raz_lib.lua

--[[
Region Areas and Zones
	an areas (or region or zone) mod that allows player (depending on privilegs)
	- to mark your (region / areas / zones) with name
	- to protect (region / areas / zones)
	- to invite / ban other players to interact in protected (region / areas / zones)
	- to allow / disallow PvP in (region / areas / zones)
	- to allow / disable Mobdamage [MvP] in (region / areas / zones)
	- to set (region / areas / zones) with an effect like hot, dot, holy, evil
	
	an (region / areas / zones) mod that allows the region_admin (privileg)
	- to create an named city (maybe portected)
	- set some building plots for the playes, so player can protect ther own (region / areas / zones) in the city

	
Copyright (c) 2019 
	ralf Weinert <downad@freenet.de>
Source Code: 	
	https://github.com/downad/raz
License: 
	GPLv3
]]--
-- sed command for functions.txt
-- sed -n -e '/--################################/,/function/p' raz_lib.lua >functions.txt


--################################
--
-- raz:load_regions_from_file()
-- load the AreaStore() from file
--
--
-- input: nothing
-- msg/error handling: no
-- return 0 = no error
function raz:load_regions_from_file()
--	minetest.log("action", "[" .. raz.modname .. "] raz:load_regions_from_file()")
	raz.raz_store:from_file(raz.worlddir .."/".. raz.store_file_name) 
	return 0 	-- No Error
end

--################################
--
-- raz:save_regions_to_file()
-- save AreaStore() to file
--
--
-- input: nothing
-- msg/error handling: 
-- return 0 = no error
function raz:save_regions_to_file()
--	minetest.log("action", "[" .. raz.modname .. "] raz:save_regions_to_file()")	
	raz.raz_store:to_file(raz.worlddir .."/".. raz.store_file_name) 
	return 0 	-- No Error
end

--################################
--
-- raz:set_region(pos1,pos2,data)
-- insert a new region, update AreaStore, save AreaStore
--
--
-- input:
-- 		pos1, pos2 		as vector
-- 		data 			as (designed) string 
--  	use: raz:create_data(owner,region_name,protected,guests_string,PvP,MvP,effect,plot,city,do_not_check_player)
-- because in the datafield could only stored a string	
-- msg/error handling: 
-- return id of new region
function raz:set_region(pos1,pos2,data)
	--minetest.log("action", "[" .. raz.modname .. "] raz:set_region(pos1,pos2,data)")	
	if type(data) ~= "string" then
		data = minetest.serialize(data)
	end
	local id = raz.raz_store:insert_area(pos1, pos2, data)
	raz.save_regions_to_file()
	return id
end

--################################
--
-- raz:delete_region(id)
-- delete region from AreaStore()
--
--
-- input: id as number
-- the get_areas return a pointer, so re-copie the areastore and 'forget' to copie the region with the id
-- check if id ~=0
-- msg/error handling:
-- return 0 - no error
-- return 1 -- "No region with this ID! func: raz:delete_region(id)", 
function raz:delete_region(id)
	minetest.log("action", "[" .. raz.modname .. "] raz:delete_region(id) ID: "..tostring(id)) 
	if raz.raz_store:get_area(id) == nil then
		-- Error
		return 1 -- "No region with this ID! func: raz:delete_region(id)",
	end 

	local counter = 0
	local temp_store = AreaStore() 
	local region_values = {}

	-- copy all regions to temp_store
	while raz.raz_store:get_area(counter) do
		if counter ~=id then
			-- no errorcheck - get_area / insert_area are build in
			region_values = raz.raz_store:get_area(counter,true,true)
			temp_store:insert_area(region_values.min, region_values.max, region_values.data)
		else
			-- no errorcheck - remove_area is build in
			raz.raz_store:remove_area(id)
		end
		counter = counter + 1
	end

	-- recreate raz.raz_store
	raz.raz_store = AreaStore()
	region_values = {}

	-- copy all value back
	counter = 0
	while temp_store:get_area(counter) do
			-- no errorcheck - get_area / insert_area are build in
			region_values = temp_store:get_area(counter,true,true)
			raz:set_region(region_values.min, region_values.max, region_values.data)
		counter = counter + 1
	end
	-- No Error
	return 0 
end

--################################
--
-- raz:update_regions_data(id,pos1,pos2,data_table)
-- update datafield  AreaStore()
--
--
-- input:
--		id				as number - the ID to change
-- 		pos1, pos2 		as vector (table)
--		data_table		as (designed) string
-- msg/error handling:
-- return true 
function raz:update_regions_data(id,pos1,pos2,data_table)
	-- minetest.log("action", "[" .. raz.modname .. "] raz:update_regions_data(id,pos1,pos2,data) ID: "..tostring(id)) 
	local data_string = minetest.serialize(data_table)

	local counter = 0

	-- create an temporary AreaStore()
	local temp_store = AreaStore() 
	local region_values = {}

