#!/bin/sh
#
# Copyright (C) 2012-2015, 2018  Etersoft
# Copyright (C) 2012-2015, 2018  Vitaly Lipatov <lav@etersoft.ru>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#

load_helper epm-install
load_helper epm-search

# for zypper before SUSE/11.0
__use_zypper_dry_run()
{
    a='' zypper install --help 2>&1 | grep -q -- "--dry-run" && echo "--dry-run"
}

__use_yum_assumeno()
{
    a='' yum --help 2>&1 | grep -q -- "--assumeno"
}


__check_yum_result()
{
    grep -q "^No package" $1 && return 1
    grep -q "^Complete!" $1 && return 0
    grep -q "Exiting on user [Cc]ommand" $1 && return 0
    # dnf issue
    grep -q "^Operation aborted." $1 && return 0
    # return default result by default
    return $2
}

__check_pacman_result()
{
    grep -q "^error: target not found:" $1 && return 1
    grep -q "^Total Installed Size:" $1 && return 0
    grep -q "^Total Download Size:" $1 && return 0
    # return default result by default
    return $2
}


_epm_do_simulate()
{
    local CMD
    local RES=0
    local filenames="$*"

    case $PMTYPE in
    	apt-rpm|apt-dpkg)
    		CMD="apt-get --simulate install"
    		;;
    	aptitude-dpkg)
    		CMD="aptitude -s install"
    		;;
    	yum-rpm)
    		if __use_yum_assumeno ; then
    			store_output sudocmd yum --assumeno install $filenames
    			__check_yum_result $RC_STDOUT $?
    		else
    			store_output sudocmd yum install $filenames <<EOF
n
EOF
    			__check_yum_result $RC_STDOUT $?
    		fi
    		RES=$?
    		clean_store_output
    		return $RES ;;
    	dnf-rpm)
    		store_output sudocmd dnf --assumeno install $filenames
    		__check_yum_result $RC_STDOUT $?
    		RES=$?
    		clean_store_output
    		return $RES ;;
    	urpm-rpm)
    		CMD="urpmi --test --auto"
    		;;
    	zypper-rpm)
    		if ! __use_zypper_dry_run >/dev/null ; then
    			fatal "zypper is too old: does not support --dry-run"
    		fi
    		CMD="zypper --non-interactive install --dry-run"
    		;;
    	emerge)
    		local res=0
    		for pkg in $filenames ; do
			is_installed $pkg && continue
			docmd emerge --pretend $pkg && continue
			pkg=1
			break
    		done
    		return $res ;;
    	opkg)
    		docmd --noaction install $filenames
    		return $res ;;
    	pacman)
    		store_output sudocmd pacman -v -S $filenames <<EOF
no
EOF
    		__check_pacman_result $RC_STDOUT $?
    		RES=$?
    		clean_store_output
    		return $RES ;;
    	slackpkg)
    		#docmd /usr/sbin/slackpkg -batch=on -default_answer=yes download
    		# just try search every package
    		# FIXME: epm_search have to return false status code if the package does not found
    		local pkg res
    		res=0
    		for pkg in $filenames ; do
    			# FIXME: -[0-0] does not work in search!
    			# FIXME: we need strict search here (not find gst-plugins-base if search for gst-plugins
    			# TODO: use short?
    			# use verbose for get package status
    			#pkg_filenames="$pkg-[0-9]" verbose=--verbose __epm_search_internal | grep -E "(installed|upgrade)" && continue
    			#pkg_filenames="$pkg" verbose=--verbose __epm_search_internal | grep -E "(installed|upgrade)" && continue
    			(pkg_filenames="$pkg" __epm_search_internal) | grep -q "^$pkg-[0-9]" && continue
    			res=1
    			info "Package '$pkg' does not found in repository."
    		done
    		return $res ;;
    	*)
    		fatal "Have no suitable simulate command for $PMTYPE"
    		;;
    esac

    sudocmd $CMD $filenames
}

epm_simulate()
{
    [ -z "$pkg_filenames" ] && info "Simulate: Skip empty list" && return 22

    local filenames="$(echo $pkg_filenames | filter_out_installed_packages)"

    [ -z "$filenames" ] && info "Simulate: All packages are already installed" && return 0

    _epm_do_simulate $filenames
    local RES=$?
    if [ -z "$quiet" ] ; then
        if [ "$RES" = 0 ] ; then
            info "Simulate result: $filenames package(s) CAN BE installed"
        else
            info "Simulate result: There are PROBLEMS with install some package(s)"
        fi
    fi
    return $RES
}