yl_speak_up/quest_api.lua

-- just some handling of variables

-- TODO: handle read (and write?) access for other players
-- TODO: add a function to check if the player has read/write access
-- TODO: mark some vars as "need to be saved" while others are less important (i.e. timestamps)

-- the keys are of the form:
-- 	$ <blank> <player name> <blank> <variable name> (makes it easier to grant read access)
-- the values are of the form:
-- 	<current player name as key> : <value of variable for that player as value>
yl_speak_up.player_vars = {}

-- store when player_vars was last saved to disc
yl_speak_up.player_vars_last_save_time = 0

-- save the data to disc; either if force_save is set or enough time has passed
yl_speak_up.save_quest_variables = function(force_save)
	if(not(force_save)
	  and (yl_speak_up.player_vars_last_save_time + yl_speak_up.player_vars_min_save_time >
	       math.floor(minetest.get_us_time()/1000000))) then
		return
	end
	local json = minetest.write_json( yl_speak_up.player_vars )
	-- actually store it on disk
	minetest.safe_file_write(yl_speak_up.worldpath..yl_speak_up.player_vars_save_file..".json", json)
end


-- load the data from disc
yl_speak_up.load_quest_variables = function()
	-- load the data from the file
	local file, err = io.open(yl_speak_up.worldpath..yl_speak_up.player_vars_save_file..".json", "r")
	if err then
		return
	end
	io.input(file)
	local text = io.read()
	-- all values saved in the tables as such are strings
	local data = minetest.parse_json(text, -1)
	io.close(file)

	if(type(data) ~= "table") then
		return
	end
	for k,v in pairs(data) do
		if(v == -1) then
			data[ k ] = {}
		end
	end
	yl_speak_up.player_vars = data
end
-- do so when this file is parsed
yl_speak_up.load_quest_variables()


-- new variables have to be added somehow
yl_speak_up.add_quest_variable = function(owner_name, variable_name)
	local k = "$ "..tostring(owner_name).." "..tostring(variable_name)
	if(not(owner_name) or not(variable_name)) then
		return false
	end
	-- create a new empty table;
	-- keys will be the names of players for which values are set
	yl_speak_up.player_vars[ k ] = {}
	-- a new variable was created - that deserves a forced save
	yl_speak_up.save_quest_variables(true)
	return true
end


-- accidentally created or no longer needed variables need to be deleted somehow
yl_speak_up.del_quest_variable = function(owner_name, variable_name)
	local k = "$ "..tostring(owner_name).." "..tostring(variable_name)
	if(not(owner_name) or not(variable_name)) then
		return false
	end
	-- a variable was deleted - that deserves a forced save
	yl_speak_up.save_quest_variables(true)
	yl_speak_up.player_vars[ k ] = nil
end


-- set the value of a variable used by a player in an NPC;
-- returns false if the variable cannot be set (i.e. does not exist)
yl_speak_up.set_quest_variable_value = function(player_name, variable_name, new_value)
	-- the owner name is alrady encoded in the variable name
	local k = tostring(variable_name)
	if(not(variable_name) or not(player_name) or not(yl_speak_up.player_vars[ k ])) then
		return false
	end
	yl_speak_up.player_vars[ k ][ player_name ] = tostring(new_value)
	-- a quest variable was changed - save that to disc (but no need to force it)
	yl_speak_up.save_quest_variables(false)
	return true
end


-- get the value of a variable used by a player in an NPC;
-- returns nil if the variable does not exist
yl_speak_up.get_quest_variable_value = function(player_name, variable_name)
	-- the owner name is alrady encoded in the variable name
	local k = tostring(variable_name)
	if(not(variable_name) or not(player_name) or not(yl_speak_up.player_vars[ k ])) then
		return nil
	end
	return yl_speak_up.player_vars[ k ][ player_name ]
end


-- which variables can player pname read and use in preconditions?
-- returns a sorted list
yl_speak_up.get_quest_variables_with_read_access = function(pname)
	if(not(pname)) then
		return {}
	end
	local liste = {}
	for k, v in pairs(yl_speak_up.player_vars) do
		local parts = string.split(k, " ")
		if(parts and parts[1] and parts[1] == "$" and parts[2] and parts[2] == pname) then
			table.insert(liste, k)
		end
	end
	-- TODO: insert those vars owned by other players where this one has read access to
	table.sort(liste)
	return liste
end


