feat: add lyric music to romanji tool

app/services/lyric_romanji_translator.py

@@ -0,0 +1,59 @@
+import os
+import re
+from app.core.deepseek_client import chat_with_openai
+from app.models.lyric_romanji_translator import FileResult
+
+timestamp_pattern = re.compile(r"^\[\d{2}:\d{2}\.\d{2}\]")
+
+def needs_romaji(lines, idx):
+    if idx + 1 < len(lines) and not timestamp_pattern.match(lines[idx + 1]):
+        return False
+    return True
+
+async def get_romaji(text: str) -> str:
+    messages = [
+        {"role": "system", "content": "Convert Japanese text into romaji only. Output romaji without explanation."},
+        {"role": "user", "content": text}
+    ]
+    return await chat_with_openai(messages)
+
+async def process_lrc_file(filepath: str) -> FileResult:
+    added_lines = 0
+    with open(filepath, "r", encoding="utf-8") as f:
+        lines = f.readlines()
+
+    new_lines = []
+    for idx, line in enumerate(lines):
+        new_lines.append(line)
+
+        if timestamp_pattern.match(line) and needs_romaji(lines, idx):
+            japanese = line.strip().split("]", 1)[-1].strip()
+            if japanese:
+                romaji = await get_romaji(japanese)
+                new_lines.append(f"{romaji}\n")
+                added_lines += 1
+
+    if added_lines > 0:
+        with open(filepath, "w", encoding="utf-8") as f:
+            f.writelines(new_lines)
+
+    return FileResult(file=filepath, processed=added_lines > 0, added_lines=added_lines)
+
+async def translate_lyric_romanji(folder_path: str):
+    results = []
+
+    if not os.path.exists(folder_path):
+        return {"results": [], "status": f"error: folder not found {folder_path}"}
+
+    for root, _, files in os.walk(folder_path):
+        for file in files:
+            if file.endswith(".lrc"):
+                filepath = os.path.join(root, file)
+                print(f"Processing: {filepath}")
+
+                result = await process_lrc_file(filepath)
+
+                # ✅ result is already a FileResult object
+                results.append(result)
+
+    return {"results": results, "status": "completed"}