#!/bin/bash

# apt-cyg: install tool for cygwin similar to debian apt-get
# 
# Copyright (C) 2005-9, Stephen Jungels
# 
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# (http://www.fsf.org/licensing/licenses/gpl.html)

# this script requires some packages

WGET=`which wget 2>/dev/null`
BZIP2=`which bzip2 2>/dev/null`
TAR=`which tar 2>/dev/null`
GAWK=`which awk 2>/dev/null`

if ! [[ "$WGET" && "$BZIP2" && "$TAR" && "$GAWK" ]]; then
	echo You must install wget, tar, gawk and bzip2 to use apt-cyg.
	exit 1
fi

MIRROR="http://ftp.snt.utwente.nl/pub/software/cygwin"

function syntax {
	echo "apt-cyg is a simple command line interface for downloading and"
	echo "installing Cygwin packages. The most frequently used commands are"
	echo "update and install."
	echo
	echo "Usage: apt-cyg command [options]"
	echo
	echo "Commands:"
	printf -- "  update\t\t\tRetrieve new list of packages\n"
	printf -- "  upgrade PACKAGE\t\tPerform an upgrade on PACKAGE\n"
	printf -- "  install PACKAGE\t\tInstall new packages\n"
	printf -- "  remove PACKAGE\t\tRemove packages\n"
	printf -- "  source PACKAGE\t\tDownload source archives to /usr/src\n"
	printf -- "  show\t\t\t\tShow installed packages\n"
	printf -- "  search PATTERN\t\tFind packages matching PATTERN\n"
	printf -- "  describe PATTERN\t\tShow description of package\n"
	printf -- "  packageof COMMAND\t\tLocate parent packages of COMMAND\n"
	echo
	echo "Options:"
	printf -- "  -m, --mirror URL\t\tUse mirror\n"
	printf -- "  -h, --help\t\t\tThis help text\n"
	printf -- "  -f, --force\t\t\tForce MD5/SHA512 checksum match\n"
	printf -- "  -v, --version\t\t\tPrint version and exit\n"
	printf -- "  -V, --verbose\t\t\tBe verbose\n"
#	printf -- "  -M, --default-mirror URL\t\t\tSet default mirror\n"
}
function version {
	echo "apt-cyg version 0.57"
	echo "Written by Stephen Jungels"
	echo "Copyright (c) 2005-9 Stephen Jungels.  Released under the GPL."
	echo "Modified by Daniel Boland 2013/2014 (dboland@xs4all.nl)"
	echo
	echo "apt-cyg version 0.6"
	echo "* fix: bug in mirror location (x86 directory)"
	echo "* added support for .xz de-compression"
	echo "* improved recursive action"
	echo "* added upgrade command"
	echo "* added source command"
	echo "apt-cyg version 0.6.1"
	echo "* modified install sequence: dependencies are installed first."
	echo "* fix: install overrides folder permissions (/var/log)"
	echo "apt-cyg version 0.6.2"
	echo "* fix: hangs on circular references (cyrus-sasl)"
	echo "apt-cyg version 0.6.3"
	echo "* added rebasing"
	echo "apt-cyg version 0.6.4"
	echo "* added --force option"
	echo "* added 64bit support"
	echo "* added support for SHA512 checksum"
}

cancelled=""
force=""

function findworkspace {
	mirrordir="`echo "$MIRROR" | sed -e "s/:/%3a/g" -e "s:/:%2f:g"`"
	echo Mirror is $MIRROR
	mkdir -p "/setup/$mirrordir"
	cd "/setup/$mirrordir"
}
function update_setup {
	path=`uname -a | awk '{printf $6}'`
	if [ $path == i686 ]; then
		path="x86"
	fi
	touch setup.ini
	mv setup.ini setup.ini.save
	echo "Downloading package list..."
	wget -N -q $MIRROR/$path/setup.bz2
	if [ $? -eq 0 ]; then
		bunzip2 setup.bz2
		mv setup setup.ini
		echo Updated setup.ini
	else
		wget -N -q $MIRROR/$path/setup.ini
		if [ $? -eq 0 ]; then
			echo Updated setup.ini
		else
			echo Error updating setup.ini, reverting
			mv setup.ini.save setup.ini
			exit 1
		fi
	fi
}
function install_package {

	local pkg="$1"
	local need_rebase=$2
	local path="release/$pkg"

	echo

	if ! [ -s "$path/desc" ]; then
		echo "Error: Package $pkg not found or ambiguous name, try updating."
		rm -R "$path"
		cancelled="yes"
		return
	fi

