-- Properties for NPC --
-- This is used when an NPC doesn't have a specific dialog but still wants to
-- make use of a (or some) generic dialog(es)

-- helper function:
-- get one property value of the NPC
yl_speak_up.get_one_npc_property = function(pname, property_name)
	if(not(pname)) then
		return nil
	end
	-- get just the property data
	return yl_speak_up.get_npc_properties(pname, false)[property_name]
end


-- helper function;
-- adds "normal" properties of the npc with a self.<property_name> prefix as well
-- if long_version is not set, a table containing all properties is returned;
-- if long_version *is* set, a table containing the table above plus additional entries is returned
yl_speak_up.get_npc_properties_long_version = function(pname, long_version)
	if(not(pname) or not(yl_speak_up.speak_to[pname])) then
		return {}
	end
	local obj = yl_speak_up.speak_to[pname].obj
	if(not(obj)) then
		return {}
	end
	local entity = obj:get_luaentity()
	if(not(entity)) then
		return {}
	end
	if(not(entity.yl_speak_up)) then
		return {}
	end
	local properties = entity.yl_speak_up.properties
	if(not(properties)) then
		properties = {}
		entity.yl_speak_up.properties = properties
	end
	-- copy other property data that is stored under self.* over as well (like i.e. self.order for mobs_redo)
	for k, v in pairs(entity) do
		local t = type(v)
		if(t == "string" or t == "number" or t == "boolean") then
			properties["self."..tostring(k)] = tostring(v)
		end
	end
	properties["self.name"] = tostring(entity.name)
	if(not(long_version)) then
		return properties
	end
	-- the long version contains additional information
	local prop_names = {}
	for k, v in pairs(properties) do
		table.insert(prop_names, k)
	end
	table.sort(prop_names)
	return {obj = obj, entity = entity, properties = properties, prop_names = prop_names}
end


-- most of the time we don't need object, entity or a list of the names of properties;
-- this returns just the properties themshelves
yl_speak_up.get_npc_properties = function(pname)
	return yl_speak_up.get_npc_properties_long_version(pname, false)
end


yl_speak_up.set_npc_property = function(pname, property_name, property_value, reason)
	if(not(pname) or not(property_name) or property_name == "") then
		return "No player name or property name given. Cannot load property data."
	end
	-- here we want a table with additional information
	local property_data = yl_speak_up.get_npc_properties_long_version(pname, true)
	if(not(property_data)) then
		return "Failed to load property data of NPC."
	end
	-- it is possible to react to property changes with special custom handlers
	if(yl_speak_up.custom_property_handler[property_name]) then
		-- the table contains the pointer to a fucntion
		local fun = yl_speak_up.custom_property_handler[property_name]
		-- call that function with the current values
		return fun(pname, property_name, property_value, property_data)
	end
	-- properties of type self. are not set directly
	if(string.sub(property_name, 1, 5) == "self.") then
		return "Properties of the type \"self.\" cannot be modified."
	end
	-- properites starting with "server" can only be changed or added manually by
	-- players with the npc_talk_admin priv
	if(string.sub(property_name, 1, 6) == "server") then
		if(not(reason) or reason ~= "manually" or not(pname)
		  or not(minetest.check_player_privs(pname, {npc_talk_admin=true}))) then
			return "Properties starting with \"server\" can only be changed by players "..
				"who have the \"npc_talk_admin\" priv."
		end
	end
	-- store it
	if(property_data.entity) then
		property_data.entity.yl_speak_up.properties[property_name] = property_value
		local n_id = yl_speak_up.speak_to[pname].n_id
		yl_speak_up.log_change(pname, n_id, "Property \""..tostring(property_name)..
					"\" set to \""..tostring(property_value).."\".")
	end
	-- TODO: handle non-npc (blocks etc)
	return "OK"
end


yl_speak_up.input_properties = function(player, formname, fields)
	local pname = player:get_player_name()
	if(not(pname) or not(yl_speak_up.speak_to[pname])) then
		return
	end
	local n_id = yl_speak_up.speak_to[pname].n_id

	if(fields and fields.back and fields.back ~= "") then
		yl_speak_up.show_fs(player, "initial_config",
			{n_id = n_id, d_id = yl_speak_up.speak_to[pname].d_id, false})
		return
	end

	local selected_row = nil
	if(fields and fields.store_new_val and fields.store_new_val ~= "" and fields.prop_val) then
		yl_speak_up.set_npc_property(pname, fields.prop_name, fields.prop_val, "manually")

	elseif(fields and fields.delete_prop and fields.delete_prop ~= "") then
		-- delete the old property
		yl_speak_up.set_npc_property(pname, fields.prop_name, nil, "manually")

	elseif(fields and fields.table_of_properties) then
		local selected = minetest.explode_table_event(fields.table_of_properties)
		if(selected.type == "CHG" or selected.type == "DLC") then
			selected_row = selected.row
		end
	end
	yl_speak_up.show_fs(player, "properties", {selected = selected_row})
end


yl_speak_up.get_fs_properties = function(pname, selected)
	if(not(pname)) then
		return ""
	end
	local n_id = yl_speak_up.speak_to[pname].n_id

