open Utils;;

let (~>) = Bytes.unsafe_of_string;;

type cursor =
    | CURSOR_INHERIT
    | CURSOR_INFO
    | CURSOR_CYCLE
    | CURSOR_FLEUR
    | CURSOR_TEXT
;;

type winstate =
    | MaxVert
    | MaxHorz
    | Fullscreen
;;

type visiblestate =
  | Unobscured
  | PartiallyObscured
  | FullyObscured
;;

let classify_key key =
  let open Keys in
  match key with
  | 0xffbe -> F1
  | 0xffc0 -> F3
  | 0xffc6 -> F9
  | 62 -> Gt
  | 91 -> Lb
  | 60 -> Lt
  | 93 -> Rb
  | 39 -> Apos
  | 0xff08 -> Backspace
  | 0xff9f -> Delete
  | 0xff54 -> Down
  | 0xff0d -> Enter
  | 61 -> Equals
  | 0xff1b -> Escape
  | 0xff50 -> Home
  | 0xff63 -> Insert
  | 0xff57 -> Jend
  | 0xffff -> KPdelete
  | 0xff99 -> KPdown
  | 0xff9c -> KPend
  | 0xff8d -> KPenter
  | 0xff95 -> KPhome
  | 0xff96 -> KPleft
  | 0xffad -> KPminus
  | 0xff9b -> KPnext
  | 0xffab -> KPplus
  | 0xff9a -> KPprior
  | 0xff98 -> KPright
  | 0xff97 -> KPup
  | 0xff51 -> Left
  | 45 -> Minus
  | 0xff56 -> Next
  | 124 -> Pipe
  | 43 -> Plus
  | 0xff55 -> Prior
  | 63 -> Question
  | 0xff53 -> Right
  | 47 -> Slash
  | 32 -> Space
  | 0xff09 -> Tab
  | 0x7e -> Tilde
  | 0xff52 -> Up
  | 48 -> N0
  | 49 -> N1
  | 50 -> N2
  | 51 -> N3
  | 52 -> N4
  | 57 -> N9
  | 66 -> CB
  | 70 -> CF
  | 71 -> CG
  | 72 -> CH
  | 78 -> CN
  | 80 -> CP
  | 81 -> CQ
  | 87 -> CW
  | 83 -> CS
  | 97 -> Ca
  | 98 -> Cb
  | 99 -> Cc
  | 101 -> Ce
  | 102 -> Cf
  | 103 -> Cg
  | 104 -> Ch
  | 105 -> Ci
  | 106 -> Cj
  | 107 -> Ck
  | 108 -> Cl
  | 109 -> Cm
  | 110 -> Cn
  | 111 -> Co
  | 112 -> Cp
  | 113 -> Cq
  | 114 -> Cr
  | 115 -> Cs
  | 116 -> Ct
  | 117 -> Cu
  | 118 -> Cv
  | 119 -> Cw
  | 120 -> Cx
  | 121 -> Cy
  | 122 -> Cz
  | n -> Code n
;;

type wid = int and screenno = int and vid = int and atom = int;;

external glxinit : string -> wid -> screenno -> vid = "ml_glxinit";;
external glxcompleteinit : unit -> unit = "ml_glxcompleteinit";;
external swapb : unit -> unit = "ml_swapb";;
external setcursor : cursor -> unit = "ml_setcursor";;
external setwinbgcol : int -> unit = "ml_setbgcol";;

(* let vlog fmt = Format.ksprintf ignore fmt;; *)

let onot = object
  method map _           = ()
  method expose          = ()
  method visible _       = ()
  method reshape _ _     = ()
  method mouse _ _ _ _ _ = ()
  method motion _ _      = ()
  method pmotion _ _     = ()
  method key _ _         = ()
  method enter _ _       = ()
  method leave           = ()
  method winstate _      = ()
  method quit: 'a. 'a    = exit 0
  method scroll _ _      = ()
end;;

class type t = object
  method map      : bool -> unit
  method expose   : unit
  method visible  : visiblestate -> unit
  method reshape  : int -> int -> unit
  method mouse    : int -> bool -> int -> int -> int -> unit
  method motion   : int -> int -> unit
  method pmotion  : int -> int -> unit
  method key      : int -> int -> unit
  method enter    : int -> int -> unit
  method leave    : unit
  method winstate : winstate list -> unit
  method quit     : 'a. 'a
  method scroll   : int -> int -> unit
end;;

type state =
    { mutable mink       : int
    ; mutable maxk       : int
    ; mutable keymap     : int array array
    ; fifo               : (bytes -> unit) Queue.t
    ; mutable seq        : int
    ; mutable protoatom  : atom
    ; mutable deleatom   : atom
    ; mutable nwmsatom   : atom
    ; mutable maxvatom   : atom
    ; mutable maxhatom   : atom
    ; mutable fulsatom   : atom
    ; mutable idbase     : int
    ; mutable wid        : int
    ; mutable fid        : int
    ; mutable fullscreen : (int -> unit)
    ; mutable setwmname  : (bytes -> unit)
    ; mutable actwin     : (unit -> unit)
    ; mutable stringatom : int
    ; mutable t          : t
    ; mutable sock       : Unix.file_descr
    ; mutable x          : int
    ; mutable y          : int
    ; mutable w          : int
    ; mutable h          : int
    ; mutable fs         : fs
    ; mutable curcurs    : cursor
    ; mutable capslmask  : int
    ; mutable numlmask   : int
    ; mutable levl3mask  : int
    ; mutable levl5mask  : int
    ; mutable xkb        : bool
    }
and fs =
    | NoFs
    | Fs of (int * int * int * int)
;;

