feat(ai): services partages A2 + SSE streaming B4 + confirmations UI B5 (#79)

backend/services/files.py

@@ -0,0 +1,86 @@
+"""File reading services shared by REST routes and the AI tool layer."""
+
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+from backend.services.errors import ServiceError
+from backend.services.paths import resolve_safe_path
+from backend.services.vaults import get_vault_root
+
+logger = logging.getLogger("obsigate.services.files")
+
+
+def read_raw_file(vault_name: str, path: str) -> dict[str, Any]:
+    """Return the raw text content of a vault file (no redaction)."""
+    root = get_vault_root(vault_name)
+    file_path = resolve_safe_path(root, path)
+
+    if not file_path.exists() or not file_path.is_file():
+        raise ServiceError(
+            f"File not found: {path}",
+            code="not_found",
+            status=404,
+            details={"vault": vault_name, "path": path},
+        )
+
+    try:
+        raw = file_path.read_text(encoding="utf-8", errors="replace")
+    except PermissionError as e:
+        logger.error(f"Permission denied reading raw file {path}: {e}")
+        raise ServiceError(f"Permission denied: cannot read file {path}", code="permission_denied", status=403) from e
+    except UnicodeDecodeError:
+        try:
+            raw = file_path.read_bytes().decode("utf-8", errors="replace")
+        except Exception as e:
+            logger.error(f"Error reading binary raw file {path}: {e}")
+            raise ServiceError(f"Cannot read file: {e!s}", code="read_error", status=500) from e
+    except Exception as e:
+        logger.error(f"Unexpected error reading raw file {path}: {e}")
+        raise ServiceError(f"Error reading file: {e!s}", code="read_error", status=500) from e
+
+    return {"vault": vault_name, "path": path, "raw": raw}
+
+
+def read_file_text(
+    vault_name: str,
+    path: str,
+    *,
+    redact: bool = True,
+    max_bytes: int | None = None,
+) -> dict[str, Any]:
+    """Return a vault file's text content, optionally redacted and size-capped.
+
+    Raises:
+        ServiceError: ``not_found`` (404), ``file_too_large`` (413) or a read
+            error (500).
+    """
+    root = get_vault_root(vault_name)
+    target = resolve_safe_path(root, path)
+
+    if not target.exists() or not target.is_file():
+        raise ServiceError(
+            f"File not found: {path}",
+            code="not_found",
+            status=404,
+            details={"vault": vault_name, "path": path},
+        )
+
+    size = target.stat().st_size
+    if max_bytes is not None and size > max_bytes:
+        raise ServiceError(
+            f"File too large ({size} bytes > {max_bytes})",
+            code="file_too_large",
+            status=413,
+            details={"vault": vault_name, "path": path, "size": size},
+        )
+
+    content = target.read_text(encoding="utf-8", errors="replace")
+
+    if redact:
+        from backend.secret_redactor import redact_file_content
+
+        content = redact_file_content(content, path)
+
+    return {"vault": vault_name, "path": path, "size": size, "content": content}