	-- copy all regions to temp_store
	while raz.raz_store:get_area(counter) do
		--minetest.log("action", "[" .. raz.modname .. "] 1. while - counter = "..tostring(counter)) 
		if counter ~=tonumber(id) then
			region_values = raz.raz_store:get_area(counter,true,true)
			temp_store:insert_area(region_values.min, region_values.max, region_values.data)
		else
			temp_store:insert_area(pos1, pos2, data_string)
		end
		
		counter = counter + 1
	end

	-- recreate raz.raz_store
	raz.raz_store = AreaStore()
	counter = 0

	-- copy all regions from temp_store to raz.raz_store
	while temp_store:get_area(counter) do
		region_values = temp_store:get_area(counter,true,true)
		raz.raz_store:insert_area(region_values.min, region_values.max, region_values.data)
		counter = counter + 1
	end
	temp_store = {}

	-- save changes
	raz:save_regions_to_file()

	return true
end


--################################
--
-- raz:table_to_string(given_table)
-- convert a table to a string, there is no key!
--
--
-- input: 
--		given_table		as table
-- msg/error handling: no
-- return string 		as string
function raz:table_to_string(given_table)
	--minetest.log("action", "[" .. raz.modname .. "] raz:table_to_string(table)")
	local return_string = ""
	for k, v in pairs(given_table) do
		if k then
			return_string = return_string..v..","
		end
	end
	return return_string
end

--################################
--
-- raz:string_in_table(given_string, given_table)
-- check if a string is in an table
--
--
-- input: 
--		given_string 	as string
--		given_table 	as table
-- msg/error handling: no
-- return true if the name is in the table
-- return false if not
function raz:string_in_table(given_string, given_table)
  for i,v in ipairs(given_table) do

    if v == given_string then
      return true
    end

  end
  return false
end

--################################
--
-- raz:remove_value_from_table(value, given_table)
-- remove a value from table
--
--
-- input: 
--		value 		as string
--		given_table as table
-- msg/error handling: no
-- return table with the removed element
function raz:remove_value_from_table(value, given_table)
	local return_table = {}
	for k, v in ipairs(given_table) do
		if k then
		    if v ~= value then
				table.insert(return_table, v)
		    end
		end
	end
	return return_table
end

--################################
--
-- raz:convert_string_to_table(string, seperator)
-- split string into a table, default seperator is ","
--
--
-- input: 
--		string 		as string
--		seperator 	as string {default: seperator = ","}
-- msg/error handling: no
-- return value_tables with the elements
function raz:convert_string_to_table(string, seperator)
	if seperator == nil then
		seperator = ","
	end
	local value_table = {}

	value_table = string.split(string,seperator)

	return value_table
end


--################################
--
-- raz:remove_double_from_string(given_string, seperator)
-- remove all doubles from string (list)
--
--
-- input: 
--		string as string
--		seperator as string {default: seperator = ","}
-- msg/error handling: no
-- return return_string ( as string) with the elements 
function raz:remove_double_from_string(given_string, seperator)
	if seperator == nil then
		seperator = ","
	end
	-- convert string to table
	--minetest.log("action", "[" .. raz.modname .. "] raz:remove_double_from_string() string = "..given_string)
	local value_table = raz:convert_string_to_table(given_string, seperator)
	local return_table = {}
	for k, v in ipairs(value_table) do
		minetest.log("action", "[" .. raz.modname .. "] raz:remove_double_from_string() k = "..tostring(k).." v = "..tostring(v) )
		if k then
		    if raz:string_in_table(v, return_table) == false then
				table.insert(return_table, v)
		    end
		end
	end
	-- convert talbe to string
	local return_string = raz:table_to_string(return_table)	
	--minetest.log("action", "[" .. raz.modname .. "] raz:remove_double_from_string() return_string = "..return_string )
	return return_string
end




--################################
--
-- raz:get_area_by_pos1_pos2(pos1, pos2)
-- get area by pos1 and pos2
--
--
-- input: 
--		pos1, pos2 as vector (table) 
-- returns the first area found
-- msg/error handling: no
-- return nil 	if there is no area
-- return id of the first found area
function raz:get_area_by_pos1_pos2(pos1, pos2)
	local found = raz.raz_store:get_areas_in_area(pos1,pos2,true,true) --accept_overlap, include_borders, include_data):
	for region_id,v in pairs(found) do
		if region_id then
			return region_id -- id of the first found area
		end
	end
	return nil
end


--################################
--
-- az:player_can_mark_region(edge1, edge2, name)
-- check if the player can_add a region!
--
--
-- input: 
--		edge1, edge2	as vector (table)
--		name			as string (playername)
-- msg/error handling: no
-- returns true - no error or region_admin
-- return 16 -- "msg: You don't have the privileg 'region_mark'! ",
-- return 22 -- "msg: Your region is too small (x)!",
-- return 23 -- "msg: Your region is too small (z)!",
-- return 24 -- "msg: Your region is too small (y)!",
-- return 25 -- "msg: Your region is too width (x)!",
-- return 26 -- "msg: Your region is too width (z)!",
-- return 27 -- "msg: Your region is too hight (y)!",
-- retunr 28 -- "msg: There are other region in. You can not mark this region",
function raz:player_can_mark_region(edge1, edge2, name)
	local can_add = true
	-- check if player privilegs
	-- if region_admin, he can place everythere, return true
	if minetest.check_player_privs(name, { region_admin = true }) then 
		return true
	elseif not raz:has_region_mark(name) then
		return 16 -- "msg: You don't have the privileg 'region_mark'! ",
	end

