RECOVERY SERVER

-- Server Program

-- Function to find and return the modem peripheral
local function findModem()
    for _, side in ipairs(peripheral.getNames()) do
        if peripheral.getType(side) == "modem" then
            return side
        end
    end
    return nil
end

local modemSide = findModem()
if not modemSide then
    print("Error: No modem found. Please attach a modem.")
    return
end

rednet.open(modemSide)

local saveDirectory = "DGOS"
local serverID = os.getComputerID()

-- Create save directory if it doesn't exist
if not fs.exists(saveDirectory) then
    fs.makeDir(saveDirectory)
end

-- Function to read the target client ID from file
local function readClientID()
    local path = "/Network/Recovery.ID"
    if fs.exists(path) then
        local file = fs.open(path, "r")
        local id = tonumber(file.readAll())
        file.close()
        return id
    else
        return nil
    end
end

local clientID = readClientID()
if not clientID then
    print("Error: No client ID found in /Network/Recovery.ID")
    return
end

-- Main loop to receive messages
while true do
    local senderID, message, protocol = rednet.receive()

    if protocol == "file_transfer" then
        print("Received file request from ID: " .. senderID)

        if type(message) == "table" and message.fileName and message.fileSize then
            print("File Name: " .. message.fileName)
            print("File Size: " .. message.fileSize .. " bytes")

            -- Automatically accept the file transfer
            local filePath = fs.combine(saveDirectory, message.fileName)
            local file = fs.open(filePath, "w")
            file.write(message.fileContent)
            file.close()
            rednet.send(senderID, { status = "Accepted" }, "confirmation")
            print("File transfer accepted and saved to " .. filePath)
        else
            print("Invalid message received.")
            rednet.send(senderID, { status = "Invalid file transfer request" }, "confirmation")
        end
    else
        print("Received unknown protocol message.")
        rednet.send(senderID, { status = "Unknown protocol" }, "confirmation")
    end
end