	# pick the latest version, which comes first

	install=`awk '/^install:/ {printf $2; exit}' "$path/desc"`

	if ! [ "$install" ]; then
		echo "Warning: could not find \"install\" in package description: obsolete package?"
		return
	fi

	echo "-- Installing $pkg --"
	echo "Downloading..."

	file=`basename $install`
	wget -q "$MIRROR/$install" -O "$path/$file"

	if [ $? -ne 0 ]; then
		echo "Error: $MIRROR/$install: download failed."
		cancelled="yes"
		return
	fi

	# check the md5

	digest=`awk '/^install: / {print $4; exit}' "$path/desc"`

	if [ ${#digest} -eq 32 ]; then
		digactual=`md5sum "$path/$file" | awk '{print $1}'`
	else
		digactual=`sha512sum "$path/$file" | awk '{print $1}'`
	fi

	if [ $digest != $digactual ]; then
		if [ $force ]; then
			echo "Warning: MD5/SHA512 sum did not match, continuing."
		else
			echo "Error: MD5/SHA512 sum did not match, try updating."
			cancelled="yes"
			return
		fi
	fi

	echo "Unpacking..."

	tar -xvf "$path/$file" -C / --no-overwrite-dir >/etc/setup/$pkg.lst

	if  [ $need_rebase -eq 1 ]; then
		echo "Rebasing..."
		for dll in `grep "\.dll$" /etc/setup/$pkg.lst`; do
			rebase -s "/$dll" 2>/dev/null
		done
	fi

	gzip -f "/etc/setup/$pkg.lst"

	# update the package database
	echo "$pkg $file 0" >>/etc/setup/installed.db

	echo "Package $pkg installed."

}
function crawl_packages {
	local pkg
	local result=0
	local depth=$1
	shift
	for pkg in $1
	do
		local path="release/$pkg"
		local need_rebase=0
		[ $verbose ] && echo "[depth:$depth:$pkg]"
		if [ $cancelled ]; then
			return $result
		elif [ $pkg == _autorebase ]; then
			result=1
		elif [[ `grep "^$pkg " /etc/setup/installed.db` ]]; then
			[ $depth -eq 0 ] && echo Package $pkg is already installed.
		elif [ -f "$path/desc" ]; then
			echo "Warning: circular reference to package $pkg, skipping."
		else
			mkdir -p "$path"
			awk -v PKG="$pkg" '/^@/ {P=$2}; P==PKG {print}' setup.ini >"$path/desc"
			requires=`awk -F: '/^requires:/ {print $2}' "$path/desc"`
			if [ "$requires" ]; then
				if [ $depth -eq 0 ]; then
					echo
					echo Package $pkg requires the following packages:
					echo $requires
					echo Reading packages...
				fi
				crawl_packages $(($depth+1)) "$requires"
				need_rebase=$?
			fi
			if ! [ $cancelled ]; then
				install_package "$pkg" $need_rebase
			fi
			rm -f "$path/desc"
		fi
	done
	return $result
}

# process options

packages=""
command=""
verbose=""

while [ "$1" ]; do
	case "$1" in
		--mirror|-m)
			MIRROR="$2"
			shift
			;;
		--help|-h)
			syntax
			exit 0
			;;
		--version|-v)
			version
			exit 0
			;;
		--verbose|-V)
			verbose="yes"
			;;
		--force|-f)
			force="yes"
			;;
		-*)
			echo "$1: No such option."
			syntax
			exit 1
			;;
		update|show|search|describe|packageof|install|remove|upgrade|source)
			command=$1
			;;
		*)
			packages="$packages $1"
			;;
	esac
	shift
done