let state =
  { mink       = max_int
  ; maxk       = min_int
  ; keymap     = E.a
  ; fifo       = Queue.create ()
  ; seq        = 0
  ; protoatom  = -1
  ; deleatom   = -1
  ; nwmsatom   = -1
  ; maxvatom   = -1
  ; maxhatom   = -1
  ; fulsatom   = -1
  ; idbase     = -1
  ; wid        = -1
  ; fid        = -1
  ; fullscreen = (fun _ -> ())
  ; setwmname  = (fun _ -> ())
  ; actwin     = (fun _ -> ())
  ; sock       = Unix.stdin
  ; t          = onot
  ; x          = -1
  ; y          = -1
  ; w          = -1
  ; h          = -1
  ; fs         = NoFs
  ; stringatom = 31
  ; curcurs    = CURSOR_TEXT
  ; capslmask  = 0
  ; numlmask   = 0
  ; levl3mask  = 0
  ; levl5mask  = 0
  ; xkb        = false
  }
;;

(* let w8 s pos i = Bytes.set s pos (Char.chr (i land 0xff));; *)
(* let r8 s pos = Char.code (Bytes.get s pos);; *)

(* let ordermagic = 'l';; *)

(* let w16 s pos i = *)
(*   w8 s pos i; *)
(*   w8 s (pos+1) (i lsr 8) *)
(* ;; *)

(* let w32 s pos i = *)
(*   w16 s pos i; *)
(*   w16 s (pos+2) (i lsr 16) *)
(* ;; *)

(* let r16 s pos = *)
(*   let rb pos1 = Char.code (Bytes.get s (pos + pos1)) in *)
(*   (rb 0) lor ((rb 1) lsl 8) *)
(* ;; *)

(* let r16s s pos = *)
(*   let i = r16 s pos in *)
(*   i - ((i land 0x8000) lsl 1) *)
(* ;; *)

(* let r32 s pos = *)
(*   let rb pos1 = Char.code (Bytes.get s (pos + pos1)) in *)
(*   let l = (rb 0) lor ((rb 1) lsl 8) *)
(*   and u = (rb 2) lor ((rb 3) lsl 8) in *)
(*   (u lsl 16) lor l *)
(* ;; *)

let makereq opcode len reqlen =
  let s = Bytes.create len in
  w8 s 0 opcode;
  w16 s 2 reqlen;
  s;
;;

let readstr sock n = try readstr sock n with End_of_file -> state.t#quit
(*   let s = Bytes.create n in *)
(*   let rec loop pos n = *)
(*     let m = tempfailureretry (Unix.read sock s pos) n in *)
(*     if m = 0 *)
(*     then state.t#quit; *)
(*     if n != m *)
(*     then ( *)
(*       ignore (tempfailureretry (Unix.select [sock] [] []) 0.01); *)
(*       loop (pos + m) (n - m) *)
(*     ) *)
(*   in *)
(*   loop 0 n; *)
(*   s; *)
(* ;; *)

let sendstr1 s pos len sock =
  vlog "%d <= %S" state.seq s;
  sendstr1 s pos len sock;
  state.seq <- state.seq + 1

(* let sendstr1 s pos len sock = *)
(*   let s = Bytes.unsafe_to_string s in *)
(*   vlog "%d <= %S" state.seq s; *)
(*   state.seq <- state.seq + 1; *)
(*   let n = tempfailureretry (Unix.write_substring sock s pos) len in *)
(*   if n != len *)
(*   then error "send %d returned %d" len n; *)
(* ;; *)

let updkmap sock resp =
  let syms = r8 resp 1 in
  let len = r32 resp 4 in
  let data =
    if len > 0
    then readstr sock (4*len)
    else E.b
  in
  let m = len / syms in
  state.keymap <- Array.make_matrix
    (state.maxk - state.mink) syms 0xffffff;
  let rec loop i = if i = m then () else
      let k = i*4*syms in
      let rec loop2 k l = if l = syms then () else
          let v = r32 data k in
          state.keymap.(i).(l) <- v;
          loop2 (k+4) (l+1)
      in
      loop2 k 0;
      loop (i+1);
  in
  loop 0;
;;

let updmodmap sock resp =
  let n = r8 resp 1 in
  let len = r16 resp 4 in
  let data =
    if len > 0
    then readstr sock (len*4)
    else E.b
  in
  if len > 0 then                      (*???*)
  let modmap = Array.make_matrix 8 n 0xffffff in
  let rec loop l = if l = 8 then () else
      let p = l*n in
      let rec loop1 m = if m = n then () else
          let p = p+m in
          let code = r8 data p in
          modmap.(l).(m) <- code;
          if l = 1
          then (
            let ki = code - state.mink in
            if ki >= 0
            then
              let a = state.keymap.(ki) in
              let rec capsloop i = if i = Array.length a || i > 3 then () else
                  let s = a.(i) in
                  if s = 0xffe5
                  then state.capslmask <- 2
                  else capsloop (i+1)
              in
              capsloop 0;
          )
          else (
            if l > 3
            then (
              let ki = code - state.mink in
              if ki >= 0
              then
                let a = state.keymap.(ki) in
                let rec lloop i = if i = Array.length a || i > 3 then () else
                    let s = a.(i) in
                    match s with
                    | 0xfe03 -> state.levl3mask <- 1 lsl l
                    | 0xfe11 -> state.levl5mask <- 1 lsl l
                    | 0xff7f -> state.numlmask  <- 1 lsl l
                    | _ -> lloop (i+1)
                in
                lloop 0;
            )
          );
          loop1 (m+1)
      in
      loop1 0;
      loop (l+1)
  in
  loop 0;
;;

