(***********************************************************************)
(*                                                                     *)
(*                                OCaml                                *)
(*                                                                     *)
                , projet Para , INRIA Rocquencourt         
(*                                                                     *)
   Copyright 1996 Institut National de Recherche en Informatique et   
   en Automatique .   All rights reserved .   This file is distributed    
   under the terms of the GNU Library General Public License , with    
(*  the special exception on linking described in file ../LICENSE.     *)
(*                                                                     *)
(***********************************************************************)

type key = string
type doc = string
type usage_msg = string
type anon_fun = (string -> unit)

type spec =
  | Unit of (unit -> unit)     (* Call the function with unit argument *)
  | Bool of (bool -> unit)     (* Call the function with a bool argument *)
  | Set of bool ref            (* Set the reference to true *)
  | Clear of bool ref          (* Set the reference to false *)
  | String of (string -> unit) (* Call the function with a string argument *)
  | Set_string of string ref   (* Set the reference to the string argument *)
  | Int of (int -> unit)       (* Call the function with an int argument *)
  | Set_int of int ref         (* Set the reference to the int argument *)
  | Float of (float -> unit)   (* Call the function with a float argument *)
  | Set_float of float ref     (* Set the reference to the float argument *)
  | Tuple of spec list         (* Take several arguments according to the
                                  spec list *)
  | Symbol of string list * (string -> unit)
  Take one of the symbols as argument and 
                                   call the function with the symbol .
                                  call the function with the symbol. *)
  | Rest of (string -> unit)   (* Stop interpreting keywords and call the
                                  function with each remaining argument *)

exception Bad of string
exception Help of string

type error =
  | Unknown of string
  | Wrong of string * string * string  (* option, actual, expected *)
  | Missing of string
  | Message of string

exception Stop of error;; (* used internally *)

open Printf

let rec assoc3 x l =
  match l with
  | [] -> raise Not_found
  | (y1, y2, y3) :: t when y1 = x -> y2
  | _ :: t -> assoc3 x t
;;

let make_symlist prefix sep suffix l =
  match l with
  | [] -> "<none>"
  | h::t -> (List.fold_left (fun x y -> x ^ sep ^ y) (prefix ^ h) t) ^ suffix
;;

let print_spec buf (key, spec, doc) =
  if String.length doc > 0 then
    match spec with
    | Symbol (l, _) ->
        bprintf buf "  %s %s%s\n" key (make_symlist "{" "|" "}" l) doc
    | _ ->
        bprintf buf "  %s %s\n" key doc
;;

let help_action () = raise (Stop (Unknown "-help"));;

let add_help speclist =
  let add1 =
    try ignore (assoc3 "-help" speclist); []
    with Not_found ->
            ["-help", Unit help_action, " Display this list of options"]
  and add2 =
    try ignore (assoc3 "--help" speclist); []
    with Not_found ->
            ["--help", Unit help_action, " Display this list of options"]
  in
  speclist @ (add1 @ add2)
;;

let usage_b buf speclist errmsg =
  bprintf buf "%s\n" errmsg;
  List.iter (print_spec buf) (add_help speclist);
;;

let usage_string speclist errmsg =
  let b = Buffer.create 200 in
  usage_b b speclist errmsg;
  Buffer.contents b;
;;

let usage speclist errmsg =
  eprintf "%s" (usage_string speclist errmsg);
;;

let current = ref 0;;

