-- Utility functions
local function loadFile(filePath)
    if not fs.exists(filePath) then
        return nil
    end
    local file = fs.open(filePath, "r")
    local content = file.readAll()
    file.close()
    return content
end

local function saveFile(filePath, content)
    local file = fs.open(filePath, "w")
    file.write(content)
    file.close()
end

local function logEvent(event)
    local logFile = "/logs/server.log"
    local log = loadFile(logFile) or ""
    log = log .. os.date("%Y-%m-%d %H:%M:%S") .. " - " .. event .. "\n"
    saveFile(logFile, log)
end

-- Main server function
local function startServer()
    local blockedIDs = {}  -- List of blocked IDs
    local offlineMode = fs.exists("OFFLINE.TXT")

    rednet.open("top")  -- Assuming the modem is on the top
    print("Webserver running...")

    while true do
        local senderID, message = rednet.receive()
        if offlineMode then
            local offlineContent = loadFile("offline.code")
            if offlineContent then
                rednet.send(senderID, offlineContent)
            else
                rednet.send(senderID, "Offline code not found.")
            end
            logEvent("Connection attempt while offline")
        elseif blockedIDs[senderID] then
            local blockContent = loadFile("block.code")
            if blockContent then
                rednet.send(senderID, blockContent)
            else
                rednet.send(senderID, "Blocked content not found.")
            end
            logEvent("Blocked ID attempted to connect: " .. senderID)
        else
            if message == "GET" then
                local webCode = loadFile("web.code")
                if webCode then
                    rednet.send(senderID, webCode)
                else
                    local missingContent = loadFile("missing.code")
                    if missingContent then
                        rednet.send(senderID, missingContent)
                    else
                        rednet.send(senderID, "Missing code not found.")
                    end
                end
                logEvent("Request fulfilled for ID: " .. senderID)
            end
        end
    end
end

-- UI Functions
local function editFile(fileName)
    local content = loadFile(fileName) or ""
    print("Current content of " .. fileName .. ":")
    print(content)
    print("\nEnter new content (end with a blank line):")
    local newContent = ""
    while true do
        local line = read()
        if line == "" then break end
        newContent = newContent .. line .. "\n"
    end
    saveFile(fileName, newContent)
    logEvent("Edited file: " .. fileName)
end

local function manageBlockedIDs()
    print("Current blocked IDs:")
    for id in pairs(blockedIDs) do
        print(id)
    end
    print("\n1. Add blocked ID")
    print("2. Remove blocked ID")
    local choice = tonumber(read())
    if choice == 1 then
        print("Enter ID to block:")
        local id = tonumber(read())
        blockedIDs[id] = true
        logEvent("Added blocked ID: " .. id)
    elseif choice == 2 then
        print("Enter ID to unblock:")
        local id = tonumber(read())
        blockedIDs[id] = nil
        logEvent("Removed blocked ID: " .. id)
    end
end

local function viewLogs()
    local logs = loadFile("/logs/server.log")
    print("Server Logs:")
    print(logs or "No logs available.")
end

local function clearLogs()
    saveFile("/logs/server.log", "")
    logEvent("Logs cleared")
    print("Logs cleared.")
end

local function backupLogs()
    local logs = loadFile("/logs/server.log")
    saveFile("/Backup/backup-logs.txt", logs or "")
    logEvent("Logs backed up")
    print("Logs backed up.")
end

-- Main UI loop
local function ui()
    while true do
        print("Choose an option:")
        print("1. Edit Web content")
        print("2. Access and Security")
        print("3. Logs")
        print("4. Exit")

        local choice = tonumber(read())

        if choice == 1 then
            print("Which file to edit?")
            print("1. web.code")
            print("2. offline.code")
            print("3. missing.code")
            print("4. block.code")
            local fileChoice = tonumber(read())
            if fileChoice == 1 then
                editFile("web.code")
            elseif fileChoice == 2 then
                editFile("offline.code")
            elseif fileChoice == 3 then
                editFile("missing.code")
            elseif fileChoice == 4 then
                editFile("block.code")
            end
        elseif choice == 2 then
            manageBlockedIDs()
        elseif choice == 3 then
            print("1. View logs")
            print("2. Clear logs")
            print("3. Backup logs")
            local logChoice = tonumber(read())
            if logChoice == 1 then
                viewLogs()
            elseif logChoice == 2 then
                clearLogs()
            elseif logChoice == 3 then
                backupLogs()
            end
        elseif choice == 4 then
            break
        end
    end
end

-- Run UI and server
parallel.waitForAny(ui, startServer)