"""Storage placement rules shared by dataset and data-processing flows."""

from __future__ import annotations

from app.core.config import get_settings


_INLINE_TEXT_FORMATS = {
    "txt", "text", "md", "markdown", "json", "jsonl", "csv", "tsv",
    "yaml", "yml", "xml", "html", "text/plain", "application/json",
    "application/jsonl", "text/csv",
}


def should_store_in_minio(
    size_bytes: int | None,
    *,
    content_type: str | None = None,
    file_format: str | None = None,
) -> bool:
    """Return whether a file is large enough to use the shared object store.

    Small files remain inline in PostgreSQL so page previews and metadata reads
    do not pay an object-storage round trip.  MinIO is still mandatory for
    large files when it is enabled.
    """

    if not get_settings().minio_enabled:
        return False
    try:
        size = max(0, int(size_bytes or 0))
    except (TypeError, ValueError):
        size = 0
    if size > get_settings().minio_inline_max_bytes:
        return True
    # Binary office/document files remain in MinIO even when small because
    # their original bytes cannot be safely represented by a text DB column.
    normalized_format = str(file_format or "").strip().lower().lstrip(".")
    normalized_type = str(content_type or "").strip().lower().split(";", 1)[0]
    if normalized_format or normalized_type:
        return not (
            normalized_format in _INLINE_TEXT_FORMATS
            or normalized_type in _INLINE_TEXT_FORMATS
            or normalized_type.startswith("text/")
        )
    return False


def storage_backend_for_size(size_bytes: int | None, *, requested: str | None = None) -> str:
    """Return ``minio`` or ``database`` for a managed file."""

    if str(requested or "").strip().lower() == "local":
        return "database"
    return "minio" if should_store_in_minio(size_bytes) else "database"