroups_Success(t *testing.T) {
	data := []byte(`<?xml version="1.0" encoding="UTF-8"?>
<metadata xmlns="http://musicbrainz.org/ns/mmd-2.0#">
  <release-group-list count="2">
    <release-group id="rg-uuid-1" type="Album">
      <title>Dark Side of the Moon</title>
      <first-release-date>1973-03-01</first-release-date>
      <artist-credit>
        <name-credit>
          <artist id="artist-uuid-1">
            <name>Pink Floyd</name>
          </artist>
        </name-credit>
      </artist-credit>
    </release-group>
    <release-group id="rg-uuid-2" type="Single">
      <title>Another Brick in the Wall</title>
      <first-release-date>1979-11-30</first-release-date>
      <artist-credit>
        <name-credit>
          <artist id="artist-uuid-1">
            <name>Pink Floyd</name>
          </artist>
        </name-credit>
      </artist-credit>
    </release-group>
  </release-group-list>
</metadata>`)

	result, err := ParseReleaseGroups(data)
	if err != nil {
		t.Fatalf("ParseReleaseGroups() error = %v", err)
	}

	if result.Count != 2 {
		t.Errorf("ParseReleaseGroups().Count = %d, want 2", result.Count)
	}

	if len(result.ReleaseGroups) != 2 {
		t.Fatalf("ParseReleaseGroups() returned %d groups, want 2", len(result.ReleaseGroups))
	}

	expected := []ReleaseGroup{
		{
			ID:          "rg-uuid-1",
			Title:       "Dark Side of the Moon",
			Type:        "Album",
			ArtistID:    "artist-uuid-1",
			ArtistName:  "Pink Floyd",
			ReleaseDate: "1973-03-01",
		},
		{
			ID:          "rg-uuid-2",
			Title:       "Another Brick in the Wall",
			Type:        "Single",
			ArtistID:    "artist-uuid-1",
			ArtistName:  "Pink Floyd",
			ReleaseDate: "1979-11-30",
		},
	}

	for i, rg := range result.ReleaseGroups {
		if rg.ID != expected[i].ID {
			t.Errorf("ReleaseGroups[%d].ID = %q, want %q", i, rg.ID, expected[i].ID)
		}
		if rg.Title != expected[i].Title {
			t.Errorf("ReleaseGroups[%d].Title = %q, want %q", i, rg.Title, expected[i].Title)
		}
		if rg.Type != expected[i].Type {
			t.Errorf("ReleaseGroups[%d].Type = %q, want %q", i, rg.Type, expected[i].Type)
		}
		if rg.ArtistID != expected[i].ArtistID {
			t.Errorf("ReleaseGroups[%d].ArtistID = %q, want %q", i, rg.ArtistID, expected[i].ArtistID)
		}
		if rg.ArtistName != expected[i].ArtistName {
			t.Errorf("ReleaseGroups[%d].ArtistName = %q, want %q", i, rg.ArtistName, expected[i].ArtistName)
		}
		if rg.ReleaseDate != expected[i].ReleaseDate {
			t.Errorf("ReleaseGroups[%d].ReleaseDate = %q, want %q", i, rg.ReleaseDate, expected[i].ReleaseDate)
		}
	}
}

func TestParseReleaseGroups_Empty(t *testing.T) {
	data := []byte(`<?xml version="1.0" encoding="UTF-8"?>
<metadata xmlns="http://musicbrainz.org/ns/mmd-2.0#">
  <release-group-list count="0">
  </release-group-list>
</metadata>`)

	result, err := ParseReleaseGroups(data)
	if err != nil {
		t.Fatalf("ParseReleaseGroups() error = %v", err)
	}

	if result.Count != 0 {
		t.Errorf("ParseReleaseGroups().Count = %d, want 0", result.Count)
	}

	if len(result.ReleaseGroups) != 0 {
		t.Errorf("ParseReleaseGroups() returned %d groups, want 0", len(result.ReleaseGroups))
	}
}

func TestParseReleaseGroups_MalformedXML(t *testing.T) {
	tests := []struct {
		name string
		data []byte
	}{
		{
			name: "truncated XML",
			data: []byte(`<?xml version="1.0"?><metadata><release-group-list>`),
		},
		{
			name: "not XML at all",
			data: []byte(`this is not xml`),
		},
		{
			name: "wrong root element",
			data: []byte(`<?xml version="1.0"?><wrongRoot><item>test</item></wrongRoot>`),
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			_, err := ParseReleaseGroups(tt.data)
			if err == nil {
				t.Fatal("ParseReleaseGroups() expected error for malformed XML, got nil")
			}
		})
	}
}

func TestParseReleaseGroups_PrimaryAndSecondaryTypes(t *testing.T) {
	data := []byte(`<?xml version="1.0" encoding="UTF-8"?>
<metadata xmlns="http://musicbrainz.org/ns/mmd-2.0#">
  <release-group-list count="2">
    <release-group id="rg-album" type="Album">
      <title>Studio Album</title>
      <primary-type>Album</primary-type>
      <first-release-date>2020-01-01</first-release-date>
      <artist-credit>
        <name-credit>
          <artist id="artist-uuid-2">
            <name>Test Artist</name>
          </artist>
        </name-credit>
      </artist-credit>
    </release-group>
    <release-group id="rg-comp" type="Album Compilation">
      <title>Greatest Hits</title>
      <primary-type>Album</primary-type>
      <secondary-type-list>
        <secondary-type>Compilation</secondary-type>
        <secondary-type>Live</secondary-type>
      </secondary-type-list>
      <first-release-date>2021-05-05</first-release-date>
      <artist-credit>
        <name-credit>
          <artist id="artist-uuid-2">
            <name>Test Artist</name>
          </artist>
        </name-credit>
      </artist-credit>
    </release-group>
  </release-group-list>
</metadata>`)

	result, err := ParseReleaseGroups(data)
	if err != nil {
		t.Fatalf("ParseReleaseGroups() error = %v", err)
	}

	if len(result.ReleaseGroups) != 2 {
		t.Fatalf("ParseReleaseGroups() returned %d groups, want 2", len(result.ReleaseGroups))
	}

	byID := make(map[string]ReleaseGroup)
	for _, rg := range result.ReleaseGroups {
		byID[rg.ID] = rg
	}

	album := byID["rg-album"]
	if album.Type != "Album" {
		t.Errorf("rg-album.Type = %q, want %q", album.Type, "Album")
	}
	if len(album.SecondaryTypes) != 0 {
		t.Errorf("rg-album.SecondaryTypes = %v, want empty", album.SecondaryTypes)
	}

	comp := byID["rg-comp"]
	if comp.Type != "Album" {
		t.Errorf("rg-comp.Type = %q, want %q", comp.Type, "Album")
	}
	// Release groups have no status attribute; the secondary type list is the
	// authoritative source for classifications like Compilation.
	if !contains(comp.SecondaryTypes, "Compilation") || !contains(comp.SecondaryTypes, "Live") {
		t.Errorf("rg-comp.SecondaryTypes = %v, want Compilation and Live", comp.SecondaryTypes)
	}
}

func contains(s []string, want string) bool {
	for _, v := range s {
		if v == want {
			return true
		}
	}
	return false
}