feat: add install command

Not wired yet

src/caelestia/utils/dots/packages.py

@@ -0,0 +1,129 @@
+import shutil
+import subprocess
+from abc import ABC, abstractmethod
+from pathlib import Path
+
+from caelestia.utils.io import fatal, info
+
+AUR_HELPERS = "paru", "yay"
+
+
+def _install_aur_helper(helper: str, noconfirm: bool = False) -> None:
+    pacman_cmd = ["sudo", "pacman", "-S", "--needed", "git", "base-devel"]
+    if noconfirm:
+        pacman_cmd.append("--noconfirm")
+    subprocess.run(pacman_cmd, check=True)
+
+    repo_url = f"https://aur.archlinux.org/{helper}.git"
+    repo_dir = f"/tmp/{helper}"
+    subprocess.run(["git", "clone", repo_url, repo_dir], check=True)
+
+    makepkg_cmd = ["makepkg", "-si"]
+    if noconfirm:
+        makepkg_cmd.append("--noconfirm")
+    subprocess.run(makepkg_cmd, cwd=repo_dir, check=True)
+
+    try:
+        shutil.rmtree(repo_dir)
+    except FileNotFoundError:
+        pass
+
+    if helper == "yay":
+        subprocess.run(["yay", "-Y", "--gendb"], check=True)
+        subprocess.run(["yay", "-Y", "--devel", "--save"], check=True)
+    else:
+        subprocess.run(["paru", "--gendb"], check=True)
+
+
+class PackageInstaller(ABC):
+    @staticmethod
+    def get(helper: str | None = None, noconfirm: bool = False) -> "PackageInstaller":
+        """Pick a package installer: the requested/detected AUR helper on Arch, else a no-op."""
+
+        # Not on Arch, can't install packages
+        if shutil.which("pacman") is None:
+            return NoopInstaller()
+
+        # Explicitly given
+        if helper:
+            if not shutil.which(helper):
+                if helper not in AUR_HELPERS:
+                    fatal(f"given AUR helper {helper} is not installed and is unable to be installed automatically.")
+
+                info(f"Given AUR helper not installed. Installing {helper}...")
+                _install_aur_helper(helper, noconfirm)
+            return ArchInstaller(helper, noconfirm)
+
+        # Not given, find installed one
+        for candidate in AUR_HELPERS:
+            if shutil.which(candidate):
+                return ArchInstaller(candidate, noconfirm)
+
+        info("No AUR helper found. Installing paru...")
+        _install_aur_helper("paru", noconfirm)
+        return ArchInstaller("paru", noconfirm)
+
+    # --- Abstract methods ---
+
+    @abstractmethod
+    def install(self, packages: list[str]) -> None: ...
+
+    @abstractmethod
+    def remove(self, packages: list[str]) -> None: ...
+
+    @abstractmethod
+    def build_install(self, directory: Path) -> list[str]:
+        """Build and install the PKGBUILD in `directory`, returning the installed package names."""
+
+
+class NoopInstaller(PackageInstaller):
+    """Used off Arch, where the dots' packages are not available via pacman/AUR."""
+
+    def install(self, packages: list[str]) -> None:
+        if packages:
+            info(f"Skipping package install (not on Arch): {', '.join(packages)}")
+
+    def remove(self, packages: list[str]) -> None:
+        if packages:
+            info(f"Skipping package removal (not on Arch): {', '.join(packages)}")
+
+    def build_install(self, directory: Path) -> list[str]:
+        info(f"Skipping local package build (not on Arch): {directory}")
+        return []
+
+
+class ArchInstaller(PackageInstaller):
+    def __init__(self, helper: str, noconfirm: bool = False) -> None:
+        self.helper = helper
+        self.flags = ["--noconfirm"] if noconfirm else []
+
+    def install(self, packages: list[str], extra_flags: list[str] = []) -> None:
+        if not packages:
+            return
+        subprocess.run([self.helper, "-S", "--needed", *self.flags, *extra_flags, *packages], check=True)
+
+    def remove(self, packages: list[str]) -> None:
+        if not packages:
+            return
+        subprocess.run([self.helper, "-Rns", *self.flags, *packages], check=True)
+
+    def build_install(self, directory: Path) -> list[str]:
+        srcinfo = subprocess.check_output(["makepkg", "--printsrcinfo"], cwd=directory, text=True)
+        names = []
+        depends = []
+        for line in srcinfo.splitlines():
+            key, sep, value = line.partition("=")
+            if not sep:
+                continue
+
+            key = key.strip()
+            if key == "pkgname":
+                names.append(value.strip())
+            elif key == "depends":
+                depends.append(value.strip())
+
+        self.install(depends, extra_flags=["--asdeps"])
+        # -f = force, -s = sync deps, -i = install
+        subprocess.run(["makepkg", "-fsi", *self.flags], cwd=directory, check=True)
+
+        return names