#!/usr/bin/env python3

import codecs
import subprocess
import os
import sys

def main():
    name = os.path.basename(sys.argv[0])
    if name == "pacorphan":
        pacorphan_main()
    elif name == "aptorphan":
        aptorphan_main()
    else:
        print("This script must be named pacorphan or aptorphan!", file=sys.stderr)
        sys.exit(1)

def pacorphan_main():
    keep_pkg_list = load_keep_pkg_list("pacorphan")
    unneeded_pkg_list = list(run(["pacman", "-Qttq"]))
    installed_pkg_list = list(run(["pacman", "-Qq"]))
    explicit_pkg_list = list(run(["pacman", "-Qeq"]))
    mark_explicit_list = []
    need_install_list = []

    for pkg in keep_pkg_list:
        if pkg in unneeded_pkg_list:
            unneeded_pkg_list.remove(pkg)

        if pkg in explicit_pkg_list:
            explicit_pkg_list.remove(pkg)
        else:
            if pkg in installed_pkg_list:
                mark_explicit_list.append(pkg)
            else:
                need_install_list.append(pkg)

    if unneeded_pkg_list:
        print("# Found packages to remove")
        print("sudo pacman -R " + " ".join(unneeded_pkg_list))
        print()

    if explicit_pkg_list:
        print("# Found explicitly installed packages to keep or remove")
        print("echo " + " ".join(explicit_pkg_list) + " | tr ' ' '\\n' >> ~/.pacorphan/keep")
        print("sudo pacman -D --asdeps " + " ".join(explicit_pkg_list))
        print()

    if mark_explicit_list:
        print("# Found packages which should be marked as explicitly installed")
        print("sudo pacman -D --asexplicit " + " ".join(mark_explicit_list))
        print()

    if need_install_list:
        print("# Found packages which should be installed")
        print("sudo pacman -S " + " ".join(need_install_list))
        print()

def aptorphan_main():
    ensure_apt_config_is_sane()

    keep_pkg_list = load_keep_pkg_list("aptorphan")
    mark_explicit_list = []
    need_install_list = []
    installed_pkg_list = list(run(["aptitude", "search", "?or(~i!~aremove,~ainstall)", "-F", "%p"]))
    explicit_pkg_list = list(run(["aptitude", "search", "?or(~i!~M!~aremove,~ainstall!~M)", "-F", "%p"]))

    for pkg in keep_pkg_list:
        if pkg in explicit_pkg_list:
            explicit_pkg_list.remove(pkg)
        else:
            if pkg in installed_pkg_list:
                mark_explicit_list.append(pkg)
            else:
                need_install_list.append(pkg)


    if mark_explicit_list:
        print("# Found packages which should be marked as explicitly installed")
        print("sudo aptitude --schedule-only install " + " ".join([("'"+x+"&m'") for x in mark_explicit_list]))
        print()

    if need_install_list:
        print("# Found packages which should be installed")
        print("sudo aptitude --schedule-only install " + " ".join(need_install_list))
        print()

    if explicit_pkg_list:
        print("# Found explicitly installed packages to keep or remove")
        print("echo " + " ".join(explicit_pkg_list) + " | tr ' ' '\\n' >> ~/.aptorphan/keep")
        print("sudo aptitude --schedule-only install " + " ".join([(x+"+M") for x in explicit_pkg_list]))
        print()

def ensure_apt_config_is_sane():
    required_config = """
APT::Install-Recommends "false";
APT::Install-Suggests "false";
APT::AutoRemove::RecommendsImportant "false";
APT::AutoRemove::SuggestsImportant "false";
""".strip().split("\n")

    actual_config = run(["apt-config", "dump"])

    missing_lines = []
    for required_line in required_config:
        for line in actual_config:
            if line == required_line:
                break
        else:
            missing_lines.append(required_line)
    if missing_lines:
        print("Missing apt-config, add these lines to /etc/apt/apt.conf.d/99recommends-disable")
        print("\n".join(missing_lines))
        sys.exit(1)


def load_keep_pkg_list(name):
    config_path = find_config_path(name)
    if not os.path.isdir(config_path):
        print("# WARNING, you should create a directory at %s" % config_path)
        return []

    result = []

    for filename in sorted(os.listdir(config_path)):
        if filename.startswith("."):
            continue
        full_filename = os.path.join(config_path, filename)
        for pkg in codecs.open(full_filename, "r", "utf-8"):
            pkg = strip_comment(pkg).strip()
            if not pkg:
                continue
            if filename[0] != "~" and pkg[0] != "~":
                if pkg in result:
                    print("# Duplicate entry:", pkg, "in file", filename)
                    continue
                result.append(pkg)
            else:
                pkg = pkg.strip("~")
                if pkg not in result:
                    print("# Redundant removal:", pkg, "in file", filename)
                    continue
                result.remove(pkg)

    return result

def find_config_path(name):
    homedir_path = os.path.expanduser("~/.%s" % name)
    if os.path.isdir(homedir_path):
        return homedir_path

    if "XDG_CONFIG_HOME" not in os.environ:
        return os.path.expanduser("~/.config/%s" % name)
    else:
        return os.path.join(os.environ["XDG_CONFIG_HOME"], name)

def strip_comment(line):
    pos = line.find("#")
    if pos >= 0:
        line = line[:pos]
    return line.strip()

def run(cmd):
    for line in subprocess.check_output(cmd).decode("utf-8").split("\n"):
        line = line.strip()
        if line:
            yield line

if __name__ == "__main__":
    main()