From 097d4488ef5ea117ba725dccecab53493bd90dc4 Mon Sep 17 00:00:00 2001
From: c0dev0id <sh+git@codevoid.de>
Date: Wed, 24 Jun 2026 17:52:25 +0200
Subject: [PATCH] Export metadata edits (title, composer, source, encrypter)
 via patchScore

---
 static/components/PaneCP.js |  2 +-
 static/exporter.js          | 29 +++++++++++++++++++++++++++--
 test-parser.mjs             | 26 ++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/static/components/PaneCP.js b/static/components/PaneCP.js
index fa1a5b4..56eb988 100644
--- a/static/components/PaneCP.js
+++ b/static/components/PaneCP.js
@@ -47,7 +47,7 @@ export const PaneCP = {
             try {
                 const raw = await fetchScoreText(props.store.credentials);
                 props.store.rawScoreText = raw;
-                const patched = patchScore(raw, props.store.scoreModel.instruments, props.store.scoreModel.bars);
+                const patched = patchScore(raw, props.store.scoreModel.instruments, props.store.scoreModel.bars, props.store.scoreModel.info);
                 await putScoreText(patched, props.store.credentials);
                 props.store.synthesisStatus = { frozen: false, currently_rendered_notes: 0, notes_in_total: 0 };
             } catch (e) {
diff --git a/static/exporter.js b/static/exporter.js
index 92d941c..2e2bee6 100644
--- a/static/exporter.js
+++ b/static/exporter.js
@@ -141,6 +141,31 @@ export function exportInstrument(instr) {
 // Replace dirty instrument blocks and dirty bar _meta blocks.
 // Voice note content in bar documents is left verbatim.
 
+const META_KEYS = ['title', 'composer', 'source', 'encrypter'];
+
+function patchMetadata(text, info) {
+    if (!info) return text;
+    const lines = text.split('\n');
+    const replaced = new Set();
+
+    const out = lines.map(line => {
+        for (const key of META_KEYS) {
+            if (line.startsWith(key + ':') && info[key] != null && info[key] !== '') {
+                replaced.add(key);
+                return `${key}: ${info[key]}`;
+            }
+        }
+        return line;
+    });
+
+    const prepend = META_KEYS
+        .filter(k => !replaced.has(k) && info[k] != null && info[k] !== '')
+        .map(k => `${k}: ${info[k]}`);
+    if (prepend.length) out.unshift(...prepend);
+
+    return out.join('\n');
+}
+
 function patchInstrumentHeader(text, instruments) {
     const lines = text.split('\n');
     const result = [];
@@ -217,11 +242,11 @@ function patchBarMeta(doc, bar) {
     return out.join('\n');
 }
 
-export function patchScore(rawScoreText, instruments, bars = []) {
+export function patchScore(rawScoreText, instruments, bars = [], info = null) {
     const SEP = '\n---\n';
     const [header, ...barDocs] = rawScoreText.split(SEP);
 
-    const patchedHeader = patchInstrumentHeader(header, instruments);
+    const patchedHeader = patchInstrumentHeader(patchMetadata(header, info), instruments);
 
     if (!barDocs.length) return patchedHeader;
 
diff --git a/test-parser.mjs b/test-parser.mjs
index 3a12ac5..3026f3c 100644
--- a/test-parser.mjs
+++ b/test-parser.mjs
@@ -403,6 +403,32 @@ ok('clean bar unchanged', barPatched.includes('beats_per_minute: 100'));
 ok('clean bar voice preserved', barPatched.includes('- D4 4'));
 ok('document separators preserved', (barPatched.match(/\n---\n/g) ?? []).length === 2);
 
+// ── patchScore metadata ────────────────────────────────────────────────────
+section('patchScore metadata');
+const META_SCORE = `title: Old Title
+composer: Old Composer
+source: Some Book
+
+instrument alpha:
+  character:
+    A: "1:0,10;1,0"
+`;
+const updatedInfo = { title: 'New Title', composer: 'New Composer', source: '', encrypter: 'Me' };
+const metaPatched = patchScore(META_SCORE, [], [], updatedInfo);
+ok('existing title replaced', metaPatched.includes('title: New Title'));
+ok('existing composer replaced', metaPatched.includes('composer: New Composer'));
+ok('empty value leaves existing line', metaPatched.includes('source: Some Book'));
+ok('new key prepended', metaPatched.includes('encrypter: Me'));
+ok('instrument block untouched', metaPatched.includes('instrument alpha:'));
+
+const META_SCORE_NO_TITLE = `composer: Bach\n\ninstrument ki:\n  character:\n`;
+const noTitlePatched = patchScore(META_SCORE_NO_TITLE, [], [], { title: 'Fugue', composer: 'Bach' });
+ok('missing title prepended', noTitlePatched.includes('title: Fugue'));
+ok('existing composer not duplicated', (noTitlePatched.match(/^composer:/mg) ?? []).length === 1);
+
+const nullInfoPatched = patchScore(META_SCORE, [], [], null);
+ok('null info leaves metadata unchanged', nullInfoPatched.includes('title: Old Title'));
+
 // ── Summary ────────────────────────────────────────────────────────────────
 console.log(`\n══ ${pass} passed, ${fail} failed ══\n`);
 process.exit(fail > 0 ? 1 : 0);