feat(mac,ios,playback,store): initial macos implementation

Packages/AmphlifyKit/Sources/Store/MemoryLibrary.swift

@@ -115,7 +115,7 @@ public actor MemoryLibrary: Library {
 
     public func tracks(byArtist id: EntityID) -> [Track] {
         tracksByID.values.filter { $0.artistID == id }
-            .sorted { (annotations[$0.id]?.playCount ?? 0, $1.title) > (annotations[$1.id]?.playCount ?? 0, $0.title) }
+            .sorted { (plays($0), $1.title) > (plays($1), $0.title) }
     }
 
     public func tracks(inGenre genre: String) -> [Track] {
@@ -181,14 +181,59 @@ public actor MemoryLibrary: Library {
     public func search(_ query: String) -> SearchResults {
         let needle = query.trimmingCharacters(in: .whitespaces)
         guard !needle.isEmpty else { return SearchResults() }
-        func matches(_ text: String) -> Bool {
-            text.range(of: needle, options: [.caseInsensitive, .diacriticInsensitive]) != nil
+        func named(_ name: String) -> Int? {
+            relevance(of: needle, in: name)
         }
+        func credited(_ title: String, _ artist: String) -> Int? {
+            [named(title), named(artist).map { $0 + 1 }].compactMap(\.self).min()
+        }
+        let popular = tracks().sorted { (plays($0), $1.title) > (plays($1), $0.title) }
+        let artists = ranked(artists()) { named($0.name) }
+        let tracks = Array(ranked(popular) { credited($0.title, $0.artistName) }.prefix(50))
+        let albums = ranked(albums(sortedBy: .title)) { credited($0.title, $0.artistName) }
+        let playlists = ranked(playlists()) { named($0.name) }
+        let candidates = artists.prefix(3).map { $0.map(SearchHit.artist) }
+            + tracks.prefix(12).map { $0.map(SearchHit.track) }
+            + albums.prefix(4).map { $0.map(SearchHit.album) }
+            + playlists.prefix(3).map { $0.map(SearchHit.playlist) }
         var results = SearchResults()
-        results.artists = artists().filter { matches($0.name) }
-        results.albums = albums(sortedBy: .title).filter { matches($0.title) }
-        results.tracks = Array(tracks().filter { matches($0.title) }.prefix(50))
-        results.playlists = playlists().filter { matches($0.name) }
+        results.top = ranked(candidates) { $0.score }.map(\.item.item)
+        results.artists = artists.map(\.item)
+        results.albums = albums.map(\.item)
+        results.tracks = tracks.map(\.item)
+        results.playlists = playlists.map(\.item)
         return results
     }
+
+    private func plays(_ track: Track) -> Int {
+        annotations[track.id]?.playCount ?? 0
+    }
+}
+
+private struct Ranked<Item> {
+    let item: Item
+    let score: Int
+
+    func map<Other>(_ transform: (Item) -> Other) -> Ranked<Other> {
+        Ranked<Other>(item: transform(item), score: score)
+    }
+}
+
+private func ranked<Item>(_ items: [Item], by score: (Item) -> Int?) -> [Ranked<Item>] {
+    items.enumerated()
+        .compactMap { offset, item in score(item).map { (Ranked(item: item, score: $0), offset) } }
+        .sorted { ($0.0.score, $0.1) < ($1.0.score, $1.1) }
+        .map(\.0)
+}
+
+private func relevance(of needle: String, in text: String) -> Int? {
+    let options: String.CompareOptions = [.caseInsensitive, .diacriticInsensitive]
+    guard let range = text.range(of: needle, options: options) else { return nil }
+    if text.compare(needle, options: options) == .orderedSame {
+        return 0
+    }
+    if range.lowerBound == text.startIndex {
+        return 1
+    }
+    return text[text.index(before: range.lowerBound)].isLetter ? 3 : 2
 }