Pear-Commerce
diff --git a/‎servers/fastapi/tests/unit/test_filename_utils.py‎
Lines changed: 32 additions & 0 deletions b/‎servers/fastapi/tests/unit/test_filename_utils.py‎
Lines changed: 32 additions & 0 deletions
diff --git a/‎servers/fastapi/utils/export_utils.py‎
Lines changed: 3 additions & 3 deletions b/‎servers/fastapi/utils/export_utils.py‎
Lines changed: 3 additions & 3 deletions
diff --git a/‎servers/fastapi/utils/filename_utils.py‎
Lines changed: 18 additions & 0 deletions b/‎servers/fastapi/utils/filename_utils.py‎
Lines changed: 18 additions & 0 deletions
@@ -0,0 +1,32 @@
+from pathvalidate import sanitize_filename
+
+from utils.filename_utils import safe_export_basename, MAX_EXPORT_BASENAME_BYTES
+
+
+def test_safe_export_basename_short_name_unchanged():
+    assert safe_export_basename("Hello World") == "Hello World"
+
+
+def test_safe_export_basename_empty_falls_back_to_presentation():
+    assert safe_export_basename("") == "presentation"
+    assert safe_export_basename("   ") == "presentation"
+
+
+def test_safe_export_basename_long_ascii_truncated_with_hash():
+    long_name = "a" * 300
+    result = safe_export_basename(long_name)
+    assert len(result.encode("utf-8")) <= MAX_EXPORT_BASENAME_BYTES
+    assert "_" in result
+
+
+def test_safe_filename_japanese_under_os_limit():
+    title = "2026下半期営業戦略 " + "あ" * 80
+    safe = safe_export_basename(sanitize_filename(title))
+    assert len(safe.encode("utf-8")) + len(".pptx") <= 255
+
+
+def test_safe_export_basename_exactly_at_limit_unchanged():
+    name = "x" * MAX_EXPORT_BASENAME_BYTES
+    result = safe_export_basename(name)
+    assert result == name
+    assert len(result.encode("utf-8")) == MAX_EXPORT_BASENAME_BYTES
@@ -7,6 +7,7 @@
 from pathvalidate import sanitize_filename
 
 from models.presentation_and_path import PresentationAndPath
+from utils.filename_utils import safe_export_basename
 from services.export_task_service import EXPORT_TASK_SERVICE
 from utils.runtime_limits import log_memory
 
@@ -28,7 +29,6 @@ def _build_presentation_export_url(presentation_id: uuid.UUID) -> tuple[str, str
     fastapi_url = _get_next_public_fastapi_url()
     if fastapi_url:
         params["fastapiUrl"] = fastapi_url
-
     return (
         f"{_get_next_public_url().rstrip('/')}/pdf-maker?{urlencode(params)}",
         fastapi_url,
@@ -48,9 +48,10 @@ async def export_presentation(
         export_as=export_as,
     )
     export_url, fastapi_url = _build_presentation_export_url(presentation_id)
+    name = (title or "").strip() or str(uuid.uuid4())
     export_result = await EXPORT_TASK_SERVICE.export_from_url(
         url=export_url,
-        title=sanitize_filename(title or str(uuid.uuid4())),
+        title=safe_export_basename(sanitize_filename(name)),
         export_as=export_as,
         fastapi_url=fastapi_url,
         cookie_header=cookie_header,
@@ -61,7 +62,6 @@ async def export_presentation(
         presentation_id=str(presentation_id),
         export_as=export_as,
     )
-
     return PresentationAndPath(
         presentation_id=presentation_id,
         path=export_result.path,
 
@@ -0,0 +1,18 @@
+import hashlib
+
+MAX_EXPORT_BASENAME_BYTES = 200
+
+
+def safe_export_basename(name: str, max_bytes: int = MAX_EXPORT_BASENAME_BYTES) -> str:
+    name = (name or "").strip() or "presentation"
+
+    encoded = name.encode("utf-8")
+
+    if len(encoded) <= max_bytes:
+        return name
+
+    suffix = hashlib.md5(encoded).hexdigest()[:8]
+    budget = max_bytes - len(suffix) - 1
+    truncated = encoded[:budget].decode("utf-8", errors="ignore").rstrip()
+
+    return f"{truncated}_{suffix}" if truncated else suffix