local sformat = string.format
local fsescape = minetest.formspec_escape

local function make_list(entries)
	local t = {}
	for k, v in ipairs(entries) do
		t[k] = fsescape(v)
	end
	return table.concat(t, ",")
end

local function S_wrapper(f, i0)
	return function(...)
		local args = {...}
		args[i0] = attrans(unpack(args,i0))
		return f(unpack(args,1,i0))
	end
end

local function f_button(x, y, w, id, text)
	return sformat("button[%f,%f;%f,0.75;%s;%s]", x, y, w, id, text)
end

local function f_checkbox(x, y, name, selected, label)
	return sformat("checkbox[%f,%f;%s;%s;%s]", x, y+0.25, name, label, selected and "true" or "false")
end

local function f_button_exit(x, y, w, id, text)
	return sformat("button_exit[%f,%f;%f,0.75;%s;%s]", x, y, w, id, text)
end

local function f_dropdown(x, y, w, id, entries, sel, indexed)
	return sformat("dropdown[%f,%f;%f,0.75;%s;%s;%d%s]",
		x, y, w, id, make_list(entries),
		sel or 1,
		indexed and ";true" or "")
end

local function f_image_button(x, y, w, h, texture, id, label, noclip, drawborder, pressed)
	local st = {string.format("%f,%f;%f,%f;%s;%s;%s", x, y, w, h, fsescape(texture), fsescape(id), fsescape(label))}
	if pressed then
		st[#st+1] = tostring(noclip or false)
		st[#st+1] = tostring(drawborder or false)
		st[#st+1] = fsescape(pressed)
	end
	return sformat("image_button[%s]", table.concat(st, ";"))
end

local function f_image_button_exit(x, y, w, h, texture, id, label)
	local st = {string.format("%f,%f;%f,%f;%s;%s;%s", x, y, w, h, fsescape(texture), fsescape(id), fsescape(label))}
	return sformat("image_button_exit[%s]", table.concat(st, ";"))
end

local function f_label(x, y, text)
	return sformat("label[%f,%f;%s]", x, y+0.25, fsescape(text))
end

local function f_field_aux(x, y, w, id, default)
	return sformat("field[%f,%f;%f,0.75;%s;;%s]", x, y, w, id, default)
end

local function f_field(x, y, w, id, label, default)
	return f_label(x, y-0.5, label) .. f_field_aux(x, y, w, id, default)
end

local function f_tabheader(x, y, w, h, id, entries, sel, transparent, border)
	local st = {string.format("%f,%f",x, y)}
	if h then
		if w then
			st[#st+1] = string.format("%f,%f", w, h)
		else
			st[#st+1] = tostring(h)
		end
	end
	st[#st+1] = tostring(id)
	st[#st+1] = make_list(entries)
	st[#st+1] = tostring(sel)
	if transparent ~= nil then
		st[#st+1] = tostring(transparent)
		if border ~= nil then
			st[#st+1] = tostring(border)
		end
	end
	return string.format("tabheader[%s]", table.concat(st, ";"))
end

local function f_textlist(x, y, w, h, id, entries, sel, transparent)
	local st = {string.format("%f,%f;%f,%f;%s;%s", x, y, w, h, id, make_list(entries))}
	if sel then
		st[#st+1] = tostring(sel)
		st[#st+1] = tostring(transparent or false)
	end
	return string.format("textlist[%s]", table.concat(st, ";"))
end

return {
	button = f_button,
	S_button = S_wrapper(f_button, 5),
	checkbox = f_checkbox,
	S_checkbox = S_wrapper(f_checkbox, 5),
	button_exit = f_button_exit,
	S_button_exit = S_wrapper(f_button_exit, 5),
	dropdown = f_dropdown,
	field = f_field,
	image_button = f_image_button,
	image_button_exit = f_image_button_exit,
	label = f_label,
	S_label = S_wrapper(f_label, 3),
	tabheader = f_tabheader,
	textlist = f_textlist,
}