#!/bin/bash
# Copyright (C) 2006 Andre Noll
# Licensed under the LGPL, version 3. See COPYING and COPYING.LESSER.

if [[ "$(type -t _gsu_setup)" != "function" ]]; then
	gsu_dir=${gsu_dir:-${BASH_SOURCE[0]%/*}}
	. $gsu_dir/common || exit 1
	_gsu_setup
fi

_gsu_node_name_pattern='[a-zA-Z_]'

_get_geometry()
{
	local x y
	result="$(stty size)"
	if (($? != 0)); then
		gsu_msg "fatal: could not get terminal geometry"
		exit 1
	fi
	x="${result#* }"
	y="${result%% *}"
	(($x > 190)) && x=190
	result="$y $x"
}

_set_dialog_ret()
{
	local ec="$1"

	case "$ec" in
	0) ret=$GSU_SUCCESS;;
	1) ret=1;; # cancelled
	*)
		result="dialog exit code $ec"
		ret=-$E_GSU_DIALOG
	esac
}

# Open a dialog box which asks the user to input a text
#
# Usage: gsu_input_box <text> <init>
#
# <text> is displayed above of the input field, which is is preset to <init>.
# The entered text is returned in $result. On success (user pressed OK)
# the function returns zero. If the user selected Cancel, the return value is
# one. On dialog errors, a negative error code is returned.
gsu_inputbox()
{
	local g text="$1" init="$2"

	_get_geometry
	g="$result"
	result="$(dialog --inputbox "$text" $g "$init" 3>&1 1>&2 2>&3 3>&-)"
	_set_dialog_ret $?
}

# Show the given file in a text box
#
# Usage: gsu_textbox <path>
#
# The box has an OK button which closes the box when activated.
gsu_textbox()
{
	local g file="$1"

	_get_geometry
	g="$result"

	ret=-$E_GSU_DIALOG
	result='textbox'
	dialog --textbox "$file" $g
	_set_dialog_ret $?
}

# Show a message in a text box
#
# Usage: gsu_msgbox <text>
#
# This is like gsu_textbox() but the text is passed as a string.
gsu_msgbox()
{
	local tmp

	# Some versions of dialog segfault if the text is too long. Hence we
	# always use a temporary file.
	gsu_make_tempfile 'gsu_msgbox.XXXXXXXXXX'
	(($ret < 0)) && return
	tmp="$result"
	trap "rm -f $tmp" EXIT
	echo "$1" > "$tmp"
	gsu_textbox "$tmp"
	rm -f "$tmp" # ignore errors
}

_gsu_menu()
{
	local header="${1:-root}"
	local items="$2"
	local i state opts num=0

	_get_geometry
	opts="$result 16"
	for i in $items; do
		let num++
		opts+=" $i $num"
	done
	result="$(dialog --menu "$gsu_banner_txt ($header)" $opts 3>&1 1>&2 2>&3 3>&-)"
	_set_dialog_ret $?
}

_get_level()
{
	local tmp="${1%%$_gsu_node_name_pattern*}"
	result="${#tmp}"
}

_get_subtree()
{
	local tree="$1" root="${2%/}"
	local first TAB='	'

	ret=-$E_GSU_MENU_TREE
	result="subtree grep failed"
	first="$(grep -n "$TAB\{1,\}$root/" <<< "$tree")" || return
	[[ -z "$first" ]] && return

	line_num="${first%%:*}"
	_get_level "${first#*:}"
	level="$result"

	#echo "line: $line_num, root: $root, indent level: $level"
	result="$(sed -e "1,${line_num}d;" <<< "$tree" \
		| sed -e "/^$TAB\{1,$level\}$_gsu_node_name_pattern/,\$d" \
		| sed -e "/^$TAB\{$(($level + 2))\}/d")"
	if (($? != 0)); then
		ret=-$E_GSU_MENU_TREE
		result="sed command for subtree $root failed"
		return
	fi
	ret=$GSU_SUCCESS
}

_get_root_nodes()
{
	local tree="$1" TAB='	'

	result="$(grep "^${TAB}${_gsu_node_name_pattern}" <<< "$tree")"
	if (($? != 0)); then
		ret=-$E_GSU_MENU_TREE
		result="root node grep failed"
		return
	fi
	ret=$GSU_SUCCESS
}

_browse()
{
	local header="$1" old_header
	local tree="$2" subtree="$3"

	while :; do
		_gsu_menu "$header" "$subtree"
		(($ret < 0)) && return
		[[ -z "$result" ]] && return # menu was cancelled
		if [[ "${result%/}" != "$result" ]]; then
			old_header="$header"
			header="$result"
			_get_subtree "$tree" "$header"
			(($ret < 0)) && return
			_browse "$header" "$tree" "$result"
			(($ret < 0)) && return
			header="$old_header"
			continue
		fi
		eval ${gsu_name}_$result
	done
}

gsu_gui()
{
	local tree="$1" subtree

	type -t dialog &> /dev/null
	if (($? != 0)); then
		gsu_msg "dialog executable not found"
		exit 1
	fi
	_get_root_nodes "$tree"
	subtree="$result"
	_browse "main menu" "$tree" "$subtree"
}