/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/**
 * Copyright (C) 2020 Jacob Barkdull
 *
 * This program is part of GNOME System Monitor.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
**/


#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <glibtop/procaffinity.h>
#include <sys/stat.h>
#include <glib/gi18n.h>

#include "proctable.h"
#include "procdialogs.h"
#include "util.h"
#include "setaffinity.h"

namespace
{
class SetAffinityData
{
public:
GtkWidget  *dialog;
pid_t pid;
GtkWidget **buttons;
guint32 cpu_count;
gboolean toggle_single_blocked;
gboolean toggle_all_blocked;
};
}

static gboolean
all_toggled (SetAffinityData *affinity)
{
  guint32 i;

  /* Check if any CPU's aren't set for this process */
  for (i = 1; i <= affinity->cpu_count; i++)
    /* If so, return FALSE */
    if (!gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (affinity->buttons[i])))
      return FALSE;

  return TRUE;
}

static void
affinity_toggler_single (GtkToggleButton *button,
                         gpointer         data)
{
  SetAffinityData *affinity = static_cast<SetAffinityData *>(data);
  gboolean toggle_all_state = FALSE;

  /* Return void if toggle single is blocked */
  if (affinity->toggle_single_blocked == TRUE)
    return;

  /* Set toggle all state based on whether all are toggled */
  if (gtk_toggle_button_get_active (button))
    toggle_all_state = all_toggled (affinity);

  /* Block toggle all signal */
  affinity->toggle_all_blocked = TRUE;

  /* Set toggle all check box state */
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (affinity->buttons[0]),
                                toggle_all_state);

  /* Unblock toggle all signal */
  affinity->toggle_all_blocked = FALSE;
}

static void
affinity_toggle_all (GtkToggleButton *toggle_all_button,
                     gpointer         data)
{
  SetAffinityData *affinity = static_cast<SetAffinityData *>(data);

  guint32 i;
  gboolean state;

  /* Return void if toggle all is blocked */
  if (affinity->toggle_all_blocked == TRUE)
    return;

  /* Set individual CPU toggles based on toggle all state */
  state = gtk_toggle_button_get_active (toggle_all_button);

  /* Block toggle single signal */
  affinity->toggle_single_blocked = TRUE;

  /* Set all CPU check boxes to specified state */
  for (i = 1; i <= affinity->cpu_count; i++)
    gtk_toggle_button_set_active (
      GTK_TOGGLE_BUTTON (affinity->buttons[i]),
      state);

  /* Unblock toggle single signal */
  affinity->toggle_single_blocked = FALSE;
}

static void
set_affinity_error (void)
{
  GtkWidget *dialog;

  /* Create error message dialog */
  dialog = gtk_message_dialog_new (GTK_WINDOW (GsmApplication::get ()->main_window),
                                   GTK_DIALOG_DESTROY_WITH_PARENT,
                                   GTK_MESSAGE_ERROR,
                                   GTK_BUTTONS_CLOSE,
                                   "GNU CPU Affinity error: %s",
                                   g_strerror (errno));

  /* Set dialog as modal */
  gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);

  /* Show the dialog */
  gtk_widget_show (dialog);

  /* Connect response signal to GTK widget destroy function */
  g_signal_connect_swapped (dialog,
                            "response",
                            G_CALLBACK (gtk_widget_destroy),
                            dialog);
}

static guint16 *
gsm_set_proc_affinity (glibtop_proc_affinity *buf,
                       GArray                *cpus,
                       pid_t                  pid)
{
#ifdef __linux__
  guint i;
  cpu_set_t set;
  guint16 cpu;

  CPU_ZERO (&set);

  for (i = 0; i < cpus->len; i++)
    {
      cpu = g_array_index (cpus, guint16, i);
      CPU_SET (cpu, &set);
    }

  if (sched_setaffinity (pid, sizeof (set), &set) != -1)
    return glibtop_get_proc_affinity (buf, pid);
#endif

  return NULL;
}

static void
execute_taskset_command (gchar **cpu_list,
                         pid_t   pid)
{
#ifdef __linux__
  gchar *pc;
  gchar *command;

  /* Join CPU number strings by commas for taskset command CPU list */
  pc = g_strjoinv (",", cpu_list);

  /* Construct taskset command */
  command = g_strdup_printf ("taskset -pc %s %d", pc, pid);

  /* Execute taskset command; show error on failure */
  if (!multi_root_check (command))
    set_affinity_error ();

  /* Free memory for taskset command */
  g_free (command);
  g_free (pc);
#endif
}

static void
set_affinity (GtkToggleButton *button,
              gpointer         data)
{
  SetAffinityData *affinity = static_cast<SetAffinityData *>(data);

  glibtop_proc_affinity get_affinity;
  glibtop_proc_affinity set_affinity;

  gchar   **cpu_list;
  GArray   *cpuset;
  guint32 i;
  gint taskset_cpu = 0;

