// SPDX-License-Identifier: GPL-2.1-or-later
/*
 * Copyright (C) 2009-2021 Cyril Hrubis <metan@ucw.cz>
 */

 /*

   Simple backend task example.

  */

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

static void redraw(gp_backend *self)
{
        gp_pixmap *pixmap = self->pixmap;
        gp_pixel white_pixel, black_pixel;

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

        gp_fill(pixmap, black_pixel);
        gp_line(pixmap, 0, 0, pixmap->w - 1, pixmap->h - 1, white_pixel);
        gp_line(pixmap, 0, pixmap->h - 1, pixmap->w - 1, 0, white_pixel);

        gp_backend_flip(self);
}

static int redraw_task_callback(gp_task *self)
{
        gp_backend *backend = self->priv;
        gp_pixel red_pixel;

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

        gp_text(backend->pixmap, NULL, backend->pixmap->w/2, 10,
                GP_ALIGN_CENTER|GP_VALIGN_BELOW,
                red_pixel, 0, "Task called!");

        gp_backend_flip(backend);

        return 0;
}

int main(int argc, char *argv[])
{
        gp_backend *backend;
        static gp_task_queue task_queue = {};
        const char *backend_opts = NULL;
        int opt;

        while ((opt = getopt(argc, argv, "b:h")) != -1) {
                switch (opt) {
                case 'b':
                        backend_opts = optarg;
                break;
                case 'h':
                        gp_backend_init_help();
                        return 0;
                break;
                default:
                        fprintf(stderr, "Invalid paramter '%c'\n", opt);
                        return 1;
                }
        }

        backend = gp_backend_init(backend_opts, 0, 0, "Backend tasks example");
        if (!backend) {
                fprintf(stderr, "Failed to initialize backend\n");
                return 1;
        }

        redraw(backend);

        gp_backend_task_queue_set(backend, &task_queue);

        gp_task redraw_task = {
                .id = "redraw task",
                .callback = redraw_task_callback,
                .priv = backend,
                .prio = GP_TASK_MIN_PRIO,
        };

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

                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;
                        case GP_KEY_T:
                                gp_backend_task_ins(backend, &redraw_task);
                        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;
                }
        }

        gp_backend_exit(backend);

        return 0;
}