from __future__ import annotations

import json
from pathlib import Path
from uuid import uuid4

from app.core.config import settings
from app.repositories.scheme_artifacts import create_scheme_artifact, list_scheme_artifacts


def _preview_storage_dir() -> Path:
    path = Path(settings.storage_preview_dir)
    path.mkdir(parents=True, exist_ok=True)
    return path


async def save_publish_preview_artifact(
    *,
    scheme_id: str,
    scheme_version_id: str,
    payload: dict,
    baseline_scheme_version_id: str | None,
) -> dict:
    artifact_dir = _preview_storage_dir() / uuid4().hex
    artifact_dir.mkdir(parents=True, exist_ok=True)
    storage_path = artifact_dir / "publish-preview.json"
    storage_path.write_text(json.dumps(payload, ensure_ascii=False, indent=2), encoding="utf-8")

    artifact = await create_scheme_artifact(
        scheme_id=scheme_id,
        scheme_version_id=scheme_version_id,
        artifact_type="publish_preview",
        artifact_variant=baseline_scheme_version_id or "default",
        storage_path=str(storage_path),
        meta_json={
            "baseline_scheme_version_id": baseline_scheme_version_id,
            "summary": payload.get("summary"),
        },
    )
    return artifact


async def get_latest_publish_preview_artifact(
    *,
    scheme_version_id: str,
    baseline_scheme_version_id: str | None,
):
    rows = await list_scheme_artifacts(scheme_version_id=scheme_version_id)
    variant = baseline_scheme_version_id or "default"

    matching = [
        row for row in rows
        if row.artifact_type == "publish_preview" and row.artifact_variant == variant
    ]
    if not matching:
        return None

    matching.sort(key=lambda row: (row.created_at, row.id), reverse=True)
    return matching[0]