#include <glib.h>
#include <gtk/gtk.h>
#include <gdk/gdk.h>
#include <sys/time.h>
#include <stdlib.h>
GtkWidget *window;
GtkWidget *vbox;
GtkWidget *hbox1;
GtkWidget *hbox2;
GtkTextView *textview;
GtkWidget *scrolledwindow;
GtkWidget *button1;
GtkWidget *button2;
GThread *thread;
volatile int thread_exec_flag01;

void append_text(GtkTextView *textview , const gchar *text);
void set_text(GtkTextView *textview, const gchar *text);
void delete_text(GtkTextView *textview);
void scroll_to_bottom(GtkScrolledWindow *scrolled_window);

double seconds() {
    struct timeval tm;
    double t ;
    static int base_sec = 0,base_usec = 0;
    gettimeofday(&tm, NULL);
    if(base_sec == 0 && base_usec == 0)
    {
        base_sec = tm.tv_sec; base_usec = tm.tv_usec; t = 0.0;
    } else {
        t = (double) (tm.tv_sec-base_sec) + ((double) (tm.tv_usec-base_usec))/1.0e6 ;
    }
    return t;
}

gpointer sieve_of_eratosthenes_func ( gpointer data ) {
    double  start_time, end_time;
    gchar    buf[512];
    int     max_number, i, j;
    char    *num_array;
    max_number = 200000;  /* max_number = 2000に設定 */
    if (NULL == (num_array = (char *)malloc(sizeof(char) * max_number))) {
         sprintf(buf, "メモリ確保に失敗しました\n");
         gdk_threads_enter();
         append_text(GTK_TEXT_VIEW(data), buf);
         gdk_threads_leave();
         return;
    };
    gdk_threads_enter();
    delete_text(GTK_TEXT_VIEW(textview));    /*     TextViewの内容を空にする */
    sprintf(buf, "エラトステネスのふるい\n素数を求めます\n");
    append_text(GTK_TEXT_VIEW(textview), buf);
    gdk_threads_leave();
    start_time = seconds();                  /*     時間計測開始     */
    num_array[0] = 0;
    num_array[1] = 0;
    for(i = 2; i < max_number; i++) {
        num_array[i] = 1;
    }
    for(i = 0; i < max_number; i++){
        if(num_array[i] != 0) {
            for(j = 2;(j * i) < max_number; j++) {
                num_array[j * i] = 0;
            }
        }
    }
    end_time = seconds();
    for(i = 0; i < max_number; i++) {
        if(num_array[i] != 0) {
            sprintf(buf, "%d\n", i);
            gdk_threads_enter();
            append_text(GTK_TEXT_VIEW(textview), buf);
            gdk_threads_leave();
        }
    }
    sprintf(buf, " 実行時間： %.4f秒\n", end_time - start_time);
    gdk_threads_enter();
    append_text(GTK_TEXT_VIEW(textview), buf);
    gdk_threads_leave();
    usleep(500000);
    gdk_threads_enter();
    scroll_to_bottom(scrolledwindow);
    gdk_threads_leave();
    free(num_array);
    thread_exec_flag01 = 0;
}

void delete_text(GtkTextView *textview){
    GtkTextBuffer *buffer;
    GtkTextIter start, end;
    buffer = gtk_text_view_get_buffer(textview);
    gtk_text_buffer_get_start_iter (buffer , &start);
    gtk_text_buffer_get_end_iter (buffer , &end);
    gtk_text_buffer_delete(buffer, &start, &end);
}

void set_text(GtkTextView *textview, const gchar *text)
{
    GtkTextBuffer *buffer;
    buffer = gtk_text_view_get_buffer(textview);
    gtk_text_buffer_set_text(buffer, text, -1);
}

void append_text(GtkTextView *textview , const gchar *text)
{
    GtkTextBuffer *buffer;
    GtkTextIter iter;
    buffer = gtk_text_view_get_buffer (textview);
    gtk_text_buffer_get_end_iter(buffer, &iter);
    gtk_text_buffer_insert(buffer, &iter, text, -1);
}

void scroll_to_bottom(GtkScrolledWindow *scrolled_window)
{
    GtkAdjustment *vadj;
    gdouble size;
    vadj = gtk_scrolled_window_get_vadjustment(scrolled_window);
    size = gtk_adjustment_get_upper(vadj) - gtk_adjustment_get_page_size(vadj);
    if (size < 0) size = 0.0;
    gtk_adjustment_set_value(vadj, size);
}

static void thread_func(GtkWidget *widget, gpointer data)
{
  GError *error;
  if (thread_exec_flag01 == 0) {
      thread_exec_flag01 = 1;
      thread = g_thread_create( sieve_of_eratosthenes_func, (gpointer)data, FALSE, &error );
  }
}

int main(int argc, char** argv)
{
  int window_width = 400;
  int window_height = 400;

  thread_exec_flag01 = 0;
  gtk_init(&argc, &argv);

  gdk_threads_init();
  gdk_threads_enter();

  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title(GTK_WINDOW(window), "Sieve of Eratosthenes");
  gtk_widget_set_size_request(window, window_width, window_height);
  gtk_container_set_border_width(GTK_CONTAINER(window), 5);

  g_signal_connect(G_OBJECT(window), "destroy", G_CALLBACK(gtk_main_quit), NULL);

  vbox = gtk_box_new(GTK_ORIENTATION_VERTICAL, 5);
  gtk_container_add(GTK_CONTAINER(window), vbox);

  scrolledwindow = gtk_scrolled_window_new(NULL, NULL);
  gtk_scrolled_window_set_shadow_type(GTK_SCROLLED_WINDOW(scrolledwindow), GTK_SHADOW_ETCHED_OUT);
  gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scrolledwindow), GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
  gtk_widget_set_size_request(GTK_SCROLLED_WINDOW(scrolledwindow), window_width, window_height - 40);
  gtk_box_pack_start(GTK_BOX(vbox), scrolledwindow, TRUE, TRUE, 0);

  textview = gtk_text_view_new();
  gtk_container_add(GTK_CONTAINER(scrolledwindow), textview);
  set_text(GTK_TEXT_VIEW(textview), "");

  hbox1 = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 5);
  gtk_box_pack_start(GTK_BOX(vbox), hbox1, FALSE, FALSE, 0);
  button1 = gtk_button_new_from_stock(GTK_STOCK_QUIT);
  g_signal_connect(G_OBJECT(button1), "clicked", G_CALLBACK(gtk_main_quit), NULL);
  gtk_box_pack_end(GTK_BOX(hbox1), button1, FALSE, FALSE, 0);
  button2 = gtk_button_new_with_label("開始");
  g_signal_connect(G_OBJECT(button2), "clicked", G_CALLBACK(thread_func), (gpointer)textview);
  gtk_box_pack_end(GTK_BOX(hbox1), button2, FALSE, FALSE, 0);

  gtk_widget_show_all(window);
  gtk_main();
  gdk_threads_leave();
  return 0;
}