let sendwithrep sock s f =
  Queue.push f state.fifo;
  sendstr1 s 0 (Bytes.length s) sock;
;;

let padcatl =
  let pad = "123" in
  fun ss ->
    let b = Buffer.create 16 in
    List.iter (Buffer.add_bytes b) ss;
    let bl = Buffer.length b in
    let pl = bl land 3 in
    if pl != 0
    then (
      Buffer.add_substring b pad 0 (4 - pl);
     );
    Buffer.to_bytes b;
;;

let padcat s1 s2 = padcatl [s1; s2];;

let internreq name onlyifexists =
  let s = makereq 16 8 8 in
  let s = padcat s name in
  w8 s 1 (if onlyifexists then 1 else 0);
  w16 s 2 (Bytes.length s / 4);
  w16 s 4 (Bytes.length name);
  s;
;;

let sendintern sock s onlyifexists f =
  let s = internreq s onlyifexists in
  sendwithrep sock s f;
;;

let createwindowreq wid parent x y w h bw eventmask vid depth mid =
  let s = makereq 1 48 12 in
  w8 s 1 depth;
  w32 s 4 wid;
  w32 s 8 parent;
  w16 s 12 x;
  w16 s 14 y;
  w16 s 16 w;
  w16 s 18 h;
  w16 s 20 bw;
  w16 s 22 0;                           (* copyfromparent *)
  w32 s 24 vid;                         (* visual *)
  w32 s 28 0x280a;                      (* valuemask =
                                         | background pixel
                                         | border pixel
                                         | event mask
                                         | colormap *)
  w32 s 32 0;                           (* background pixel *)
  w32 s 36 0;                           (* border pixel*)
  w32 s 40 eventmask;
  w32 s 44 mid;
  s;
;;

let createcolormapreq mid wid vid =
  let s = makereq 78 16 4 in
  w8 s 1 0;
  w32 s 4 mid;
  w32 s 8 wid;
  w32 s 12 vid;
  s;
;;

let getgeometryreq wid =
  let s = makereq 14 8 2 in
  w32 s 4 wid;
  s;
;;

let mapreq wid =
  let s = makereq 8 8 2 in
  w32 s 4 wid;
  s;
;;

let getkeymapreq first count =
  let s = makereq 101 8 2 in
  w8 s 4 first;
  w8 s 5 count;
  s;
;;

let changepropreq wid prop typ format props =
  let s = makereq 18 24 0 in
  let s = padcat s props in
  w8 s 1 0;
  w16 s 2 (Bytes.length s / 4);
  w32 s 4 wid;
  w32 s 8 prop;
  w32 s 12 typ;
  w8 s 16 format;
  let ful = Bytes.length props / (match format with
    | 8 -> 1
    | 16 -> 2
    | 32 -> 4
    | n -> error "no idea what %d means" n)
  in
  w32 s 20 ful;
  s;
;;

let getpropreq delete wid prop typ =
  let s = makereq 20 24 6 in
  w8 s 1 (if delete then 1 else 0);
  w32 s 4 wid;
  w32 s 8 prop;
  w32 s 12 typ;
  w32 s 16 0;
  w32 s 20 2;
  s;
;;

let configurewindowreq wid mask values =
  let s = makereq 12 12 0 in
  let s = padcat s values in
  w16 s 2 (Bytes.length s / 4);
  w32 s 4 wid;
  w16 s 8 mask;
  s;
;;

let s32 n =
  let s = Bytes.create 4 in
  w32 s 0 n;
  s;
;;

let clientmessage format seq wid typ data =
  let s = makereq 33 12 0 in
  let s = padcat s data in
  w8 s 1 format;
  w16 s 2 seq;
  w32 s 4 wid;
  w32 s 8 typ;
  s;
;;

let sendeventreq propagate destwid mask data =
  let s = makereq 25 12 11 in
  let s = padcat s data in
  w8 s 1 propagate;
  w16 s 2 11;
  w32 s 4 destwid;
  w32 s 8 mask;
  s;
;;

let getmodifiermappingreq () =
  makereq 119 4 1;
;;

let queryextensionreq name =
  let s = makereq 98 8 0 in
  let s = padcat s name in
  w16 s 2 (Bytes.length s / 4);
  w16 s 4 (Bytes.length name);
  s;
;;