	-- check minimum
	if math.abs(edge1.x - edge2.x) < raz.minimum_width then 
		return 22 -- "msg: Your region is too small (x)!",
	end
	if math.abs(edge1.z - edge2.z) < raz.minimum_width then 
		return 23 -- "msg: Your region is too small (z)!",
	end
	if math.abs(edge1.y - edge2.y) < raz.minimum_height then 
		return 24 -- "msg: Your region is too small (y)!",
	end

	-- check maximum
	if math.abs(edge1.x - edge2.x) >= raz.maximum_width then 
		return 25 -- "msg: Your region is too width (x)!",
	end
	if math.abs(edge1.z - edge2.z) >= raz.maximum_width then 
		return 26 -- "msg: Your region is too width (z)!",
	end
	if math.abs(edge1.y - edge2.y) >= raz.maximum_height then 
		return 27 -- "msg: Your region is too hight (y)!",
	end	

	-- check building plot	
	-- is this region on an other region / do all other region have the plot attrribute?
	local is_plot = raz:region_is_plot(edge1, edge2)
	if is_plot == false then
		can_add = 28 -- "msg: There are other region in. You can not mark this region",
	end

	return can_add	
end

--################################
--
-- raz:create_landrush_edges(pos)
-- create_landrush_edges!
--
--
-- input: 
--		pos			as table
-- msg/error handling: no
-- returns pos1, pos2
function raz:create_landrush_edges(pos)
	-- vector(x,y,z) y -> up/down
	local pos1 = vector.new(pos.x + (raz.landrush_width/-2), pos.y + (raz.landrush_height/-2), pos.z + (raz.landrush_width/-2) ) 	-- down
	local pos2 = vector.new(pos.x + (raz.landrush_width/2), pos.y + (raz.landrush_height/2), pos.z + (raz.landrush_width/2) )		-- up
	return pos1, pos2
end


--################################
--
-- raz:create_data(owner,region_name,protected,guests_string,PvP,MvP,effect,plot,city,do_not_check_player)
-- create the designed data string for the AreaStore()
--
--
-- input:
--		owner,region_name		as strings, MUST be!
--		protected				as boolean, if missing the rest is set to default
--		guests_string			as string, if missing the rest is set to default
--		PvP,MvP					as booleans, if missing the rest is set to default
--		effect					as string, if missing the rest is set to default
--		plot,city				as boolean, if missing the rest is set to default
--		do_not_check_player		as boolean, if missing the rest is set to default
-- 			the flag -do_not_check_player = true allows to create regions for owners who are not player - maybe because you will convert an areas.dat for an other system.
-- data must be an designed string like
-- data = "return {[\"owner\"] = \"playername\", [\"region_name\"] = \"Meine Wiese mit Haus\" , [\"protected\"] = true, 
--			[\"guests\"] = \"none/string\", [\"PvP\"] = false, [\"MvP\"] = true, [\"effect\"] = \"none\", [\"plot\"] = false, [\"city\"] = true}"
-- because in the datafield could only stored a string
-- msg/error handling:
-- return data_string for insert_area(edge1, edge2, DATA) as string
function raz:create_data(owner,region_name,protected,guests_string,PvP,MvP,effect,plot,city,do_not_check_player)
	minetest.log("action", "[" .. raz.modname .. "] raz:create_data(...)"	)
	-- check input-values
	local player = minetest.get_player_by_name(owner)
	if not player and do_not_check_player ~= true then
		owner = minetest.setting_get("name")
	end
	if not type(region_name) == "string" then
		return 1 -- there is an error
	end
	if not type(protected) == "boolean" or protected == nil then
		protected = raz.default.protected
	end
	if not type(guests_string) == "string" or guests_string == nil then
		guests_string = raz.default.guests
	end
	if not type(PvP) == "boolean" or PvP == nil then
		PvP = raz.default.PvP
	end
	if not type(MvP) == "boolean" or MvP == nil then
		MvP = raz.default.MvP
	end
	if not type(effect) == "string" or effect == nil then
		effect = raz.default.effect
	end
	if not type(plot) == "boolean" or plot == nil then
		plot = raz.default.plot
	end
	if not type(city) == "boolean" or city == nil then
		city = raz.default.city
	end
	-- only for debugging
	if raz.debug == true then
		minetest.log("action", "[" .. raz.modname .. "] ***********************************************")
		minetest.log("action", "[" .. raz.modname .. "] region_name: "..tostring(region_name))
		minetest.log("action", "[" .. raz.modname .. "] owner: "..tostring(owner))
		minetest.log("action", "[" .. raz.modname .. "] protected: "..tostring(protected))
		minetest.log("action", "[" .. raz.modname .. "] guests: "..tostring(guests_string))
		minetest.log("action", "[" .. raz.modname .. "] plot: "..tostring(plot))
		minetest.log("action", "[" .. raz.modname .. "] city: "..tostring(city))
		minetest.log("action", "[" .. raz.modname .. "] PvP: "..tostring(PvP))
		minetest.log("action", "[" .. raz.modname .. "] MvP: "..tostring(MvP))
		minetest.log("action", "[" .. raz.modname .. "] effect: "..tostring(effect))
	end
	-- create the datastring
	local data_string = "return {[\"owner\"] = \""..owner.."\", [\"region_name\"] = \""..region_name.."\", [\"protected\"] = "..tostring(protected)..
		", [\"guests\"] = \""..guests_string.."\", [\"PvP\"] = "..tostring(PvP)..", [\"MvP\"] = "..tostring(MvP)..
		", [\"effect\"] = \""..effect.."\", [\"plot\"] = "..tostring(plot)..", [\"city\"] = "..tostring(city).."}" 
 
