community[patch]: Enhance iMessage chat loader with timestamp parsing and message ownership (#14804)

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/community/langchain_community/chat_loaders/imessage.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from datetime import datetime
 from pathlib import Path
 from typing import TYPE_CHECKING, Iterator, List, Optional, Union
 
@@ -12,6 +13,20 @@ if TYPE_CHECKING:
     import sqlite3
 
 
+def nanoseconds_from_2001_to_datetime(nanoseconds: int) -> datetime:
+    # Convert nanoseconds to seconds (1 second = 1e9 nanoseconds)
+    timestamp_in_seconds = nanoseconds / 1e9
+
+    # The reference date is January 1, 2001, in Unix time
+    reference_date_seconds = datetime(2001, 1, 1).timestamp()
+
+    # Calculate the actual timestamp by adding the reference date
+    actual_timestamp = reference_date_seconds + timestamp_in_seconds
+
+    # Convert to a datetime object
+    return datetime.fromtimestamp(actual_timestamp)
+
+
 class IMessageChatLoader(BaseChatLoader):
     """Load chat sessions from the `iMessage` chat.db SQLite file.
 
@@ -92,17 +107,17 @@ class IMessageChatLoader(BaseChatLoader):
         results: List[HumanMessage] = []
 
         query = """
-        SELECT message.date, handle.id, message.text, message.attributedBody
+        SELECT message.date, handle.id, message.text, message.is_from_me, message.attributedBody
         FROM message
         JOIN chat_message_join ON message.ROWID = chat_message_join.message_id
         JOIN handle ON message.handle_id = handle.ROWID
         WHERE chat_message_join.chat_id = ?
         ORDER BY message.date ASC;
-        """
+        """  # noqa: E501
         cursor.execute(query, (chat_id,))
         messages = cursor.fetchall()
 
-        for date, sender, text, attributedBody in messages:
+        for date, sender, text, is_from_me, attributedBody in messages:
             if text:
                 content = text
             elif attributedBody:
@@ -116,7 +131,11 @@ class IMessageChatLoader(BaseChatLoader):
                     content=content,
                     additional_kwargs={
                         "message_time": date,
+                        "message_time_as_datetime": nanoseconds_from_2001_to_datetime(
+                            date
+                        ),
                         "sender": sender,
+                        "is_from_me": bool(is_from_me),
                     },
                 )
             )

libs/community/tests/unit_tests/chat_loaders/test_imessage.py

@@ -1,3 +1,4 @@
+import datetime
 import pathlib
 
 from langchain_community.chat_loaders import imessage, utils
@@ -14,8 +15,27 @@ def test_imessage_chat_loader() -> None:
 
     assert chat_sessions[0]["messages"], "Chat messages should not be empty"
 
+    first_message = chat_sessions[0]["messages"][0]
+
     # message content in text field
-    assert "Yeh" in chat_sessions[0]["messages"][0].content, "Chat content mismatch"
+    assert "Yeh" in first_message.content, "Chat content mismatch"
+
+    # time parsed correctly
+    expected_message_time = 720845450393148160
+    assert (
+        first_message.additional_kwargs["message_time"] == expected_message_time
+    ), "unexpected time"
+
+    expected_parsed_time = datetime.datetime(2023, 11, 5, 2, 50, 50, 393148)
+    assert (
+        first_message.additional_kwargs["message_time_as_datetime"]
+        == expected_parsed_time
+    ), "date failed to parse"
+
+    # is_from_me parsed correctly
+    assert (
+        first_message.additional_kwargs["is_from_me"] is False
+    ), "is_from_me failed to parse"
 
     # short message content in attributedBody field
     assert (