(* 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
open Slave_types

module G = Guestfs

type connect_menu = {
  connect_menu : GMenu.menu;
  connect_kvm_item : GMenu.menu_item;
  connect_xen_item : GMenu.menu_item;
  connect_none_item : GMenu.menu_item;
  connect_uri_item : GMenu.menu_item;
  open_disk_item : GMenu.menu_item;
  reopen_item : GMenu.menu_item;
  quit_item : GMenu.menu_item;
}

type guest_menu = {
  guest_menu : GMenu.menu;
  guest_inspection_item : GMenu.menu_item;
}

type help_menu = {
  help_menu : GMenu.menu;
  about_item : GMenu.menu_item;
}

class window =
  (* Window. *)
  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 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 =
    let menu = factory#add_submenu "_Connect" in
    let factory = new GMenu.factory menu ~accel_group in
    let kvm = factory#add_item "Connect to local _KVM hypervisor" in
    let xen = factory#add_item "Connect to local _Xen hypervisor" in
    let none = factory#add_item "_Connect to default hypervisor" in
    let uri = factory#add_item "Connect to a _libvirt URI ..." in
    ignore (factory#add_separator ());
    let opend = factory#add_item "_Open disk image ..." ~key:GdkKeysyms._O in
    ignore (factory#add_separator ());
    let reopen = factory#add_item "Reopen current guest" in
    ignore (factory#add_separator ());
    let quit = factory#add_item "E_xit" ~key:GdkKeysyms._Q in
    { connect_menu = menu; connect_kvm_item = kvm;
      connect_xen_item = xen; connect_none_item = none;
      connect_uri_item = uri;
      open_disk_item = opend; reopen_item = reopen; quit_item = quit } in

  let guest_menu =
    let menu = factory#add_submenu "_Guest" in
    let factory = new GMenu.factory menu ~accel_group in
    let inspection = factory#add_item "Operating system information ..." in
    { guest_menu = menu; guest_inspection_item = inspection } in

  let help_menu =
    let menu = factory#add_submenu "_Help" in
    let factory = new GMenu.factory menu ~accel_group in
    let about = factory#add_item "About guest filesystem browser ..." in
    { help_menu = menu; about_item = about } in

  (* Top toolbar. *)
  let hbox =
    let hbox = GPack.hbox ~border_width:4 ~packing:vbox#pack () in
    hbox#pack (mklabel "Guest: ");
    hbox in

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

  (* Refresh button.
   * http://stackoverflow.com/questions/2188659/stock-icons-not-shown-on-buttons
   *)
  let refresh_button =
    let image = GMisc.image ~stock:`REFRESH () in
    let b = GButton.button ~packing:hbox#pack () in
    b#set_image (image :> GObj.widget);
    b in

  (* Throbber. *)
  let throbber_static = Throbber.static () in
  let throbber_animation = Throbber.animation () in
  let throbber =
    (* Workaround for http://caml.inria.fr/mantis/view.php?id=4732 *)
    let from = Obj.magic 3448763 (* `END *) in
    GMisc.image ~pixbuf:throbber_static ~packing:(hbox#pack ~from) () in

  (* Main part of display is the file tree. *)
  (* Create the filetree inside a scrolled window. *)
  let sw = GBin.scrolled_window
    ~hpolicy:`AUTOMATIC ~vpolicy:`ALWAYS
    ~packing:(vbox#pack ~expand:true ~fill:true) () in
  let tree = new Filetree.tree ~packing:sw#add () in

  (* Status bar and progress bar at the bottom. *)
  let hbox = GPack.hbox ~spacing:4 ~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

  (* Signals. *)
  let connect_kvm_signal = new GUtil.signal () in
  let connect_xen_signal = new GUtil.signal () in
  let connect_none_signal = new GUtil.signal () in
  let connect_uri_signal = new GUtil.signal () in
  let open_disk_signal = new GUtil.signal () in
  let reopen_signal = new GUtil.signal () in
  let inspection_signal = new GUtil.signal () in
  let about_signal = new GUtil.signal () in

object (self)
  inherit GUtil.ml_signals [connect_kvm_signal#disconnect;
                            connect_xen_signal#disconnect;
                            connect_none_signal#disconnect;
                            connect_uri_signal#disconnect;
                            open_disk_signal#disconnect;
                            reopen_signal#disconnect;
                            inspection_signal#disconnect;
                            about_signal#disconnect]

  method connect_kvm_signal = connect_kvm_signal#connect ~after
  method connect_xen_signal = connect_xen_signal#connect ~after
  method connect_none_signal = connect_none_signal#connect ~after
  method connect_uri_signal = connect_uri_signal#connect ~after
  method open_disk_signal = open_disk_signal#connect ~after
  method reopen_signal = reopen_signal#connect ~after
  method inspection_signal = inspection_signal#connect ~after
  method about_signal = about_signal#connect ~after

  initializer
    ignore (statusbar_context#push title);
    window#show ();

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

    (* Accel_group. *)
    window#add_accel_group accel_group;