	-- is the player editing this npc? if not: abort
	if(not(yl_speak_up.edit_mode[pname])
	  or (yl_speak_up.edit_mode[pname] ~= n_id)) then
		return ""
	end

	-- we want the long version with additional information
	local property_data = yl_speak_up.get_npc_properties_long_version(pname, true)
	if(not(property_data)) then
		-- something went wrong - there really is nothing useful we can do
		-- if the NPC we want to interact with doesn't exist or is broken
		return
	end
	local s = ""
	if(not(property_data.prop_names)) then
		property_data.prop_names = {}
	end
	local anz_prop = #property_data.prop_names
	for i, k in ipairs(property_data.prop_names) do
		local v = property_data.properties[k]
		s = s.."#BBBBFF,"..minetest.formspec_escape(k)..","..minetest.formspec_escape(v)..","
	end
	s = s.."#00FF00,add,Add a new property"

	if(not(selected) or selected == "") then
		selected = -1
	end
	local add_selected = "label[3.5,6.5;No property selected.]"
	selected = tonumber(selected)
	if(selected > anz_prop + 1 or selected < 1) then
		selected = -1
	elseif(selected > anz_prop) then
		add_selected = "label[0.2,6.5;Add new property:]"..
			"field[3.0,6.5;3.5,1.0;prop_name;;]"..
			"label[6.5,6.5;with value:]"..
			"field[8.2,6.5;4.5,1.0;prop_val;;]"..
			"button[8.2,7.8;2.0,1.0;store_new_val;Store]"
	-- external properties can usually only be read but not be changed
	elseif(string.sub(property_data.prop_names[selected], 1, 5) == "self."
	  and not(yl_speak_up.custom_property_handler[property_data.prop_names[selected]])) then
		add_selected = "label[3.5,6.5;Properties of the type \"self.\" usually cannot be modified.]"
	elseif(string.sub(property_data.prop_names[selected], 1, 6) == "server"
	  and not(minetest.check_player_privs(pname, {npc_talk_admin=true}))) then
		add_selected = "label[3.5,6.5;Properties starting with \"server\" can only be "..
				"changed by players\nwho have the \"npc_talk_admin\" priv."
	else
		local name = property_data.prop_names[selected]
		local val = minetest.formspec_escape(property_data.properties[name])
		local name_esc = minetest.formspec_escape(name)
		add_selected = "label[0.2,6.5;Change property:]"..
			"field[3.0,6.5;3.5,1.0;prop_name;;"..name_esc.."]"..
			"label[6.5,6.5;to value:]"..
			"field[8.2,6.5;4.5,1.0;prop_val;;"..val.."]"..
			"button[8.2,7.8;2.0,1.0;store_new_val;Store]"..
			"button[10.4,7.8;2.0,1.0;delete_prop;Delete]"
	end
	if(selected < 1) then
		selected = ""
	end
	local dialog = yl_speak_up.speak_to[pname].dialog
	local npc_name = minetest.formspec_escape(dialog.n_npc or "- nameless -")
	return "size[12.5,8.5]" ..
		"label[2,0;Properties of "..npc_name.." (ID: "..tostring(n_id).."):]"..
		"tablecolumns[color,span=1;text;text]"..
		"table[0.2,0.5;12,4.0;table_of_properties;"..s..";"..tostring(selected).."]"..
		"tooltip[0.2,0.5;12,4.0;"..
			"Click on \"add\" to add a new property.\n"..
			"Click on the name of a property to change or delete it.]"..
		"label[2.0,4.5;"..
			"Properties are important for NPC that want to make use of generic dialogs.\n"..
			"Properties can be used to determine which generic dialog(s) shall apply to\n"..
			"this particular NPC and how they shall be configured. You need the\n"..
			"\"npc_talk_admin\" priv to edit properties starting with the text \"server\".]"..
		"button[5.0,7.8;2.0,0.9;back;Back]"..
		add_selected
end