local modname = minetest.get_current_modname()
local function trans(st,...)
	return minetest.translate(modname,st,...)
end
local function fs_t(st,...)
	return minetest.formspec_escape(trans(st,...))
end
local function show_formspec(itemstack,pname)
	local formspec = ""
	formspec = formspec.."formspec_version[3]"
	formspec = formspec.."size[10.5,7.5]"

	formspec = formspec.."label[0.2,0.4;Advanced Trains Remote Control v1]"

	formspec = formspec.."button_exit[6.6,0.2;3.7,0.8;bind_train;Bind To New Train]"

	local train_id = itemstack:get_meta():get("bound_train")
	if not train_id or not advtrains.trains[train_id] then
		formspec = formspec.."label[0.2,1.2;Remote Control: Not Bound]"
		formspec = formspec.."label[0.2,1.6;Punch a train with the controller to bind it]"
	else
		formspec = formspec.."label[0.2,1.2;Remote Control: Train %s]"
		formspec = formspec.."label[0.2,1.6;Train Length: %s wagon(s)]"
		formspec = formspec.."label[0.2,2;Train Length: %sm]"

		formspec = formspec.."textarea[0.2,2.9;5.8,0.8;ext_disp;External Display;%s]"
		formspec = formspec.."textarea[0.2,4.1;5.8,0.8;int_disp;Internal Display;%s]"
		formspec = formspec.."field[0.2,6.5;2.8,0.8;line;Line;%s]"
		formspec = formspec.."field[0.2,5.3;5.8,0.8;rc;Routing Code;%s]"
		formspec = formspec.."button[3.2,6.5;2.8,0.8;update_info;Update Train Info]"

		formspec = formspec.."label[6.6,1.6;Maximum Speed: %s m/s]"
		formspec = formspec.."field[6.6,2.9;1.9,0.8;speed_input;Set Speed;%d]"
		formspec = formspec.."button[8.8,2.9;1.5,0.8;send_speed;Confirm]"
		formspec = formspec.."field[6.6,4.1;1.9,0.8;atc_input;Send ATC Command;]"
		formspec = formspec.."button[8.8,4.1;1.5,0.8;send_atc;Send]"
		formspec = formspec.."button[6.6,5.3;3.7,0.8;reverse;Reverse]"

		formspec = formspec.."label[6.6,2;Door Control]"
		formspec = formspec.."scrollbaroptions[min=1;max=3;smallstep=1;largestep=1;thumbsize=1;arrows=hide]scrollbar[6.6,2.2;3.7,0.2;horizontal;door;%d]"
		
		formspec = formspec.."checkbox[6.6,6.6;ars_disable;Disable ARS;%s]"
		formspec = formspec.."checkbox[6.6,7.1;autocouple;Autocouple;%s]"

		formspec = formspec.."button[9.1,6.5;1.2,0.8;estop;STOP!]"
				
		local train = advtrains.trains[train_id]
	
		formspec = string.format(formspec,
			train_id,
			#train.trainparts,
			train.trainlen,
			train.text_outside or "",
			train.text_inside or "",
			train.line or "",
			train.routingcode or "",
			train.max_speed,
			train.velocity,
			((train.door_open or 0) + 2),
			tostring(train.ars_disable),
			tostring(train.autocouple or train.atc_wait_autocouple)
		)
	end
	minetest.show_formspec(pname,modname..":controller",formspec)
end

minetest.register_on_player_receive_fields(function(player,formname,fields)
	if formname ~= modname..":controller" then return end
	local pname = player:get_player_name()
	if not pname then return end
	local itemstack = player:get_wielded_item()
	if itemstack:get_name() ~= modname..":remote_control" then return end
	
	local item_meta = itemstack:get_meta()
	local train_id = item_meta:get("bound_train")
	if not train_id and not fields.bind_train then
		return
	end
	local train = advtrains.trains[train_id]
	local door_scroll = minetest.explode_scrollbar_event(fields.door)
	--[[list of fields:
		active fields:
			bind_train
			update_info
			send_speed
			send_atc
			reverse
			door
			ars_disable
			autocouple
			estop
		data fields:
			ext_disp
			int_disp
			line
			rc
			speed_input
			atc_input
	--]]
	