let getkeysym pkpk code mask =
  if (pkpk >= 0xff80 && pkpk <= 0xffbd)
     || (pkpk >= 0x11000000 && pkpk <= 0x1100ffff)
  then (
    if mask land state.numlmask != 0
    then
      let keysym = state.keymap.(code-state.mink).(1) in
      if keysym = 0 then pkpk else keysym
    else pkpk
  )
  else (
    let shift =
      if pkpk land 0xf000 = 0xf000
      then 0
      else (mask land 1) lxor ((mask land state.capslmask) lsr 1)
    in
    let index =
      if state.xkb && mask land 0x2000 != 0
      then
        shift + 2
      else
        let l3 = (mask land state.levl3mask) != 0 in
        let l4 = (mask land state.levl5mask) != 0 in
        shift +
          if l3 then (if l4 then 8 else 4) else (if l4 then 6 else 0)
    in
    let keysym = state.keymap.(code-state.mink).(index) in
    if index land 1 = 1 && keysym = 0
    then state.keymap.(code-state.mink).(index - 1)
    else keysym
  )
;;

let getkeysym code mask =
  let pkpk = state.keymap.(code-state.mink).(0) in
  if state.xkb && pkpk lsr 8 = 0xfe (* XKB *)
  then 0
  else getkeysym pkpk code mask
;;

let readresp sock =
  let resp = readstr sock 32 in
  let opcode = r8 resp 0 in
  match opcode land lnot 0x80 with
  | 0 ->                                (* error *)
      let s = resp in
      let code = r8 s 1
      and serial = r16 s 2
      and resid = r32 resp 4
      and min = r16 s 8
      and maj = r8 s 10 in
      error "code=%d serial=%d resid=%#x min=%d maj=%d\n%S"
        code serial resid min maj (Bytes.unsafe_to_string resp);

  | 1 ->                                (* response *)
      let rep = Queue.pop state.fifo in
      rep resp;

  | 2 ->                                (* key press *)
      if Array.length state.keymap > 0
      then
        let code = r8 resp 1 in
        let mask = r16 resp 28 in
        let keysym = getkeysym code mask in
        vlog "keysym = %x %c mask %#x code %d"
          keysym (Char.unsafe_chr keysym) mask code;
        state.t#key keysym mask;

  | 3 ->                                (* key release *)
      if Array.length state.keymap > 0
      then
        let code = r8 resp 1 in
        let mask = r16 resp 28 in
        let keysym = getkeysym code mask in
        vlog "release keysym = %x %c mask %#x code %#d"
          keysym (Char.unsafe_chr keysym) mask code

  | 4 ->                                (* buttonpress *)
      let n = r8 resp 1
      and x = r16s resp 24
      and y = r16s resp 26
      and m = r16 resp 28 in
      state.t#mouse n true x y m;
      vlog "press %d" n

  | 5 ->                                (* buttonrelease *)
      let n = r8 resp 1
      and x = r16s resp 24
      and y = r16s resp 26
      and m = r16 resp 28 in
      state.t#mouse n false x y m;
      vlog "release %d %d %d" n x y

  | 6 ->                                (* motion *)
      let x = r16s resp 24 in
      let y = r16s resp 26 in
      let m = r16 resp 28 in
      if m land 0x1f00 = 0
      then state.t#pmotion x y
      else state.t#motion x y;
      vlog "move %dx%d => %d" x y m

  | 7 ->                                (* enter *)
      let x = r16s resp 24
      and y = r16s resp 26 in
      state.t#enter x y;
      vlog "enter %d %d" x y

  | 8 ->                                (* leave *)
      state.t#leave

  | 18 ->                               (* unmap *)
      state.t#map false;
      vlog "unmap";

  | 19 ->                               (* map *)
      state.t#map true;
      vlog "map";

  | 12 ->                               (* exposure *)
      vlog "exposure";
      state.t#expose

  | 15 ->                               (* visibility *)
      let v = r8 resp 8 in
      let vis =
        match v with
        | 0 -> Unobscured
        | 1 -> PartiallyObscured
        | 2 -> FullyObscured
        | _ ->
            dolog "unknown visibility %d" v;
            Unobscured
      in
      state.t#visible vis;
      vlog "visibility %d" v;

  | 34 ->                               (* mapping *)
      state.keymap <- E.a;
      let s = getkeymapreq state.mink (state.maxk-state.mink-1) in
      sendwithrep sock s (updkmap sock);
      state.capslmask <- 0;
      state.levl3mask <- 0;
      state.levl5mask <- 0;
      state.numlmask  <- 0;
      let s = getmodifiermappingreq () in
      sendwithrep sock s (updmodmap sock);

  | 33 ->                               (* clientmessage *)
      let atom = r32 resp 8 in
      if atom = state.protoatom
      then (
        let atom = r32 resp 12 in
        if atom = state.deleatom
        then state.t#quit
      );
      vlog "atom %#x" atom

  | 21 ->                               (* reparent *)
      vlog "reparent"

  | 22 ->                               (* configure *)
      let x = r16s resp 16
      and y = r16s resp 18
      and w = r16 resp 20
      and h = r16 resp 22 in
      vlog "configure cur [%d %d %d %d] conf [%d %d %d %d]"
        state.x state.y state.w state.h
        x y w h
      ;
      if w != state.w || h != state.h
      then (
        state.t#reshape w h;
      );
      state.w <- w;
      state.h <- h;
      state.x <- x;
      state.y <- y;
      state.t#expose