let parse_argv_dynamic ?(current=current) argv speclist anonfun errmsg =
  let l = Array.length argv in
  let b = Buffer.create 200 in
  let initpos = !current in
  let stop error =
    let progname = if initpos < l then argv.(initpos) else "(?)" in
    begin match error with
      | Unknown "-help" -> ()
      | Unknown "--help" -> ()
      | Unknown s ->
          bprintf b "%s: unknown option '%s'.\n" progname s
      | Missing s ->
          bprintf b "%s: option '%s' needs an argument.\n" progname s
      | Wrong (opt, arg, expected) ->
          bprintf b "%s: wrong argument '%s'; option '%s' expects %s.\n"
                  progname arg opt expected
      | Message s ->
          bprintf b "%s: %s.\n" progname s
    end;
    usage_b b !speclist errmsg;
    if error = Unknown "-help" || error = Unknown "--help"
    then raise (Help (Buffer.contents b))
    else raise (Bad (Buffer.contents b))
  in
  incr current;
  while !current < l do
    let s = argv.(!current) in
    if String.length s >= 1 && s.[0] = '-' then begin
      let action =
        try assoc3 s !speclist
        with Not_found -> stop (Unknown s)
      in
      begin try
        let rec treat_action = function
        | Unit f -> f ();
        | Bool f when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try f (bool_of_string arg)
            with Invalid_argument "bool_of_string" ->
                   raise (Stop (Wrong (s, arg, "a boolean")))
            end;
            incr current;
        | Set r -> r := true;
        | Clear r -> r := false;
        | String f when !current + 1 < l ->
            f argv.(!current + 1);
            incr current;
        | Symbol (symb, f) when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            if List.mem arg symb then begin
              f argv.(!current + 1);
              incr current;
            end else begin
              raise (Stop (Wrong (s, arg, "one of: "
                                          ^ (make_symlist "" " " "" symb))))
            end
        | Set_string r when !current + 1 < l ->
            r := argv.(!current + 1);
            incr current;
        | Int f when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try f (int_of_string arg)
            with Failure "int_of_string" ->
                   raise (Stop (Wrong (s, arg, "an integer")))
            end;
            incr current;
        | Set_int r when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try r := (int_of_string arg)
            with Failure "int_of_string" ->
                   raise (Stop (Wrong (s, arg, "an integer")))
            end;
            incr current;
        | Float f when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try f (float_of_string arg);
            with Failure "float_of_string" ->
                   raise (Stop (Wrong (s, arg, "a float")))
            end;
            incr current;
        | Set_float r when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try r := (float_of_string arg);
            with Failure "float_of_string" ->
                   raise (Stop (Wrong (s, arg, "a float")))
            end;
            incr current;
        | Tuple specs ->
            List.iter treat_action specs;
        | Rest f ->
            while !current < l - 1 do
              f argv.(!current + 1);
              incr current;
            done;
        | _ -> raise (Stop (Missing s))
        in
        treat_action action
      with Bad m -> stop (Message m);
         | Stop e -> stop e;
      end;
      incr current;
    end else begin
      (try anonfun s with Bad m -> stop (Message m));
      incr current;
    end;
  done;
;;

let parse_argv ?(current=current) argv speclist anonfun errmsg =
  parse_argv_dynamic ~current:current argv (ref speclist) anonfun errmsg;
;;

let parse l f msg =
  try
    parse_argv Sys.argv l f msg;
  with
  | Bad msg -> eprintf "%s" msg; exit 2;
  | Help msg -> printf "%s" msg; exit 0;
;;

let parse_dynamic l f msg =
  try
    parse_argv_dynamic Sys.argv l f msg;
  with
  | Bad msg -> eprintf "%s" msg; exit 2;
  | Help msg -> printf "%s" msg; exit 0;
;;

let second_word s =
  let len = String.length s in
  let rec loop n =
    if n >= len then len
    else if s.[n] = ' ' then loop (n+1)
    else n
  in
  try loop (String.index s ' ')
  with Not_found -> len
;;

let max_arg_len cur (kwd, spec, doc) =
  match spec with
  | Symbol _ -> max cur (String.length kwd)
  | _ -> max cur (String.length kwd + second_word doc)
;;

let add_padding len ksd =
  match ksd with
  | (_, _, "") ->
      (* Do not pad undocumented options, so that they still don't show up when
       * run through [usage] or [parse]. *)
      ksd
  | (kwd, (Symbol (l, _) as spec), msg) ->
      let cutcol = second_word msg in
      let spaces = String.make (len - cutcol + 3) ' ' in
      (kwd, spec, "\n" ^ spaces ^ msg)
  | (kwd, spec, msg) ->
      let cutcol = second_word msg in
      let spaces = String.make (len - String.length kwd - cutcol) ' ' in
      let prefix = String.sub msg 0 cutcol in
      let suffix = String.sub msg cutcol (String.length msg - cutcol) in
      (kwd, spec, prefix ^ spaces ^ suffix)
;;

let align speclist =
  let completed = add_help speclist in
  let len = List.fold_left max_arg_len 0 completed in
  List.map (add_padding len) completed
;;

