Computercraft Mailingsystem - DEV/BETA [UPDATE 4]

--It is currently possible to transfer messages over about 128 blocks between 2 computers by setting up a mail-server in the middle
--Each Node (Server and Client need any type of network modem

--The code may not be the prettiest of codes and also not one of the most efficient ones but it currently works really smoothly

--THIS PROGRAM IS STILL UNDER DEVELOPMENT AND MAY GET SOME UPDATES UNTIL THE FINAL VERSION



-- local variables --------- local variables --------- local variables --------- local variables --
local modem = nil
local tArgs = { ... }

local cl_modemside, cl_type
local key = nil

local username, password

local prt_transmit = 1912
local prt_receive = 1997



-- functions ---- functions ---- functions ---- functions ---- functions ---- functions ---- functions --
function getModemSides()

    local mc = 0
    local modemlist = {}
    local sides = rs.getSides()

    for i=1,6 do
        if peripheral.getType(sides[i]) == "modem" then
            mc = mc + 1
            modemlist[mc] = sides[i]
        end
    end
    return(modemlist)

end

function clear()
    shell.run("clear");
end

function getModemToRun(cm)

    if table.getn(cm) == 0 then
        clear()
        print("There is no modem connected to this device!")
        error()
    elseif table.getn(cm) > 1 then
        repeat
            clear()
            print("===================================================")
            print("=                      SETUP                      =")
            print("===================================================")
            print()
            print("You have multipe modems connected")
            print("Connected modems:")
            for i=1,table.getn(cm) do
                print(i .. ": " .. cm[i])
            end
            local answer=tonumber(read())
        until answer ~= nil and answer > 0 and answer <= table.getn(cm)
        return answer
    end
    return 1
end

function genKey(length)
    length = tonumber(length)
    if length == nil or length < 1 then
        length = 1
    end
    local value = ""
    local hex_values = {"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"}
    for i=1,length do
        value = value .. hex_values[math.floor(math.random()*36)+1]
    end
    return value
end

function writeConfig()

    local h = fs.open("config/mail.cfg", "w")

    h.writeLine(cl_modemside)
    h.writeLine(cl_type)

    h.close()

end

function transmit(data)
    modem.transmit(prt_transmit, prt_receive, textutils.serialize(data))
end

function receive()
    modem.open(prt_transmit)
    local timeout = os.startTimer(2)
    while true do
        event = {os.pullEvent()}
        if event[1] == "modem_message" then
            modem.close(prt_transmit)
            return textutils.unserialize(event[5])
        elseif event[1] == "timer" and event[2] == timeout then
            return {""}
        end
    end
end

function login()
    print("Username: ")
    user=read()
    print("Password: ")
    pass=read("*")
    return user, pass
end






-- code --------- code --------- code --------- code --------- code --------- code --------- code --------- code --

if tostring(tArgs[1]) == "?" then
    print("This program is a mailing-software. Running this program the first time will start the installation-wizzard.")

    print()
    print(" -r    will reinstall the program")
    error()
elseif tostring(tArgs[1]) == "-r" then

    if fs.exists("config/mail.cfg") then
        shell.run("rm config/mail.cfg")
        shell.run("rm mailserver")
        shell.run("rm startup")
    end
end

if fs.exists("config/mail.cfg") then

    local h = fs.open("config/mail.cfg", "r")

    cl_modemside = h.readLine();
    cl_type = h.readLine();

    h.close()

    if peripheral.getType(cl_modemside) ~= "modem" then
        cl_modemside = getModemSides()[getModemToRun(getModemSides())]
        writeConfig()
    end
else

    cl_modemside = getModemSides()[getModemToRun(getModemSides())]
    repeat
        clear()
        -------=========================-=========================
        print("===================================================")
        print("=                      SETUP                      =")
        print("===================================================")
        print()
        print("What role does tis machine have?")
        print("It is a:")
        print("1 => Client")
        print("2 => Server")
        print("3 => Repeater")

        answer=tonumber(read())
    until answer ~= nil and ( answer == 1 or answer == 2 or answer == 3 )

    if answer == 1 then
        cl_type = "client"
    elseif answer == 2 then
        cl_type = "server"
        shell.run("mkdir mailserver")

        local h = fs.open("startup", "w")
        h.writeLine('shell.run("'.. shell.getRunningProgram() .. '")')
        h.close()
    elseif answer == 3 then
        cl_type = "repeater"
        local h = fs.open("startup", "w")
        h.writeLine('shell.run("'.. shell.getRunningProgram() .. '")')
        h.close()
    end

    writeConfig()
end
modem = peripheral.wrap(cl_modemside)

