Feature: Enable users to customize date parsing via plugins (#11931)

src/documents/plugins/date_parsing/base.py

@@ -0,0 +1,124 @@
+import datetime
+import logging
+from abc import ABC
+from abc import abstractmethod
+from collections.abc import Iterator
+from dataclasses import dataclass
+from types import TracebackType
+
+try:
+    from typing import Self
+except ImportError:
+    from typing_extensions import Self
+
+import dateparser
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass(frozen=True, slots=True)
+class DateParserConfig:
+    """
+    Configuration for a DateParser instance.
+
+    This object is created by the factory and passed to the
+    parser's constructor, decoupling the parser from settings.
+    """
+
+    languages: list[str]
+    timezone_str: str
+    ignore_dates: set[datetime.date]
+
+    # A "now" timestamp for filtering future dates.
+    # Passed in by the factory.
+    reference_time: datetime.datetime
+
+    # Settings for the default RegexDateParser
+    # Other plugins should use or consider these, but it is not required
+    filename_date_order: str | None
+    content_date_order: str
+
+
+class DateParserPluginBase(ABC):
+    """
+    Abstract base class for date parsing strategies.
+
+    Instances are configured via a DateParserConfig object.
+    """
+
+    def __init__(self, config: DateParserConfig):
+        """
+        Initializes the parser with its configuration.
+        """
+        self.config = config
+
+    def __enter__(self) -> Self:
+        """
+        Enter the runtime context related to this object.
+
+        Subclasses can override this to acquire resources (connections, handles).
+        """
+        return self
+
+    def __exit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
+    ) -> None:
+        """
+        Exit the runtime context related to this object.
+
+        Subclasses can override this to release resources.
+        """
+        # Default implementation does nothing.
+        # Returning None implies exceptions are propagated.
+
+    def _parse_string(
+        self,
+        date_string: str,
+        date_order: str,
+    ) -> datetime.datetime | None:
+        """
+        Helper method to parse a single date string using dateparser.
+
+        Uses configuration from `self.config`.
+        """
+        try:
+            return dateparser.parse(
+                date_string,
+                settings={
+                    "DATE_ORDER": date_order,
+                    "PREFER_DAY_OF_MONTH": "first",
+                    "RETURN_AS_TIMEZONE_AWARE": True,
+                    "TIMEZONE": self.config.timezone_str,
+                },
+                locales=self.config.languages,
+            )
+        except Exception as e:
+            logger.error(f"Error while parsing date string '{date_string}': {e}")
+            return None
+
+    def _filter_date(
+        self,
+        date: datetime.datetime | None,
+    ) -> datetime.datetime | None:
+        """
+        Helper method to validate a parsed datetime object.
+
+        Uses configuration from `self.config`.
+        """
+        if (
+            date is not None
+            and date.year > 1900
+            and date <= self.config.reference_time
+            and date.date() not in self.config.ignore_dates
+        ):
+            return date
+        return None
+
+    @abstractmethod
+    def parse(self, filename: str, content: str) -> Iterator[datetime.datetime]:
+        """
+        Parses a document's filename and content, yielding valid datetime objects.
+        """