import archinstall
import re
import shutil
import logging
import asyncio
import os
from pathlib import Path

__version__ = 0.4

SUDOERS_FMT = "etc/sudoers.d/{user}"


class PackageClassifier:
    def split(self, packages):
        aur, std = [], []
        for pkg in packages:
            try:
                if (
                    archinstall.lib.general.SysCommand(f"pacman -Ss {pkg}").exit_code
                    == 0
                ):
                    std.append(pkg)
                else:
                    aur.append(pkg)
            except archinstall.lib.exceptions.SysCallError:
                aur.append(pkg)
        return std, aur


class UserManager:
    def __init__(self, user: str, mount_location: Path, installation):
        self.user = user
        self.mount_location = mount_location
        self.installation = installation
        self.user_created = False

    def _run_chroot(self, command):
        return self.installation.arch_chroot(command, run_as=self.user)

    def _sudoers(self):
        return self.mount_location / f"etc/sudoers.d/{self.user}"

    def _home(self):
        return self.mount_location / f"home/{self.user}"

    def create(self):
        if self.user_created:
            return

        archinstall.lib.output.log(
            f"Creating temporary user {self.user}", level=logging.INFO
        )
        self.installation.add_additional_packages(["fakeroot", "base-devel"])

        self._sudoers().write_text(f"{self.user} ALL=(ALL:ALL) NOPASSWD: ALL\n")

        password = archinstall.lib.models.users.Password(plaintext="somethingrandom")
        user = archinstall.lib.models.users.User(
            username=self.user, password=password, groups=[], sudo=False
        )
        self.installation.create_users([user])

        self._home().mkdir(parents=True, exist_ok=True)
        self.installation.arch_chroot(
            f"/usr/bin/chown {self.user}:{self.user} /home/{self.user}"
        )

        self.user_created = True

    def cleanup(self):
        if not self.user_created:
            return

        archinstall.lib.output.log(f"Cleaning up user {self.user}", level=logging.INFO)
        try:
            self._run_chroot("/usr/bin/gpgconf --kill gpg-agent")
            self._run_chroot(f"/usr/bin/killall -u {self.user}")
        except archinstall.lib.exceptions.SysCallError:
            pass

        self.installation.arch_chroot(f"/usr/bin/userdel {self.user}")
        shutil.rmtree(self._home(), ignore_errors=True)
        self._sudoers.unlink(missing_ok=True)
        self.user_created = False


class PackageDownloader:
    def __init__(self, user: str, mount_location: Path, installation):
        self.user = user
        self.mount_location = mount_location
        self.downloaded = []
        self.installation = installation

    def _run(self, command):
        return self.installation.arch_chroot(command, run_as=self.user)

    async def _download_package(self, package: str):
        package_file = f"{package}.tar.gz"
        url = f"https://aur.archlinux.org/cgit/aur.git/snapshot/{package_file}"
        dest = f"/home/{self.user}/{package_file}"

        try:
            loop = asyncio.get_event_loop()
            await loop.run_in_executor(
                None, lambda: self._run(f"/usr/bin/curl {url} > {dest}")
            )
            self.downloaded.append(package)
        except Exception as e:
            archinstall.lib.output.log(
                f"Failed to download {package}: {e}", level=logging.ERROR, fg="red"
            )

    async def download(self, packages):
        archinstall.log(f"Downloading AUR packages: {packages}", level=logging.INFO)
        semaphore = asyncio.Semaphore(3)

        async def sem_task(pkg):
            async with semaphore:
                await self._download_package(pkg)

        await asyncio.gather(*(sem_task(pkg) for pkg in packages))


class PackageInstaller:
    def __init__(self, user: str, mount_location: Path, installation):
        self.user = user
        self.mount_location = mount_location
        self.installation = installation
        self.installed = []
        self.installed_dirs = []

    def _run(self, command):
        return self.installation.arch_chroot(command, run_as=self.user)

    def _untar(self, package: str):
        self._run(
            f"/usr/bin/tar --directory /home/{self.user}/ -xvzf /home/{self.user}/{package}.tar.gz"
        )

    def install(self, package: str):
        self._untar(package)
        build_dir = self.mount_location / "home" / self.user / package

        try:
            with (build_dir / "PKGBUILD").open() as fh:
                content = fh.read()
            gpgkeys = re.findall(r"validpgpkeys=\((.*)\)", content)
            for key in gpgkeys:
                key = key.strip("'\" ")
                self._run(f"/usr/bin/gpg --recv-keys {key}")
        except FileNotFoundError:
            archinstall.lib.output.log(
                f"Missing PKGBUILD for {package}", level=logging.ERROR, fg="red"
            )
            return

        cmd = (
            f"cd /home/{self.user}/{package} && makepkg --force --noconfirm --needed -si"
        )
        result = self._run(f'/bin/bash -c "{cmd}"')
        if result.exit_code != 0:
            archinstall.lib.output.log(
                f"Build failed for {package}", level=logging.ERROR, fg="red"
            )
            return

        self.installed_dirs.append(build_dir)


class Plugin:
    def __init__(self):
        self.user = os.getenv("AUR_USER", "packagebuilder")
        self.lazy_initd = False

    def _lazy_init(self):
        self.installation = archinstall.lib.storage.storage["session"]
        self.classifier = PackageClassifier()
        self.mount_location = Path(self.installation.target)
        self.usermgr = UserManager(self.user, self.mount_location, self.installation)
        self.downloader = PackageDownloader(
            self.user, self.mount_location, self.installation
        )
        self.installer = PackageInstaller(
            self.user, self.mount_location, self.installation
        )
        self.lazy_initd = True

    def on_pacstrap(self, packages: list[str]) -> list[str]:
        if not self.lazy_initd:
            self._lazy_init()

        std, aur = self.classifier.split(packages)
        if not aur:
            return std

        self.usermgr.create()

        asyncio.run(self.downloader.download(aur))

        for pkg in self.downloader.downloaded:
            self.installer.install(pkg)

        self.usermgr.cleanup()

        return std