#include <stdlib.h>
#include <stdio.h>    
#include <setjmp.h>    
#include <unistd.h> 
#include <pthread.h> 
#include <signal.h>
#include "x_opengl.h"

#include "app_ipc.h"
#include "util.h"

#include "boinc_gl.h"
#include "graphics_api.h"
#include "graphics_impl.h"

#define BOINC_WINDOW_CLASS_NAME "BOINC_app"

#define TIMER_INTERVAL_MSEC 30

static bool visible = true;
static int current_graphics_mode = MODE_HIDE_GRAPHICS;
static int acked_graphics_mode;
static int xpos = 100, ypos = 100;
static int clicked_button;
static int win=0;
static void set_mode(int mode);
static APP_INIT_DATA aid;

// This callback is invoked when a user presses a key.
//
void keyboardD(unsigned char key, int x, int y) {
    if (current_graphics_mode == MODE_FULLSCREEN) {
        set_mode(MODE_HIDE_GRAPHICS);
    }
}

void keyboardU(unsigned char key, int x, int y) {
    if (current_graphics_mode == MODE_FULLSCREEN) {
        set_mode(MODE_HIDE_GRAPHICS);
    }
}

void mouse_click(int button, int state, int x, int y){
    clicked_button = button;
    if (current_graphics_mode == MODE_FULLSCREEN) {
        set_mode(MODE_HIDE_GRAPHICS);
    } else {
        if (state) {
            boinc_app_mouse_button(x, y, button, false);
        } else {
            boinc_app_mouse_button(x, y, button, true);
        }
    }
}

void mouse_click_move(int x, int y){
    if (current_graphics_mode == MODE_FULLSCREEN){
        set_mode(MODE_HIDE_GRAPHICS);
    } else if (clicked_button == 2){
        boinc_app_mouse_move(x, y, false, false, true);
    } else if (clicked_button == 1){
        boinc_app_mouse_move(x, y, false, true, false);
    } else if (clicked_button == 0){
        boinc_app_mouse_move(x, y, true, false, false);
    } else{
        boinc_app_mouse_move(x, y, false, false, false);
    }
}

static void maybe_render() {
    int width, height;
    if (visible && (current_graphics_mode != MODE_HIDE_GRAPHICS)) {
        width = glutGet(GLUT_WINDOW_WIDTH);
        height = glutGet(GLUT_WINDOW_HEIGHT);
        if (throttled_app_render(width, height, dtime())) {
            glutSwapBuffers();
        }
    }
}

static void close_func() {
    if (boinc_is_standalone()) {
        exit(0);
    } else {
        set_mode(MODE_HIDE_GRAPHICS);
    }
}

static void make_new_window(int mode){
    if (mode == MODE_WINDOW || mode == MODE_FULLSCREEN){
        glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH); 
        glutInitWindowPosition(xpos, ypos);
        glutInitWindowSize(600, 400); 
        g_bmsp->boinc_get_init_data_hook(aid);
        if (!strlen(aid.app_name)) {
            strcpy(aid.app_name, "BOINC Application");
        }
        win = glutCreateWindow(aid.app_name); 

        glutReshapeFunc(app_graphics_resize);
        glutKeyboardFunc(keyboardD);
        glutKeyboardUpFunc(keyboardU);
        glutMouseFunc(mouse_click);
        glutMotionFunc(mouse_click_move);
        glutDisplayFunc(maybe_render); 
        
        app_graphics_init();
        glEnable(GL_DEPTH_TEST);    
        
        if (mode == MODE_FULLSCREEN) {
            glutFullScreen();
        }
    }
}

void KillWindow() {
    if (win) {
        glutDestroyWindow(win);
        win = 0;
    }
}

void set_mode(int mode) {
    if (mode == current_graphics_mode) return;
    KillWindow();
    current_graphics_mode = mode;
    if (mode != MODE_HIDE_GRAPHICS) {
        make_new_window(mode);
    }
}

static void wait_for_initial_message() {
    (*g_bmsp->app_client_shmp)->shm->graphics_reply.send_msg(
        xml_graphics_modes[MODE_HIDE_GRAPHICS]
    );
    acked_graphics_mode = MODE_HIDE_GRAPHICS;
    while (1) {
        if ((*g_bmsp->app_client_shmp)->shm->graphics_request.has_msg()) {
            break;
        }
        sleep(1);
    }
}

static void timer_handler(int) {
    char buf[MSG_CHANNEL_SIZE];
    GRAPHICS_MSG m;

