"""Fetch library sources — clone from GitHub or resolve local Quicklisp path."""

from __future__ import annotations

import subprocess
from pathlib import Path

from cl_macros.ext.library_index import LibraryInfo

REPOS_DIR = Path("data/repos")


class SourceFetcher:
    def __init__(self, repos_dir: Path | None = None):
        self.repos_dir = repos_dir or REPOS_DIR

    def fetch(self, lib: LibraryInfo) -> Path:
        """Clone or update library, return path to source root."""
        dest = self.repos_dir / lib.name
        dest.parent.mkdir(parents=True, exist_ok=True)

        if dest.exists() and (dest / ".git").exists():
            self._update(dest)
        else:
            self._clone(lib.repo, dest)
        return dest

    def get_source_files(self, lib: LibraryInfo) -> list[Path]:
        """Return all .lisp source files from a library."""
        root = self.fetch(lib)
        src_root = root / lib.cl_source_dir if lib.cl_source_dir else root
        if not src_root.exists():
            src_root = root
        return sorted(
            p for p in src_root.rglob("*.lisp")
            if not p.name.endswith("-test.lisp") and "t/" not in str(p.relative_to(root))
            or self._is_main_test_dir(p, root)
        )

    def get_test_files(self, lib: LibraryInfo) -> list[Path]:
        """Return test .lisp files from a library."""
        root = self.fetch(lib)
        test_files = list(root.rglob("t/*.lisp")) + list(root.rglob("tests/*.lisp"))
        return sorted(set(test_files))

    def get_all_lisp_files(self, lib: LibraryInfo) -> list[Path]:
        """Return all .lisp files (source + test)."""
        return sorted(set(self.get_source_files(lib) + self.get_test_files(lib)))

    def _clone(self, url: str, dest: Path) -> None:
        try:
            subprocess.run(
                ["git", "clone", "--depth", "1", url, str(dest)],
                check=True,
                capture_output=True,
                timeout=120,
            )
        except subprocess.CalledProcessError as e:
            raise RuntimeError(
                f"Failed to clone {url}: {e.stderr.decode() if e.stderr else e}"
            ) from e

    def _update(self, dest: Path) -> None:
        try:
            subprocess.run(
                ["git", "-C", str(dest), "pull", "--ff-only"],
                check=True,
                capture_output=True,
                timeout=60,
            )
        except subprocess.CalledProcessError:
            pass  # Stale clone is better than nothing

    @staticmethod
    def _is_main_test_dir(p: Path, root: Path) -> bool:
        """Allow test files if they're in the main test directory."""
        rel = p.relative_to(root)
        parts = rel.parts
        return len(parts) > 0 and parts[0] == "t"