// SPDX-License-Identifier: GPL-2.1-or-later
/*
 * Copyright (C) 2009-2023 Cyril Hrubis <metan@ucw.cz>
 */

 /*

   Simple backend timers example.

  */

#include <stdio.h>
#include <gfxprim.h>

static gp_pixel black_pixel, white_pixel;
static unsigned int timer1_expirations = 0;
static unsigned int timer2_expirations = 0;

static uint32_t timer_callback(gp_timer *self)
{
        uint32_t next = random() % 10000;

        printf("Timer %s callback called, rescheduling after %u.\n",
               self->id, (unsigned) next);

        timer2_expirations++;

        return next;
}

static void redraw(gp_backend *backend)
{
        gp_fill(backend->pixmap, black_pixel);

        gp_print(backend->pixmap, NULL, 10, 10,
                 GP_ALIGN_RIGHT | GP_VALIGN_BELOW,
                 white_pixel, black_pixel, "Timer 1 expirations %u",
                 timer1_expirations);

        gp_print(backend->pixmap, NULL, 10, 30,
                 GP_ALIGN_RIGHT | GP_VALIGN_BELOW,
                 white_pixel, black_pixel, "Timer 2 expirations %u",
                 timer2_expirations);

        gp_backend_flip(backend);
}

int main(void)
{
        gp_backend *backend;
        const char *backend_opts = NULL;

        backend = gp_backend_init(backend_opts, 200, 100, "Backend Timers Example");

        if (!backend) {
                fprintf(stderr, "Failed to initialize backend\n");
                return 1;
        }

        black_pixel = gp_rgb_to_pixmap_pixel(0x00, 0x00, 0x00, backend->pixmap);
        white_pixel = gp_rgb_to_pixmap_pixel(0xff, 0xff, 0xff, backend->pixmap);

        gp_fill(backend->pixmap, black_pixel);
        gp_backend_flip(backend);

        /*
         * Periodic timer with 1000ms interval. As the callback is set to NULL
         * Timer Event is pushed to event queue upon expiration. The backend
         * timer callback returns the .period value, which reschedulles the
         * timer. You can also set .period to GP_TIMER_STOP which would make the
         * timer oneshot.
         *
         * NOTE: The .expires is set to 0 which means that the timer first
         *       expires as soon as we enter the backend wait call.
         */
        gp_timer timer1 = {
                .expires = 0,
                .period = 1000,
                .id = "Timer 1",
        };

        /*
         * Timer with a callback, this timer gets scheduled depending on ouput
         * from callback, GP_TIMER_STOP means disable the timer.
         */
        gp_timer timer2 = {
                .expires = 5000,
                .id = "Timer 2",
                .callback = timer_callback,
        };

        gp_backend_add_timer(backend, &timer1);
        gp_backend_add_timer(backend, &timer2);

        /* Handle events */
        for (;;) {
                gp_event *ev = gp_backend_wait_event(backend);

                gp_ev_dump(ev);

                switch (ev->type) {
                case GP_EV_KEY:
                        switch (ev->val) {
                        case GP_KEY_ESC:
                        case GP_KEY_Q:
                                gp_backend_exit(backend);
                                return 0;
                        break;
                        }
                break;
                case GP_EV_SYS:
                        switch (ev->code) {
                        case GP_EV_SYS_RESIZE:
                                gp_backend_resize_ack(backend);
                                redraw(backend);
                        break;
                        case GP_EV_SYS_QUIT:
                                gp_backend_exit(backend);
                                return 0;
                        break;
                        }
                break;
                case GP_EV_TMR:
                        timer1_expirations++;
                        redraw(backend);
                break;
                }
        }

        gp_backend_exit(backend);

        return 0;
}