--
-- (C) 2020 - ntop.org
--
local dirs = ntop.getDirs()
local info = ntop.getInfo()
local prefs = ntop.getPrefs()

local defined_alert_notifications = {}
local page_utils = require('page_utils')
local telemetry_utils = require("telemetry_utils")
local alert_notification = require("alert_notification")

local ALARM_THRESHOLD_LOW = 60
local ALARM_THRESHOLD_HIGH = 90

--
-- NOTE
-- scripts/lua/modules/menu_alert_notifications.lua will call all NON-LOCAL functions in this file in sequence
-- each function will displaya badge if required
--

local function create_DHCP_range_missing_notification()

    local title = i18n("about.configure_dhcp_range")
    local description = i18n("about.dhcp_range_missing_warning", {
        name = i18n("prefs.toggle_host_tskey_title"),
        url = ntop.getHttpPrefix() .. "/lua/if_stats.lua?page=config",
        dhcp_url = ntop.getHttpPrefix() .. "/lua/if_stats.lua?page=dhcp"
    })

    return alert_notification:create("DHCP_missing_range", title, description, "warning", nil, "if_stats.lua?page=dhcp;if_stats.lua?page=config")

end

-- ###############################################################

local function create_DCHP_monitoring_notification()

    local title = i18n("about.dhcp_monitoring_title")
    local description = i18n("about.host_identifier_warning", {
        name=i18n("prefs.toggle_host_tskey_title"),
        url = ntop.getHttpPrefix().."/lua/if_stats.lua?page=config"
    })

    return alert_notification:create("DHCP_monitoring", title, description, "warning")

end

-- ###############################################################

local function create_geo_ip_alert_notification()
    local title = i18n("geolocation_unavailable_title")
    local description = i18n("geolocation_unavailable", {
        url = "https://github.com/ntop/ntopng/blob/dev/doc/README.geolocation.md",
        target = "_blank",
        icon = "fas fa-external-link-alt"
    })

    return alert_notification:create("geoip_alert", title, description,
                                     "warning", nil, "nedge/system_setup/")
end

-- ###############################################################

local function create_contribute_alert_notification()
    local title = i18n("about.contribute_to_project")
    local description = i18n("about.telemetry_data_opt_out_msg", {
        tel_url = ntop.getHttpPrefix() .. "/lua/telemetry.lua",
        ntop_org = "https://www.ntop.org/"
    })
    local action = {
        url = ntop.getHttpPrefix() .. '/lua/admin/prefs.lua?tab=telemetry',
        title = i18n("configure")
    }

    return alert_notification:create("contribute_alert", title, description,
                                     "info", action, "/lua/admin/prefs.lua")
end

-- ###############################################################

local function create_tempdir_alert_notification()
    local title = i18n("warning")
    local description = i18n("about.datadir_warning")
    local action = {
        url = "https://www.ntop.org/support/faq/migrate-the-data-directory-in-ntopng/"
    }

    return alert_notification:create("tempdir_alert", title, description,
                                     "warning", action)
end

-- ###############################################################

local function create_update_ntopng_notification(body)
    local title = i18n("update")
    return alert_notification:create("update_alert", title, body, "info")
end

-- ###############################################################

local function create_too_many_flows_notification(level)
    local title = i18n("too_many_flows")
    local desc = i18n("about.you_have_too_many_flows",
                      {product = info["product"]})

    return alert_notification:create("toomanyflows_alert", title, desc, level)
end

-- ###############################################################

local function create_too_many_hosts_notification(level)
    local title = i18n("too_many_hosts")
    local desc = i18n("about.you_have_too_many_hosts",
                      {product = info["product"]})

    return alert_notification:create("toomanyhosts_alert", title, desc, level)
end

-- ###############################################################

local function create_remote_probe_clock_drift_notification(level)
    local title = i18n("remote_probe_clock_drift")
    local desc = i18n("about.you_need_to_sync_remote_probe_time",
                      {url = ntop.getHttpPrefix() .. "/lua/if_stats.lua"})

    return alert_notification:create("remoteprobleclockdrift_alert", title,
                                     desc, level)
end

-- ##################################################################

local function create_flow_dump_alert_notification()
    local title = i18n("flow_dump_not_working_title")
    local description = i18n("flow_dump_not_working",
                             {icon = "fas fa-external-link-alt"})
    return alert_notification:create("flow_dump_alert", title, description,
                                     "warning")
end

