Implement existing lyrics revision flow

2026-09-13 20:51:31 +02:00
parent 5e1d3d7246
commit 1bf84ca049
3 changed files with 224 additions and 1 deletions
@@ -0,0 +1,61 @@
+import Foundation
+
+public final class ExistingLyricsRevisionDirector: Sendable {
+    private let aiService: any AIService
+
+    public init(aiService: any AIService) {
+        self.aiService = aiService
+    }
+
+    public func reviseExistingLyrics(
+        in project: SongProject,
+        sourceLyrics: Lyrics? = nil,
+        instruction: String,
+        mode: LyricsRevisionMode,
+        conversation: [AIConversationMessage] = [],
+        localeIdentifier: String? = nil,
+        revisedAt: Date = Date()
+    ) async throws -> SongProjectUpdateResult {
+        guard mode != .writeFromIdea else {
+            throw ExistingLyricsRevisionDirectorError.unsupportedMode(mode)
+        }
+
+        let trimmedInstruction = instruction.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmedInstruction.isEmpty else {
+            throw ExistingLyricsRevisionDirectorError.emptyInstruction
+        }
+
+        let lyricsToRevise = sourceLyrics ?? project.lyrics
+        guard !lyricsToRevise.text.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else {
+            throw ExistingLyricsRevisionDirectorError.emptySourceLyrics
+        }
+
+        let request = LyricsRevisionRequest(
+            context: AIRequestContext(
+                userInstruction: trimmedInstruction,
+                conversation: conversation,
+                localeIdentifier: localeIdentifier
+            ),
+            project: project,
+            sourceLyrics: lyricsToRevise,
+            mode: mode
+        )
+        let result = try await aiService.reviseLyrics(from: request)
+
+        var updatedProject = project
+        updatedProject.lyrics = result.lyrics
+        updatedProject.updatedAt = revisedAt
+
+        return SongProjectUpdateResult(
+            project: updatedProject,
+            changedScopes: [.lyrics],
+            notes: result.notes
+        )
+    }
+}
+
+public enum ExistingLyricsRevisionDirectorError: Error, Equatable, Sendable {
+    case emptyInstruction
+    case emptySourceLyrics
+    case unsupportedMode(LyricsRevisionMode)
+}