(* Guestfs Browser.
 * Copyright (C) 2010 Red Hat Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *)

open Printf

open Utils

module G = Guestfs

(* Main window state. *)
type window_state = {
  window : GWindow.window;
  view : Filetree.t;
  vmcombo : GEdit.combo_box GEdit.text_combo;
  throbber : GMisc.image;
  throbber_static : GdkPixbuf.pixbuf;
  statusbar : GMisc.statusbar;
  statusbar_context : GMisc.statusbar_context;
  progress_bar : GRange.progress_bar;
}

(* Set the statusbar text. *)
let set_statusbar ws msg =
  ws.statusbar_context#pop ();
  ignore (ws.statusbar_context#push msg)

let clear_statusbar ws = set_statusbar ws ""

(* Clear the filetree. *)
let clear_view ws =
  Filetree.clear ws.view

(* Callback from Connect -> ... menu items. *)
let rec connect_to ws uri =
  (match uri with
   | None -> set_statusbar ws "Connecting to default libvirt ..."
   | Some uri -> set_statusbar ws (sprintf "Connecting to %s ..." uri)
  );
  clear_view ws;
  Slave.discard_command_queue ();
  Slave.connect uri (when_connected ws uri)

(* Called back when connected to a new hypervisor. *)
and when_connected ws uri doms =
  (match uri with
   | None -> set_statusbar ws "Connected to default libvirt"
   | Some uri -> set_statusbar ws (sprintf "Connected to %s" uri)
  );
  (* Populate the VM combo box. *)
  let combo, (model, column) = ws.vmcombo in
  model#clear ();
  List.iter (
    fun { Slave.dom_name = name } ->
      let row = model#append () in
      model#set ~row ~column name
  ) doms

(* When a new domain is selected by the user, eg through vmcombo. *)
let rec open_domain ws name =
  set_statusbar ws (sprintf "Opening %s ..." name);
  clear_view ws;
  Slave.discard_command_queue ();
  Slave.open_domain name (when_opened_domain ws name)

(* Called back when domain was opened successfully. *)
and when_opened_domain ws name data =
  debug "when_opened_domain callback";
  set_statusbar ws (sprintf "Opened %s" name);
  when_opened_common ws name data

(* When a set of disk images is selected by the user. *)
and open_disk_images ws images =
  match images with
  | [] -> ()
  | images ->
      set_statusbar ws (sprintf "Opening disk image %s ..."
                          (String.concat " " images));
      clear_view ws;
      Slave.discard_command_queue ();
      Slave.open_images images (when_opened_disk_images ws images)

(* Called back when disk image(s) were opened successfully. *)
and when_opened_disk_images ws images data =
  match images with
  | [] -> ()
  | image :: _ as images ->
      debug "when_opened_disk_images callback";
      set_statusbar ws (sprintf "Opened disk image %s"
                          (String.concat " " images));
      when_opened_common ws image data

(* Common code for when_opened_domain/when_opened_disk_images. *)
and when_opened_common ws name data =
  (* Dump some of the inspection data in debug messages. *)
  List.iter (fun (dev, t) -> debug "filesystem: %s: %s" dev t)
    data.Slave.insp_all_filesystems;
  List.iter (
    fun { Slave.insp_root = root; insp_type = typ; insp_distro = distro;
          insp_major_version = major; insp_minor_version = minor } ->
      debug "root device %s contains %s %s %d.%d" root typ distro major minor;
  ) data.Slave.insp_oses;

  Filetree.add ws.view name data

let throbber_busy ws () =
  (*throbber#set_pixbuf animation*)
  (* XXX Workaround because no binding for GdkPixbufAnimation: *)
  let file = Filename.dirname Sys.argv.(0) // "Throbber.gif" in
  ws.throbber#set_file file

let throbber_idle ws () =
  ws.throbber#set_pixbuf ws.throbber_static

(* This is called in the main thread whenever a command fails in the
 * slave thread.  The command queue has been cleared before this is
 * called, so our job here is to reset the main window, and if
 * necessary to turn the exception into an error message.
 *)
let failure ws exn =
  let title = "Error" in
  let msg = Printexc.to_string exn in
  debug "failure hook: %s" msg;
  let icon = GMisc.image () in
  icon#set_stock `DIALOG_ERROR;
  icon#set_icon_size `DIALOG;
  GToolbox.message_box ~title ~icon msg

let rec open_main_window () =
  (* I prototyped the basic window layout using Glade, but have
   * implemented it by hand to give us more flexibility.
   *)
  let title = "Guest Filesystem Browser" in
  let window = GWindow.window ~width:700 ~height:700 ~title () in
  let vbox = GPack.vbox ~packing:window#add () in

