--
-- (C) 2019-22 - ntop.org
--

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

local host_alert_keys = require "host_alert_keys"

local alert_creators = require "alert_creators"
local json = require("dkjson")
-- Import the classes library.
local classes = require "classes"
-- Make sure to import the Superclass!
local alert = require "alert"

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

local host_alert_score_threshold = classes.class(alert)

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

host_alert_score_threshold.meta = {
  alert_key = host_alert_keys.host_alert_score_threshold,
  i18n_title = "alerts_thresholds_config.score_threshold_title",
  icon = "fas fa-fw fa-life-ring",
  has_attacker = true,
}

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

-- @brief Prepare an alert table used to generate the alert
-- @return A table with the alert built
function host_alert_score_threshold:init(threshold)
   -- Call the parent constructor
   self.super:init()

   self.alert_type_params = {
      threshold = threshold,
   }
end

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

-- @brief Format an alert into a human-readable string
-- @param ifid The integer interface id of the generated alert
-- @param alert The alert description table, including alert data such as the generating entity, timestamp, granularity, type
-- @param alert_type_params Table `alert_type_params` as built in the `:init` method
-- @return A human-readable string
function host_alert_score_threshold.format(ifid, alert, alert_type_params)
  local alert_consts = require("alert_consts")
  local host = alert_consts.formatHostAlert(ifid, alert["ip"], alert["vlan_id"])
  local threshold = alert_type_params["threshold"] or 0
  local as_cli_or_srv = i18n("client")
  local as_cli = true
  local vlan_id = tonumber(alert["vlan_id"] or 0)

  -- Checks if alerted host is a client or a server.
  if alert_type_params["is_client_alert"] == false then
    as_cli_or_srv = i18n("server")
    as_cli = false
  end

  local flows_info_href = ""

  -- Checks if host is still in memory, in case add link to live flows on the alert description.
  if interface.getHostInfo(hostinfo2hostkey(alert)) then
    flows_info_href = '[ '..i18n("check_live")..':  <a href="' .. ntop.getHttpPrefix().."/lua/flows_stats.lua?host="..host..'&alert_type=alerted" data-placement="bottom" title="Live Flow Explorer"><i class="fas fa-search-plus"></i></a> ] '
  end
  
  -- Checks if ClickHouse is enabled, in case add link to historical flows on the alert description.
  if ntop.isClickHouseEnabled() then
    local extra_params = {
      ifid = {
        value = ifid,
        operator = "eq"
      },
      epoch_begin = {
        value = tonumber(alert.tstamp) - 600, -- 10 minutes before the trigger of the alert
        operator = "eq"
      },
      epoch_end = {
        value = alert.tstamp_end, -- If the alert ended, means that the score decreased, no need of 10 minutes
        operator = "eq"
      },
      score = {
        value = 0,
        operator = "gt"
      }
    }
    
    if(vlan_id > 0) then
      extra_params.vlan_id = {
        value = vlan_id,
        operator = "eq"
      }
    end      

    if(as_cli) then 
        extra_params.cli_ip = {
          value = alert["ip"],
          operator = "eq"
        }
    else 
        extra_params.srv_ip = {
          value = alert["ip"],
          operator = "eq"
        }
    end

    flows_info_href = flows_info_href..'[ '..i18n("check_historical")..': <a href="' .. add_historical_flow_explorer_button_ref(extra_params,true) ..'" data-placement="bottom" title="Historical Flow Explorer"><i class="fas fa-search-plus"></i></a> ]' 
  end

  -- threshold due to threshold crossed
  return i18n("alert_messages.score_threshold", {
      entity = host,
      cli_or_srv = as_cli_or_srv,
      value = alert_type_params["value"],
      threshold = threshold,
      flows_info = flows_info_href
  })
end

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

return host_alert_score_threshold
