(*

Module: Xymon_Alerting

  Parses xymon alerting files 

Author: Francois Maillard <fmaillard@gmail.com>

About: Reference

  This lens tries to keep as close as possible to `man 5 alerts.cfg` where possible.

About: License

   This file is licenced under the LGPL v2+, like the rest of Augeas.

About: Lens Usage

   To be documented

About: Not supported

   File inclusion are not followed

About: Configuration files

   This lens applies to /etc/xymon/alerts.d/*.cfg and /etc/xymon/alerts.cfg. See <filter>.

About: Examples

   The <Test_Xymon_Alerting> file contains various examples and tests.

*)

module Xymon_Alerting =

    autoload xfm

    (************************************************************************

     * Group:                 USEFUL PRIMITIVES

     *************************************************************************)

    (* View: store_word *)

    let store_word  = store /[^ =\t\n#]+/

    (* View: comparison The greater and lesser than operators *)

    let comparison  = store /[<>]/

    (* View: equal *)

    let equal       = Sep.equal

    (* View: ws *)

    let ws          = Sep.space

    (* View: eol *)

    let eol         = Util.eol

    (* View: ws_or_eol *)

    let ws_or_eol   = del /([ \t]+|[ \t]*\n[ \t]*)/ " "

    (* View: comment *)

    let comment = Util.comment

    (* View: empty *)

    let empty   = Util.empty

    (* View: include *)

    let include         = [ key "include" . ws . store_word . eol ]

    (************************************************************************

     * Group:                 MACRO DEFINITION

     *************************************************************************)

    (* View: macrodefinition

         A string that starts with $ and that is assigned something *)

    let macrodefinition = [ key /\$[^ =\t\n#\/]+/ . Sep.space_equal . store Rx.space_in . eol ]

    (* View: flag

         A flag value *)

    let flag (kw:string) = Build.flag kw

    (* View: kw_word

         A key=value value *)

    let kw_word (kw:regexp) = Build.key_value kw equal store_word

    (************************************************************************

     * Group:                 FILTERS 

     *************************************************************************)

    (* View: page

         The (ex)?page filter definition *)

    let page      = kw_word /(EX)?PAGE/

    (* View: group

         The (ex)?group filter definition *)

    let group     = kw_word /(EX)?GROUP/

    (* View: host

         The (ex)?host filter definition *)

    let host      = kw_word /(EX)?HOST/

    (* View: service

         The (ex)?service filter definition *)

    let service   = kw_word /(EX)?SERVICE/

    (* View: color

         The color filter definition *)

    let color     = kw_word "COLOR"

    (* View: time

         The time filter definition *)

    let time      = kw_word "TIME"

    (* View: duration

         The duration filter definition *)

    let duration  = [ key "DURATION" . [ label "operator" . comparison ] . [ label "value" . store_word ] ]

    (* View: recover

         The recover filter definition *)

    let recover   = flag "RECOVER"

    (* View: notice

         The notice filter definition *)

    let notice    = flag "NOTICE"

    (* View: rule_filter

         Filters are made out of any of the above filter definitions *)

    let rule_filter = page | group | host | service

                    | color | time | duration | recover | notice

    (* View: filters

         One or more filters *)

    let filters = [ label "filters" . Build.opt_list rule_filter ws ]

    (* View: filters_opt

         Zero, one or more filters *)

    let filters_opt = [ label "filters" . (ws . Build.opt_list rule_filter ws)? ]

    (* View: kw_word_filters_opt

         A <kw_word> entry with optional filters *)

    let kw_word_filters_opt (kw:string) = [ key kw . equal . store_word . filters_opt ]

    (* View: flag_filters_opt

         A <flag> with optional filters *) 

    let flag_filters_opt (kw:string) = [ key kw . filters_opt ]

    (************************************************************************

     * Group:                 RECIPIENTS

     *************************************************************************)

    (* View: mail

         The mail recipient definition *)

    let mail      = [ key "MAIL" . ws . store_word . filters_opt ]

    (* View: script

         The script recipient definition *)

    let script    = [ key "SCRIPT" . ws . [ label "script" . store_word ]

                  . ws . [ label "recipient" . store_word ] . filters_opt ]

    (* View: ignore

         The ignore recipient definition *)

    let ignore    = flag_filters_opt "IGNORE"

    (* View: format

         The format recipient definition *)

    let format    = kw_word_filters_opt "FORMAT"

    (* View: repeat

         The repeat recipient definition *)

    let repeat    = kw_word_filters_opt "REPEAT"

    (* View: unmatched

         The unmatched recipient definition *)

    let unmatched = flag_filters_opt "UNMATCHED"

    (* View: stop

         The stop recipient definition *)

    let stop      = flag_filters_opt "STOP"

    (* View: macro

         The macro recipient definition *)

    let macro     = [ key /\$[^ =\t\n#\/]+/ . filters_opt ]

    (* View: recipient

         Recipients are made out of any of the above recipient definitions *)

    let recipient = mail | script | ignore | format | repeat | unmatched

                  | stop | macro

    let recipients = [ label "recipients" . Build.opt_list recipient ws_or_eol ]

    (************************************************************************

     * Group:                 RULES

     *************************************************************************)

    (* View: rule

         Rules are made of rule_filter and then recipients sperarated by a whitespace *)

    let rule = [ seq "rules" . filters . ws_or_eol . recipients . eol ] 

    (* View: lns

         The Xymon_Alerting lens *)

    let lns = ( rule | macrodefinition | include | empty | comment )*

    (* Variable: filter *)

    let filter = incl "/etc/xymon/alerts.d/*.cfg"

               . incl "/etc/xymon/alerts.cfg"

               . Util.stdexcl

    let xfm = transform lns filter