ungana

commit 0a95a8a2bef159c55da7aa97865d962bfed294e6
parent dc666df7747f7aefdb2ee89a08e4cfc8fd303977
Author: Carlosokumu <carlosokumu254@gmail.com>
Date:   Tue, 19 Aug 2025 14:49:51 +0300

add an AttachmentManager that:
- creates attachment
- validates attachment file type according to ctx rules.
- returns a SHA256 digest of the file content.

Diffstat:
A
calendarapp/attachment/attachment_manager.py
 | 
51
+++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 51 insertions(+), 0 deletions(-)
diff --git a/calendarapp/attachment/attachment_manager.py b/calendarapp/attachment/attachment_manager.py
@@ -0,0 +1,50 @@
+import os
+import hashlib
+import mimetypes
+
+class AttachmentManager:
+    def __init__(self):
+        pass
+
+    def create_attachment(self, file_path: str, ctx: str):
+        if not os.path.exists(file_path):
+            raise FileNotFoundError(f"Attachment file not found: {file_path}")
+        if not os.access(file_path, os.R_OK):
+            raise PermissionError(f"Cannot read attachment file: {file_path}")
+
+        self.validate(file_path, ctx)
+        digest = self.digest(file_path)
+
+        mime_type, _ = mimetypes.guess_type(file_path)
+        if not mime_type:
+            raise ValueError(f"Cannot determine MIME type of {file_path}")
+
+        value = f"sha256:{digest}"
+        params = {
+            "FMTTYPE": mime_type,
+            "CTX": ctx,
+        }
+        return ("ATTACH", value, params)
+
+
+
+    def validate(self, file_path: str, ctx: str) -> None:
+        """Validate attachment file type according to ctx rules."""
+        if not os.path.isfile(file_path):
+            raise FileNotFoundError(f"Attachment file not found: {file_path}")
+
+        mime_type, _ = mimetypes.guess_type(file_path)
+
+        if ctx == "poster" and not (mime_type and mime_type.startswith("image/")):
+            raise ValueError(f"Poster must be an image file, got {mime_type}")
+
+        if ctx == "long" and not (mime_type and mime_type.startswith("text/")):
+            raise ValueError(f"Long attachment must be a text file, got {mime_type}")
+
+    def digest(self, file_path: str) -> str:
+        """Return SHA256 digest of the file content."""
+        h = hashlib.sha256()
+        with open(file_path, "rb") as f:
+            for chunk in iter(lambda: f.read(4096), b""):
+                h.update(chunk)
+        return h.hexdigest()
+\ No newline at end of file