from __future__ import annotations

from fastapi import HTTPException, status

from app.repositories.scheme_versions import list_scheme_versions


async def select_baseline_scheme_version(
    *,
    scheme_id: str,
    draft_scheme_version_id: str,
    override_scheme_version_id: str | None = None,
):
    versions = await list_scheme_versions(scheme_id=scheme_id, limit=200, offset=0)

    if override_scheme_version_id:
        for row in versions:
            if row.scheme_version_id == override_scheme_version_id:
                if row.scheme_version_id == draft_scheme_version_id:
                    raise HTTPException(
                        status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
                        detail="Baseline override must differ from current draft scheme version",
                    )
                return row, "override"

        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Baseline override scheme version not found",
        )

    published_candidates = [
        row for row in versions
        if row.scheme_version_id != draft_scheme_version_id and row.status == "published"
    ]
    if published_candidates:
        return published_candidates[0], "published"

    previous_candidates = [
        row for row in versions
        if row.scheme_version_id != draft_scheme_version_id
    ]
    if previous_candidates:
        return previous_candidates[0], "previous"

    return None, "none"