--[[

 DEJFBank Banking Server Software
 Version 1.00

]]--

function cls()
    term.clear()
    term.setCursorPos(1,1)
end

-- Check if the floppy disk containing user data is present.
cls()
if not fs.exists("disk") then
    print("ERROR: User data disk is not present!")
end

-- Start up rednet
print("Starting up banking server...")
rednet.open("top")
rednet.host("InfoServe", "BSMain")
print("Banking server online.")
print("")

-- Look for requests indefinitely.
while true do
    senderId, message, protocol = rednet.receive("InfoServe")

    if message == "UserLoginInfoRequest" then
        print("Received: UserLoginInfoRequest from "..senderId)
        rednet.send(senderId, "RequestAccepted", "InfoServe")
        print("Sent: RequestAccepted to "..senderId)
        senderID, message, protocol = rednet.receive("InfoServe")
        if not senderId == senderId then -- OBSOLETE
            print("ERROR: Another computer interfered with our session. My spaghetti code can't cope.")
        else
            print("Received username: "..message.." from "..senderId)
            -- We check if the username and password matches the sent credentials.
            if fs.exists("disk/"..message) then
                local fsReadHandle = fs.open("disk/"..message, "r")
                if fsReadHandle then
                    password = fsReadHandle.readLine()
                    fsReadHandle.close()
                    senderId, message, protocol = rednet.receive("InfoServe")
                    print("Received password: "..message.." from "..senderId)
                    if message ~= password then
                        rednet.send(senderId, "CredentialsInvalid", "InfoServe")
                        print("Sent: CredentialsInvalid to "..senderId)
                    elseif message == password then
                        rednet.send(senderId, "CredentialsValid", "InfoServe")
                        print("Sent: CredentialsValid to "..senderId)
                    end
                end
            else
                rednet.send(senderId, "CredentialsInvalid", "InfoServe")
                print("Sent: CredentialsInvalid to "..senderId)
            end
        end
    end

    if message == "UserDataRequest" then
        print("Received: UserDataRequest from "..senderId)
        senderId, message, protocol = rednet.receive("InfoServe")
        if not senderID == senderId then -- OBSOLETE
            print("ERROR: Another computer interfered with our session. My spaghetti code can't cope.")
        else
            print("Received username: "..message.." from "..senderId)
            local fsReadHandle = fs.open("disk/"..message, "r")
            if fsReadHandle then
                password = fsReadHandle.readLine()
                balance = fsReadHandle.readLine()
                fsReadHandle.close()
                rednet.send(senderId, balance, "InfoServe")
                print("Sent balance: "..balance.." to "..senderId)
            else
                rednet.send(senderId, "Fake", "InfoServe")
                print("Sent Fake")
            end
        end
    end

    if message == "UserModifyDataRequest" then
        print("Received an UserModifyDataRequest from "..senderId)
        senderId, message, protocol = rednet.receive("InfoServe")
        print("Received sendamount: "..message.." from "..senderId)
        local sendamount = message
        senderId, message, protocol = rednet.receive("InfoServe")
        print("Received accountname: "..message.." from "..senderId)
        local accountname = message
        senderId, message, protocol = rednet.receive("InfoServe")
        print("Received username: "..message.." from "..senderId)
        local username = message
        local fsReadHandle = fs.open("disk/"..username, "r")
        if fsReadHandle then
            fsReadHandle.readLine()
            balance = fsReadHandle.readLine()
            fsReadHandle.close()
            if balance < sendamount then
                rednet.send(senderId, "DataModInvalid", "InfoServe")
                print("Sent DataModInvalid")
            elseif accountname == username then
                rednet.send(senderId, "DataModInvalid", "InfoServe")
                print("Sent DataModInvalid")
            else
                -- Here we temporarily store the user and recipient files in variables so we can use them later.
                local fsUserReadHandle = fs.open("disk/"..username, "r")
                userpassword = fsUserReadHandle.readLine()
                userbalance = fsUserReadHandle.readLine()
                fsUserReadHandle.close()

                local fsRecReadHandle = fs.open("disk/"..accountname, "r")
                recpassword = fsRecReadHandle.readLine()
                recbalance = fsRecReadHandle.readLine()
                fsRecReadHandle.close()


                local fsUserWriteHandle = fs.open("disk/"..username, "w")
                fsUserWriteHandle.writeLine(userpassword)
                fsUserWriteHandle.writeLine(tonumber(userbalance) - sendamount)
                fsUserWriteHandle.close()

                local fsRecWriteHandle = fs.open("disk/"..accountname, "w")
                fsRecWriteHandle.writeLine(recpassword)
                fsRecWriteHandle.writeLine(tonumber(recbalance) + sendamount)
                fsRecWriteHandle.close()
                rednet.send(senderId, "DataModValid", "InfoServe")
                print("Sent DataModValid to "..senderId)
                print("Done transaction")
            end
        end
    end

    if message == "UserDepositRequest" then
        print("Received an UserDepositRequest from "..senderId)
        senderId, message, protocol = rednet.receive("InfoServe")
        print("Received amount: "..message.." from "..senderId)
        local sendamount = message
        senderId, message, protocol = rednet.receive("InfoServe")
        print("Received accountname: "..message.." from "..senderId)
        local accountname = message

        -- Here we temporarily store the user files in variables so we can use them later.
        local fsRecReadHandle = fs.open("disk/"..accountname, "r")
        recpassword = fsRecReadHandle.readLine()
        recbalance = fsRecReadHandle.readLine()
        fsRecReadHandle.close()

        local fsRecWriteHandle = fs.open("disk/"..accountname, "w")
        fsRecWriteHandle.writeLine(recpassword)
        fsRecWriteHandle.writeLine(tonumber(recbalance) + sendamount)
        fsRecWriteHandle.close()
        print("Done transaction")

        --end
    end

    if message == "UserCreationRequest" then
        print("Received UserCreationRequest from "..senderId)
        rednet.send(senderId, "RequestAccepted", "InfoServe")
        print("Sent RequestAccepted to "..senderId)
        senderId, message, protocol = rednet.receive("InfoServe")
        print("Received username "..message.." from "..senderId)
        newusername = message
        senderId, message, protocol = rednet.receive("InfoServe")
        print("Received password "..message.." from "..senderId)
        newpassword = message

        if not fs.exists("disk/"..newusername) then
            local fsWriteHandle = fs.open("disk/"..newusername, "w")
            fsWriteHandle.writeLine(newpassword)
            fsWriteHandle.writeLine("1000")
            fsWriteHandle.close()
            rednet.send(senderId, "UserAccountCreationSuccess", "InfoServe")
            print("Sent UserAccountCreationSuccess to "..senderId)
        else
            rednet.send(senderId, "UserAccountCreationFail", "InfoServe")
            print("Sent UserAccountCreationFail to "..senderId)
        end
    end
end