#!/bin/bash

UPDATE_AFTER=43200 # 12 hours

usage() {
cat <<HELP
Cross-platform package manager wrapper

usage: $(basename "$0") [cask] OPTION [PACKAGE]

   SINGLE PACKAGE ACTIONS
   (i)nstall : install a given package
   (r)emove  : remove a given package
   (p)urge   : remove a given package and any related config files
   (s)earch  : search for a package
   (m)anual  : install a locally downloaded package (e.g.: a .deb file)

   UPDATING
   (u)pdate  : update all installed packages
   (c)ache   : update the package cache / repository

               NOTE: update, install, and num-updates will automatically
               update the cache if it is old

   MISC
   (l)ist            : list installed packages
   (nu) num-updates  : number of packages with updates
   (np) num-packages : number of installed packages


https://github.com/keithieopia/piu

Copyright (c) 2017-2018 Timothy Keith
Licensed under the MIT license.
HELP
}


# Distro Specific
########################################################################

#
# Alpine Linux
#

apk_install() { sudo apk add "$@"; }
apk_update()  { sudo apk upgrade; }
apk_remove()  { sudo apk del "$@"; }
apk_purge()   { sudo apk del "$@" && sudo apk cache clean; }
apk_search()  { apk search -v "$@"; }
apk_list()    { apk info; }
apk_manual()  { sudo apk add --allow-untrusted "$@"; }

apk_repo_age() {
	find /var/cache/apk -type f -print0 | xargs -0 stat -c %Z | sort | tail -1
}

apk_repo_update() {
	if ! sudo -n apk update &> /dev/null; then
		echo "out-of-date"
		exit 1
	fi
}

apk_num_updates() {
	echo "not implemented yet!" && exit 1;
}

apk_num_pkgs() {
	apk list | wc -l
}

#
# Arch Linux
#

pacman_install() { sudo pacman -S "$@"; }
pacman_update()  { sudo pacman -Su; }
pacman_remove()  { sudo pacman -Rs "$@"; }
pacman_purge()   { sudo pacman -Rns "$@"; }
pacman_search()  { pacman -Ss "$@"; }
pacman_list()    { pacman -Qqe; }
pacman_manual()  { sudo pacman -U "$@"; }

pacman_repo_age() {
	stat -c '%Y' '/var/cache/pacman/pkg'
}

pacman_repo_update() {
	if ! sudo -n pacman -Sy &> /dev/null; then
		echo "out-of-date"
		exit 1
	fi
}

pacman_num_updates() {
	pacman -Qu | wc -l
}

pacman_num_pkgs() {
	pacman_list | wc -l
}

#
# Void Linux
#

xbps_install() { sudo xbps-install "$@"; }
xbps_update()  { sudo xbps-install -Su; }
xbps_remove()  { sudo xbps-remove -R "$@"; }
xbps_purge()   { sudo xbps-remove -R "$@" && sudo xbps-remove -Oo; }
xbps_search()  { xbps-query -Rs "$@"; }
xbps_list()    { xbps-query -l; }
xbps_manual()  { echo "not implemented yet!" && exit 1; }

xbps_repo_age() {
	stat -c '%Y' '/var/db/xbps/https___alpha_de_repo_voidlinux_org_current'
}

xbps_repo_update() {
	if ! sudo -n xbps-install -S &> /dev/null; then
		echo "out-of-date"
		exit 1
	fi
}

xbps_num_updates() {
	xbps-install -nu | wc -l
}

xbps_num_pkgs() {
	xbps-query -l | wc -l
}

#
# Debian / Ubuntu
#

apt_install() { sudo apt install "$@"; }
apt_update()  { sudo apt upgrade; }
apt_remove()  { sudo apt remove "$@"; }
apt_purge()   { sudo apt purge "$@"; }
apt_search()  { apt search "$@"; }
apt_list()    { dpkg-query -f '${binary:Package}\n' -W; }
apt_manual()  { sudo dpkg -i "$@"; }

apt_repo_age() {
	stat -c '%Y' '/var/cache/apt/pkgcache.bin'
}

apt_repo_update() {
	if ! sudo -n apt update &> /dev/null; then
		echo 'out-of-date'
		exit 1
	fi
}