	return data_string
end

--################################
--
-- raz:get_region_data_by_id(id,no_deserialize)
-- get pos1, pos2 and data of an region 
--
--
-- input: 
--		id 
--		no_deserialize as boolean {default: no_deserialize = nil}
--						no_deserialize = true then return data as string!
--						no_deserialize ~= true then return data as table!
-- msg/error handling:
-- return pos1,pos2 and data (as 3 tables)
-- return 3 - no region with this ID
function raz:get_region_data_by_id(id,no_deserialize)
--	minetest.log("action", "[" .. raz.modname .. "] raz:get_region_data_by_id(id) ID: "..tostring(id).." value = "..minetest.serialize(raz.raz_store:get_area(id,true,true) )) 
	local region_values = ""
	local pos1 = ""
	local pos2 = ""
	local data --= {}
	if raz.raz_store:get_area(id) then 
		region_values = raz.raz_store:get_area(id,true,true)
		pos1 = region_values.min
		pos2 = region_values.max
		if no_deserialize ~= true then
			data = minetest.deserialize(region_values.data)
		else
			data = region_values.data
		end
		return pos1,pos2,data
	end
	-- Error
	return 3 -- [3] = "No region with this ID!"
end

--################################
--
-- raz:get_region_datatable(id)
-- get the data-field of a regions 
--
--
-- input: id
-- get the data field of a given region 
-- msg/error handling: no 
-- return data as table
function raz:get_region_datatable(id)
	--	no_deserialize == false
	local pos1,pos2,data = raz:get_region_data_by_id(id,false)
	return data
end

--################################
--
-- raz:get_data_string_by_id(id)
-- get the data field of a given region and compose a string  
--
--
-- input:
-- 		id			as number
-- msg/error handling: 
-- return data_string
-- return 29 -- "ERROR: No region with this ID! func: raz:get_region_datatable(id)",
function raz:get_data_string_by_id(id)
	local region_values = raz.raz_store:get_area(id,true,true)
	if region_values ~= nil then
		local pos1 = "["..region_values.min.x..","..region_values.min.y..","..region_values.min.z.."]"
		local pos2 = "["..region_values.max.x..","..region_values.max.y..","..region_values.max.z.."]"
		local data = minetest.deserialize(region_values.data)
		local data_string = "\nID "..id..": "..data.region_name.." owned by "..data.owner.." \n( "..pos1.." / "..pos2.." )"
		if data.protected then
			data_string = data_string..", is protected"
		end
		if data.guests ~= (nil or ",") then 
			data_string = data_string..", Guests: "..data.guests
		end
		if data.PvP then
			data_string = data_string..", PvP enable"
		end
		if data.MvP == false then
			data_string = data_string..", Mobs do no damage"
		end
		if data.effect ~="none" then
			data_string = data_string..", effects: " ..tostring(data.effect)
		end
		if data.plot then
			data_string = data_string..", is building plot"
		end
		if data.city then
			data_string = data_string..", is a city"
		end
		return data_string
	end
	return 29 -- "ERROR: No region with this ID! func: raz:get_region_datatable(id)",
end

--################################
--
-- raz:get_region_attribute(id, region_attribute)
-- get one attribute from data-field of a regions 
--
--
-- input: 
--			id					as number
--			region_attribute 	as sting
-- get the data field of a given region 
-- and returns the value from one attribute 
-- msg/error handling: no 
-- return return_value
function raz:get_region_attribute(id, region_attribute)
	local data = raz:get_region_datatable(id)
	--minetest.log("action", "[" .. raz.modname .. "] get_region_attribute! input ID= "..tostring(id).." region_attribute = "..region_attribute )  
		