*********************************************************************
                                                                     
                                OCaml                                
                                                                     
                                                                     
  the special exception on linking described in file ../LICENSE.     
                                                                     
*********************************************************************
 Call the function with unit argument 
 Call the function with a bool argument 
 Set the reference to true 
 Set the reference to false 
 Call the function with a string argument 
 Set the reference to the string argument 
 Call the function with an int argument 
 Set the reference to the int argument 
 Call the function with a float argument 
 Set the reference to the float argument 
 Take several arguments according to the
                                  spec list 
 Stop interpreting keywords and call the
                                  function with each remaining argument 
 option, actual, expected 
 used internally 
 Do not pad undocumented options, so that they still don't show up when
       * run through [usage] or [parse]. 
                , projet Para , INRIA Rocquencourt         
   Copyright 1996 Institut National de Recherche en Informatique et   
   en Automatique .   All rights reserved .   This file is distributed    
   under the terms of the GNU Library General Public License , with    

type key = string
type doc = string
type usage_msg = string
type anon_fun = (string -> unit)

type spec =
  | Symbol of string list * (string -> unit)
  Take one of the symbols as argument and 
                                   call the function with the symbol .
                                  call the function with the symbol. *)

exception Bad of string
exception Help of string

type error =
  | Unknown of string
  | Missing of string
  | Message of string


open Printf

let rec assoc3 x l =
  match l with
  | [] -> raise Not_found
  | (y1, y2, y3) :: t when y1 = x -> y2
  | _ :: t -> assoc3 x t
;;

let make_symlist prefix sep suffix l =
  match l with
  | [] -> "<none>"
  | h::t -> (List.fold_left (fun x y -> x ^ sep ^ y) (prefix ^ h) t) ^ suffix
;;

let print_spec buf (key, spec, doc) =
  if String.length doc > 0 then
    match spec with
    | Symbol (l, _) ->
        bprintf buf "  %s %s%s\n" key (make_symlist "{" "|" "}" l) doc
    | _ ->
        bprintf buf "  %s %s\n" key doc
;;

let help_action () = raise (Stop (Unknown "-help"));;

let add_help speclist =
  let add1 =
    try ignore (assoc3 "-help" speclist); []
    with Not_found ->
            ["-help", Unit help_action, " Display this list of options"]
  and add2 =
    try ignore (assoc3 "--help" speclist); []
    with Not_found ->
            ["--help", Unit help_action, " Display this list of options"]
  in
  speclist @ (add1 @ add2)
;;

let usage_b buf speclist errmsg =
  bprintf buf "%s\n" errmsg;
  List.iter (print_spec buf) (add_help speclist);
;;

let usage_string speclist errmsg =
  let b = Buffer.create 200 in
  usage_b b speclist errmsg;
  Buffer.contents b;
;;

let usage speclist errmsg =
  eprintf "%s" (usage_string speclist errmsg);
;;

let current = ref 0;;