  /* Create string array for taskset command CPU list */
  cpu_list = g_new0 (gchar *, affinity->cpu_count);

  /* Check whether we can get process's current affinity */
  if (glibtop_get_proc_affinity (&get_affinity, affinity->pid) != NULL)
    {
      /* If so, create array for CPU numbers */
      cpuset = g_array_new (FALSE, FALSE, sizeof (guint16));

      /* Run through all CPUs set for this process */
      for (i = 0; i < affinity->cpu_count; i++)
        /* Check if CPU check box button is active */
        if (gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (affinity->buttons[i + 1])))
          {
            /* If so, get its CPU number as 16bit integer */
            guint16 n = i;

            /* Add its CPU for process affinity */
            g_array_append_val (cpuset, n);

            /* Store CPU number as string for taskset command CPU list */
            cpu_list[taskset_cpu] = g_strdup_printf ("%i", i);
            taskset_cpu++;
          }

      /* Set process affinity; Show message dialog upon error */
      if (gsm_set_proc_affinity (&set_affinity, cpuset, affinity->pid) == NULL)
        {
          /* If so, check whether an access error occurred */
          if (errno == EPERM or errno == EACCES)
            /* If so, attempt to run taskset as root, show error on failure */
            execute_taskset_command (cpu_list, affinity->pid);
          else
            /* If not, show error immediately */
            set_affinity_error ();
        }

      /* Free memory for CPU strings */
      for (i = 0; i < affinity->cpu_count; i++)
        g_free (cpu_list[i]);

      /* Free CPU array memory */
      g_array_free (cpuset, TRUE);
    }
  else
    {
      /* If not, show error message dialog */
      set_affinity_error ();
    }

  /* Destroy dialog window */
  gtk_widget_destroy (affinity->dialog);
}

static void
create_single_set_affinity_dialog (GtkTreeModel *model,
                                   GtkTreePath  *path,
                                   GtkTreeIter  *iter,
                                   gpointer      data)
{
  GsmApplication *app = static_cast<GsmApplication *>(data);

  ProcInfo        *info;
  SetAffinityData *affinity_data;
  GtkWidget       *cancel_button;
  GtkWidget       *apply_button;
  GtkWidget       *dialog_vbox;
  GtkWidget       *label;
  GtkWidget       *scrolled;
  GtkStyleContext *scrolled_style;
  GtkGrid         *cpulist_grid;

  guint16               *affinity_cpus;
  guint16 affinity_cpu;
  glibtop_proc_affinity affinity;
  guint32 affinity_i;
  gint button_n;
  gchar                 *button_text;

  /* Get selected process information */
  gtk_tree_model_get (model, iter, COL_POINTER, &info, -1);

  /* Return void if process information comes back not true */
  if (!info)
    return;

  /* Create affinity data object */
  affinity_data = new SetAffinityData ();

  /* Set initial check box array */
  affinity_data->buttons = g_new (GtkWidget *, app->config.num_cpus);

  /* Create dialog window */
  affinity_data->dialog = GTK_WIDGET (g_object_new (GTK_TYPE_DIALOG,
                                                    "title", _("Set Affinity"),
                                                    "use-header-bar", TRUE,
                                                    "destroy-with-parent", TRUE,
                                                    NULL));

  /* Add cancel button to header bar */
  cancel_button = gtk_dialog_add_button (GTK_DIALOG (affinity_data->dialog),
                                         _("_Cancel"),
                                         GTK_RESPONSE_CANCEL);

  /* Add apply button to header bar */
  apply_button = gtk_dialog_add_button (GTK_DIALOG (affinity_data->dialog),
                                        _("_Apply"),
                                        GTK_RESPONSE_APPLY);

  /* Set dialog window "transient for" */
  gtk_window_set_transient_for (GTK_WINDOW (affinity_data->dialog),
                                GTK_WINDOW (GsmApplication::get ()->main_window));

  /* Set dialog window to be resizable */
  gtk_window_set_resizable (GTK_WINDOW (affinity_data->dialog), TRUE);

  /* Set default dialog window size */
  gtk_widget_set_size_request (affinity_data->dialog, 600, 430);

  /* Set dialog box padding ("border") */
  gtk_container_set_border_width (GTK_CONTAINER (affinity_data->dialog), 5);

  /* Get dialog content area VBox */
  dialog_vbox = gtk_dialog_get_content_area (GTK_DIALOG (affinity_data->dialog));

  /* Set dialog VBox padding ("border") */
  gtk_container_set_border_width (GTK_CONTAINER (dialog_vbox), 10);

  /* Set dialog VBox spacing */
  gtk_box_set_spacing (GTK_BOX (dialog_vbox), 10);

  /* Add selected process pid to affinity data */
  affinity_data->pid = info->pid;

  /* Add CPU count to affinity data */
  affinity_data->cpu_count = app->config.num_cpus;

