HouseChat

--[[
  HouseChat by houseofkraft
]]--

--[[
NOTE: This version of HouseChat is outdated. You can access the newer version by using this link:
http://pastebin.com/uAqJU632
]]--

local args = { ... }
local sides = rs.getSides()
if #args < 1 then
     printError("Usages:")
     printError("housechat host <server>")
     printError("housechat join <server> <username>")
     return
end

-- Modem checking
local modemFound = false
for k,v in pairs(sides) do
     if peripheral.getType(v) == "modem" then
        rednet.open(v)
        modemFound = true
    end
end
if not modemFound then
    printError("No modem found!")
    return
end

-- Client Functions
local function findID(server)
    info = {server}
    rednet.broadcast("findID", info)
    id, message = rednet.receive()
     if message == "found" then
        local sid = id
     end
    return sid
end

local function sendMessage(server, username, message)
  info = {username, message}
  local sid = findID(server)
  rednet.send(sid, "sendMessage", info)
end

local function joinServer(server, user)
    local sid = findID(server)
  if sid then
    info = {server, user}
    rednet.send(sid, "connect", info)
  else
    return false
  end
end

local function leaveServer(server, user)
     local sid = findID(server)
     if sid then
        info = {server, user}
        rednet.send(sid, "leave", info)
     end
end

if args[1] == "host" then
    if #args < 2 then
        printError("Usage: housechat host <server>")
        return
     end
     local sUsers = {}
     local nUsers = 0
     local sIDs = {}
     local sName = args[2]
     local function handle()
          while true do
             id, message, info = rednet.receive()
             if message == "findID" then
                local server = info[1]
                  if server == sName then
                        rednet.send(id, "found")
               end
             elseif message == "connect" then
                  local server = info[1]
                  local user = info[2]
                  if server == sName then
                       nUsers = nUsers + 1
                       table.insert(sUsers, user)
                        table.insert(sIDs, id)
                       username = "Console"
                       sendMessage(server, username, "* "..user.." has joined "..sName)
                    end
            elseif message == "leave" then
                    local server = info[1]
                    local user = info[2]
                    if server == sName then
                        nUsers = nUsers - 1
                        username = "Console"
                        sendMessage(server, username, "* "..user.." has left "..sName)
                        for k,v in pairs(sUsers) do
                            -- Trying to find where the user is in the table
                            if v == user then
                                table.remove(sUsers, k)
                            end
                        end
                    end
                    for k,v in pairs(sIDs) do
                        -- Once again, trying to find where the user's ID is in the table
                        if v == id then
                            table.remove(sIDs, k)
                        end
                    end
        elseif message == "sendMessage" then
             for k,v in pairs(sIDs) do
                  local username = info[1]
                  local m = info[2]
                  info = {username, m}
                  rednet.send(tonumber(v), "newMessage", info)
         end
        end
    end
  end
  local function display()
        while true do
            term.clear()
            term.setCursorPos(1,1)
            if nUsers == 1 then
                    print("1 user connected")
            else
                    print(nUsers.." users connected")
            end
            print()
            write("Users:")
            if #sUsers == 1 then
                for k,v in pairs(sUsers) do
                        write(" "..v)
                    end
            else
                    for k,v in pairs(sUsers) do
                        write(" "..v..",")
                end
            end
            os.sleep(0)
        end
  end
  parallel.waitForAll(handle, display)
elseif args[1] == "join" then
    local server = args[2]
    local us = args[3]
    joinServer(server, us)
    term.clear()
    term.setCursorPos(1,1)
    local function receive()
        term.clear()
        while true do
            term.setCursorPos(1,1)
            id, message, info = rednet.receive()
            if message == "newMessage" then
                    local u = info[1]
                    local m = info[2]
                    if u == "Console" then
                      term.setTextColor(colors.yellow)
                      print(m)
                    else
                      term.setTextColor(colors.white)
                      print("<"..u.."> "..m)
                end
            end
        end
  end
  receive()
end