[CC - Logsys] - Client

if(not fs.exists("sha256"))then
    print("sha256 is required to run this program.")
    print("download? [Y][N]")
    local _, key = os.pullEvent("key")
    if(key == keys.y)then
        --]] Attempt to download SHA256...
        if(http.checkURL("http://pastebin.com/raw/gsFrNjbt") and http)then
            local file = http.get("http://pastebin.com/raw/gsFrNjbt")
            local contents = file.readAll()
            file.close()
            local file = fs.open("sha256","w")
            file.write(contents)
            file.close()
            print("Sha256 downloaded successfully!")
            print("You may have to edit sha256 and remove the 'local' from the function sha256()")
            os.loadAPI("sha256")
        else
            error("Failed to retrieve sha256 (Invaild URL) or HTTP not enabled. ")
        end
    else
        error("Program needs sha256 to run. ")
    end
else
    os.loadAPI("sha256")
end

function getModemSide()
    local listOfSides = rs.getSides()

    for i = 1, #listOfSides do
        if(peripheral.isPresent(listOfSides[i]) and peripheral.getType(listOfSides[i]) == "modem")then
            return listOfSides[i]
        end
    end

    error("No modem found, please attach a modem. ")
end

function hash(txt)
    return sha256.sha256(txt)
end

local function sendLoginRequest(serverprotocol,request,username,password)
    local hashcol = sha256.sha256(serverprotocol)
    rednet.broadcast("nil",hashcol)
    local serverid, mes, _ = rednet.receive(hashcol,2)
    if(mes == nil)then
        return "no-connection"
    end
    if(mes:sub(1,8) == "[LOGSYS]")then
        rednet.send(serverid,request,hashcol)
        rednet.send(serverid,{username,sha256.sha256(password)},hashcol)
        local _, mes, _ = rednet.receive(hashcol,2)
        if(mes=="")then print("WARNING: server might have crashed!") end
        return mes
    end
end


function checkLogin(serverprotocol,username,password)
    return sendLoginRequest(serverprotocol,"checkLogin",username,password)
end

function deleteLogin(serverprotocol,username,password)
    return sendLoginRequest(serverprotocol,"deleteLogin",username,password)
end

function createLogin(serverprotocol,username,password)
    return sendLoginRequest(serverprotocol,"createLogin",username,password)
end

function customRequest(serverprotocol,crequest,datatable)
    local hashcol = sha256.sha256(serverprotocol)
    rednet.broadcast("nil",hashcol)
    local serverid, mes, _ = rednet.receive(hashcol,2)
    if(mes == nil)then
        print("No connection to server!")
        return false
    end
    if(mes:sub(1,8) == "[LOGSYS]")then
        rednet.send(serverid,crequest,hashcol)
        rednet.send(serverid,datatable,hashcol)
        local _, mes, _ = rednet.receive(hashcol,2)
        if(mes=="")then print("WARNING: server might have crashed!") end
        return mes
    end
end