let parse_argv_dynamic ?(current=current) argv speclist anonfun errmsg =
  let l = Array.length argv in
  let b = Buffer.create 200 in
  let initpos = !current in
  let stop error =
    let progname = if initpos < l then argv.(initpos) else "(?)" in
    begin match error with
      | Unknown "-help" -> ()
      | Unknown "--help" -> ()
      | Unknown s ->
          bprintf b "%s: unknown option '%s'.\n" progname s
      | Missing s ->
          bprintf b "%s: option '%s' needs an argument.\n" progname s
      | Wrong (opt, arg, expected) ->
          bprintf b "%s: wrong argument '%s'; option '%s' expects %s.\n"
                  progname arg opt expected
      | Message s ->
          bprintf b "%s: %s.\n" progname s
    end;
    usage_b b !speclist errmsg;
    if error = Unknown "-help" || error = Unknown "--help"
    then raise (Help (Buffer.contents b))
    else raise (Bad (Buffer.contents b))
  in
  incr current;
  while !current < l do
    let s = argv.(!current) in
    if String.length s >= 1 && s.[0] = '-' then begin
      let action =
        try assoc3 s !speclist
        with Not_found -> stop (Unknown s)
      in
      begin try
        let rec treat_action = function
        | Unit f -> f ();
        | Bool f when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try f (bool_of_string arg)
            with Invalid_argument "bool_of_string" ->
                   raise (Stop (Wrong (s, arg, "a boolean")))
            end;
            incr current;
        | Set r -> r := true;
        | Clear r -> r := false;
        | String f when !current + 1 < l ->
            f argv.(!current + 1);
            incr current;
        | Symbol (symb, f) when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            if List.mem arg symb then begin
              f argv.(!current + 1);
              incr current;
            end else begin
              raise (Stop (Wrong (s, arg, "one of: "
                                          ^ (make_symlist "" " " "" symb))))
            end
        | Set_string r when !current + 1 < l ->
            r := argv.(!current + 1);
            incr current;
        | Int f when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try f (int_of_string arg)
            with Failure "int_of_string" ->
                   raise (Stop (Wrong (s, arg, "an integer")))
            end;
            incr current;
        | Set_int r when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try r := (int_of_string arg)
            with Failure "int_of_string" ->
                   raise (Stop (Wrong (s, arg, "an integer")))
            end;
            incr current;
        | Float f when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try f (float_of_string arg);
            with Failure "float_of_string" ->
                   raise (Stop (Wrong (s, arg, "a float")))
            end;
            incr current;
        | Set_float r when !current + 1 < l ->
            let arg = argv.(!current + 1) in
            begin try r := (float_of_string arg);
            with Failure "float_of_string" ->
                   raise (Stop (Wrong (s, arg, "a float")))
            end;
            incr current;
        | Tuple specs ->
            List.iter treat_action specs;
        | Rest f ->
            while !current < l - 1 do
              f argv.(!current + 1);
              incr current;
            done;
        | _ -> raise (Stop (Missing s))
        in
        treat_action action
      with Bad m -> stop (Message m);
         | Stop e -> stop e;
      end;
      incr current;
    end else begin
      (try anonfun s with Bad m -> stop (Message m));
      incr current;
    end;
  done;
;;

let parse_argv ?(current=current) argv speclist anonfun errmsg =
  parse_argv_dynamic ~current:current argv (ref speclist) anonfun errmsg;
;;

let parse l f msg =
  try
    parse_argv Sys.argv l f msg;
  with
  | Bad msg -> eprintf "%s" msg; exit 2;
  | Help msg -> printf "%s" msg; exit 0;
;;

let parse_dynamic l f msg =
  try
    parse_argv_dynamic Sys.argv l f msg;
  with
  | Bad msg -> eprintf "%s" msg; exit 2;
  | Help msg -> printf "%s" msg; exit 0;
;;

let second_word s =
  let len = String.length s in
  let rec loop n =
    if n >= len then len
    else if s.[n] = ' ' then loop (n+1)
    else n
  in
  try loop (String.index s ' ')
  with Not_found -> len
;;

let max_arg_len cur (kwd, spec, doc) =
  match spec with
  | Symbol _ -> max cur (String.length kwd)
  | _ -> max cur (String.length kwd + second_word doc)
;;

let add_padding len ksd =
  match ksd with
  | (_, _, "") ->
      ksd
  | (kwd, (Symbol (l, _) as spec), msg) ->
      let cutcol = second_word msg in
      let spaces = String.make (len - cutcol + 3) ' ' in
      (kwd, spec, "\n" ^ spaces ^ msg)
  | (kwd, spec, msg) ->
      let cutcol = second_word msg in
      let spaces = String.make (len - String.length kwd - cutcol) ' ' in
      let prefix = String.sub msg 0 cutcol in
      let suffix = String.sub msg cutcol (String.length msg - cutcol) in
      (kwd, spec, prefix ^ spaces ^ suffix)
;;

let align speclist =
  let completed = add_help speclist in
  let len = List.fold_left max_arg_len 0 completed in
  List.map (add_padding len) completed
;;