	-- check if the attribute is allowed
	if not raz:string_in_table(region_attribute, raz.region_attribute) then
		return 8 -- "msg: The region_attribute did not fit!",
	end
    local return_value = ""

	if 	region_attribute == "protect" then
		return_value = data.protected 
	elseif 	region_attribute == "region_name" then
		return_value = data.region_name
	elseif 	region_attribute == "owner" then
		return_value = data.owner
	elseif 	region_attribute == "guest" then
		return_value = data.guests
	elseif 	region_attribute == "PvP" then
		return_value = data.PvP
	elseif 	region_attribute == "MvP" then
		return_value = data.MvP
	elseif 	region_attribute == "effect" then
		return_value = data.effect
	elseif 	region_attribute == "plot" then
		return_value = data.plot
	elseif 	region_attribute == "city" then
		return_value = data.city
	end 

	return return_value
end

--################################
--
-- raz:get_combat_attributs_for_pos(pos)
--	get PvP and MvP as pos for this region
--
--
-- input: pos
-- get the data field attributes PvP and MvP of a given posision 
-- msg/error handling: no 
-- return PvP, MvP as boolean or nil
function raz:get_combat_attributs_for_pos(pos)
	local PvP = nil
	local MvP = nil
	local data_table = {}
	-- get all region for this position
	for id, v in pairs(raz.raz_store:get_areas_for_pos(pos)) do
		if id then
			data_table = raz:get_region_datatable(id)

			-- pvp_only_in_pvp_regions = true
			-- if there are more regions at the same position PvP = true in all
			-- pvp_only_in_pvp_regions = false
			-- if there are more regions at the same position PvP = false in all
			if raz.pvp_only_in_pvp_regions == true then
				if PvP == nil or PvP == false then
					PvP = data_table.PvP
				end
			else
				if PvP == nil or PvP == true then
					PvP = data_table.PvP
				end
			end

			-- if there are more regions at the same position MvP = false in all
			-- true can nil can be changed
			if MvP == nil or MvP == true then
				MvP = data_table.MvP
			end
		end
	end
	return PvP,MvP
end


--################################
--
-- raz:get_owner_for_pos(pos)
-- get_owner_for_pos(pos)
--
--
-- input: pos
-- get the data field attributes owner of a given posision 
-- msg/error handling: no 
-- return owner 	as string
function raz:get_owner_for_pos(pos)
	local owner = ""
	local data_table = {}
	-- get all region for this position
	for regions_id, v in pairs(raz.raz_store:get_areas_for_pos(pos)) do
		if regions_id then
			data_table = raz:get_region_datatable(regions_id)
			owner = owner..", "..raz:get_region_attribute(regions_id, "owner")
		end
	end
	if owner == "" then
		return nil
	else
		return owner
	end
end

--################################
--
-- raz:get_region_center_by_name_and_pos(name, pos)
-- find the center of a region found by name and pos
--
--
-- input:
--		name 	as string
--		pos		as vector
-- get the first area of player at pos 
-- calculate the center and return center_pos 
-- msg/error handling: no 
-- return center_pos as vector
-- retrun 34 -- "msg: There are no region at that pos! ",
function raz:get_region_center_by_name_and_pos(name, pos)
	local data_table = {}
	local center_pos = 34 -- "msg: There are no region at that pos! ",
	local pos1 , pos2
	-- get all region for this position
	for regions_id, v in pairs(raz.raz_store:get_areas_for_pos(pos)) do
		if regions_id then
			pos1, pos2, data_table = raz:get_region_data_by_id(regions_id)
			if name == raz:get_region_attribute(regions_id, "owner") then
				center_pos = raz:get_center_of_box(pos1, pos2)
				return pos1, pos2, center_pos
			end
		end
	end
	return nil, nil, 34
end

--################################
--
-- raz:get_center_of_box(pos1, pos2)
-- find the center of box with pos1 and pos2
--
--
-- input:
--		pos1, pos2		as vector
-- calculate the center and return center_pos 
-- msg/error handling: no 
-- return center_pos as vector
function raz:get_center_of_box(pos1, pos2)
	minetest.log("action", "[" .. raz.modname .. "] get_center_of_box pos1 = "..minetest.serialize(pos1) )  
	minetest.log("action", "[" .. raz.modname .. "] get_center_of_box pos2 = "..minetest.serialize(pos2) )  

	local x,y,z
	x = math.abs( pos1.x - pos2.x ) / 2
	y = math.abs( pos1.y - pos2.y ) / 2
	z = math.abs( pos1.z - pos2.z ) / 2
	minetest.log("action", "[" .. raz.modname .. "] get_center_of_box x = "..tostring(x) )  
	minetest.log("action", "[" .. raz.modname .. "] get_center_of_box x = "..tostring(y) )  
	minetest.log("action", "[" .. raz.modname .. "] get_center_of_box x = "..tostring(z) )  

	if pos1.x < pos2.x then
		x = x + pos1.x
	else
		x = x + pos2.x
	end
	if pos1.y < pos2.y then
		y = y + pos1.y
	else
		y = y + pos2.y
	end
	if pos1.z < pos2.z then
		z = z + pos1.z
	else
		z = z + pos2.z
	end