  | 28 ->
      let atom = r32 resp 8 in
      if atom = state.nwmsatom
      then
        let s = getpropreq false state.wid atom 4 in
        sendwithrep sock s (fun resp ->
          let len = r32 resp 4 in
          let nitems = r32 resp 16 in
          let wsl =
            if len = 0
            then []
            else
              let s = readstr sock (len*4) in
              let rec loop wsl i = if i = nitems then wsl else
                  let atom = r32 s (i*4) in
                  let wsl =
                    if atom = state.maxhatom
                    then MaxHorz::wsl
                    else (
                      if atom = state.maxvatom
                      then MaxVert::wsl
                      else (
                        if atom = state.fulsatom
                        then (
                          state.fs <- Fs (state.x, state.y, state.w, state.h);
                          Fullscreen::wsl
                        )
                        else wsl
                      )
                    )
                  in loop wsl (i+1)
              in
              loop [] 0
          in
          state.t#winstate (List.sort compare wsl)
        );

  | n ->
      dolog "event %d %S" n (Bytes.unsafe_to_string resp)
;;

let readresp sock =
  let rec loop () =
    readresp sock;
    if hasdata sock then loop ();
  in
  loop ();
;;

let sendstr s ?(pos=0) ?(len=Bytes.length s) sock =
  sendstr1 s pos len sock;
  if hasdata sock then readresp sock;
;;

let reshape w h =
  if state.fs = NoFs
  then
    let s = Bytes.create 8 in
    w32 s 0 w;
    w32 s 4 h;
    let s = configurewindowreq state.wid 0x000c s in
    sendstr s state.sock;
  else state.fullscreen state.wid
;;

let activatewin () =
  state.actwin ();
;;

let syncsendwithrep sock secstowait s f =
  let completed = ref false in
  sendwithrep sock s (fun resp -> f resp; completed := true);
  let now = Unix.gettimeofday in
  let deadline = now () +. secstowait in
  let rec readtillcompletion () =
    let sf deadline =
      let timeout = deadline -. now () in
      if timeout <= 0.0
      then [], [], []
      else Unix.select [sock] [] [] timeout
    in
    let r, _, _ = tempfailureretry sf deadline in
    match r with
    | [] -> error "didn't get X response in %f seconds, aborting" secstowait
    | _ ->
        readresp sock;
        if not !completed
        then readtillcompletion ()
  in
  readtillcompletion ();
;;

let mapwin () =
  let s = mapreq state.wid in
  sendstr s state.sock;
;;

let syncsendintern sock secstowait s onlyifexists f =
  let s = internreq s onlyifexists in
  syncsendwithrep sock secstowait s f;
;;

let setup disp sock rootwid screennum w h =
  let s = readstr sock 2 in
  let n = Bytes.length s in
  if n != 2
  then error "failed to read X connection setup response n=%d" n;
  match Bytes.get s 0 with
  | '\000' ->
      let reasonlen = r8 s 1 in
      let s = readstr sock 6 in
      let maj = r16 s 0
      and min = r16 s 2
      and add = r16 s 4 in
      let len = add*4 in
      let data = readstr sock len in
      let reason = Bytes.sub data 0 reasonlen in
      error "X connection failed maj=%d min=%d reason=%S"
        maj min (Bytes.unsafe_to_string reason)

  | '\002' -> failwith "X connection setup failed: authentication required";

  | '\001' ->
      let s       = readstr sock 38 in
      let maj     = r16 s 0
      and min     = r16 s 2
      and add     = r16 s 4
      and idbase  = r32 s 10
      and idmask  = r32 s 14
      and vlen    = r16 s 22
      and screens = r8 s 26
      and formats = r8 s 27
      and minkk   = r8 s 32
      and maxkk   = r8 s 33 in
      let data = readstr sock (4*add-32) in
      let vendor = Bytes.sub data 0 vlen in
      let pos = ((vlen+3) land lnot 3) + formats*8 in

      if screennum >= screens
      then error "invalid screen %d, max %d" screennum (screens-1);

      let pos =
        let rec findscreen n pos = if n = screennum then pos else
            let pos =
              let ndepths = r8 data (pos+39) in
              let rec skipdepths n pos = if n = ndepths then pos else
                  let pos =
                    let nvisiuals = r16 data (pos+2) in
                    pos + nvisiuals*24 + 8
                  in
                  skipdepths (n+1) pos
              in
              skipdepths n (pos+40)
            in
            findscreen (n+1) pos
        in
        findscreen 0 pos
      in
      let root = if rootwid = 0 then r32 data pos else rootwid in
      let rootw = r16 data (pos+20)
      and rooth = r16 data (pos+22)
      and rootdepth = r8 data (pos+38)in

      state.mink <- minkk;
      state.maxk <- maxkk;
      state.idbase <- idbase;
      vlog "vendor = %S, maj=%d min=%d" (Bytes.unsafe_to_string vendor) maj min;
      vlog "screens = %d formats = %d" screens formats;
      vlog "minkk = %d maxkk = %d" minkk maxkk;
      vlog "idbase = %#x idmask = %#x" idbase idmask;
      vlog "root=%#x %dx%d" root rootw rooth;
      vlog "wmm = %d, hmm = %d" (r16 data (pos+24)) (r16 data (pos+26));
      vlog "visualid = %#x" (r32 data (pos+32));
      vlog "root depth = %d" rootdepth;

      let wid = state.idbase in
      let mid = wid+1 in
      let fid = mid+1 in

      state.wid <- wid;
      state.fid <- fid;

