from __future__ import annotations

from collections.abc import Iterable
from pathlib import Path

from vuln_scan.core.models import Ecosystem
from vuln_scan.ecosystems.base import EcosystemHandler


class EcosystemRegistry:
    """
    Registry that manages ecosystem handlers.

    Supports:
    - lookup by ecosystem (O(1))
    - lookup by manifest (exact + glob)
    """

    def __init__(self, handlers: Iterable[EcosystemHandler]):
        handlers = tuple(handlers)

        if not handlers:
            raise ValueError("EcosystemRegistry requires at least one handler")

        self._handlers = handlers

        by_ecosystem: dict[Ecosystem, EcosystemHandler] = {}

        for handler in handlers:
            if handler.ecosystem in by_ecosystem:
                raise ValueError(f"Duplicate handler for ecosystem {handler.ecosystem}")

            by_ecosystem[handler.ecosystem] = handler

        self._by_ecosystem = by_ecosystem

    # ---------------------------------------------------------
    # Lookup methods
    # ---------------------------------------------------------

    def for_manifest(self, manifest_path: str | Path) -> EcosystemHandler | None:
        """
        Return handler for a manifest file.

        Supports:
        - exact filename match
        - glob patterns
        """
        filename = Path(manifest_path).name

        for handler in self._handlers:
            if handler.supports_manifest(filename):
                return handler

        return None

    def for_ecosystem(self, ecosystem: Ecosystem) -> EcosystemHandler | None:
        return self._by_ecosystem.get(ecosystem)

    # ---------------------------------------------------------

    @property
    def handlers(self) -> tuple[EcosystemHandler, ...]:
        return self._handlers