"""Target scraper plugin discovery module.

Auto-detects *_targets_scraper.py files and exposes their scrapers.
"""

from __future__ import annotations

import importlib
import pkgutil
import re
from abc import ABC, abstractmethod
from pathlib import Path


class BaseTargetScraper(ABC):
    """Base class for target scrapers."""

    def __init__(self, url: str = "") -> None:
        self.url = url

    @abstractmethod
    def fetch_targets(self) -> dict:
        """Fetch targets and their core lists. Returns dict matching target YAML format."""
        ...

    @staticmethod
    def pinned_revision(platform: str, platforms_dir: str | None = None) -> str:
        """The upstream revision platforms/<platform>.yml was scraped at.

        A target list describes the same release as the platform's BIOS
        list: read on its own "latest stable tag", a Recalbox 10.2 board list
        filtered 10.1.1 systems. Moving to a new release is a rescrape of the
        platform first.
        """
        import yaml

        directory = Path(platforms_dir) if platforms_dir else (
            Path(__file__).resolve().parents[3] / "platforms"
        )
        with open(directory / f"{platform}.yml", encoding="utf-8") as handle:
            source = str((yaml.safe_load(handle) or {}).get("source", ""))
        for pattern in (
            r"^https://raw\.githubusercontent\.com/[^/]+/[^/]+/([^/]+)/",
            r"^https://github\.com/[^/]+/[^/]+/(?:blob|tree)/([^/]+)/",
            r"^https://gitlab\.com/.+?/-/(?:raw|blob|tree)/([^/]+)/",
        ):
            match = re.match(pattern, source)
            if match:
                return match.group(1)
        raise RuntimeError(
            f"platforms/{platform}.yml names no pinned revision in its source "
            f"({source!r}): rescrape the platform first"
        )

    def write_output(self, data: dict, output_path: str) -> None:
        """Write target data to YAML file."""
        try:
            import yaml
        except ImportError:
            raise ImportError("PyYAML required: pip install pyyaml")
        from common import write_text_atomic

        write_text_atomic(
            output_path, yaml.dump(data, default_flow_style=False, sort_keys=False)
        )


_scrapers: dict[str, type] = {}


def discover_target_scrapers() -> dict[str, type]:
    """Auto-discover all *_targets_scraper.py modules."""
    if _scrapers:
        return _scrapers
    package_dir = Path(__file__).parent
    for finder, name, ispkg in pkgutil.iter_modules([str(package_dir)]):
        if not name.endswith("_targets_scraper"):
            continue
        module = importlib.import_module(f".{name}", package=__package__)
        platform_name = getattr(module, "PLATFORM_NAME", None)
        scraper_class = getattr(module, "Scraper", None)
        if platform_name and scraper_class:
            _scrapers[platform_name] = scraper_class
    return _scrapers