      let vid = glxinit disp wid screennum in
      let ndepths = r8 data (pos+39) in
      let rec finddepth n' pos =
        if n' = ndepths
        then error "cannot find depth for visual %#x" vid;
        let depth = r8 data pos in
        let nvisuals = r16 data (pos+2) in
        let rec findvisual n pos =
          if n = nvisuals
          then finddepth (n'+1) pos
          else
            let id = r32 data pos in
            if id = vid
            then depth
            else findvisual (n+1) (pos+24)
        in
        findvisual 0 (pos+8)
      in
      let depth = finddepth 0 (pos+40) in

      let s = createcolormapreq mid root vid in
      sendstr s sock;

      let mask = 0
        + 0x00000001                    (* KeyPress *)
        (* + 0x00000002 *)              (* KeyRelease *)
        + 0x00000004                    (* ButtonPress *)
        + 0x00000008                    (* ButtonRelease *)
        + 0x00000010                    (* EnterWindow *)
        + 0x00000020                    (* LeaveWindow *)
        + 0x00000040                    (* PointerMotion *)
        (* + 0x00000080 *)              (* PointerMotionHint *)
        (* + 0x00000100 *)              (* Button1Motion *)
        (* + 0x00000200 *)              (* Button2Motion *)
        (* + 0x00000400 *)              (* Button3Motion *)
        (* + 0x00000800 *)              (* Button4Motion *)
        (* + 0x00001000 *)              (* Button5Motion *)
        + 0x00002000                    (* ButtonMotion *)
        (* + 0x00004000 *)              (* KeymapState *)
        + 0x00008000                    (* Exposure *)
        + 0x00010000                    (* VisibilityChange *)
        + 0x00020000                    (* StructureNotify *)
        (* + 0x00040000 *)              (* ResizeRedirect *)
        (* + 0x00080000 *)              (* SubstructureNotify *)
        (* + 0x00100000 *)              (* SubstructureRedirect *)
        (* + 0x00200000 *)              (* FocusChange *)
        + 0x00400000                    (* PropertyChange *)
        (* + 0x00800000 *)              (* ColormapChange *)
        (* + 0x01000000 *)              (* OwnerGrabButton *)
      in

      let s = createwindowreq wid root 0 0 w h 0 mask vid depth mid in
      sendstr s sock;

      sendintern sock (~> "WM_PROTOCOLS") false (fun resp ->
        state.protoatom <- r32 resp 8;
        sendintern
          sock (~> "WM_DELETE_WINDOW") false (fun resp ->
          state.deleatom <- r32 resp 8;
          let s = s32 state.deleatom in
          let s = changepropreq wid state.protoatom 4 32 s in
          sendstr s sock;
        );
      );

      sendintern sock (~> "WM_CLIENT_MACHINE") false (fun resp ->
        let atom = r32 resp 8 in
        let empty = E.s in
        let hostname =
          try Unix.gethostname ()
          with exn ->
            dolog "error getting host name: %s" @@ exntos exn;
            empty
        in
        if hostname != empty
        then
          let s = changepropreq wid atom state.stringatom 8
              (~> hostname) in
          sendstr s sock;
          sendintern sock (~> "_NET_WM_PID") false (fun resp ->
            let atom = r32 resp 8 in
            let pid = Unix.getpid () in
            let s = s32 pid in
            let s = changepropreq wid atom 6(*cardinal*) 32 s in
            sendstr s sock;
        )
      );

      state.actwin <- (fun () ->
        let s = Bytes.create 4 in
        let s = configurewindowreq wid 0x40 s in
        sendstr s state.sock;
        let s = mapreq wid in
        sendstr s state.sock;
      );

      sendintern sock (~> "_NET_ACTIVE_WINDOW") true (fun resp ->
        let atom = r32 resp 8 in
        state.actwin <- (fun () ->
          let data = Bytes.make 20 '\000' in
          let cm = clientmessage 32 0 wid atom data in
          let s = sendeventreq 0 root 0x180000 cm in
          sendstr s state.sock;
        );
      );

      syncsendintern sock 2.0 (~> "WM_CLASS") false (fun resp ->
        let atom = r32 resp 8 in
        let llpp = ~> "llpp\000llpp\000" in
        let s = changepropreq wid atom 31 8 llpp in
        sendstr s sock;
      );

      let s = getkeymapreq state.mink (state.maxk-state.mink) in
      sendwithrep sock s (updkmap sock);

      let s = getmodifiermappingreq () in
      sendwithrep sock s (updmodmap sock);

      sendintern sock (~> "UTF8_STRING") true (fun resp ->
        let atom = r32 resp 8 in
        if atom != 0
        then state.stringatom <- atom;
      );

      let setwmname s =
        let s = changepropreq wid 39 state.stringatom 8 s in
        sendstr s state.sock;
      in
      state.setwmname <- setwmname;
      sendintern sock (~> "_NET_WM_NAME") true (fun resp ->
        let atom = r32 resp 8 in
        if atom != 0
        then state.setwmname <- (fun s ->
          setwmname s;
          let s = changepropreq wid atom state.stringatom 8 s in
          sendstr s state.sock;
        );
      );

      state.fullscreen <- (fun wid ->
        let s = Bytes.create 16 in
        match state.fs with
        | NoFs ->
            w32 s 0 0;
            w32 s 4 0;
            w32 s 8 rootw;
            w32 s 12 rooth;
            let s = configurewindowreq wid 0x000f s in
            sendstr s state.sock;
            state.fs <- Fs (state.x, state.y, state.w, state.h);

