# autoepatch - Automatic patch scripting
# Copyright (C) 2006 Gentoo Foundation
#
# 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.
#
# You should have received a copy of the GNU General Public License
# along with autoepatch; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

# Check for gpatch present and use that if available; if not
# and patch is not GNU patch, warn that autoepatch might not
# work as intended
gpatch() {
    if [[ -n ${GNU_PATCH} ]]; then
	"${GNU_PATCH}" "$@"
	return $?
    fi

    GNU_PATCH=$(type -p gpatch)
    if [[ -z ${GNU_PATCH} ]]; then
	if ! type -p patch; then
	    eerror "Unable to find a patch command to use"
	    return 1
	fi

	GNU_PATCH=$(type -p patch)
	if ! "${GNU_PATCH}" --version </dev/null | grep -q "Free Software Foundation" &>/dev/null; then
	    ewarn "The ${GNU_PATCH} binary is not a GNU patch version, autoepatch might misbehave"
	fi
    fi

    gpatch "${@}"
    return $?
}

# Alias a working find(1), so that we can make sure the -exec {} + works.
# OpenBSD find(1) is stone age.
find() {
    local findcmd="@findcmd@"

    # We assume that if no find is specified, then we're using a decent
    # version of find(1).
    [[ "${findcmd//@/|}" == "|findcmd|" ]] && findcmd="$(type -P find)"

    "${findcmd}" "$@"
    return $?
}

# Simple wrapper around debianutils mktemp and BSD mktemp,
# based on the emktemp function in eutils.eclass by
# Mike Frysinger (vapier@gentoo.org)
#
# Takes just 1 optional parameter (the directory to create tmpfile in)
emktemp() {
    local exe="touch"
    if [[ $1 == -d ]]; then
	exe="mkdir"
	shift
    fi
    local topdir=$1
    
    if [[ -z ${topdir} ]] ; then
	# ${T} is an ebuild variable, respect it
	[[ -z ${T} ]] \
	    && topdir="/tmp" \
	    || topdir=${T}
    fi

    if [[ -z $(type -p mktemp) ]] ; then
	local tmp=/
	while [[ -e ${tmp} ]] ; do
	    tmp=${topdir}/tmp.${RANDOM}.${RANDOM}.${RANDOM}
	done
	${exe} "${tmp}" || ${exe} -p "${tmp}"
	echo "${tmp}"
    else
	local mktemptype
	mktemp -V &>/dev/null && \
	    mktemptype="debianutils" || \
	    mktemptype="bsd"

	if [[ ${exe} == "touch" ]] ; then
	    [[ ${mktemptype} == "debianutils" ]] \
		&& mktemp -p "${topdir}" \
		|| TMPDIR="${topdir}" mktemp -t tmp
	else
	    [[ ${mktemptype} == "debianutils" ]] \
		&& mktemp -d "${topdir}" \
		|| TMPDIR="${topdir}" mktemp -dt tmp
	fi
    fi
}

#
# See if we can apply $2 on $1, and if so, do it
#
try_patch() {
    local target=$1
    local patch=$2
    local ret

    local patchname="$(basename "$(dirname "${patch}")")-${patch##*/}"
    if [[ -d "${target}" ]]; then
	pushd "${target}" &>/dev/null

	gpatch -g0 -p0 --dry-run <"${patch}" &> "${T}/autoepatch.$$.${patchname}.log" || \
	    return 1

	ebegin "  Applying ${patchname} ..."
	patch -g0 -p0 --no-backup-if-mismatch "${patch}" &> "${T}/autoepatch.$$.${patchname}.log"
	ret=$?
	eend ${ret}
	
	popd &>/dev/null
	return ${ret}
    else
	gpatch -g0 --dry-run "${target}" "${patch}" &> "${T}/autoepatch.$$.${patchname}.log" || \
	    return 1

	ebegin "  Applying ${patchname} ..."
	patch -g0 --no-backup-if-mismatch "${target}" "${patch}" &> "${T}/autoepatch.$$.${patchname}.log"
	ret=$?
	eend ${ret}
	
	popd &>/dev/null
	return ${ret}
    fi

    # Should never happen
    return 1
}