	return vector.new( x, y, z)
end

--################################
--
-- raz:region_is_plot(pos1,pos2)
-- region_is_plot(pos1,pos2)
--
--
-- input: 
--		pos1,pos2 	as table
-- msg/error handling: 
-- return true  - if the player can mark this region
-- 		a region is a building plot if 
--			all regions have - plot = true
--			one region has city = true and all of the others regions have plot = true 
-- return false - the region is not allowed to build in 
-- return nil	- no region in there
function raz:region_is_plot(pos1,pos2)
-- get all regions in this box
	local found = raz.raz_store:get_areas_in_area(pos1,pos2,true,true) --accept_overlap, include_borders, include_data):
	local is_city = false
	local is_city_plot = false
	local is_plot = true
	local count = 0
	-- loop all region
	for region_id,v in pairs(found) do
		-- if in one region the city-attribut is set is counts for all region there!
		minetest.log("action", "[" .. raz.modname .. "] region_is_plot! region_id "..tostring(region_id) )  
--		minetest.log("action", "[" .. raz.modname .. "] region_is_plot! city "..tostring(raz:get_region_attribute(region_id,"city")) )  
--		minetest.log("action", "[" .. raz.modname .. "] region_is_plot! plot "..tostring(raz:get_region_attribute(region_id,"plot")) )  

		if raz:get_region_attribute(region_id,"city") == true then
			is_city = true
			if raz:get_region_attribute(region_id,"plot") == true then
				is_city_plot = true
			end
		else
			if not raz:get_region_attribute(region_id,"plot") == true then
				is_plot = false
			end			
		end
		-- are there more than 1 region
		count = count + 1 
	end
	-- check:
	minetest.log("action", "[" .. raz.modname .. "] region_is_plot! count "..tostring(count) )  
	minetest.log("action", "[" .. raz.modname .. "] region_is_plot! plot "..tostring(is_plot) )  
	minetest.log("action", "[" .. raz.modname .. "] region_is_plot! city "..tostring(is_city) )  
	if count == 0 then
		return nil			-- no regions found
	end
	-- 1 region - then the plot must be set
	if count == 1 then
		if is_city_plot == true or is_plot == true then
			return true
		end	
	-- 2 or more region - then city in one region and plot in all of the other region has to be set.
	else
		if is_city == true and is_plot == true then
			return true
		end		
	end	
	return false 	-- no building plot
end

--################################
--
-- raz:region_set_attribute(name, id, region_attribute, value, bool)
-- set an attribute in an datastring of an region
--
--
-- input: 
--		name				as string, playername
--		id					as number, region id
--		region_attribute	as string
--		value				as boolean or string, depending on region_attribute
--		bool				as boolean, only used for invite or ban guest
-- the default bool is 'nil' - this bool is used to add or remove guests 
-- this function checks id, region_attribut and value = bool or value = string (effects - hot, bot, holy, dot, choke, evil)
-- msg/error handling:
-- return info: text -- no error
-- return 2 -- "ERROR: No region with this ID! func: raz:region_set_attribute(name, id, region_attribute, value),
-- return 8 -- "ERROR: The region_attribute dit not fit! func: raz:region_set_attribute(name, id, region_attribute, value)",
-- return 9 -- "ERROR: There is no Player with this name! func: raz:region_set_attribute(name, id, region_attribute, value)",
-- return 10 -- "ERROR: Wrong effect! func: raz:region_set_attribute(name, id, region_attribute, value)",
-- return 11 -- "ERROR: You are not the owner of this region! func: raz:region_set_attribute(name, id, region_attribute, value)",
-- return 12 -- "ERROR: No Player with this name is in the guestlist! func: raz:region_set_attribute(name, id, region_attribute, value)",
function raz:region_set_attribute(name, id, region_attribute, value, bool)
	local region_values = ""
	local pos1 = ""
	local pos2 = ""
	local data = {}
	-- return message
	local err_msg = "info: Region with ID: "..id.." modified attribute "..tostring(region_attribute).." with value "..tostring(value)
	