apt_num_updates() {
	apt list --upgradeable 2>/dev/null | tail -n +2 | wc -l
}

apt_num_pkgs() {
	apt_list | wc -l
}

#
# Red Hat / Fedora
#

dnf_install() { sudo dnf install -C "$@"; }
dnf_update()  { sudo dnf upgrade; }
dnf_remove()  { sudo dnf remove -C "$@"; }
dnf_purge()   {
    # yum / dnf remove works just like apt's purge
    # https://unix.stackexchange.com/questions/8191/what-is-fedoras-equivalent-of-apt-get-purge/8193
    sudo dnf remove "$@"
}
dnf_search()  { dnf search -C "$@"; }
dnf_list()    { dnf list installed -C | awk '{if(NR>1)print $1}'; }
dnf_manual()  { sudo dnf localinstall "$@"; }

dnf_repo_age() {
	stat -c '%Y' '/var/cache/dnf/packages.db'
}

dnf_repo_update() {
	if ! dnf clean metadata && dnf check-update &> /dev/null; then
		echo 'out-of-date'
		exit 1
	fi
}

dnf_num_updates() {
	dnf check-update | awk '{if(NR>2)print $1}' | wc -l
}

dnf_num_pkgs() {
	dnf_list | wc -l
}

#
# macOS
#

brew_install() { brew $BREW_CASK install "$@"; }
brew_update()  { brew $BREW_CASK upgrade; }
brew_remove()  { brew $BREW_CASK uninstall "$@"; }
brew_search()  { brew $BREW_CASK search "$@"; }
brew_list()    { brew $BREW_CASK list; }

brew_repo_age() {
	date +%s
}

brew_repo_update() {
	brew update
}

brew_num_updates() {
	echo "not implemented yet!" && exit 1;
}

brew_num_pkgs() {
	brew_list | wc -l
}

is_darwin() {
	uname -a | grep Darwin > /dev/null;
}

# Abstraction
########################################################################

repo_update_if_needed() {
	CURRENT_TIME=$(date '+%s')
	LAST_UPDATE=$(eval "${PKGMAN}"_repo_age)

	if ((CURRENT_TIME-LAST_UPDATE > UPDATE_AFTER)); then
		eval "${PKGMAN}"_repo_update
	fi
}

# Find the current distribution
if [ -f /etc/os-release ]; then
	if grep -q arch /etc/os-release; then
		PKGMAN='pacman'
	elif grep -q debian /etc/os-release; then
		PKGMAN='apt'
	elif grep -q void /etc/os-release; then
		PKGMAN='xbps'
	elif grep -q alpine /etc/os-release; then
		PKGMAN='apk'
	elif grep -q fedora /etc/os-release; then
		PKGMAN='dnf'
	else
		echo "ERROR: I currently don't have support for your distro"
		exit 1
	fi
else
	if is_darwin; then
		PKGMAN='brew'
	else
		echo "Error: cannot detect platform"
		exit 1
	fi
fi

# find what we're doing
########################################################################

# make leading dashes optional, out of tradition
if is_darwin; then
  # Detect cask argument
  if [ "$1" == "cask" ]; then
    BREW_CASK="cask"
    shift 1
  fi

  action=$(echo "$1" | sed 's/^-*//g')
else
  action=$(echo "$1" | sed 's/^-*//g' --)
fi

case "$action" in
	s | search)
		shift 1
		eval ${PKGMAN}_search "$@"
		;;

	r | remove)
		shift 1
		eval ${PKGMAN}_remove "$@"
		;;

	p | purge)
		shift 1
		eval ${PKGMAN}_purge "$@"
		;;

	l | list)
		eval ${PKGMAN}_list
		;;

	i | install)
		shift 1
		repo_update_if_needed
		eval ${PKGMAN}_install "$@"
		;;

	u | update)
		repo_update_if_needed
		eval ${PKGMAN}_update
		;;

	nu | num-updates)
		eval ${PKGMAN}_num_updates
		;;

	np | num-packages)
		eval ${PKGMAN}_num_pkgs
		;;

	c | cache)
		eval ${PKGMAN}_repo_update
		;;

	m | manual)
		eval ${PKGMAN}_manual
		;;

	*)
		usage
		;;
esac