#!/bin/sh

version="0.4"

if ! which dialog > /dev/null 2>&1; then
	echo "Could not find dialog, do 'pacman -S dialog'." 1>&2
	exit 4
fi

for e in "$EDITOR" "$VISUAL" vim vi joe mcedit nano pico e3 jed ne emacs; do
	w=$(which $e 2> /dev/null)
	if [ -n "$w" -a -x "$w" ]; then
		texted="$w"
		break
	fi
done

if [ ! -x "$texted" ]; then
	echo "Could not find any text editor." 1>&2
	exit 2
fi

tmpdir=$(mktemp -d 2> /dev/null)
if [ $? != 0 ]; then
	echo "Unable to create a temporary directory." 1>&2
	exit 1
fi

menu_common() {
	cat << EOF > $tmpdir/dialog
--backtitle "dotpac $version - get rid of /{boot,etc}/*.pac* files, \
by swiergot@gmail.com"
--no-shadow
--begin $1 $2
EOF
}

menu_main() {
	rm -f $tmpdir/files

	i=1

	for cf in $(find /etc /boot -name '*.pac*' | sort); do
		echo "$i $cf" >> $tmpdir/files
		i=$(expr $i + 1)
	done

	if [ ! -s $tmpdir/files ]; then
		menu_common 10 5
		cat << EOF >> $tmpdir/dialog
--ok-label "Exit"
--msgbox "No *.pac* files have been found in /etc and /boot."
5 70
EOF

		dialog --file $tmpdir/dialog
		return 1
	fi

	menu_common 3 15
	cat << EOF >> $tmpdir/dialog
--ok-label "Next"
--menu "The following backup files have been found in /etc and /boot. \
Please select a file you want to process."
20 50 11
EOF

	cat $tmpdir/files >> $tmpdir/dialog
	dialog --file $tmpdir/dialog 2> $tmpdir/exitcode

	if [ $? != 0 ]; then
		return 1
	fi

	choice=$(cat $tmpdir/exitcode)
	choice=$(expr $choice + 6)
	file=$(sed -n ${choice}p $tmpdir/dialog | cut -d ' ' -f 2)

	if [[ "$file" == *.pacnew ]]; then
		menu_pacnew "$file"
	elif [[ "$file" == *.pacsave ]]; then
		menu_pacsave "$file"
	else
		echo "It looks like you have found a bug. Please contact the author." 1>&2
		exit 3
	fi
}

menu_actions() {
	diff -u "$2" "$1" > $tmpdir/diff

	if [ -s $tmpdir/diff ]; then
		menu_common 3 1
		cat << EOF >> $tmpdir/dialog
--exit-label "Next"
--textbox $tmpdir/diff
21 78
EOF

		dialog --file $tmpdir/dialog

		menu_common 6 12
		cat << EOF >> $tmpdir/dialog
--ok-label "Finish"
--menu "Now that you know why $1 was left and you have seen the differences \
between the two files, you can decide what to do with them. What would you like to do?"
15 56 5
1 "Remove the $3 file."
2 "Remove the $3 file and edit the $4 one."
3 "Replace the $4 file with the $5 and edit."
4 "Just replace the $4 file with the $5."
5 "Nothing."
EOF

		dialog --file $tmpdir/dialog 2> $tmpdir/exitcode

		if [ $? != 0 ]; then
			return 0
		fi

		choice=$(cat $tmpdir/exitcode)

		if [ $choice == 5 ]; then
			return 0
		elif [ $choice == 1 ]; then
			rm -f "$1"
		elif [ $choice == 2 ]; then
			rm -f "$1"
			"$texted" "$2"
		elif [ $choice == 3 ]; then
			mv -f "$1" "$2"
			"$texted" "$2"
		elif [ $choice == 4 ]; then
			mv -f "$1" "$2"
		fi

		return 0
	else
		menu_common 8 15
		cat << EOF >> $tmpdir/dialog
--yesno "Both files:\n\n  $2\n  $1\n\nare exactly the same. It is safe to remove \
the latter. Do you want to do this?"
11 50
EOF

		dialog --file $tmpdir/dialog

		if [ $? == 0 ]; then
			rm -f "$1"
		fi

		return 0
	fi
}

menu_pacnew() {
	file=$(dirname "$1")/$(basename "$1" .pacnew)

	menu_common 9 3
	cat << EOF >> $tmpdir/dialog
--ok-label "Next"
--msgbox "During the last upgrade of a package that owns $file, pacman did not \
touch the file because it had been marked as NoUpgrade in /etc/pacman.conf. \
\n\nDifferences between both files will now be displayed."
9 74
EOF

	dialog --file $tmpdir/dialog

	menu_actions "$1" "$file" "new" "old" "new one"
}

menu_pacsave() {
	file=$(dirname "$1")/$(basename "$1" .pacsave)

	if [ -f "$file" ]; then
		menu_common 7 3
		cat << EOF >> $tmpdir/dialog
--ok-label "Next"
--msgbox "During the last upgrade of a package that owns $file, the file was \
backed up as $1 and replaced with a new one. The new file differs from its \
previous original version that you had modified. You need to make your changes \
again, taking these differences into account.\n\nDifferences between both files \
will now be displayed."
12 74
EOF

		dialog --file $tmpdir/dialog

		menu_actions "$1" "$file" "backup" "new" "backup"
	else
		menu_common 9 3
		cat << EOF >> $tmpdir/dialog
--ok-label "Next"
--msgbox "Since $1 has not been found, it can be assumed that $file was created \
during removal of a package that owned the original file."
8 74
EOF

		dialog --file $tmpdir/dialog

		menu_common 3 1
		cat << EOF >> $tmpdir/dialog
--exit-label "Next"
--textbox "$1"
21 78
EOF

		dialog --file $tmpdir/dialog

		menu_common 9 15
		cat << EOF >> $tmpdir/dialog
--yesno "You can safely remove $1 if you are sure you will not need it anymore. \
Do you want to do this?"
8 50
EOF

		dialog --file $tmpdir/dialog

		if [ $? == 0 ]; then
			rm -f "$1"
		fi

		return 0
	fi
}

bye=0

while [ $bye == 0 ]; do
	menu_main
	bye=$?
done

rm -rf $tmpdir
clear