feat(search): parse advanced search with whoosh-compat and delete the hand-written translator

src/documents/search/_errors.py

@@ -0,0 +1,71 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
+
+class SearchQueryError(ValueError):
+    """
+    Base for user-fixable search query errors.
+
+    Carries a message safe to surface to the user (no internal details). The
+    view layer catches this and returns an HTTP 400, so any future subclass
+    gets the same treatment.
+    """
+
+
+class InvalidDateQuery(SearchQueryError):
+    """Raised when a date field value or range bound cannot be parsed."""
+
+    def __init__(self, field: str | None, value: str | None) -> None:
+        self.field = field
+        self.value = value
+        super().__init__(f"Invalid date value {value!r} for field {field!r}.")
+
+
+class InvalidNumberQuery(SearchQueryError):
+    """Raised when a numeric field value or range bound cannot be parsed."""
+
+    def __init__(self, field: str | None, value: str | None) -> None:
+        self.field = field
+        self.value = value
+        super().__init__(f"Invalid numeric value {value!r} for field {field!r}.")
+
+
+class QueryTooLongError(SearchQueryError):
+    """Raised when a query string exceeds the maximum allowed length.
+
+    whoosh-compat's fieldname tagger is O(n^2) in plain word characters, so an
+    unbounded query is a CPU-exhaustion vector against a single request
+    handler. This is a hard boundary, not a validation nicety.
+    """
+
+    def __init__(self, length: int, limit: int) -> None:
+        self.length = length
+        self.limit = limit
+        super().__init__(
+            f"The search query is too long ({length} characters). "
+            f"The maximum allowed length is {limit} characters.",
+        )
+
+
+class MultipleSearchQueryErrors(SearchQueryError):
+    """Aggregates every user-fixable error from one parse, not just the first."""
+
+    def __init__(self, errors: Sequence[SearchQueryError]) -> None:
+        self.errors = tuple(errors)
+        super().__init__("; ".join(str(e) for e in self.errors))
+
+
+def search_query_error_messages(e: SearchQueryError) -> list[str]:
+    """The user-facing message list for a SearchQueryError.
+
+    Every offending value's message, not just the first, so the user can
+    fix them all in one round-trip. Shared by every view that maps
+    SearchQueryError to an HTTP 400.
+    """
+    if isinstance(e, MultipleSearchQueryErrors):
+        return [str(sub) for sub in e.errors]
+    return [str(e)]