function do_update {
	findworkspace
	update_setup
}
function do_packageof {
	for pkg in $packages
	do
		key=`which "$pkg" 2>/dev/null | sed -r 's/^\///'`
		if ! [ "$key" ]; then
		  key="$pkg"
		fi
		for manifest in /etc/setup/*.lst.gz
		do
		  if [[ `gunzip -c $manifest | grep "$key"` ]]; then
		    package=`basename $manifest | sed -r 's/.lst.gz//'`
		    echo "Found $key in package $package"
		  fi
		done
	done
}
function do_search {
	findworkspace
	for pkg in $packages
	do
		echo ""
		echo Searching for installed packages matching $pkg:
		awk '/[^ ]+ [^ ]+ 0/ {if ($1 ~ query) print $1}' query="$pkg" /etc/setup/installed.db
		echo ""
		echo Searching for installable packages matching $pkg:
		cat setup.ini | awk -v query="$pkg" \
		  'BEGIN{RS="\n\n@ "; FS="\n"; ORS="\n"} {if ($1 ~ query) {print $1}}'
	done
}
function do_describe {
	findworkspace
	echo
	for pkg in $packages
	do
		awk -v PKG="$pkg" '/^@/ {P=$2}; P==PKG {print}' setup.ini
	done
}
function do_install {
	findworkspace
	if ! [ -e "setup.ini" ]; then
		update_setup
	elif ! [ -s "setup.ini" ]; then
		echo "Package list corrupted. Trying update..."
		update_setup
#		if ! [ $? -eq 0 ]; then
#			echo "Failure updating setup.ini from $MIRROR."
#			exit 1
#		fi
	fi
	crawl_packages 0 "$packages"
	if ! [ $cancelled ]; then
		# run all postinstall scripts
		list=`ls -U /etc/postinstall/*.sh 2>/dev/null`
		if [ "$list" ]; then
			echo
			echo Running postinstall scripts:
			for script in $list
			do
				echo "   $script..."
				$script
				mv $script $script.done
			done
		fi
	fi
}
function do_remove {
	for pkg in $packages
	do

#		already=`grep -c "^$pkg " /etc/setup/installed.db`
		if ! [[ `grep "^$pkg " /etc/setup/installed.db` ]]; then
			echo Package $pkg is not installed, skipping removal.
			continue
		fi
	
#		dontremove="cygwin coreutils gawk bzip2 tar wget bash"
		for req in cygwin coreutils gawk bzip2 tar wget bash
		do
			if test "-$pkg-" = "-$req-"
			then
			  echo "Cannot remove $pkg. Package is part of the system."
			  exit 1
			fi
		done
		if ! [ -e "/etc/setup/$pkg.lst.gz" ]; then
			echo Package manifest missing, cannot remove $pkg.
			exit 1
		fi

#		echo
		echo "Removing $pkg..."

		# run preremove scripts
		if [ -e "/etc/preremove/$pkg.sh" ]; then
			"/etc/preremove/$pkg.sh"
			rm "/etc/preremove/$pkg.sh"
		fi

		# remove installed files
		gunzip -c /etc/setup/$pkg.lst.gz | awk '{print "/" $0}' | xargs rm -f 2>/dev/null
		rm "/etc/setup/$pkg.lst.gz"
		rm -f /etc/postinstall/$pkg.sh.done

		# remove entry from package database
		cp /etc/setup/installed.db /etc/setup/installed.db.save
		awk -v PKG="$pkg" '$1 != PKG {print}' /etc/setup/installed.db.save >/etc/setup/installed.db

		echo Package $pkg removed.

	done
}
function do_upgrade {
	do_update
	for pkg in $packages
	do
		desc=`awk -v PKG="$pkg" '/^@/ {P=$2}; P==PKG {print}' setup.ini`
		file=`echo "$desc" | awk '/^install:/ {printf $2; exit}'`
		echo
		if ! [ $file ]; then
			echo Package $pkg not found or ambiguous name
			exit 1
		fi
		version=`echo "$desc" | awk '/^version:/ {printf $2; exit}'`
		doc=`basename $file`
		if [ -e "release/$pkg/$doc" ]; then
			echo "Cannot upgrade package $pkg $version: No newer version available."
		else
			do_remove "$pkg"
			rm -f "release/$pkg/desc"		# legacy!
			do_install "$pkg"
			if ! [ $cancelled ]; then
				echo
				echo "Package $pkg upgraded to version $version"
			fi
		fi
	done
}
function do_source {
	findworkspace
	for pkg in $packages
	do
		path="release/$pkg"
		mkdir -p "$path"
		awk -v PKG="$pkg" '/^@/ {P=$2}; P==PKG {print}' setup.ini >"$path/desc"
		if ! [ -s "$path/desc" ]; then
			echo "Package $pkg not found or ambiguous name."
			rm -R "$path"
			exit 1
		fi
		source=`awk '/^source:/ {printf $2; exit}' "$path/desc"` 
		if ! [ "$source" ]; then
			echo "Could not find \"source\" in package description: obsolete package?"
			exit 1
		fi
		echo
		echo "Downloading..."
		file=`basename $source`
		wget -q "$MIRROR/$source" -O "/usr/src/$file"
		echo "installed: /usr/src/$file"
		rm -f "$path/desc"
	done
}
function do_show {
	echo "The following packages are installed:"
	awk '{print $1}' /etc/setup/installed.db | sort
}

if ! [ $command ]; then
	syntax
elif [ "$command" == show ]; then
	do_show
elif [ "$command" == update ]; then
	do_update
elif ! [ "$packages" ]; then
	syntax
else
	do_$command
fi