from __future__ import annotations

import logging
from datetime import datetime, timezone
from pathlib import Path

from fastapi import HTTPException, status

from app.core.config import settings
from app.repositories.scheme_artifacts import create_scheme_artifact
from app.repositories.scheme_versions import update_scheme_version_display_artifact
from app.services.storage import save_display_svg
from app.services.svg_display_processor import ALLOWED_MODES, generate_display_svg


logger = logging.getLogger(__name__)


async def regenerate_display_artifact(
    *,
    scheme_id: str,
    scheme_version_id: str,
    upload_id: str,
    original_filename: str,
    sanitized_storage_path: str,
    mode: str,
) -> dict:
    if mode not in ALLOWED_MODES:
        raise HTTPException(
            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
            detail=f"Unsupported display mode: {mode}",
        )

    svg_path = Path(sanitized_storage_path)
    if not svg_path.exists() or not svg_path.is_file():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Sanitized SVG not found for current scheme version",
        )

    sanitized_bytes = svg_path.read_bytes()

    try:
        display_bytes, meta = generate_display_svg(sanitized_bytes, mode)
    except Exception as exc:
        logger.exception(
            "display_svg.regenerate failed scheme_id=%s scheme_version_id=%s mode=%s",
            scheme_id,
            scheme_version_id,
            mode,
        )
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail=f"Current scheme version is not ready for display rendering: {exc.__class__.__name__}",
        )

    storage_path = save_display_svg(
        upload_id=upload_id,
        filename=original_filename,
        content=display_bytes,
    )

    await create_scheme_artifact(
        scheme_id=scheme_id,
        scheme_version_id=scheme_version_id,
        artifact_type="display_svg",
        artifact_variant=mode,
        storage_path=storage_path,
        status="ready",
        meta_json=meta,
    )

    if mode == settings.svg_display_mode:
        await update_scheme_version_display_artifact(
            scheme_version_id=scheme_version_id,
            display_svg_storage_path=storage_path,
            display_svg_status="ready",
            display_svg_generated_at=datetime.now(timezone.utc),
        )

    return {
        "scheme_id": scheme_id,
        "scheme_version_id": scheme_version_id,
        "artifact_type": "display_svg",
        "artifact_variant": mode,
        "storage_path": storage_path,
        "meta": meta,
        "generated_at": datetime.now(timezone.utc).isoformat(),
    }