--
-- (C) 2013-23 - ntop.org
--
local dirs = ntop.getDirs()
package.path = dirs.installdir .. "/scripts/lua/modules/?.lua;" .. package.path

-- Import the classes library.
local classes = require "classes"
local alert_severities = require "alert_severities"

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

local Alert = classes.class()

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

function Alert:init()
end

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

function Alert:format()
    -- tprint("base format")
end

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

-- @brief Function called to set standard information:
--        - score
--        - subtype
--        - granularity
--        Those information could be set using standard functions
--        like set_score() or set_granularity
function Alert:set_info(params)
    local alert_consts = require "alert_consts"
    local script = params.check
    if (not self.score or self.score == 0) then
        self.score = ntop.mapSeverityToScore(script.severity.severity_id or 0 --[[ no score ]] )
    end

    if params.entity_info then
        self.subtype = params.entity_info.name or ""
    end

    self.granularity = alert_consts.alerts_granularities[params.granularity]
end

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

function Alert:_build_type_info()
    local type_info = {
        -- Keys necessary for the engine
        alert_type = self.meta,
        subtype = self.subtype,
        granularity = self.granularity,
        score = self.score,
        device_type = self.device_type,
        device_name = self.device_name,
        -- Stuff added in subclasses :init
        alert_type_params = self.alert_type_params or {}
    }

    -- Add the attacker to the alert params (if present)
    if self.attacker then
        type_info.alert_type_params.attacker = self.attacker
    end

    -- Add the victim to the alert params (if present)
    if self.victim then
        type_info.alert_type_params.victim = self.victim
    end

    return type_info
end

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

function Alert:_check_alert_data()
    if self == nil then
        return true
    end

    if self.meta.has_victim and not self.victim then
        traceError(TRACE_ERROR, TRACE_CONSOLE, "alert.alert_error.configuration.no_victim")
        return false
    end

    if self.meta.has_attacker and not self.attacker then
        traceError(TRACE_ERROR, TRACE_CONSOLE, "alert.alert_error.configuration.no_attacker")
        return false
    end

    return true
end

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

function Alert:trigger(entity_info, when, cur_alerts)
    local alerts_api = require "alerts_api"

    if not self._check_alert_data() then
        return
    end

    return alerts_api.trigger(entity_info, self:_build_type_info(), nil, cur_alerts)
end

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

function Alert:release(entity_info, when, cur_alerts)
    local alerts_api = require "alerts_api"

    if not self._check_alert_data() then
        return
    end

    return alerts_api.release(entity_info, self:_build_type_info(), nil, cur_alerts)
end

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

function Alert:store(entity_info)
    local alerts_api = require "alerts_api"

    if not self._check_alert_data() then
        return
    end

    return alerts_api.store(entity_info, self:_build_type_info())
end

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

function Alert:set_score(score)
    self.score = tonumber(score)
end

-- @brief Methods to set score defaults, keep them in sync with
-- ntop_defines.h
function Alert:set_score_notice()
    self.score = ntop.mapSeverityToScore(alert_severities.notice.severity_id)
end
function Alert:set_score_warning()
    self.score = ntop.mapSeverityToScore(alert_severities.warning.severity_id)
end
function Alert:set_score_error()
    self.score = ntop.mapSeverityToScore(alert_severities.error.severity_id)
end
function Alert:set_score_critical()
    self.score = ntop.mapSeverityToScore(alert_severities.critical.severity_id)
end
function Alert:set_score_emergency()
    self.score = ntop.mapSeverityToScore(alert_severities.emergency.severity_id)
end

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

function Alert:set_subtype(subtype)
    self.subtype = subtype
end

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

function Alert:set_granularity(granularity)
    local alert_consts = require "alert_consts"

    self.granularity = alert_consts.alerts_granularities[granularity]
    if (self.granularity == nil) then
        print("[ERROR] Unknown granularity\n")
        tprint(granularity)
        print(debug.traceback())
    end
end

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

-- @brief Functions to set L2-related data, e.g., device type and name
function Alert:set_device_type(devtype)
    self.device_type = tonumber(devtype)
end
function Alert:set_device_name(devname)
    self.device_name = tostring(devname)
end

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

function Alert:set_attacker(attacker)
    self.attacker = attacker
end
function Alert:set_victim(victim)
    self.victim = victim
end
function Alert:set_origin(origin)
    self.origin = origin
end
function Alert:set_target(target)
    self.target = target
end

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

return Alert

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