open Ocamlbuild_plugin
open Command
open Myocamlbuild_config
open Format

let print_list l =
  Printf.eprintf "%![";
  List.iter (fun s -> Printf.eprintf " '%s' " s) l;
  Printf.eprintf "]\n%!"


(*let cxx_flags = S (List.map ( fun x -> A x) cxx_flags)*)
let _A x = A x
let _S ?(extra=N) l = S (List.map (fun e -> (S [extra; _A e] )) l)
;;

let cxx_flags = ref [ _S cxx_flags ]

let project_dirs = [ src_path; include_path ]
let cxx_include_flags = _S cxx_includes
let cxx_link_flags = ref  [ _S cxx_lpaths; _S cxx_libs]
let native_link_flags = ref (List.map (fun s -> s ^ ".cmxa") ocaml_link)
let byte_link_flags =  ref ("-custom" :: (List.map (fun s -> s ^ ".cma") ocaml_link))
let link_flags = [ A"-linkpkg" ]

let native_compile_flags = ref [A"-fno-PIC"]
let compile_flags = ref []

let dwsize = sprintf "-DWORDSIZE%i" Sys.word_size

(* Utils *)
let ( @= ) r l = r := !r @ l
let ( =:: ) r e = r := e :: !r

(* Pre-processed files *)
let pp_macro_options = ref
  [ A "-parser"; A "macro"; A dwsize; A "-I"; P include_path ]

let include_full_path =  Pathname.pwd / include_path
module Depends =
struct
open Scanf
let scan_include ml =
  let ic = try open_in ml with
      _ -> open_in (include_full_path / ml)
  in
  let includes = ref [] in
  try
    while true do
      let s = input_line ic in
      try
	if String.length s > 0 then sscanf s " INCLUDE \"%s@\"" ((=::) includes)
      with
	  Scan_failure _ -> ()
    done; []
  with End_of_file -> close_in ic; !includes

let ocaml ml =
  let rec loop file =
    let includes = scan_include file in
    List.fold_left (fun a i -> (loop i) @ a) includes includes
  in
  let includes = loop ml in
    dep [ "file:" ^ ml ]
      (List.map (fun s ->  include_path / s) includes)

let parse_depends file depfile =
  let ichan = open_in depfile in
  let iscan = Scanning.from_channel ichan in
  let () = bscanf iscan " %s@: " ignore in
  let () = bscanf iscan " %s " ignore in
  let includes = ref [] in
  try
    while true do
      try
	let s = bscanf iscan " %s " (fun s -> s) in
	if s = "" then raise End_of_file;
	if s <> "\\" then includes =::s
      with
	  Scan_failure _ -> ()
    done; []
  with
      End_of_file -> close_in ichan; !includes

let uniq l =
  let rec loop l acc =
    match l with
      | []  -> acc
      | [ e ] -> e::acc
      | e1 :: ((e2 :: _) as ll) ->
	loop ll (if e1 = e2 then acc else e1 :: acc)
  in
  loop (List.sort compare l) []

let cxx cpp =
  let depfile = ( cpp ^ ".depends") in
  let cmd = Cmd (S[ A cxx_cmd ; S !cxx_flags; cxx_include_flags ; A"-MM";
		    A "-MG"; A "-MF";  P depfile; P cpp])
  in
  let () = Command.execute ~quiet:true ~pretend:false cmd in
  let includes = parse_depends cpp depfile in
  List.filter (Pathname.is_relative) (uniq includes)
end

let cxx_compile env build =
  let src = env "%.cpp" and obj = env "%.o" in
  let local_include = Depends.cxx src in
  let local_dispatch = List.map (fun p -> List.map (fun p' -> p'/p) project_dirs) local_include in
  let  () = ignore (build local_dispatch) in
  Cmd(S[A cxx_cmd; A "-o" ; P obj; A "-c";  S !cxx_flags; cxx_include_flags; P src])

(* Native compile and link action *)

let ocamlfind x = S[ A"ocamlfind"; x ; A "-package"; A ocamlfind_packages ]

let ppopt l = List.map (fun e -> S[ A"-ppopt"; e ]) l

let () = dispatch begin
  function
    | Before_rules ->

      Options.ocamlc := ocamlfind  (A"ocamlc");
      Options.ocamlopt := ocamlfind (A"ocamlopt");
      Options.ocamldep := ocamlfind (A"ocamldep");
      Options.ocamldoc := ocamlfind (A"ocamldoc");
      Options.ocamlmktop := ocamlfind (A"ocamlmktop");


      if (List.mem "profile" !Options.tags) then begin
	pp_macro_options @= [ A "-DPROFILE" ];
	native_compile_flags @= [A "-p" ];
	native_link_flags @= [ "-p" ];
	cxx_flags @= [ A "-pg" ];
	cxx_link_flags @= [ A "-pg" ];
      end;

      if (List.mem "debug" !Options.tags) then begin
	pp_macro_options @= [ A "-DDEBUG" ];
	cxx_flags @= [ A "-O0"; A "-g" ];
	cxx_link_flags @= [ A "-g" ];
      end
      else begin
	compile_flags @= [A "-noassert"];
	pp_macro_options @= [ A "-unsafe" ];
	native_compile_flags @= [ A "-inline"; A ocaml_inline ];
	cxx_flags @= [ A "-O3" ]
      end;

      let dir_path = Pathname.pwd / src_path in
      let dir = Pathname.readdir dir_path in

      Array.iter (fun entry ->
	if Pathname.check_extension entry "ml" then
	  Depends.ocaml (src_path / entry)
	(* else if Pathname.check_extension entry "cpp" then
	  Depends.cxx (src_path / entry) *)
      ) dir;

    | After_rules ->
      dep [ "link" ] cstub_lib;
      rule "compile cpp -> o" ~prod:"%.o" ~deps:[ "%.cpp"] cxx_compile;

      let syntax_flags = S ([ A "-syntax"; A "camlp4o";
			    S (ppopt [A "-printer" ; A"Camlp4OCamlAstDumper"]);
			    S (ppopt !pp_macro_options) ])
      in
      flag [ "ocaml"; "ocamldep"] syntax_flags;
      flag [ "ocaml"; "compile" ] (S[ A "-cc"; A cxx_cmd; syntax_flags; S !compile_flags ]);
      flag [ "ocaml"; "native"; "compile" ] (S !native_compile_flags);
      flag [ "ocaml"; "link" ]
	(S [ S link_flags ; A "-cc"; A cxx_cmd; A "-cclib" ;
	     Quote (S [ _S cstub_lib;  S !cxx_link_flags]) ]);
      flag [ "ocaml"; "byte"; "link" ] (_S !byte_link_flags);
      flag [ "ocaml"; "native"; "link" ] (_S !native_link_flags);
      flag [ "c"; "ocamlmklib"] (S[ A "-custom"; ])
    | _ -> ()
end