  /* Set default toggle signal block states */
  affinity_data->toggle_single_blocked = FALSE;
  affinity_data->toggle_all_blocked = FALSE;

  /* Create a label describing the dialog windows intent */
  label = GTK_WIDGET (procman_make_label_for_mmaps_or_ofiles (
                        _("Select CPUs \"%s\" (PID %u) is allowed to run on:"),
                        info->name.c_str (),
                        info->pid));

  /* Add label to dialog VBox */
  gtk_box_pack_start (GTK_BOX (dialog_vbox), label, FALSE, TRUE, 0);

  /* Create scrolled box ("window") */
  scrolled = gtk_scrolled_window_new (NULL, NULL);

  /* Add view class to scrolled box style */
  scrolled_style = gtk_widget_get_style_context (scrolled);
  gtk_style_context_add_class (scrolled_style, "view");

  /* Set scrolled box vertical and horizontal policies */
  gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled),
                                  GTK_POLICY_AUTOMATIC,
                                  GTK_POLICY_AUTOMATIC);

  /* Set scrolled box shadow */
  gtk_scrolled_window_set_shadow_type (GTK_SCROLLED_WINDOW (scrolled),
                                       GTK_SHADOW_IN);

  /* Create grid for CPU list */
  cpulist_grid = GTK_GRID (gtk_grid_new ());

  /* Set CPU list grid padding ("border") */
  gtk_container_set_border_width (GTK_CONTAINER (cpulist_grid), 10);

  /* Set grid row spacing */
  gtk_grid_set_row_spacing (cpulist_grid, 10);

  /* Create toggle all check box */
  affinity_data->buttons[0] = gtk_check_button_new_with_label (_("Run on all CPUs"));
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (affinity_data->buttons[0]), TRUE);
  gtk_widget_set_hexpand (affinity_data->buttons[0], TRUE);

  /* Get process's current affinity */
  affinity_cpus = glibtop_get_proc_affinity (&affinity, info->pid);

  /* Set toggle all check box based on whether all CPUs are set for this process */
  gtk_toggle_button_set_active (
    GTK_TOGGLE_BUTTON (affinity_data->buttons[0]),
    affinity.all);

  /* Add toggle all check box to CPU grid */
  gtk_grid_attach (cpulist_grid, affinity_data->buttons[0], 0, 0, 1, 1);

  /* Run through all CPU buttons */
  for (button_n = 1; button_n < app->config.num_cpus + 1; button_n++)
    {
      /* Set check box label value to CPU [1..2048] */
      button_text = g_strdup_printf (_("CPU %d"), button_n);

      /* Create check box button for current CPU */
      affinity_data->buttons[button_n] = gtk_check_button_new_with_label (button_text);
      gtk_widget_set_hexpand (affinity_data->buttons[button_n], TRUE);

      /* Add check box to CPU grid */
      gtk_grid_attach (cpulist_grid, affinity_data->buttons[button_n], 0, button_n, 1, 1);

      /* Connect check box to toggler function */
      g_signal_connect (affinity_data->buttons[button_n],
                        "toggled",
                        G_CALLBACK (affinity_toggler_single),
                        affinity_data);

      /* Free check box label value gchar */
      g_free (button_text);
    }

  /* Run through all CPUs set for this process */
  for (affinity_i = 0; affinity_i < affinity.number; affinity_i++)
    {
      /* Get CPU button index */
      affinity_cpu = affinity_cpus[affinity_i] + 1;

      /* Set CPU check box active */
      gtk_toggle_button_set_active (
        GTK_TOGGLE_BUTTON (affinity_data->buttons[affinity_cpu]),
        TRUE);
    }

  /* Add CPU grid to scrolled box */
  gtk_container_add (GTK_CONTAINER (scrolled), GTK_WIDGET (cpulist_grid));

  /* Add scrolled box to dialog VBox */
  gtk_box_pack_start (GTK_BOX (dialog_vbox), scrolled, TRUE, TRUE, 0);

  /* Swap click signal on "Cancel" button */
  g_signal_connect_swapped (cancel_button,
                            "clicked",
                            G_CALLBACK (gtk_widget_destroy),
                            affinity_data->dialog);

  /* Connect click signal on "Apply" button */
  g_signal_connect (apply_button,
                    "clicked",
                    G_CALLBACK (set_affinity),
                    affinity_data);

  /* Connect toggle all check box to (de)select all function */
  g_signal_connect (affinity_data->buttons[0],
                    "toggled",
                    G_CALLBACK (affinity_toggle_all),
                    affinity_data);

  /* Show dialog window */
  gtk_widget_show_all (affinity_data->dialog);
}

void
create_set_affinity_dialog (GsmApplication *app)
{
  /* Create a dialog window for each selected process */
  gtk_tree_selection_selected_foreach (app->selection,
                                       create_single_set_affinity_dialog,
                                       app);
}
