--[[
Illarion Server

This program is free software: you can redistribute it and/or modify it under
the terms of the GNU Affero General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option) any
later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
details.

You should have received a copy of the GNU Affero General Public License along
with this program.  If not, see <http://www.gnu.org/licenses/>.
]]
--- Base Script: Messages
--
-- The purpose of this script is to offer a simple class that allows handling
-- messages in all sorts of scripts. It will handle storing and accessing the
-- messages in a efficient way.
--
-- @release 1.0
-- @author Martin Karing
--
-- @usage:
--      Create a new message object:
--      msgs = Messages();
--
--      Append messages to the message object:
--      msgs:addMessage("German Text 1", "English Text 1");
--      msgs:addMessage("German Text 2", "English Text 2");
--
--      Get the count of messages in the message object:
--      #msgs == 2
--
--      Get a message from the message object:
--      germanMessage, englishMessage = msgs:getMessage(2);
--      germanMessage == "German Text 2"
--      englishMessage == "English Text 2"
--
--      Get a random message from the message object:
--      germanMessage, englishMessage = msgs:getRandomMessage();
--      The result is similar to msgs:getMessage(index), just the index is
--      selected randomly.

local class = require("base.class")
local M = {}
-- create messages class
M.Messages = class(function(msg)
    msg.__german = {}
    msg.__english = {}
    msg.__count = 0
end)

--- Add a message.
-- Using this function you are able to add a message to the storage. The message
-- needs to be avaiable in both languages and is insert to the internal tables
-- upon calling this function.<br>
-- <br>
-- @param gerMsg the german version of the message
-- @param engMsg the english version of the message
-- <br>
-- @return The index of the added message
function M.Messages:addMessage(gerMsg, engMsg)
    if gerMsg == nil or gerMsg == "" then
        if engMsg == nil or engMsg == "" then
            -- ignore empty messages.
            return
        end
        gerMsg = "Translation Missing: "..engMsg
    end
    if engMsg == nil or engMsg == "" then
        engMsg = "Translation Missing: "..gerMsg
    end
    table.insert(self.__german, gerMsg)
    table.insert(self.__english, engMsg)
    self.__count = self.__count + 1
    return self.__count
end

--- Get a random message.
-- This function selects randomly a message from the stored messages and returns
-- the german and the english version.<br>
-- <br>
-- @return the german version of the message and the english version of the
--      message
function M.Messages:getRandomMessage()
    local messageID = math.random(1, self.__count)
    return self.__german[messageID], self.__english[messageID]
end

--- Get a specified message from the list.
-- This function returns a message that is enlisted at a specified index.<br>
-- <br>
-- @param index the index of the message
-- <br>
-- @return the german version of the message and the english version of the
--      message or a error message in case the index value is out of bounds
function M.Messages:getMessage(index)
    if index < 1 or index > self.__count then
        error("Index out of bounds")
    end
    return self.__german[index], self.__english[index]
end

--- Check if this instance contains any messages.
-- <br>
-- @return true in case there are messages stored in this object
function M.Messages:hasMessages()
    return self.__count > 0
end

--- Get the amount of stored messages.
-- This meta method is called by the unary operator # and returns the amount of
-- messages stored in this object.<br>
-- <br>
-- @return the amount of messages stored in this object
function M.Messages:__len()
    return self.__count
end

return M