#!/usr/bin/python3
""" Delete packages from a repository.

Functions:
==========
    del_pkgfiles(cachedir, pkgs)
    repo_remove(db, pkgs, opts=None)
"""

import argparse
import logging
import subprocess
import sys

import packaging_scripts.pacmanconf as pacmanconf
import packaging_scripts.pkgfiles as pkgfiles

# ========== Constants ==========
REPO_REMOVE_CMD = '/usr/bin/repo-remove'
DB_EXT = 'db.tar.xz'

# ========== Logging setup ==========
console_formatter = logging.Formatter('==> %(levelname)s %(message)s')
syslog = logging.getLogger(__name__)
syslog.setLevel(logging.DEBUG)

stdout_handler = logging.StreamHandler(sys.stdout)
stdout_handler.setLevel(logging.INFO)
stdout_handler.setFormatter(console_formatter)

stderr_handler = logging.StreamHandler()
stderr_handler.setLevel(logging.ERROR)
stderr_handler.setFormatter(console_formatter)

syslog.addHandler(stdout_handler)
syslog.addHandler(stderr_handler)


# ========== Functions ==========
def del_pkgfiles(cachedir, pkgs):
    """ Remove package files from the repository directory.

    :param cachedir: directory to operate on
    :type cachedir: str, bytes, or path-like object
    :param pkgs: names of packages to remove
    :type pkgs: any container object
    """
    syslog.info(f"Removing package files from {cachedir}")
    syslog.debug(f"Packages: {pkgs}")

    for pkg in pkgs:
        for pkgfile in pkgfiles.get_pkgfiles(pkg, directory=cachedir) +\
                       pkgfiles.get_pkgfiles(pkg, directory=cachedir,
                                             signatures_only=True):
            pkgfile.unlink()
            syslog.info(f"Removed {pkgfile}")


def repo_remove(db, pkgs, opts=None):
    """ Run repo-remove.

    :param repo: the repository to remove from
    :type repo: str
    :param pkgs: the names of the packages to remove
    :type pkgs: any iterable
    :param opts: extra options to pass to repo-remove
    :type opts: list
    :raises: subprocess.CalledProcessError if repo-remove failed
    """
    syslog.info('Removing packages from database')
    syslog.debug(f"Options: {opts}")
    syslog.debug(f"Packages: {pkgs}")

    cmd = [REPO_REMOVE_CMD]

    if opts is not None:
        cmd.extend(opts)

    cmd.append(db)
    cmd.extend(pkgs)
    syslog.debug(f"Final repo-remove command: {cmd}")

    remove_process = subprocess.run(cmd,
                                    check=True,
                                    capture_output=True,
                                    text=True)

    syslog.debug(remove_process.stdout)
    if remove_process.stderr:
        syslog.error(remove_process.stderr)

    syslog.info('Finished removing packages from database')


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('-s', '--sign',
                        dest='opts',
                        action='append_const',
                        const='--sign',
                        help='sign repository file')
    parser.add_argument('-v', '--verbose',
                        action='store_true',
                        help='increase script verbosity')
    parser.add_argument('repository',
                        choices=pacmanconf.list_configured_repos(),
                        help='the repository to operate on',
                        metavar='repo')
    parser.add_argument('packages',
                        default=None,
                        nargs='+',
                        help='packages to remove')

    args = parser.parse_args()
    repo = args.repository
    pkgs = args.packages
    opts = args.opts

    cachedir = f"/var/cache/pacman/{repo}"
    # this assumes that the db file for the repo
    # has the same name as that repo
    db = f"{cachedir}/{repo}/.{DB_EXT}"

    if args.verbose:
        stdout_handler.setLevel(logging.DEBUG)

    del_pkgfiles(cachedir, pkgs)

    try:
        repo_remove(repo, pkgs, opts)
    except subprocess.CalledProcessError as e:
        syslog.error(e)
        exit(2)