-- which variables can player pname write and use in effects/results?
yl_speak_up.get_quest_variables_with_write_access = function(pname)
	if(not(pname)) then
		return {}
	end
	local liste = {}
	for k, v in pairs(yl_speak_up.player_vars) do
		local parts = string.split(k, " ")
		if(parts and parts[1] and parts[1] == "$" and parts[2] and parts[2] == pname) then
			table.insert(liste, k)
		end
	end
	-- TODO: insert those vars owned by other players where this one has write access to
	table.sort(liste)
	return liste
end


yl_speak_up.input_fs_manage_variables = function(player, formname, fields)
	local pname = player:get_player_name()
	if(fields and fields.back_from_msg) then
		yl_speak_up.show_fs(player, "manage_variables")
		return
	end
	-- add a new variable?
	if(fields and fields.add_variable) then
		if(not(fields.add_variable_name) or fields.add_variable_name == ""
		  or fields.add_variable_name:trim() == "") then
			yl_speak_up.show_fs(player, "msg", {
				input_to = "yl_speak_up:manage_variables",
				formspec = "size[6,2]"..
					"label[0.2,0.5;Please enter the name of your variable!]"..
					"button[1.5,1.5;2,0.9;back_from_msg;Back]"})
			return
		end
		-- TODO: limit names to something more sensible?
		fields.add_variable_name = fields.add_variable_name:trim()
		local res = yl_speak_up.add_quest_variable(pname, fields.add_variable_name)
		local text = "A new variable named\n     \""..tostring(fields.add_variable_name)..
			"\"\nhas been created."
		if(not(res)) then
			text = "Failed to create variable named\n      \""..
				tostring(fields.add_variable_name).."\"."
		end
		yl_speak_up.show_fs(player, "msg", {
			input_to = "yl_speak_up:manage_variables",
			formspec = "size[6,2]"..
				"label[0.2,0.0;"..minetest.formspec_escape(text).."]"..
				"button[1.5,1.5;2,0.9;back_from_msg;Back]"})
		return

	end
	-- try to go back to the last formspec shown before this one
	if(not(yl_speak_up.speak_to[pname])) then
		return
	end
	local last_fs = yl_speak_up.speak_to[pname][ "working_at" ]
	yl_speak_up.show_fs(player, last_fs)
end


yl_speak_up.get_fs_manage_variables = function(player, param)
	return "size[12,4]"..
		"label[2.0,-0.2;* Manage your variables *]"..
		"label[0.2,1.0;Create this new variable:]"..
		"field[3.7,1.3;6.0,0.6;add_variable_name;;]"..
		"button[9.4,1.0;2.5,0.6;add_variable;Create variable]"..
		"tooltip[add_variable;Enter the name of your new variable.]"..
		-- TODO: delete variable
		"button[2.0,3.5;1.0,0.6;back;Back]"
end


-- variables are personalized; they are prefixed by "$ <PLAYER_NAME> <VAR_NAME>"

-- helper function;
-- strip "$ PNAME " from variable names (but only for those owned by player with name pname)
yl_speak_up.strip_pname_from_var = function(var_name, pname)
	local parts = string.split(var_name, " ")
	if(parts and parts[1] and parts[1] == "$" and parts[2] and parts[2] == pname) then
		table.remove(parts, 1) -- remove "$"
		table.remove(parts, 1) -- remove pname
		return table.concat(parts, " ")
	end
	return var_name
end


-- does the opposite of the function above; adds "$ PNAME " if needed
yl_speak_up.add_pname_to_var = function(var_name, pname)
	local parts = string.split(var_name, " ")
	if(parts and parts[1] and parts[1] ~= "$") then
		return "$ "..tostring(pname).." "..tostring(var_name)
	end
	return var_name
end


-- helper function for yl_speak_up.input_fs_edit_option_related
-- and yl_speak_up.get_fs_edit_option_p_and_e_state
yl_speak_up.strip_pname_from_varlist = function(var_list, pname)
	local var_list_text = ""
	-- strip pname from the variable names
	for i, v in ipairs(var_list) do
		var_list[i] = yl_speak_up.strip_pname_from_var(v, pname)
		-- useful for presenting a list
		var_list_text = var_list_text..","..minetest.formspec_escape(tostring(var_list[i]))
	end
	return var_list_text
end