#!/bin/sh -efux
#
# Copyright (C) 2006-2007  Alexey Gladkov <legion@altlinux.org>
# Copyright (C) 2006  Dmitry V. Levin <ldv@altlinux.org>
# Copyright (C) 2006  Sergey Vlasov <vsu@altlinux.org>
#
# gear-update updates subdirectory from source archive/directory.
#
# This file 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 this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
#

. gear-sh-functions

show_help() {
	cat <<EOF
Usage: $PROG [Options] <source> [<subdirectory>]

Utility to update subdirectory from source. Current directory 
will be updated if second argument is not specified.

Options:

  -u,--unpack-dir=DIR define directory name in archive;
  -t,--type=TYPE      define type of souece. It may on 
                      of items: 'dir', 'tar' or 'zip';
  -f,--force          remove files from the <dst-directory>
                      even if untracked or modified files found;
  --ignore-exclude    ignore .gitignore and .git/info/exclude;
  -U,--unpack-all     unpack all subdirectories in archive;
  -v,--verbose        print a message for each action;
  -V,--version        print program version and exit;
  -h,--help           show this text and exit.

Report bugs to http://bugs.altlinux.ru/

EOF
	exit
}

print_version() {
	cat <<EOF
$PROG version $PROG_VERSION
Written by Alexey Gladkov <legion@altlinux.org>

Copyright (C) 2006-2007  Alexey Gladkov <legion@altlinux.org>
Copyright (C) 2006  Dmitry V. Levin <ldv@altlinux.org>
Copyright (C) 2006  Sergey Vlasov <vsu@altlinux.org>
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
EOF
	exit
}

source_type=
get_type_by_source() {
	local mimetype="$(file -biz "$source" |tr [:upper:] [:lower:])"
	case "${mimetype#application/x-}" in
		tar*)	source_type="tar" ;;
		zip)	source_type="zip" ;;
		*)
			[ ! -d "$source" ] || source_type="dir"
			;;
	esac
}

subdir=
unpack_all=
validate_subdir() {
	local source_lscmd= n quoted_subdir
	case "$source_type" in
		tar) source_lscmd="tar -tf"    ;;
		zip) source_lscmd="zipinfo -1" ;;
		dir) subdir="$source" ;;
		*) fatal "$source_type: unknown source type" ;;
	esac
	[ -z "$unpack_all" ] || return 0
	[ -n "$subdir" ] ||
		subdir="$($source_lscmd "$source" |sed -e 's#\(^\|/\?\)\./#\1#g' |cut -d/ -f1 |sort -u)"

	n="$(printf %s\\n "$subdir" |wc -l)"
	[ "$n" -le 1 ] || fatal "too many subdirectories: $(printf %s "$subdir" |tr \\n \ )"
	[ "$n" -eq 1 ] || fatal "$source: directory not found"

	[ -n "$source_lscmd" ] || return 0

	quoted_subdir="$(quote_sed_regexp "$subdir")"
	$source_lscmd "$source" |grep -qs "^$quoted_subdir/\?\$" ||
		fatal "$source: directory not found in archive"
}

check_destdir() {
	[ "$#" -eq 2 ] || fatal "check_destdir: more arguments required"
	[ "$2" != "." -o ! -d "$2/.git" -o ! -d "$1/.git" ] ||
		fatal "$dstdir/.git: unable to replace git direstory"
}

workdir=
destdir=
exit_handler()
{
	local rc=$?
	trap - EXIT
	[ -z "$workdir" ] || rm -rf -- "$workdir"
	if [ "$rc" -gt 0 ]; then
		# Rollback actions
		if [ -d "$destdir" ]; then
			find "$destdir" -mindepth 1 -maxdepth 1 ! -name '.git' -print0 |
				xargs -r0 rm $verbose -rf --
		else
			rm $verbose -f -- "$destdir"
		fi
		mkdir -p -- "$destdir"
		cd "$destdir"
		git-checkout-index -a
		info "unable to unpack new archive"
	fi
	exit $rc
}