    (* Menu entries emit signals. *)
    ignore (connect_menu.connect_kvm_item#connect#activate
              ~callback:connect_kvm_signal#call);
    ignore (connect_menu.connect_xen_item#connect#activate
              ~callback:connect_xen_signal#call);
    ignore (connect_menu.connect_none_item#connect#activate
              ~callback:connect_none_signal#call);
    ignore (connect_menu.connect_uri_item#connect#activate
              ~callback:connect_uri_signal#call);
    ignore (connect_menu.open_disk_item#connect#activate
              ~callback:open_disk_signal#call);
    ignore (connect_menu.reopen_item#connect#activate
              ~callback:reopen_signal#call);
    ignore (guest_menu.guest_inspection_item#connect#activate
              ~callback:inspection_signal#call);
    ignore (help_menu.about_item#connect#activate
              ~callback:about_signal#call);

    (* VM combo box when changed by the user.
     * The refresh button acts like changing the VM combo too.
     *)
    let combo, (model, column) = vmcombo in
    ignore (
      combo#connect#changed
        ~callback:(
          fun () ->
            match combo#active_iter with
            | None -> () (* nothing selected *)
            | Some row -> self#open_domain (model#get ~row ~column)
        )
    );
    ignore (
      refresh_button#connect#clicked
        ~callback:(
          fun () ->
            match combo#active_iter with
            | None -> () (* nothing selected *)
            | Some row -> self#open_domain (model#get ~row ~column)
        )
    )

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

  (* Return the filetree. *)
  method tree = tree

  (* Connect to the given URI. *)
  method connect_to uri () =
    tree#clear ();
    Slave.discard_command_queue ();
    Slave.connect uri (self#when_connected uri)

  (* Called back when connected to a new hypervisor. *)
  method private when_connected uri doms =
    self#populate_vmcombo doms

  (* Populate the VM combo box. *)
  method private populate_vmcombo doms =
    let combo, (model, column) = vmcombo in
    model#clear ();
    List.iter (
      fun { 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. *)
  method private open_domain name =
    tree#clear ();
    Slave.discard_command_queue ();
    Slave.open_domain name (self#when_opened_domain name)

  (* Called back when domain was opened successfully. *)
  method private when_opened_domain name data =
    debug "when_opened_domain callback";
    self#when_opened_common name data

  (* When a set of disk images is selected by the user. *)
  method open_disk_images images =
    match images with
    | [] -> ()
    | images ->
        tree#clear ();
        Slave.discard_command_queue ();
        Slave.open_images images (self#when_opened_disk_images images)

  (* Called back when disk image(s) were opened successfully. *)
  method private when_opened_disk_images images data =
    match images with
    | [] -> ()
    | (image, _) :: _ ->
        debug "when_opened_disk_images callback";
        self#when_opened_common image data

  (* Called to reopen the handle. *)
  method reopen () =
    tree#clear ();
    Slave.discard_command_queue ();
    Slave.reopen self#when_reopened

  method private when_reopened data =
    debug "when_reopened callback";
    self#when_opened_common "Reopened"(*XXX we lost the original name*) data

  (* Common code for when_opened_domain/when_opened_disk_images. *)
  method private when_opened_common name data =
    (* Dump some of the inspection data in debug messages. *)
    List.iter (fun (dev, t) -> debug "filesystem: %s: %s" dev t)
      data.insp_all_filesystems;
    List.iter (
      fun { 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.insp_oses;

    tree#add_os name data

  (* Public callbacks. *)
  method throbber_busy () =
    throbber#set_pixbuf throbber_animation

  method throbber_idle () =
    throbber#set_pixbuf throbber_static

  method progress (position, total) =
    if position = 0L && total = 1L then
      progress_bar#pulse ()
    else (
      let frac = Int64.to_float position /. Int64.to_float total in
      if frac < 0. || frac > 1. then
        eprintf "warning: progress bar out of range: %Ld / %Ld (%g)\n"
          position total frac;
      let frac = if frac < 0. then 0. else if frac > 1. then 1. else frac in
      progress_bar#set_fraction frac
    )

  (* 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.
   *)
  method failure exn =
    let raw_msg = Printexc.to_string exn in
    debug "failure hook: %s" raw_msg;

    let title, msg = pretty_string_of_exn exn in
    let icon = GMisc.image () in
    icon#set_stock `DIALOG_ERROR;
    icon#set_icon_size `DIALOG;
    GToolbox.message_box ~title ~icon msg

  (* Do what the user asked on the command line. *)
  method run_cli_request = function
  | Cmdline.Empty_window -> ()
  | Cmdline.Open_images images ->
      self#open_disk_images images
  | Cmdline.Open_guest guest ->
      (* Open libvirt connection, and in the callback open the guest. *)
      let uri = connect_uri () in
      Slave.connect uri (self#when_connected_cli_request guest)

  method private when_connected_cli_request guest doms =
    self#populate_vmcombo doms;

    (* "guest" should match a domain in "doms".  Check this and
     * get the index of it.
     *)
    let rec loop i = function
      | [] ->
          failwith "guest %s not found (do you need to use --connect?)" guest
      | d::ds when d = guest -> i
      | _::ds -> loop (i+1) ds
    in
    let i = loop 0 (List.map (fun { dom_name = name } -> name) doms) in

    let combo, _ = vmcombo in
    combo#set_active i

end