	--bind train
	if fields.bind_train then
		item_meta:set_string("bound_train","")
		item_meta:set_string("description","Unbound Controller")
		player:set_wielded_item(itemstack)
		minetest.chat_send_player(pname,trans("Punch a train with the controller to bind it"))
		return
	--update info
	elseif fields.update_info then
		train.text_outside = fields.ext_disp or ""
		train.text_inside = fields.int_disp or ""
		train.line = fields.line or ""
		train.routingcode = fields.rc or ""
		minetest.after(0, advtrains.invalidate_path, train_id)
		return
	--send speed command
	elseif fields.send_speed then
		local current_v,speed_input = train.velocity,tonumber(fields.speed_input)
		if not tonumber(speed_input) then
			minetest.chat_send_player(pname,trans("Speed must be a number"))
			return
		end
		local command
		local acc
		speed_input = tonumber(speed_input)
		if current_v == speed_input then
			minetest.chat_send_player(pname,trans("Speed unchanged"))
			return
		elseif current_v < speed_input then
			command = "S"..speed_input
			acc = "accelerating"
		elseif current_v > speed_input then
			command = "B"..speed_input
			acc = "braking"
		end
		advtrains.atc.train_set_command(train,command,true)
		minetest.chat_send_player(pname,trans("Train "..acc.." to "..speed_input))
		return
	--send atc command
	elseif fields.send_atc then
		if fields.atc_input == "" then
			minetest.chat_send_player(pname,trans("No ATC command to send"))
			return
		end
		advtrains.atc.train_set_command(train,fields.atc_input,true)
		return
	-- send reverse command
	elseif fields.reverse then
		if train.velocity ~= 0 then
			minetest.chat_send_player(pname,trans("Please stop the train before reversing"))
			return
		end
		advtrains.invert_train(train_id)
		advtrains.train_ensure_init(train_id,train)
		-- advtrains.atc.train_reset_command(train)
		minetest.chat_send_player(pname,trans("Train reversed"))
		return
	--door control
	elseif door_scroll.type == "CHG" then
		train.door_open = door_scroll.value-2
		return
	-- ars_disable
	elseif fields.ars_disable then
		if not advtrains.interlocking then
			return
		end
		advtrains.interlocking.ars_set_disable(train,minetest.is_yes(fields.ars_disable))
		return
	-- autocouple
	elseif fields.autocouple == "true" then
		train.autocouple = true
		return
	elseif fields.autocouple == "false" then
		train.autocouple = nil
		return
	-- emergency stop button
	elseif fields.estop then
		advtrains.atc.train_set_command(train,"BB",true)
		minetest.chat_send_player(pname,trans("Emergency Brake applied"))
		return
	end
end)

minetest.register_craftitem(modname..":remote_control",{
	description = trans("Train Controller"),
	short_description = trans("Unbound Train Controller"),
	groups = {},
	inventory_image = "advtrains_rc_controller.png",
	wield_image = "advtrains_rc_controller.png",
	stack_max = 1,
	on_use = function(itemstack, user, pointed_thing)
		local pname = user:get_player_name()
		if not pname or pname == "" then
			return
		end
		if not minetest.check_player_privs(pname, {train_admin=true}) then
			minetest.chat_send_player(pname, "Insufficient privileges to use this!")
			return
		end
		
		local meta = itemstack:get_meta()
		local bound_train = meta:get_string("bound_train") -- set to nil to enable bind-mode
		if bound_train == "" then bound_train = nil end
		if pointed_thing.type == "object" then
			local object = pointed_thing.ref:get_luaentity()
			local data = advtrains.wagons[object.id]
			if data == nil then return end
			if not bound_train then -- bind to this train
				meta:set_string("bound_train",data.train_id)
				meta:set_string("description",string.format("Train Controller\nBound to %s",data.train_id))
			end
		end
		show_formspec(itemstack,pname)
		return itemstack
	end,
})