  (* Menus. *)
  let connect_kvm_item, connect_xen_item, connect_none_item, _, _ =
    make_menubar window vbox ~packing:vbox#pack () in

  (* Top toolbar. *)
  let vmcombo, throbber, throbber_static =
    make_toolbar ~packing:vbox#pack () in

  (* Main part of display is the file tree. *)
  let view = make_filetree ~packing:(vbox#pack ~expand:true ~fill:true) () in

  (* Status bar and progress bar. *)
  let hbox = GPack.hbox ~packing:vbox#pack () in
  let progress_bar = GRange.progress_bar ~packing:hbox#pack () in
  let statusbar = GMisc.statusbar ~packing:(hbox#pack ~expand:true) () in
  let statusbar_context = statusbar#new_context ~name:"Standard" in
  ignore (statusbar_context#push title);

  window#show ();

  (* Construct the window_state struct. *)
  let ws = {
    window = window;
    view = view;
    vmcombo = vmcombo;
    throbber = throbber; throbber_static = throbber_static;
    statusbar = statusbar; statusbar_context = statusbar_context;
    progress_bar = progress_bar
  } in

  (* Connect up the callback for menu entries etc.  These require the
   * window_state struct in callbacks.
   *)

  (* Connect to different hypervisors. *)
  ignore (connect_kvm_item#connect#activate
            ~callback:(fun () -> connect_to ws (Some "qemu:///system")));
  ignore (connect_xen_item#connect#activate
            ~callback:(fun () -> connect_to ws (Some "xen:///")));
  ignore (connect_none_item#connect#activate
            ~callback:(fun () -> connect_to ws None));

  (* VM combo box when changed by the user. *)
  let combo, (model, column) = ws.vmcombo in
  ignore (
    combo#connect#changed
      ~callback:(
        fun () ->
          match combo#active_iter with
          | None -> () (* nothing selected *)
          | Some row -> open_domain ws (model#get ~row ~column)
      )
  );

  ws

and make_menubar window vbox ~packing () =
  let menubar = GMenu.menu_bar ~packing:vbox#pack () in
  let factory = new GMenu.factory menubar in
  let accel_group = factory#accel_group in
  let connect_menu = factory#add_submenu "_Connect" in

  let factory = new GMenu.factory connect_menu ~accel_group in
  let connect_kvm_item = factory#add_item "Connect to local _KVM hypervisor" in
  let connect_xen_item = factory#add_item "Connect to local _Xen hypervisor" in
  let connect_none_item = factory#add_item "_Connect to default hypervisor" in
  let connect_uri_item = factory#add_item "Connect to a _libvirt URI ..." in
  ignore (factory#add_separator ());
  let open_image_item =
    factory#add_item "_Open disk image ..." ~key:GdkKeysyms._O in
  ignore (factory#add_separator ());
  let quit_item = factory#add_item "E_xit" ~key:GdkKeysyms._Q in

  (* Quit. *)
  let quit _ = GMain.quit (); false in
  ignore (window#connect#destroy ~callback:GMain.quit);
  ignore (window#event#connect#delete ~callback:quit);
  ignore (quit_item#connect#activate
            ~callback:(fun () -> ignore (quit ()); ()));

  window#add_accel_group accel_group;

  connect_kvm_item, connect_xen_item, connect_none_item,
  connect_uri_item, open_image_item

(* Top toolbar.  In fact, not a toolbar because you don't seem to be
 * able to put a combo box into a toolbar, so it's just an hbox for now.
 *)
and make_toolbar ~packing () =
  let hbox = GPack.hbox ~border_width:4 ~packing () in

  (* Combo box for displaying virtual machine names. *)
  hbox#pack (mklabel "Guest: ");
  let vmcombo = GEdit.combo_box_text ~packing:hbox#pack () in

  (* Throbber. *)
  let static = Throbber.static () in
  (*let animation = Throbber.animation () in*)
  let throbber =
    GMisc.image ~pixbuf:static ~packing:(hbox#pack ~from:`END) () in

  vmcombo, throbber, static

and make_filetree ~packing () =
  let sw =
    GBin.scrolled_window ~packing ~hpolicy:`AUTOMATIC ~vpolicy:`ALWAYS () in
  Filetree.create ~packing:sw#add ()