1 files changed, 85 insertions, 42 deletions

diff --git a/src/tangara/database/track.cpp b/src/tangara/database/track.cpp
index 49babb6a..ad9db1ba 100644
--- a/src/tangara/database/track.cpp
+++ b/src/tangara/database/track.cpp
@@ -20,6 +20,7 @@
 
 namespace database {
 
+static constexpr char kAllArtistDelimiters[] = ";";
 static constexpr char kGenreDelimiters[] = ",;";
 
 auto tagName(Tag t) -> std::string {
@@ -28,6 +29,8 @@ auto tagName(Tag t) -> std::string {
       return "title";
     case Tag::kArtist:
       return "artist";
+    case Tag::kAllArtists:
+      return "all_artists";
     case Tag::kAlbum:
       return "album";
     case Tag::kAlbumArtist:
@@ -91,6 +94,50 @@ auto tagToString(const TagValue& val) -> std::string {
   return "";
 }
 
+/*
+ * Utility for taking a string containing delimited tags, and splitting it out
+ * into a vector of individual tags.
+ */
+auto parseDelimitedTags(const std::string_view s,
+                        const char* delimiters,
+                        std::pmr::vector<std::pmr::string>& out) -> void {
+  out.clear();
+  std::string src = {s.data(), s.size()};
+  char* token = std::strtok(src.data(), delimiters);
+
+  auto trim_and_add = [&](std::string_view s) {
+    std::string copy = {s.data(), s.size()};
+
+    // Trim the left
+    copy.erase(copy.begin(),
+               std::find_if(copy.begin(), copy.end(), [](unsigned char ch) {
+                 return !std::isspace(ch);
+               }));
+
+    // Trim the right
+    copy.erase(std::find_if(copy.rbegin(), copy.rend(),
+                            [](unsigned char ch) { return !std::isspace(ch); })
+                   .base(),
+               copy.end());
+
+    // Ignore empty strings.
+    if (!copy.empty()) {
+      out.push_back({copy.data(), copy.size()});
+    }
+  };
+
+  if (token == NULL) {
+    // No delimiters found in the input. Treat this as a single result.
+    trim_and_add(s);
+  } else {
+    while (token != NULL) {
+      // Add tokens until no more delimiters found.
+      trim_and_add(token);
+      token = std::strtok(NULL, delimiters);
+    }
+  }
+}
+
 auto TrackTags::create() -> std::shared_ptr<TrackTags> {
   return std::allocate_shared<TrackTags,
                               std::pmr::polymorphic_allocator<TrackTags>>(
@@ -108,21 +155,23 @@ auto valueOrMonostate(std::optional<T> t) -> TagValue {
 auto TrackTags::get(Tag t) const -> TagValue {
   switch (t) {
     case Tag::kTitle:
-      return valueOrMonostate(title_);
+      return valueOrMonostate(title());
     case Tag::kArtist:
-      return valueOrMonostate(artist_);
+      return valueOrMonostate(artist());
+    case Tag::kAllArtists:
+      return allArtists();
     case Tag::kAlbum:
-      return valueOrMonostate(album_);
+      return valueOrMonostate(album());
     case Tag::kAlbumArtist:
-      return valueOrMonostate(album_artist_);
+      return valueOrMonostate(albumArtist());
     case Tag::kDisc:
-      return valueOrMonostate(disc_);
+      return valueOrMonostate(disc());
     case Tag::kTrack:
-      return valueOrMonostate(track_);
+      return valueOrMonostate(track());
     case Tag::kAlbumOrder:
       return albumOrder();
     case Tag::kGenres:
-      return genres_;
+      return genres();
   }
   return std::monostate{};
 }
@@ -135,6 +184,9 @@ auto TrackTags::set(Tag t, std::string_view v) -> void {
     case Tag::kArtist:
       artist(v);
       break;
+    case Tag::kAllArtists:
+      allArtists(v);
+      break;
     case Tag::kAlbum:
       album(v);
       break;
@@ -165,6 +217,7 @@ auto TrackTags::allPresent() const -> std::vector<Tag> {
   };
   add_if_present(Tag::kTitle, title_);
   add_if_present(Tag::kArtist, artist_);
+  add_if_present(Tag::kAllArtists, !allArtists_.empty());
   add_if_present(Tag::kAlbum, album_);
   add_if_present(Tag::kAlbumArtist, album_artist_);
   add_if_present(Tag::kDisc, disc_);
@@ -187,6 +240,16 @@ auto TrackTags::artist() const -> const std::optional<std::pmr::string>& {
 
 auto TrackTags::artist(std::string_view s) -> void {
   artist_ = s;
+  maybeSynthesizeAllArtists();
+}
+
+auto TrackTags::allArtists() const -> std::span<const std::pmr::string> {
+  return allArtists_;
+}
+
+auto TrackTags::allArtists(const std::string_view s) -> void {
+  parseDelimitedTags(s, kAllArtistDelimiters, allArtists_);
+  maybeSynthesizeAllArtists();
 }
 
 auto TrackTags::album() const -> const std::optional<std::pmr::string>& {
@@ -198,6 +261,9 @@ auto TrackTags::album(std::string_view s) -> void {
 }
 
 auto TrackTags::albumArtist() const -> const std::optional<std::pmr::string>& {
+  if (!album_artist_) {
+    return artist_;
+  }
   return album_artist_;
 }
 
@@ -230,41 +296,7 @@ auto TrackTags::genres() const -> std::span<const std::pmr::string> {
 }
 
 auto TrackTags::genres(const std::string_view s) -> void {
-  genres_.clear();
-  std::string src = {s.data(), s.size()};
-  char* token = std::strtok(src.data(), kGenreDelimiters);
-
-  auto trim_and_add = [this](std::string_view s) {
-    std::string copy = {s.data(), s.size()};
-
-    // Trim the left
-    copy.erase(copy.begin(),
-               std::find_if(copy.begin(), copy.end(), [](unsigned char ch) {
-                 return !std::isspace(ch);
-               }));
-
-    // Trim the right
-    copy.erase(std::find_if(copy.rbegin(), copy.rend(),
-                            [](unsigned char ch) { return !std::isspace(ch); })
-                   .base(),
-               copy.end());
-
-    // Ignore empty strings.
-    if (!copy.empty()) {
-      genres_.push_back({copy.data(), copy.size()});
-    }
-  };
-
-  if (token == NULL) {
-    // No delimiters found in the input. Treat this as a single genre.
-    trim_and_add(s);
-  } else {
-    while (token != NULL) {
-      // Add tokens until no more delimiters found.
-      trim_and_add(token);
-      token = std::strtok(NULL, kGenreDelimiters);
-    }
-  }
+  parseDelimitedTags(s, kGenreDelimiters, genres_);
 }
 
 /*
@@ -293,6 +325,17 @@ auto TrackTags::Hash() const -> uint64_t {
   return komihash_stream_final(&stream);
 }
 
+/*
+ * Adds the current 'artist' tag to 'allArtists' if needed. Many tracks lack a
+ * fine-grained 'ARTISTS=' tag (or equivalent), but pushing down this nuance to
+ * consumers of TrackTags adds a lot of complexity.
+ */
+auto TrackTags::maybeSynthesizeAllArtists() -> void {
+  if (allArtists_.empty() && artist_) {
+    allArtists_.push_back(*artist_);
+  }
+}
+
 auto database::TrackData::clone() const -> std::shared_ptr<TrackData> {
   auto data = std::make_shared<TrackData>();
   data->id = id;