"""Common interface of the render engines."""

from __future__ import annotations

from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from pathlib import Path

from ..models import ConvertRequest


@dataclass
class ChunkRender:
    """Result of rendering a single chunk."""

    path: Path
    page_count: int
    # Anchor name to zero based page index inside this chunk.
    anchor_pages: dict[str, int] = field(default_factory=dict)


class RenderEngine(ABC):
    name: str

    @abstractmethod
    async def available(self) -> bool:
        """True when the engine can render right now."""

    @abstractmethod
    async def render_chunk(
        self,
        html: str,
        base_url: str | None,
        request: ConvertRequest,
        output_path: Path,
        total_pages: int | None = None,
        asset_gate=None,
    ) -> ChunkRender:
        """Render one chunk into output_path."""

    async def shutdown(self) -> None:
        """Release engine resources. Default is a no-op."""
        return None

    @property
    def supports_anchor_pages(self) -> bool:
        """True when the engine can report on which page an anchor landed."""
        return False