-- From TekMail Client

local serverID = 0
local routerID = 0
local clientID = os.getComputerID()
local reqCounter = 0

local loggedInUser, loggedInPass

local function discoverNearestRouter(timeout)
    timeout = timeout or 15
    local knownRouters = {}
    local start = os.clock()
    while os.clock() - start < timeout do
        local remaining = timeout - (os.clock() - start)

        local id, msg = rednet.receive(remaining)
        if id then
            if type(msg) == "table" and msg.type == "router_broadcast" then
                local ridStr = msg.id
                local ridNum = tonumber((ridStr or ""):match("^(%d+)%[")) or id
                if ridNum then
                    knownRouters[ridNum] = msg.coords or {}
                end
            end
        end
    end
    if next(knownRouters) == nil then return nil end

    local gx, gy, gz = nil, nil, nil
    if gps and gps.locate then
        pcall(function()
            gx, gy, gz = gps.locate(3)
        end)
    end
    local selectedID = nil
    if gx and gy and gz then
        local minDist = math.huge
        for rid, pos in pairs(knownRouters) do
            if pos.x and pos.y and pos.z then
                local dx, dy, dz = pos.x - gx, pos.y - gy, pos.z - gz
                local dist = math.sqrt(dx*dx + dy*dy + dz*dz)
                if dist < minDist then
                    minDist = dist
                    selectedID = rid
                end
            end
        end
    end
    if not selectedID then
        for rid in pairs(knownRouters) do
            selectedID = rid
            break
        end
    end
    return selectedID
end

routerID = discoverNearestRouter(15)

local function initializeModem()
    local sides = {"left","right","top","bottom","front","back"}
    for _, side in ipairs(sides) do
        local pType = peripheral.getType(side)
        if pType == "wireless_modem" or pType == "modem" then
            rednet.open(side)
            print("[Modem] Modem opened on side: " .. side)
            return true
        end
    end
    print("[Error] No modem found. Exiting.")
    return false
end

    local function attemptLogin(username, password)
        rednet.send(routerID, {
            type = "client_request",
            fromClient = clientID,
            payload = { type = "login", username = username, password = password }
        })
        local _, response = rednet.receive(5)

        if response and response.status == "ok" then
            loggedInUser = username
            loggedInPass = password
            okMsg = "Logged in."
            errMsg = nil
            drawFields()
            sleep(1)
            term.setCursorBlink(false)
            return true
        end

        error("Invalid login information.")
    end

local function requestReply(payload, timeout)
    timeout = timeout or 5
    reqCounter = reqCounter + 1
    payload.reqID = tostring(clientID) .. "-" .. tostring(reqCounter) .. "-" .. tostring(math.random(1, 1000000))
    rednet.send(routerID, {
        type = "client_request",
        fromClient = clientID,
        payload = payload
    })
    local timer = os.startTimer(timeout)
    while true do
        local event, p1, p2 = os.pullEvent()
        if event == "rednet_message" then
            local msg = p2
            if type(msg) == "table" and msg.type == "server_response" and type(msg.payload) == "table" then
                msg = msg.payload
            end
            if type(msg) == "table" and msg.reqID == payload.reqID and msg.status ~= nil then
                return msg
            end
        elseif event == "timer" and p1 == timer then
            return nil
        end
    end
end

-- end copied code

initializeModem()

local function sendNewMail(recipient, messageContent)
    print("User to impersonate:")
    loggedInUser = read()
    -- loggedInPass = read("*")
    local payload = {
        type = "send",
        from = loggedInUser,
        to = recipient,
        content = messageContent
    }

    local response = requestReply(payload)

    -- Check if the server acknowledged the message
    if response and response.status == "ok" then
        print("Mail sent successfully!")
        return true
    else
        print("Failed to send mail or timed out.")
        return false
    end
end

sendNewMail("Admin", "Hi there ;)")