(* Intefraces module for Augeas

   Author: Free Ekanayaka <free@64studio.com>

   Reference: man dhclient.conf

   The only difference with the reference syntax is that this lens assumes

   that statements end with a new line, while the reference syntax allows

   new statements to be started right after the trailing ";" of the

   previous statement. This should not be a problem in real-life

   configuration files as statements get usually split across several

   lines, rather than merged in a single one.

*)

module Dhclient =

   autoload xfm

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

 *                           USEFUL PRIMITIVES

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

let eol               = Util.eol

let comment           = Util.comment

let comment_or_eol    = Util.comment_or_eol

let empty             = Util.empty

(* Define separators *)

let sep_spc           = del /[ \t\n]+/ " "

let sep_scl           = del /[ \t]*;/ ";"

let sep_obr           = del /[ \t\n]*\{\n]*/ " {\n"

let sep_cbr           = del /[ \t\n]*\}/ " }"

let sep_com           = del /[ \t\n]*,[ \t\n]*/ ","

let sep_slh           = del "\/" "/"

let sep_col           = del ":" ":"

let sep_eq            = del /[ \t]*=[ \t]*/ "="

(* Define basic types *)

let word              = /[A-Za-z0-9_.-]+(\[[0-9]+\])?/

(* Define fields *)

(* TODO: there could be a " " in the middle of a value ... *)

let sto_to_spc        = store /[^\\#,;{}" \t\n]+|"[^\\#"\n]+"/

let sto_to_spc_noeval = store /[^=\\#,;{}" \t\n]|[^=\\#,;{}" \t\n][^\\#,;{}" \t\n]*|"[^\\#"\n]+"/

let sto_to_scl        = store /[^ \t\n][^;\n]+[^ \t]|[^ \t;\n]+/

let rfc_code          = [ key "code" . sep_spc . store word ]

                      . sep_eq

                      . [ label "value" . sto_to_scl ]

let eval              = [ label "#eval" . Sep.equal . sep_spc . sto_to_scl ]

let sto_number        = store /[0-9][0-9]*/

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

 *                         SIMPLE STATEMENTS

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

let stmt_simple_re    = "timeout"

                      | "retry"

                      | "select-timeout"

                      | "reboot"

                      | "backoff-cutoff"

                      | "initial-interval"

                      | "do-forward-updates"

                      | "reject"

let stmt_simple       = [ key stmt_simple_re

                        . sep_spc

                        . sto_to_spc

                        . sep_scl

                        . comment_or_eol ]

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

 *                          ARRAY STATEMENTS

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

(* TODO: the array could also be empty, like in the request statement *)

let stmt_array_re     = "media"

                      | "request"

                      | "require"

let stmt_array        = [ key stmt_array_re

                        . sep_spc

                        . counter "stmt_array"

                        . [ seq "stmt_array" . sto_to_spc ]

                        . [ sep_com . seq "stmt_array" . sto_to_spc ]*

                        . sep_scl . comment_or_eol ]

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

 *                          HASH STATEMENTS

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

let stmt_hash_re      = "send"

                      | "option"

let stmt_args         = ( [ key word . sep_spc . sto_to_spc_noeval ]

                          | [ key word . sep_spc . (rfc_code|eval) ] )

                        . sep_scl

                        . comment_or_eol

let stmt_hash         = [ key stmt_hash_re

                        . sep_spc

                        . stmt_args ]

let stmt_opt_mod_re   = "append"

                      | "prepend"

                      | "default"

                      | "supersede"

let stmt_opt_mod      = [ key stmt_opt_mod_re

                        . sep_spc

                        . stmt_args ]

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

 *                         BLOCK STATEMENTS

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

let stmt_block_re     = "interface"

                      | "lease"

                      | "alias"

let stmt_block_opt_re = "interface"

                      | "script"

                      | "bootp"

                      | "fixed-address"

                      | "filename"

                      | "server-name"

                      | "medium"

                      | "vendor option space"

(* TODO: some options could take no argument like bootp *)

let stmt_block_opt    = [ key stmt_block_opt_re

                         . sep_spc

                         . sto_to_spc

                         . sep_scl

                         . comment_or_eol ]

let stmt_block_date_re

                      = "renew"

                      | "rebind"

                      | "expire"

let stmt_block_date   = [ key stmt_block_date_re

                        . [ sep_spc . label "weekday" . sto_number ]

                        . [ sep_spc . label "year"    . sto_number ]

                        . [ sep_slh . label "month"   . sto_number ]

                        . [ sep_slh . label "day"     . sto_number ]

                        . [ sep_spc . label "hour"    . sto_number ]

                        . [ sep_col . label "minute"  . sto_number ]

                        . [ sep_col . label "second"  . sto_number ]

                        . sep_scl

                        . comment_or_eol ]

let stmt_block_arg    = sep_spc . sto_to_spc

let stmt_block_entry  = sep_spc

                      . ( stmt_array

                        | stmt_hash

                        | stmt_opt_mod

                        | stmt_block_opt

                        | stmt_block_date )

let stmt_block        = [ key stmt_block_re

                        . stmt_block_arg?

                        . sep_obr

                        . stmt_block_entry+

                        . sep_cbr

                        . comment_or_eol ]

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

 *                              LENS & FILTER

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

let statement = (stmt_simple|stmt_opt_mod|stmt_array|stmt_hash|stmt_block)

let lns               = ( empty

                        | comment

                        | statement )*

let filter            = incl "/etc/dhcp3/dhclient.conf"

                      . incl "/etc/dhcp/dhclient.conf"

                      . incl "/etc/dhclient.conf"

let xfm                = transform lns filter