#!/usr/bin/python

import codecs
import subprocess
import os
import sys

PACORPHAN_PATH = os.path.expanduser("~/.pacorphan")

keep_pkg_list = []
mark_explicit_list = []
need_install_list = []
unneeded_pkg_list = []
installed_pkg_list = []
explicit_pkg_list = []

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

for dirpath, dirnames, filenames in os.walk(PACORPHAN_PATH):
    for filename in filenames:
        if filename.startswith("."):
            continue
        filename = os.path.join(dirpath, filename)
        for pkg in codecs.open(filename, "r", "utf-8"):
            pkg = strip_comment(pkg)
            if pkg in keep_pkg_list:
                print("# Duplicate entry: " + pkg)
            if pkg:
                keep_pkg_list.append(pkg.strip())

for pkg in subprocess.check_output(["pacman", "-Qq"]).decode("utf-8").split():
    installed_pkg_list.append(pkg.strip())

for pkg in subprocess.check_output(["pacman", "-Qtq"]).decode("utf-8").split():
    unneeded_pkg_list.append(pkg.strip())

for pkg in subprocess.check_output(["pacman", "-Qeq"]).decode("utf-8").split():
    explicit_pkg_list.append(pkg.strip())


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")
    print("echo " + " ".join(explicit_pkg_list) + " | tr ' ' '\\n' >> ~/.pacorphan/keep")
    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()