	-- ckeck is this ID in AreaStore()?
	if raz.raz_store:get_area(id) then
		-- get region values 
		pos1,pos2,data = raz:get_region_data_by_id(id)
		-- check if player is owner of the regions
		if name ~= data.owner then
			if not minetest.check_player_privs(name, { region_admin = true }) then
				return 11 -- "ERROR: You are not the owner of this region! func: raz:region_set_attribute(name, id, region_attribute, value)",
			end
		end
		-- check if the attribute is allowed
		if not raz:string_in_table(region_attribute, raz.region_attribute) then
			return 8 -- "ERROR: The region_attribute dit not fit! func: raz:region_set_attribute(name, id, region_attribute, value)",
		end
		-- modify the attribute
		if 	region_attribute == "protect" then
			if type(value) == "boolean" then 
				data.protected = value 
			end 
		elseif 	region_attribute == "region_name" then
			if type(value) == "string" then 
				data.region_name = value
			end 
		elseif 	region_attribute == "owner" then
			if type(value) == "string" then 
				-- check player"
				if not minetest.player_exists(value) then --player then
					return 9 -- "ERROR: There is no Player with this name! func: raz:region_set_attribute(name, id, region_attribute, value)",
				end			
				data.owner = value
			end 
		elseif 	region_attribute == "guest" and bool == true then
			if type(value) == "string" then 
				-- check player"
				--local player = minetest.get_player_by_name(value)
				if not minetest.player_exists(value) then --player then
					return 9 -- "ERROR: There is no Player with this name! func: raz:region_set_attribute(name, id, region_attribute, value)",
				end			
				if data.guests == "," or data.guests == nil then
					data.guests = value
				else
					--check	if guest/value is in string guests
					local given_table = raz:convert_string_to_table(data.guests, ",")
					if not raz:string_in_table(value, given_table) then
						data.guests = data.guests..","..value 
					else
						return 15
					end
				end
				err_msg = err_msg.." guest added. "
			end 
		elseif 	region_attribute == "guest" and bool == false then
			if type(value) == "string" then 
				-- check guests
				local guests = raz:convert_string_to_table(data.guests, ",")
				if not raz:string_in_table(value, guests) then
					return 12 -- "ERROR: No Player with this name is in the guestlist! func: raz:region_set_attribute(name, id, region_attribute, value)",
				end
				-- remove value from guests
				guests = raz:remove_value_from_table(value, guests)
				-- data.guests must be an STRING!
				local new_guest_string = raz:table_to_string(guests)
				data.guests = new_guest_string
				err_msg = err_msg.." guest banned. "

			end 
		elseif 	region_attribute == "PvP" then
			if type(value) == "boolean" then 
				data.PvP = value 
			end 
		elseif 	region_attribute == "MvP" then
			if type(value) == "boolean" then 
				data.MvP = value 
			end 
		elseif 	region_attribute == "plot" then
			if type(value) == "boolean" then 
				data.plot = value 
			end 
		elseif 	region_attribute == "city" then
			if type(value) == "boolean" then 
				data.city = value 
			end 		elseif 	region_attribute == "effect" then
			if type(value) == "string" then 
				-- check effects"
				if not raz:string_in_table(value, raz.region_effects) then
					return 10 -- "ERROR: Wrong effect! func: raz:region_set_attribute(name, id, region_attribute, value)",
				end 
				data.effect = value 
			end 

		end
		-- update_regions_data(id,pos1,pos2,data)
		if not raz:update_regions_data(id,pos1,pos2,data) then
			return 7 -- "ERROR: in update_regions_data! func: raz:region_set_attribute(id, region_attribute, bool)", 
		end
		return err_msg
	else
		-- Error
		return 2 -- [2] = "No region with this ID!"
	end
end

--################################
--
-- raz:file_exists(file)
-- file exist?
--
--
-- input: 
--		file 
-- msg/error handling: no
-- return f
function raz:file_exists(file)
  local f = io.open(file, "rb")
  if f then f:close() end
  return f ~= nil
end

--################################
--
-- raz:lines_from(file)
-- get all lines from a file
--
--
-- input: file
-- get all lines from a file, returns an empty 
-- list/table if the file does not exist
-- msg/error handling: no
-- return {} if file does not exist
-- return lines as table
function raz:lines_from(file)
	if not file_exists(file) then return {} end
	local lines = {}
	for line in io.lines(file) do 
	lines[#lines + 1] = line
	end
	return lines
end

 

--#---------------------------------------
--
-- Error handling
--
--#---------------------------------------
--
--
--################################
--
-- raz:msg_handling(err, name)
-- handle errors and messages
--
--
-- input: 
--		err as number or string
--		err 0 -> no error, no output
--		name as string {default: name = nil}
-- this function handles messages and errors
-- if name ~= nil check name and chat_send msg to name
-- if err == "", nil or 0 -> no Error: nothing happens
-- else minetest.log("error",
-- the raz.error_text[err] is defined in init.
-- msg/error handling:
-- return NOTHING - everything is ok
function raz:msg_handling(err, name)
	if err == "" or err == nil or err == 0 then
		return 
	end
	--minetest.log("action", "[" .. raz.modname .. "] ##########################################################")
	--minetest.log("action", "[" .. raz.modname .. "] msg_handling -err: " .. tostring(err))
	--minetest.log("action", "[" .. raz.modname .. "] type(err): " .. type(err))
	--minetest.log("action", "[" .. raz.modname .. "] name: " .. tostring(name))
	
	if type(err) == "string" then
		-- is err an info
		if err:sub(1, 5) == "info:" then
			minetest.log("action", "[" .. raz.modname .. "]".. err:sub(6, -1))	
		else 
			minetest.log("error", "[" .. raz.modname .. "] Error: ".. err)	
		end
	elseif type(err) == "number" then
		minetest.log("error", "[" .. raz.modname .. "] Error: ".. raz.error_text[err])	
	end
	if name == nil then 
		return
	end
	-- if name exists send chat
	if minetest.player_exists(name) then 
		if type(err) == "number" then
			minetest.chat_send_player(name, raz.error_text[err])
		else
			minetest.chat_send_player(name, tostring(err) )
		end
	end
end



