UI enhancements, i18n, history drawer, and requested features

server/prompts.mjs

@@ -91,6 +91,7 @@ Output ONE short Suno style description.
 Requirements:
 - A cohesive, production-ready combination of genres, instruments, BPM, mood,
   and vocal style (or "instrumental, no vocals" if appropriate).
+- If the user provides a music idea, tailor the style to complement it naturally.
 - Comma-separated keywords. No sentences, no bullet points, no labels.
 - Maximum 25 words.
 - Output ONLY the style description line — no quotes, no commentary, no prefix,
@@ -108,6 +109,8 @@ Output ONE short Suno style description.
 
 Requirements:
 - DELIBERATELY combine genres, eras, or instruments that don't normally mix.
+- If the user provides a music idea, use it as a jumping-off point for an
+  unexpected, surprising twist on that idea.
 - The combination should still be parseable by Suno: use real instrument and
   genre names, include a BPM, mention a vocal style.
 - Comma-separated keywords. No sentences, no bullet points, no labels.
@@ -122,12 +125,40 @@ Examples of the expected output (do NOT copy these verbatim):
 - medieval lute and drum & bass, fingerpicked strings, reese bass, 174 BPM
 - tuvan throat singing over tropical house, guttural vocals, marimba, 120 BPM`;
 
+export const SYSTEM_PROMPT_LYRICS_PARTIAL = `You are a music production assistant specializing in Suno AI song creation.
+
+The user has existing lyrics and wants to regenerate a SPECIFIC selected passage only.
+
+Rules:
+- Rewrite ONLY the selected passage. Keep everything outside it exactly the same.
+- Match the existing rhyme scheme, meter, and section structure.
+- Keep the same emotional tone, language, and Suno section tags.
+- The lyrics must NOT reference the genre, instruments, or music production.
+- Output ONLY the rewritten passage text — no JSON, no explanation, no quotes around it.
+- Do NOT include section tags in your output unless the selected passage already contained them.`;
+
 export function buildSystemPrompt(req) {
+  if (req.section === 'lyrics_partial') return SYSTEM_PROMPT_LYRICS_PARTIAL;
   if (req.section === 'all') return SYSTEM_PROMPT_ALL;
   return SYSTEM_PROMPT_PARTIAL;
 }
 
 export function buildUserMessage(req) {
+  if (req.section === 'lyrics_partial') {
+    return [
+      `Music idea: ${req.input}`,
+      `Language: ${req.language}`,
+      req.mood ? `Mood: ${req.mood}` : '',
+      req.vocals ? `Vocals: ${req.vocals}` : '',
+      '',
+      'Full current lyrics:',
+      req.context?.lyrics ?? '',
+      '',
+      'Selected passage to rewrite:',
+      req.selected_text ?? '',
+    ].filter(l => l !== null).join('\n');
+  }
+
   const lines = [];
   lines.push(`Music idea: ${req.input}`);
   lines.push(`Language: ${req.language}`);
@@ -145,6 +176,8 @@ export function buildUserMessage(req) {
   return lines.join('\n');
 }
 
-export function buildStylePrompt(mode) {
-  return mode === 'crazy' ? SYSTEM_PROMPT_STYLE_CRAZY : SYSTEM_PROMPT_STYLE_NORMAL;
+export function buildStylePrompt(mode, idea) {
+  const base = mode === 'crazy' ? SYSTEM_PROMPT_STYLE_CRAZY : SYSTEM_PROMPT_STYLE_NORMAL;
+  if (!idea || !idea.trim()) return base;
+  return base + `\n\nUser's music idea (use as context for tailoring the style): "${idea.trim()}"`;
 }