        | Fs (x, y, w, h) ->
            w32 s 0 x;
            w32 s 4 y;
            w32 s 8 w;
            w32 s 12 h;
            let s = configurewindowreq wid 0x000f s in
            sendstr s state.sock;
            state.fs <- NoFs;
      );

      sendintern sock (~> "_NET_WM_STATE") true (fun resp ->
        state.nwmsatom <- r32 resp 8;
        if state.nwmsatom != 0
        then (
          sendintern sock (~> "_NET_WM_STATE_MAXIMIZED_VERT") true (fun resp ->
            state.maxvatom <- r32 resp 8;
          );
          sendintern sock (~> "_NET_WM_STATE_MAXIMIZED_HORZ") true (fun resp ->
            state.maxhatom <- r32 resp 8;
          );
          sendintern sock (~> "_NET_WM_STATE_FULLSCREEN") true (fun resp ->
            state.fulsatom <- r32 resp 8;
            if state.fulsatom != 0
            then
              state.fullscreen <-
                (fun wid ->
                  let data = Bytes.make 20 '\000' in
                  let fs, f =
                    match state.fs with
                    | NoFs -> Fs (-1, -1, -1, -1), 1
                    | Fs _ -> NoFs, 0
                  in
                  w32 data 0 f;
                  w32 data 4 state.fulsatom;

                  let cm = clientmessage 32 0 wid state.nwmsatom data in
                  let s = sendeventreq 0 root 0x180000 cm in
                  sendstr s sock;
                  state.fs <- fs;
                );
          );
        );
      );
      let s = queryextensionreq (~> "XKEYBOARD") in
      sendwithrep
        sock s (fun resp ->
                let present = r8 resp 8 in
                if present != 0
                then (
                  let maj = r8 resp 9 in
                  let s = Bytes.create 8 in
                  w8 s 0 maj;   (* XKB *)
                  w8 s 1 0;     (* XKBUseExtension *)
                  w16 s 2 2;    (* request-length *)
                  w16 s 4 1;    (* wantedMajor *)
                  w16 s 6 0;    (* watnedMinor *)
                  sendwithrep
                    sock s
                    (fun resp ->
                     let supported = r8 resp 1 in
                     state.xkb <- supported != 0
                    )
                );
               );
      let s = getgeometryreq wid in
      syncsendwithrep sock 2.0 s (fun resp ->
        glxcompleteinit ();
        let w = r16 resp 16
        and h = r16 resp 18 in
        state.w <- w;
        state.h <- h;
      );

  | c ->
      error "unknown conection setup response %d" (Char.code c)
;;

let getauth haddr dnum =
  let haddr =
    if emptystr haddr || haddr = "localhost"
    then
      try Unix.gethostname ()
      with exn ->
        dolog "failed to resolve `%S': %s" haddr @@ exntos exn;
        haddr
    else haddr
  in
  let path =
    try Sys.getenv "XAUTHORITY"
    with Not_found ->
      try Filename.concat (Sys.getenv "HOME") ".Xauthority"
      with Not_found -> E.s
  in
  let readauth ic =
    let r16be s =
      let rb pos = Char.code (Bytes.get s pos) in
      (rb 1) lor ((rb 0) lsl 8)
    in
    let rec find () =
      let rs () =
        let s = really_input_string ic 2 in
        let n = r16be (~> s) in
        really_input_string ic n
      in
      let family = really_input_string ic 2 in
      let addr = rs () in
      let nums = rs () in
      let optnum =
        try Some (int_of_string nums)
        with exn ->
          dolog
            "display number(%S) is not an integer (corrupt %S?): %s"
            nums path @@ exntos exn;
          None
      in
      let name = rs () in
      let data = rs () in

      vlog "family %S addr %S(%S) num %S(%d) name %S data %S"
        family addr haddr nums dnum name data;
      match optnum with
      | Some num when addr = haddr && num = dnum ->
          name, data
      | _ -> find ()
    in
    let name, data =
      try find ()
      with
      | End_of_file -> E.s, E.s
      | exn ->
        dolog "exception while reading X authority data (%S): %s"
          path @@ exntos exn;
        E.s, E.s
    in
    close_in ic;
    name, data;
  in
  if emptystr path
  then E.s, E.s
  else
    match open_in_bin path with
    | ic -> readauth ic
    | (exception exn) ->
       dolog "failed to open X authority file `%S' : %s" path @@ exntos exn;
       E.s, E.s
;;