TEMP=`getopt -n $PROG -o f,t:,d:,a,v,V,h -l ignore-exclude,unpack-all,force,type:,subdir:,verbose,version,help -- "$@"` || show_usage
eval set -- "$TEMP"

force=
ignore_exclude=
while :; do
	case "$1" in
	    --ignore-exclude) ignore_exclude=1
		;;
	    -a|--unpack-all) unpack_all=1
		;;
	    -f|--force) force=1
		;;
	    -t|--type) shift; source_type="$1"
		;;
	    -d|--unpack-dir) shift; subdir="$1"
		;;
	    -v|--verbose) verbose=-v
		;;
	    -V|--version) print_version
	    	;;
	    -h|--help) show_help
		;;
	    --) shift; break
		;;
	    *) fatal "unrecognized option: $1"
		;;
	esac
	shift
done

[ "$#" -ge 1 ] || show_usage 'Not enough arguments.'
source="$(readlink -ev "$1")"; shift
destdir="$(readlink -ev "${1:-.}")"

[ "$source" != "$destdir" ] ||
	fatal "\`$source' and \`$destdir' are the same place"
[ -d "$destdir" ] ||
	fatal "$destdir: directory not available"

# Move to topdir
cd "$(git-rev-parse --show-cdup)"
topdir="$(readlink -ev .)"
destdir="$destdir/"
destdir="${destdir#$topdir/}"

[ "$destdir" = "${destdir#/}" ] ||
	fatal "$destdir: directory out of \`$topdir' tree."
[ -n "$destdir" ] && destdir="${destdir%/}" || destdir="."
git-rm -n "$destdir" >/dev/null

if [ -z "$force" ]; then
	out="$(git diff --name-only -- "$destdir"
		git-ls-files --directory --others --exclude-per-directory=.gitignore -- "$destdir")"
	[ -z "$out" ] || fatal "$destdir: untracked or modified files found"
fi

[ -n "$source_type" ] || get_type_by_source
validate_subdir

# Trap for rollback
trap exit_handler HUP INT QUIT TERM EXIT

# Remove obsolete source
find "$destdir" -mindepth 1 -maxdepth 1 ! -name '.git' -print0 |
	xargs -r0 rm $verbose -rf --
[ "$destdir" = "." ] || rmdir $verbose -- "$destdir"

# Copy new sources
case "$source_type" in
	tar)
		workdir="$(mktemp -d "$PROG.XXXXXXXXX")"
		dir="$workdir"
		if [ -z "$unpack_all" ]; then
			printf %s\\n "$subdir/" |tar -T- -C "$workdir" -xf "$source"
			dir="$dir/$subdir"
		else
			tar -C "$workdir" -xf "$source"
		fi
		check_destdir "$dir" "$destdir"
		mv -f -- "$dir" "$destdir"
		;;
	zip)
		workdir="$(mktemp -d "$PROG.XXXXXXXXX")"
		dir="$workdir"
		if [ -z "$unpack_all" ]; then
			unzip "$source" "$subdir/*" -d "$workdir"
			dir="$dir/$subdir"
		else
			unzip "$source" -d "$workdir"			
		fi
		check_destdir "$dir" "$destdir"
		mv -f -- "$dir" "$destdir"
		;;
	dir)
		check_destdir "$subdir" "$destdir"
		cp -a -- "$subdir" "$destdir"
		;;
esac
[ -d "$destdir" ] ||
	fatal "$destdir: result of extraction is not a directory"

if [ -n "$ignore_exclude" ]; then
	git-ls-files -z "$destdir" |
		git-update-index --remove --force-remove -z --stdin
	git-ls-files -z --others --modified "$destdir" |
		git-update-index --add ${verbose:+--verbose} -z --stdin
else
	git-rm $verbose "$destdir"
	git-add $verbose "$destdir"
fi