-- ##################################################################

function defined_alert_notifications.DHCP_hosts(container)

    local ifs = interface.getStats()
    local is_pcap_dump = interface.isPcapDumpInterface()
    local is_packet_interface = interface.isPacketInterface()
    local is_admin = isAdministrator()

    local lbd_serialize_by_mac = (_POST["lbd_hosts_as_macs"] == "1") or
                                     (ntop.getPref(string.format("ntopng.prefs.ifid_%u.serialize_local_broadcast_hosts_as_macs",ifs.id)) == "1")

    if (ifs.has_seen_dhcp_addresses and is_admin and (not is_pcap_dump) and
        is_packet_interface) then

        if (not lbd_serialize_by_mac) and
            (ntop.getPref(string.format("ntopng.prefs.ifid_%u.disable_host_identifier_message", ifs.id)) ~= "1") then

                table.insert(container, create_DCHP_monitoring_notification())

        elseif isEmptyString(_POST["dhcp_ranges"]) then

            local dhcp_utils = require("dhcp_utils")
            local ranges = dhcp_utils.listRanges(ifs.id)

            if (table.empty(ranges)) then
                table.insert(container, create_DHCP_range_missing_notification())
            end
        end

    end

end

-- ##################################################################

--- Create an instance for the geoip alert notification
--- if the user doesn't have geoIP installed
--- @param container table The table where the notification will be inserted
function defined_alert_notifications.geo_ip(container)
    if isAdministrator() and not ntop.hasGeoIP() then
        table.insert(container, create_geo_ip_alert_notification())
    end
end

--- Create an instance for the temp working directory alert
--- if ntopng is running inside /var/tmp
--- @param container table The table where the notification will be inserted
function defined_alert_notifications.temp_working_dir(container)
    if (dirs.workingdir == "/var/tmp/ntopng") then
        table.insert(container, create_tempdir_alert_notification())
    end
end

--- Create an instance for contribute alert notification
--- @param container table The table where the notification will be inserted
function defined_alert_notifications.contribute(container)
    if (not info.oem) and (not telemetry_utils.dismiss_notice()) then
        table.insert(container, create_contribute_alert_notification())
    end
end

-- ###############################################################

function defined_alert_notifications.update_ntopng(container)
    -- check if ntopng is oem and the user is an Administrator
    local is_not_oem_and_administrator = isAdministrator() and not info.oem
    local message = check_latest_major_release()

    if is_not_oem_and_administrator and not isEmptyString(message) then
        table.insert(container, create_update_ntopng_notification(message))
    end
end

-- ###############################################################

function defined_alert_notifications.too_many_hosts(container)
    local level = nil
    local hosts = interface.getNumHosts()
    local hosts_pctg = math.floor(1 + ((hosts * 100) / prefs.max_num_hosts))

    if (hosts_pctg >= ALARM_THRESHOLD_LOW and hosts_pctg <= ALARM_THRESHOLD_HIGH) then
        level = "warning"
    elseif (hosts_pctg > ALARM_THRESHOLD_HIGH) then
        level = "danger"
    end

    if (level ~= nil) then
        table.insert(container, create_too_many_hosts_notification(level))
    end
end

-- ###############################################################

function defined_alert_notifications.too_many_flows(container)
    local level = nil
    local flows = interface.getNumFlows()
    local flows_pctg = math.floor(1 + ((flows * 100) / prefs.max_num_flows))

    if (flows_pctg >= ALARM_THRESHOLD_LOW and flows_pctg <= ALARM_THRESHOLD_HIGH) then
        level = "warning"
    elseif (flows_pctg > ALARM_THRESHOLD_HIGH) then
        level = "danger"
    end

    if (level ~= nil) then
        table.insert(container, create_too_many_flows_notification(level))
    end
end

-- ###############################################################

function defined_alert_notifications.remote_probe_clock_drift(container)
    local ifstats = interface.getStats()
    local is_system_interface = page_utils.is_system_view()

    if (ifstats["probe.remote_time"] ~= nil) and (not is_system_interface) then
        local tdiff = math.abs(os.time() - ifstats["probe.remote_time"])
        local level = nil

        if (tdiff >= 10 and tdiff <= 30) then
            level = "warning"
        elseif (tdiff > 30) then
            level = "danger"
        end

        if (level ~= nil) then
            table.insert(container,
                         create_remote_probe_clock_drift_notification(level))
        end
    end
end

-- ###############################################################

--- Create an instance for the nIndex alert notification
--- if nIndex is not able to start/run/dump
--- @param container table The table where the notification will be inserted
function defined_alert_notifications.flow_dump(container)
    local ifstats = interface.getStats()

    if isAdministrator() and prefs.is_dump_flows_enabled and
        prefs.is_dump_flows_runtime_enabled and not ifstats.isFlowDumpDisabled and
        not ifstats.isFlowDumpRunning and not ifstats.isViewed then
        table.insert(container, create_flow_dump_alert_notification())
    end
end

-- ###############################################################

return defined_alert_notifications