let init t rootwid w h platform =
  let d =
    try Sys.getenv "DISPLAY"
    with exn ->
      error "cannot get DISPLAY evironment variable: %s" @@ exntos exn
  in
  let getnum w b e =
    if b = e
    then error "invalid DISPLAY(%s) %S" w d
    else
      let s = String.sub d b (e - b) in
      try int_of_string s
      with exn ->
        error "invalid DISPLAY %S can not parse %s(%S): %s"
          d w s @@ exntos exn
  in
  let rec phost pos =
    if pos = String.length d
    then error "invalid DISPLAY %S no display number specified" d
    else (
      if d.[pos] = ':'
      then
        let rec pdispnum pos1 =
          if pos1 = String.length d
          then getnum "display number" (pos+1) pos1, 0
          else
            match d.[pos1] with
            | '.' ->
                let dispnum = getnum "display number" (pos+1) pos1 in
                let rec pscreennum pos2 =
                  if pos2 = String.length d
                  then getnum "screen number" (pos1+1) pos2
                  else
                    match d.[pos2] with
                    | '0' .. '9' -> pscreennum (pos2+1)
                    | _ ->
                        error "invalid DISPLAY %S, cannot parse screen number" d
                in
                dispnum, pscreennum (pos1+1)
            | '0' .. '9' -> pdispnum (pos1+1)
            | _ ->
                error "invalid DISPLAY %S, cannot parse display number" d
        in
        String.sub d 0 pos, pdispnum (pos+1)
      else phost (pos+1)
    )
  in
  let host, (dispnum, screennum) = phost 0 in
  let aname, adata = getauth host dispnum in
  let fd =
    let fd, addr =
      if emptystr host || host.[0] = '/' || host = "unix"
      then
        let addr =
          match platform with
          | Utils.Posx -> Unix.ADDR_UNIX d
          | Utils.Plinux ->
             Unix.ADDR_UNIX ("\000/tmp/.X11-unix/X" ^ string_of_int dispnum)
          | Utils.Punknown | Utils.Psun | Utils.Pbsd | Utils.Pcygwin ->
             Unix.ADDR_UNIX ("/tmp/.X11-unix/X" ^ string_of_int dispnum)
        in
        Unix.socket Unix.PF_UNIX Unix.SOCK_STREAM 0, addr
      else
        let h =
          try Unix.gethostbyname host
          with exn -> error "cannot resolve %S: %s" host @@ exntos exn
        in
        let addr = h.Unix.h_addr_list.(0) in
        let port = 6000 + dispnum in
        let fd = Unix.socket Unix.PF_INET Unix.SOCK_STREAM 0 in
        fd, (Unix.ADDR_INET (addr, port))
    in
    try Unix.connect fd addr; fd
    with exn -> error "failed to connect to X: %s" @@ exntos exn
  in
  cloexec fd;
  let s = Bytes.create 12 in
  let s = padcat s (~> aname) in
  let s = padcat s (~> adata) in
  Bytes.set s 0 ordermagic;
  w16 s 2 11;
  w16 s 4 0;
  w16 s 6 (String.length aname);
  w16 s 8 (String.length adata);
  sendstr1 s 0 (Bytes.length s) fd;
  state.sock <- fd;
  setup d fd rootwid screennum w h;
  state.t <- t;
  fd, state.w, state.h;
;;

let settitle s =
  state.setwmname (~> s);
;;

let setcursor cursor =
  if cursor != state.curcurs
  then (
    setcursor cursor;
    state.curcurs <- cursor;
   )
;;

let fullscreen () =
  state.fullscreen state.wid;
;;

let metamask = 0x40;;
let altmask = 8;;
let shiftmask = 1;;
let ctrlmask = 4;;

let withalt mask = mask land altmask != 0;;
let withctrl mask = mask land ctrlmask != 0;;
let withshift mask = mask land shiftmask != 0;;
let withmeta mask = mask land metamask != 0;;
let withnone mask = mask land (altmask + ctrlmask + shiftmask + metamask) = 0;;

let xlatt, xlatf =
  let t = Hashtbl.create 20
  and f = Hashtbl.create 20 in
  let add n nl k =
    List.iter (fun s -> Hashtbl.add t s k) (n::nl);
    Hashtbl.add f k n
  in
  let addc c =
    let s = String.make 1 c in
    add s [] (Char.code c)
  in
  let addcr a b =
    let an = Char.code a and bn = Char.code b in
    for i = an to bn do addc (Char.chr i) done;
  in
  addcr '0' '9';
  addcr 'a' 'z';
  addcr 'A' 'Z';
  String.iter addc "`~!@#$%^&*()-_=+\\|[{]};:,./<>?";
  for i = 0 to 29 do add ("f" ^ string_of_int (i+1)) [] (0xffbe + i) done;
  add "space" [] 0x20;
  add "ret" ["return"; "enter"] 0xff0d;
  add "tab" [] 0xff09;
  add "left" [] 0xff51;
  add "right" [] 0xff53;
  add "home" [] 0xff50;
  add "end" [] 0xff57;
  add "ins" ["insert"] 0xff63;
  add "del" ["delete"] 0xffff;
  add "esc" ["escape"] 0xff1b;
  add "pgup" ["pageup"] 0xff55;
  add "pgdown" ["pagedown"] 0xff56;
  add "backspace" [] 0xff08;
  add "up" [] 0xff52;
  add "down" [] 0xff54;
  add "menu" [] 0xff67;
  t, f;
;;

let keyname k =
  try Hashtbl.find xlatf k
  with Not_found -> Printf.sprintf "%#x" k;
;;

let namekey name =
  try Hashtbl.find xlatt name
  with Not_found ->
    if String.length name = 1
    then Char.code name.[0]
    else int_of_string name;
;;

let keypadtodigitkey key =
  if key >= 0xffb0 && key <= 0xffb9 (* keypad numbers *)
  then key - 0xffb0 + 48 else key
;;

let isspecialkey key =
  key land 0xff00 = 0xff00      (* keyboard *)
  || key land 0xfe00 = 0xfe00   (* xkb *)
  || key land 0xfd00 = 0xfd00   (* 3270 *)
;;

let fontsizefactor () = 1