feat: file edit added

webui/backend/app/services/file_ops_service.py

@@ -3,11 +3,12 @@ from __future__ import annotations
 from pathlib import Path
 
 from backend.app.api.errors import AppError
-from backend.app.api.schemas import DeleteResponse, MkdirResponse, RenameResponse, ViewResponse
+from backend.app.api.schemas import DeleteResponse, MkdirResponse, RenameResponse, SaveResponse, ViewResponse
 from backend.app.fs.filesystem_adapter import FilesystemAdapter
 from backend.app.security.path_guard import PathGuard
 
 TEXT_PREVIEW_MAX_BYTES = 256 * 1024
+TEXT_EDIT_MAX_BYTES = 256 * 1024
 TEXT_CONTENT_TYPES = {
     ".txt": "text/plain",
     ".log": "text/plain",
@@ -146,7 +147,7 @@ class FileOpsService:
 
         return DeleteResponse(path=resolved_target.relative)
 
-    def view(self, path: str) -> ViewResponse:
+    def view(self, path: str, for_edit: bool = False) -> ViewResponse:
         resolved_target = self._path_guard.resolve_existing_path(path)
 
         if resolved_target.absolute.is_dir():
@@ -173,6 +174,14 @@ class FileOpsService:
                 details={"path": resolved_target.relative},
             )
 
+        if for_edit and resolved_target.absolute.stat().st_size > TEXT_EDIT_MAX_BYTES:
+            raise AppError(
+                code="file_too_large",
+                message="File is too large for edit",
+                status_code=409,
+                details={"path": resolved_target.relative},
+            )
+
         try:
             preview = self._filesystem.read_text_preview(
                 resolved_target.absolute,
@@ -194,9 +203,71 @@ class FileOpsService:
             encoding="utf-8",
             truncated=preview["truncated"],
             size=preview["size"],
+            modified=preview["modified"],
             content=preview["content"],
         )
 
+    def save(self, path: str, content: str, expected_modified: str) -> SaveResponse:
+        resolved_target = self._path_guard.resolve_existing_path(path)
+
+        if resolved_target.absolute.is_dir():
+            raise AppError(
+                code="type_conflict",
+                message="Source must be a file",
+                status_code=409,
+                details={"path": resolved_target.relative},
+            )
+        if not resolved_target.absolute.is_file():
+            raise AppError(
+                code="type_conflict",
+                message="Unsupported path type for save",
+                status_code=409,
+                details={"path": resolved_target.relative},
+            )
+        if self._content_type_for(resolved_target.absolute) is None:
+            raise AppError(
+                code="unsupported_type",
+                message="File type is not supported for edit",
+                status_code=409,
+                details={"path": resolved_target.relative},
+            )
+        if len(content.encode("utf-8")) > TEXT_EDIT_MAX_BYTES:
+            raise AppError(
+                code="file_too_large",
+                message="File is too large for edit",
+                status_code=409,
+                details={"path": resolved_target.relative},
+            )
+
+        current_modified = self._filesystem.modified_iso(resolved_target.absolute)
+        if current_modified != expected_modified:
+            raise AppError(
+                code="conflict",
+                message="File changed since it was opened",
+                status_code=409,
+                details={"path": resolved_target.relative},
+            )
+
+        try:
+            saved = self._filesystem.write_text_file(
+                resolved_target.absolute,
+                content=content,
+                encoding="utf-8",
+            )
+        except OSError as exc:
+            raise AppError(
+                code="io_error",
+                message="Filesystem operation failed",
+                status_code=500,
+                details={"reason": str(exc)},
+            )
+
+        return SaveResponse(
+            path=resolved_target.relative,
+            size=saved["size"],
+            modified=saved["modified"],
+        )
+
     @staticmethod
     def _join_relative(base: str, name: str) -> str:
         return f"{base}/{name}" if base else name