    int new_mode;
    if (*g_bmsp->app_client_shmp) {
        if ((*g_bmsp->app_client_shmp)->shm->graphics_request.get_msg(buf)) {
            (*g_bmsp->app_client_shmp)->decode_graphics_msg(buf, m);
            switch (m.mode) {
            case MODE_REREAD_PREFS:
                //only reread graphics prefs if we have a window open
                //
                switch (current_graphics_mode){
                case MODE_WINDOW:
                case MODE_FULLSCREEN:
                    app_graphics_reread_prefs();
                    break;
                }
                break;
            case MODE_HIDE_GRAPHICS:
            case MODE_WINDOW:
            case MODE_FULLSCREEN:
            case MODE_BLANKSCREEN:
                set_mode(m.mode);
                break;
            }
        }
        if (acked_graphics_mode != current_graphics_mode) {
            bool sent = (*g_bmsp->app_client_shmp)->shm->graphics_reply.send_msg(
                xml_graphics_modes[current_graphics_mode]
            );
            if (sent) acked_graphics_mode = current_graphics_mode;
        }
    }
    maybe_render();
    glutTimerFunc(TIMER_INTERVAL_MSEC, timer_handler, 0);
}

static jmp_buf jbuf;
static pthread_t graphics_thread;
static struct sigaction original_signal_handler;
static bool tried_to_install_abort_handler=false;

void restart() {
    if (pthread_equal(pthread_self(), graphics_thread)) {
        atexit(restart);
        longjmp(jbuf, 1);
    }
}

// we will only arrive here if the signal handler was sucessfully
// installed.  If we are in the graphics thread, we just return back
// into xwin_graphics_event_loop.  If we are in the main thread, then
// restore the old signal handler and raise SIGABORT.
void restart_sig(int signal_number /* not used, always == SIGABRT */) {
    if (pthread_equal(pthread_self(), graphics_thread)) {
        // alternative approach is for the signal hander to call exit().
        fprintf(stderr, "Caught SIGABRT in graphics thread\n");
        longjmp(jbuf, 1);
    }
    else {
        // In non-graphics thread: use original signal handler
        fprintf(stderr, "Caught SIGABRT in non-graphics thread\n");
	if (sigaction(SIGABRT, &original_signal_handler, NULL)) {
	    perror("Unable to restore SIGABRT signal handler in non-graphics thread\n");
	    // what to do? call abort(3)??  call exit(nonzero)???
	    // boinc_finish()???? Here we just return.
	}
	else {
	  // we could conceivably try to call the old signal handler
	  // directly.  But this means checking how its flags/masks
	  // are set, making sure it's not NULL (for no action) and so
	  // on.  This seems simpler and more robust. On the other
	  // hand it may take some time for the signal to be
	  // delivered, and during that time, what's going to be
	  // executing?
	  raise(SIGABRT);
	}
	return;
    }
}


void xwin_graphics_event_loop() {
	char* args[] = {"foobar", 0};
	int one=1;
    static bool glut_inited = false;
    int restarted;
    int retry_interval_sec=32;
    struct sigaction sa;
    sa.sa_handler = restart_sig;
    sa.sa_flags = SA_RESTART;

    graphics_thread = pthread_self();

    atexit(restart);

try_again:
    restarted = setjmp(jbuf);

    // install signal handler to catch abort() from GLUT.  Note that
    // signal handlers are global to ALL threads, so the signal
    // handler that we record here in &original_signal_handler is the
    // previous one that applied to BOTH threads
    if (!tried_to_install_abort_handler) {
        tried_to_install_abort_handler=true;
	if (sigaction(SIGABRT, &sa, &original_signal_handler)) {
	    perror("unable to install signal handler to catch SIGABORT");
	}
    }
      
    if (restarted) {
        //fprintf(stderr, "graphics thread restarted\n"); fflush(stderr);
        if (glut_inited) {
            // here the user must have closed the window,
            // which causes GLUT to call exit().
            //
#ifdef __APPLE_CC__
            glutInit(&one, args);
#endif

#if 0
	    // NOTE: currently when run standalone, killing the
	    // graphics window does NOT kill the application.  If it's
	    // desired to kill the application in standalone mode,
	    // insert something here like this
	    if (boinc_is_standalone())
	        exit(0);
#endif


            set_mode(MODE_HIDE_GRAPHICS);
        } else {
            // here glutInit() must have failed and called exit() or
            // raised SIGABRT.
            //
            retry_interval_sec *= 2;
            sleep(retry_interval_sec);
            goto try_again;
        }
    } else {
        glutInit(&one, args);
        glut_inited = true;
        if (boinc_is_standalone()) {
            set_mode(MODE_WINDOW);
        } else {
            // don't proceed until we've opened a window;
            // otherwise glutMainLoop() will abort
            //
            while (current_graphics_mode == MODE_HIDE_GRAPHICS) {
                wait_for_initial_message();
                timer_handler(0);
            }
        }
    }
    glutTimerFunc(TIMER_INTERVAL_MSEC, timer_handler, 0);
    glutMainLoop();
}

const char *BOINC_RCSID_c457a14644 = "$Id$";