if cl_type == "server" then
    clear()
    -------=========================-=========================
    print("===================================================")
    print("=                  Computercraft                  =")
    print("=                   Mail-Server                   =")
    print("=                   Version 1.0                   =")
    print("=                   by BeminAbe                   =")
    print("===================================================")
    print("")
    print("There are multiple ways of adding People.")
    print("You can add yourself as a user from a client or")
    print("you start this server with -u <username> <password>")
    print("")
    print("Wireless Modems have a range which is 64 blocks")
    print("It can go up to 384 blocks at max. buildheight")
    print("You can use the repeater function built into this")
    print("system to extend the transmission range.")
    while true do
        data = receive()

        if data[2] == "login" then
            user = data[3]
            pass = data[4]
            transmit({data[1].."-", "auth",fs.exists("mailserver/"..user.."/"..pass)})
        elseif data[2] == "register" then
            user = data[3]
            pass = data[4]
            transmit({data[1].."-", "auth",not(fs.exists("mailserver/"..user))})
            if fs.exists("mailserver/"..user) == false then
                print("mailserver/"..user.."/"..pass)
                shell.run("mkdir mailserver/"..user.."/"..pass)
            end
        elseif data[2] == "finduser" then
            user = data[3]
            transmit({data[1].."-", "usercheck",fs.exists("mailserver/"..user)})
        elseif data[2] == "sendmail" then
            from = data[3]
            to = data[4]
            title = data[5]
            message = data[6]

            transmit({data[1].."-", "sentmail",true})

            title = title:gsub(" ", "_")

            local h = fs.open("mailserver/" .. to .. "/inbox/new/"..title, "w")

            h.writeLine("Title: " .. title)
            h.writeLine("From: " .. from)
            h.writeLine("To: you(" .. to .. ")")
            h.writeLine("\n"..message)

            h.close()

            local h = fs.open("mailserver/" .. from .. "/inbox/sent/"..title, "w")

            h.writeLine("Title: " .. title)
            h.writeLine("From: " .. from)
            h.writeLine("To: you(" .. to .. ")")
            h.writeLine("\n"..message)

            h.close()

        elseif data[2] == "dir" then
            user = data[3]
            subdir = textutils.unserialize(data[4])

            sd =""
            for k, v in pairs(subdir)  do
                if v ~= nil then
                    sd = sd .. v .. "/"
                end
            end

            if fs.isDir("mailserver/"..user.."/inbox/"..sd) then
                transmit({data[1].."-", "ls_dir", textutils.serialize(fs.list("mailserver/"..user.."/inbox/"..sd))})
            else
                local h = fs.open("mailserver/"..user.."/inbox/"..sd, "r")
                message = h.readAll()
                h.close()
                if message == "" then
                    message = "\n\n                  [Unknown Message]";
                end
                transmit({data[1].."-", "message", message})
            end
        elseif data[2] == "rm" then
            user = data[3]
            subdir = textutils.unserialize(data[4])

            sd =""
            for k, v in pairs(subdir)  do
                if v ~= nil then
                    sd = sd .. v .. "/"
                end
            end

            shell.run("rm mailserver/"..user.."/inbox/"..sd)
        elseif data[2] == "archive" then
            user = data[3]
            subdir = textutils.unserialize(data[4])

            sd =""
            for k, v in pairs(subdir)  do
                if v ~= nil then
                    sd = sd .. v .. "/"
                end
            end

            shell.run("mv mailserver/"..user.."/inbox/"..sd .. " mailserver/" .. user .. "/inbox/archive/" .. subdir[table.getn(subdir)])

        else

        end
    end
elseif cl_type == "client" then
    while true do
        repeat
            clear()
            -------=========================-=========================
            print("===================================================")
            print("=                Login or Register                =")
            print("===================================================")
            print("")
            print("1: Login")
            print("2: Register")
            action=tonumber(read())

            tries = 0
            username = nil
            repeat
                if action == 1 then
                    clear()
                    -------=========================-=========================
                    print("===================================================")
                    print("=                      Login                      =")
                    print("===================================================")
                    print()
                    if username ~= nil then
                        print("Username or Password invalid!")
                    end
                    username,password = login()
                    key = genKey(16)
                    transmit({key, "login", username, password})
                elseif action == 2 then
                    clear()
                    -------=========================-=========================
                    print("===================================================")
                    print("=                  Registration                   =")
                    print("===================================================")
                    print()
                    if username ~= nil then
                        print("Username already taken!")
                    end
                    username,password = login()
                    key = genKey(16)
                    transmit({key, "register", username, password})
                end
                repeat
                    data = receive()
                until string.sub(data[1],0,16) == key and data[2] == "auth"
                tries = tries + 1
                if tries >= 3 then
                    action = ""
                end

            until data[3] == true or not(action == 1 or action == 2)

        until action == 1 or action == 2

        repeat
            clear()
            print("===================================================")
            print("=             What do you want to do?             =")
            print("===================================================")
            print("")
            print("1: Write a message to someone")
            print("2: Check if I have a new message")
            print("0: Exit")
            action=tonumber(read())


