/******************************************************************************
* FILE:   main.cc
*         The main function and general functionality of the tetris game.
*
* Author: Dana Vrajitoru, IUSB
* Class:  C481 B581 Computer Graphics
******************************************************************************/

#include <iostream>
using namespace std;
#include <stdlib.h>
#include <time.h>
#include <gnome.h>
#include "tetris_brick.h"
#include "gui_handle.h"
#include "draw.h"

gint Next_frame(gpointer data);
void Connect_signals(GtkWidget *app, GtkWidget *area);

gint Event_press_key(GtkWidget *widget, GdkEvent *event, gpointer data);
void Event_move_left(GtkWidget *widget);
void Event_move_right(GtkWidget *widget);
void Event_drop(GtkWidget *widget);
void New_game();
void Change_statusbar(char *message);

Table_type the_table;
Tetris_brick the_brick;
int game_end = 0;
GtkWidget *status_bar;
const int INTERVAL = 300;

int main(int argc, char **argv)
{
  int i;
  GtkWidget *app;
  GtkWidget *area;
  
  srand(time(NULL));
  gnome_init("tetris", "1.0", argc, argv);
  app = gnome_app_new("tetris", "Gnome Tetris");
  Make_menus(app);

  area = gtk_drawing_area_new();
  gtk_widget_set_usize(area, T_WIDTH*C_WIDTH, T_HEIGHT*C_HEIGHT);
  gnome_app_set_contents(GNOME_APP(app),area);

  status_bar = gtk_statusbar_new();
  gnome_app_set_statusbar(GNOME_APP(app), status_bar);
  Change_statusbar("A simple Tetris game");

  Insert_menu(app);
  Connect_signals(app, area);

  gtk_widget_show_all(app);
  Init_gc(area);
  Init_pixmaps(area);

  Make_empty_table(the_table);
  Draw_table(the_table);
  Draw_brick(the_brick);
  //Test_pixmaps(area);
  //gtk_signal_connect(GTK_OBJECT(area), "event", 
  //                   GTK_SIGNAL_FUNC(Event_draw), NULL);
  gtk_timeout_add(INTERVAL, Next_frame, (gpointer) area);

  gtk_main();
  exit(0);
}

// Defines the events to be applied to the application.
void Connect_signals(GtkWidget *app, GtkWidget *area)
{
  gtk_signal_connect(GTK_OBJECT(app), "delete_event", 
		     GTK_SIGNAL_FUNC(Event_delete), NULL);
  gtk_signal_connect(GTK_OBJECT(app), "destroy", 
		     GTK_SIGNAL_FUNC(Event_destroy), NULL);
  gtk_signal_connect(GTK_OBJECT(app), "key_press_event",
		     GTK_SIGNAL_FUNC(Event_press_key), (gpointer)area);
}

// The most important function in the game that defines the next move.
gint Next_frame(gpointer data)
{
  int old_x, old_y;
  if (!game_end) {
    old_x = the_brick.pos_x;
    old_y = the_brick.pos_y;
    if (!the_brick.Move_down(the_table)) {
      the_brick.Write_brick(the_table);
      the_brick.Set_brick();
      if (!the_brick.Check_position(the_table))
	game_end = 1;
    }
    else {
      Erase_brick(the_brick, old_x, old_y);
      Draw_brick(the_brick);
    }
    Draw((GtkWidget *)data);
  }
}

// Callback for a key being pressed.
gint Event_press_key(GtkWidget *widget, GdkEvent *event, gpointer data)
{
  GdkEventKey *key = (GdkEventKey *) event;
  if (key->keyval == GDK_Left)
    Event_move_left((GtkWidget *)data);
  else if (key->keyval == GDK_Right)
    Event_move_right((GtkWidget *)data);
  else if (key->keyval == GDK_space)
    Event_drop((GtkWidget *)data);
}

// Move the brick to the left.
void Event_move_left(GtkWidget *widget)
{
  int old_x = the_brick.pos_x;
  int old_y = the_brick.pos_y;
  if (the_brick.Move_left(the_table)) {
    Erase_brick(the_brick, old_x, old_y);
    Draw_brick(the_brick);
    Draw(widget);
  }
}

// Move the brick to the right.
void Event_move_right(GtkWidget *widget)
{
  int old_x = the_brick.pos_x;
  int old_y = the_brick.pos_y;
  if (the_brick.Move_right(the_table)) {
    Erase_brick(the_brick, old_x, old_y);
    Draw_brick(the_brick);
    Draw(widget);
  }
}

// Move the brick all the way down.
void Event_drop(GtkWidget *widget)
{
  int old_x = the_brick.pos_x;
  int old_y = the_brick.pos_y;
  while (the_brick.Move_down(the_table));
  Erase_brick(the_brick, old_x, old_y);
  Draw_brick(the_brick);
  Draw(widget);
}

void New_game()
{
  game_end = 0;
  Make_empty_table(the_table);
  Draw_table(the_table);
  the_brick.Set_brick();
  Draw_brick(the_brick);
}

// Function to update the score shown on the status bar
gint Event_score(gpointer data)
{
  char score_str[50];

  // returning "true" keeps the timer going
  return (true);
}

void Change_statusbar(char *message)
{
  int context_id;

  // get a context ID for successive calls
  context_id = gtk_statusbar_get_context_id((GtkStatusbar *)status_bar, 
					    "StatusBar");

  // pop off the old message from the status bar stack
  gtk_statusbar_pop((GtkStatusbar *)status_bar, context_id);

  // push the message onto the status bar stack
  gtk_statusbar_push((GtkStatusbar *)status_bar, context_id, message);
}