#!/bin/bash
#
#  rejmerge (pkgutils)
#
#  Copyright (c) 2000-2004 Per Liden
#
#  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 this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
#  USA.
#

# zsh/bash portability stuff
if [ -z "$ZSH_VERSION" ]; then
    port_read()
    {
	read -n 1 "$@"
    }
    port_type()
    {
	type -t "$@"
    }
else
    alias port_read='read -k 1'
    alias port_type='type'
    setopt braceexpand
fi

info_n()
{
    echo -n "=======> $1"
}

info()
{
    info_n "$1"
    echo
}

interrupted()
{
    echo
    info "Aborted."
    exit 1
}

atexit()
{
    if [ -f "$TMPFILE" ]; then
	rm -f "$TMPFILE"
    fi
}

rejmerge_diff()
{
    diff -u "$1" "$2" > "$3"
}

rejmerge_merge()
{
    diff --old-group-format="%<" \
	--new-group-format="%>" \
	--changed-group-format="<<<<< MERGE CONFLICT $1 >>>>>
%<<<<<< MERGE CONFLICT $2 >>>>>
%><<<<< END MERGE CONFLICT >>>>>
" \
    "$1" "$2" > "$3"

    REJMERGE_MERGE_INFO="$(grep -c '^<<<<< END MERGE CONFLICT >>>>>$' "$3") merge conflict(s)."
}

merge_menu()
{
    rejmerge_merge "$1" "$2" "$TMPFILE"

    while :; do
	info "Merged $1"
	$PAGER "$TMPFILE"

	if [ "$REJMERGE_MERGE_INFO" ]; then
	    info "$REJMERGE_MERGE_INFO"
	    unset REJMERGE_MERGE_INFO
	fi

	while :; do
	    info_n "[I]nstall [E]dit [V]iew [S]kip? "
	    port_read CMD
	    echo

	    case "$CMD" in
		i|I)
		    # Keep permissions
		    $SUDO sh -c "cat $TMPFILE > $1"
		    $SUDO rm -f "$2"
		    break 2
		    ;;
		e|E)
		    $EDITOR "$TMPFILE"
		    break 1
		    ;;
		v|V) break 1 ;;
		s|S) break 2 ;;
	    esac
	done
    done

    : > "$TMPFILE"
}

diff_menu()
{
    rejmerge_diff "$1" "$2" "$TMPFILE"

    while :; do
	info "$1"
	$PAGER "$TMPFILE"
	while :; do
	    info_n "[K]eep [U]pgrade [M]erge [D]iff [S]kip? "
	    port_read CMD
	    echo

	    case "$CMD" in
		k|K)
		    $SUDO rm -f "$2"
		    break 2
		    ;;
		u|U)
		    $SUDO sh -c "cat $2 > $1"
		    break 2
		    ;;
		m|M)
		    merge_menu "$1" "$2"
		    break 2
		    ;;
		d|D)
		    break 1
		    ;;
		s|S)
		    break 2
		    ;;
	    esac
	done
    done

    : > "$TMPFILE"
}

file_menu()
{
    while :; do
	info "$1"
	file "$1" "$2"
	while :; do
	    info_n "[K]eep [U]pgrade [D]iff [S]kip? "
	    port_read CMD
	    echo

	    case "$CMD" in
		k|K)
		    $SUDO rm -f "$2"
		    break 2
		    ;;
		u|U)
		    $SUDO sh -c "$2 > $1"
		    break 2
		    ;;
		d|D)
		    break 1
		    ;;
		s|S)
		    break 2
		    ;;
	    esac
	done
    done
}

print_help()
{
    cat << EOF
usage: $REJMERGE_COMMAND [options]
options:
  -r,   --root <path>         specify alternative root
  -v,   --version             print version and exit
  -h,   --help                print help and exit
EOF
}

parse_options()
{
    while [ "$1" ]; do
	case $1 in
	    -r|--root)
		if [ ! "$2" ]; then
		    echo "$REJMERGE_COMMAND: option $1 requires an argument"
		    exit 1
		fi
		REJMERGE_ROOT="$2"
		REJMERGE_CONF="$2$REJMERGE_CONF"
		REJECTED_DIR="$2$REJECTED_DIR"
		shift ;;
	    -v|--version)
		echo "$REJMERGE_COMMAND (pkgutils) $REJMERGE_VERSION"
		exit 0 ;;
	    -h|--help)
		print_help
		exit 0 ;;
	    *)
		echo "$REJMERGE_COMMAND: invalid option $1"
		exit 1 ;;
	esac
	shift
    done

    if [ ! -d "$REJECTED_DIR" ]; then
	echo "$REJMERGE_COMMAND: $REJECTED_DIR not found"
	exit 1
    fi
}

main()
{
    parse_options "$@"

    if [ "$UID" -eq 0 ]; then
	echo "$REJMERGE_COMMAND: don't merge rejected files as root"
	exit 1
    fi

    # Read configuration
    if [ -f "$REJMERGE_CONF" ]; then
	source "$REJMERGE_CONF"
    fi

    REJECTED_FILES_FOUND=no

    # Check regular files
    for REJECTED_FILE in $(find $REJECTED_DIR -type f); do
	INSTALLED_FILE="$REJMERGE_ROOT${REJECTED_FILE##$REJECTED_DIR}"
	if [ ! -e "$INSTALLED_FILE" ] || cmp -s "$INSTALLED_FILE" "$REJECTED_FILE"; then
	    $SUDO rm -f "$REJECTED_FILE"
	else
	    REJECTED_FILES_FOUND=yes
	    diff_menu "$INSTALLED_FILE" "$REJECTED_FILE"
	fi
    done

    # Check non-regular files
    for REJECTED_FILE in $(find $REJECTED_DIR ! -type d ! -type f); do
	INSTALLED_FILE="$REJMERGE_ROOT${REJECTED_FILE##$REJECTED_DIR}"
	if [ ! -e "$INSTALLED_FILE" ]; then
	    $SUDO rm -f "$REJECTED_FILE"
	else
	    REJECTED_FILES_FOUND=yes
	    file_menu "$INSTALLED_FILE" "$REJECTED_FILE"
	fi
    done

    # Remove empty directories
    $SUDO find $REJECTED_DIR -mindepth 1 -depth -empty -exec rmdir {} \;

    if [ "$REJECTED_FILES_FOUND" = no ]; then
	echo "Nothing to merge"
    fi

    exit 0
}

trap "interrupted" HUP INT QUIT TERM
trap "atexit" EXIT

export LC_ALL=POSIX

readonly REJMERGE_VERSION="5.18"
readonly REJMERGE_COMMAND="${0##*/}"
unset REJMERGE_ROOT
REJMERGE_CONF="/etc/rejmerge.conf"
REJECTED_DIR="/var/lib/pkg/rejected"
PAGER=more
SUDO=/usr/bin/sudo
EDITOR=${EDITOR:-vi}
TMPFILE=$(mktemp) || exit 1

main "$@"