            if action == 1 then
                data = {}
                repeat
                    clear()
                    print("===================================================")
                    print("=                      Mails                      =")
                    print("===================================================")
                    print()
                    print("Please keep in mind titles are used in the inbox")
                    print("That means you can overwrite mails")
                    print("Also don't write too long mails. They cant be read")
                    print()
                    if data[3] == false then
                        print("Target not found.")
                    end
                    print("Sending to: ")
                    user=read()
                    key = genKey(16)
                    transmit({key, "finduser", user})

                    repeat
                        data = receive()
                    until string.sub(data[1],0,16) == key and data[2] == "usercheck"

                until data[2] == "usercheck" and data[3] == true

                print("Title: ")
                title=read()
                print("Message: ")
                message=read()
                repeat
                    key = genKey(16)
                    transmit({key,"sendmail", username, user, title, message})

                    repeat
                        data = receive()
                    until string.sub(data[1],0,16) == key and data[2] == "sentmail"
                until data[2] == "sentmail" and data[3] == true
            elseif action == 2 then


                local subdir = {}
                local page = 1
                repeat
                    key = genKey(16)
                    transmit({key, "dir", username, textutils.serialize(subdir)})

                    repeat
                        data = receive()
                    until string.sub(data[1],0,16) == key and ( data[2] == "ls_dir" or data[2] == "message" )

                    txt = ""
                    dircontent =  textutils.unserialize(data[3])
                    if data[2] == "ls_dir" then

                         for k, v in pairs(textutils.unserialize(data[3])) do
                            if v ~= nil then
                                txt = txt .. k .. ": " .. v .. "\n"
                            end
                        end



                        clear()
                        print("===================================================")
                        print("=                      Mails                      =")
                        print("===================================================")
                        print("0: <back 1 folder>")
                        print(txt)
                        lines = select(2, txt:gsub('\n', '\n'))
                        for i=1, 10 - lines do
                            print()
                        end
                        print("===================================================")
                        print("<- back 10 (B)         EXIT e     (F) 10 forward ->")
                        print("===================================================")

                        action=string.lower(read())
                         if action == "b" then
                            if page > 1 then
                                page = page - 1
                            end
                        elseif action == "f" then
                            if lines == 10 then
                                page = page + 1
                            end
                        elseif action ~= "0" and tonumber(action) ~= nil then
                            page = 1
                            subdir[table.getn(subdir) +1] = dircontent[tonumber(action)]
                        elseif action == "0" and tonumber(action) ~= nil then
                            page = 1
                            subdir[table.getn(subdir)] = nil

                        end

                    elseif data[2] == "message" then

                        repeat
                            clear()
                            print("===================================================")
                            print("=                     Message                     =")
                            print("===================================================")
                            print(data[3])
                            lines = select(2, data[3]:gsub('\n', '\n'))
                            for i=1, 11 - lines do
                                print()
                            end
                            print("===================================================")
                            print("= delete (D)           EXIT e          (A) archive=")
                            print("===================================================")

                            action=string.lower(read())
                            if action == "d" then
                                key = genKey(16)
                                transmit({key, "rm", username, textutils.serialize(subdir)})
                                action = "e"
                            elseif action == "a" then
                                key = genKey(16)
                                transmit({key, "archive", username, textutils.serialize(subdir)})
                                action = "e"
                            end

                        until action == "e"
                        action = ""
                        page = 1
                        subdir[table.getn(subdir)] = nil

                    end

                until action == "e"
                action = 2

            end

        until action == 0

    end

elseif cl_type=="repeater" then
    modem.open(prt_transmit)
    modem.open(prt_receive)
    keys = {{"key",5},{"keyyyyy",1}}
    while true do

        local timeout = os.startTimer(1)
        while true do
            event = {os.pullEvent()}
            if event[1] == "modem_message" then

                -- local h = fs.open("config/repeater.log", "a")
                -- for k, v in pairs(event)  do
                    -- if v ~= nil then
                        -- h.writeLine(k .. ": " .. v)
                    -- end
                -- end

                -- h.writeLine("---------------------------------------------")

                -- h.close()

                donotsend = false
                for k, v in pairs( keys ) do
                    val1 = textutils.unserialize(event[5])

                    if v[1] == val1[1] then
                        v[2] = 0
                        donotsend = true
                    end
                end

                print("transmiting: " .. tostring(donotsend))

                if not(donotsend) then
                    modem.transmit(event[3], event[4], event[5])
                    val1 = textutils.unserialize(event[5])
                    keys[table.getn(keys) +1] = {val1[1], 0}
                end

            elseif event[1] == "timer" and event[2] == timeout then
                old_keys = keys
                keys = {}
                for k, v in pairs( old_keys ) do
                    print(k, " ", v[1], " ", v[2])
                    v[2] = v[2] + 1
                    if v[2] < 4 then
                        keys[table.getn(keys)+1] = old_keys[k]
                    end
                end
                print("---------------")
                break
            end
        end

    end
end