--################################
--
-- raz:print_regions()
-- print all regions
--
--
-- input: nothing
-- msg/error handling: no
-- print a List of all regions to the minetest.log
-- for debug only
function raz:print_regions()
	if raz.debug == false then
		return
	end
	minetest.log("action", "[" .. raz.modname .. "] raz:print_regions")

	raz.regions = {}
	local counter = 0
	local region_values = ""
	local pos1 = ""
	local pos2 = ""
	local data = ""
	minetest.log("action", "[" .. raz.modname .. "] Print list of stored regions.")
	while raz.raz_store:get_area(counter) do
		region_values = raz.raz_store:get_area(counter,true,true)
		pos1 = region_values.min
		pos2 = region_values.max
		data = region_values.data

		minetest.log("action", "[" .. raz.modname .. "] ------------------")
		minetest.log("action", "[" .. raz.modname .. "] region (" .. counter .. ") ")
		minetest.log("action", "[" .. raz.modname .. "] pos1 (x,y,z) "..tostring(pos1["x"])..",".. tostring(pos1["y"])..","..tostring(pos1["z"]))
		minetest.log("action", "[" .. raz.modname .. "] pos2 (x,y,z) "..tostring(pos2["x"])..",".. tostring(pos2["y"])..","..tostring(pos2["z"]))
		minetest.log("action", "[" .. raz.modname .. "] data ".. tostring(data))

		counter = counter + 1
	end
end

--################################
--
-- raz:print_region_datatable_for_id(id)
-- print the region with the id
--
--
-- input: id as number, region_id
-- msg/error handling: no
-- a debug function for region_datatable
function raz:print_region_datatable_for_id(id)
	if raz.debug == false then
		return
	end
	minetest.log("action", "[" .. raz.modname .. "] raz:print_region_datatable_for_id(id)")
	if raz.raz_store:get_area(id) then
		local region_data = raz:get_region_datatable(id) 

		-- name of the region
		local region_name = region_data.region_name
		-- owner of the region
		local owner = region_data.owner
		-- is the region protected?
		-- true: only owner can 'dig' in the region
		local protected = region_data.protected
		-- guest
		local guests = region_data.guests --guests is a string
		-- is this an PvP region?
		local PvP = region_data.PvP
		-- can Mobs damage the Player?
		local MvP = region_data.MvP
		-- has the region a special effect?
		-- hot: heal over time 
		-- fot: feed over time
		-- bot:	breath ober time
		-- holy: heal, feed an breath over time
		-- dot: damage over time
		-- starve: reduce food over time
		-- choke: reduce breath over time
		-- evil: steals food, blood, breath over time
		local effect = region_data.effect
		-- is the plot-flag set?
		local plot = region_data.plot
		-- is the city-flag set?
		local city = region_data.city
		minetest.log("action", "[" .. raz.modname .. "] Values of the region ("..id..")")
		minetest.log("action", "[" .. raz.modname .. "] region_name: "..tostring(region_name))
		minetest.log("action", "[" .. raz.modname .. "] owner: "..tostring(owner))
		minetest.log("action", "[" .. raz.modname .. "] protected: "..tostring(protected))
		minetest.log("action", "[" .. raz.modname .. "] guests: "..tostring(guests))
		minetest.log("action", "[" .. raz.modname .. "] PvP: "..tostring(PvP))
		minetest.log("action", "[" .. raz.modname .. "] MvP: "..tostring(MvP))
		minetest.log("action", "[" .. raz.modname .. "] effect: "..tostring(effect))
		minetest.log("action", "[" .. raz.modname .. "] plot: "..tostring(plot))
		minetest.log("action", "[" .. raz.modname .. "] city: "..tostring(city))
	else
		minetest.log("action", "[" .. raz.modname .. "] No Values for the Region with the ID: "..id)
	end
end

--################################
--
-- raz.markPos1 = .... (name)
-- Marks region position 1
--
--
-- input: 
--	name 		as string, playername
-- msg/error handling: no
raz.markPos1 = function(name)
	local pos = raz.command_players[name].pos1
	if raz.marker1[name] ~= nil then -- Marker already exists
		raz.marker1[name]:remove() -- Remove marker
		raz.marker1[name] = nil
	end
	if pos ~= nil then -- Add marker
		raz.marker1[name] = minetest.add_entity(pos, "raz:pos1")
		raz.marker1[name]:get_luaentity().active = true
	end
end

--################################
--
-- raz.markPos2 = .... (name)
-- Marks region position 2
--
--
-- input: 
--	name 		as string, playername
-- msg/error handling: no
raz.markPos2 = function(name)
	local pos = raz.command_players[name].pos2
	if raz.marker2[name] ~= nil then -- Marker already exists
		raz.marker2[name]:remove() -- Remove marker
		raz.marker2[name] = nil
	end
	if pos ~= nil then -- Add marker
		raz.marker2[name] = minetest.add_entity(pos, "raz:pos2")
		raz.marker2[name]:get_luaentity().active = true
	end
end