/* animation.c - boot animation
 *
 * Copyright (C) 2009 Red Hat, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * Written by: William Jon McCann <jmccann@redhat.com>
 */

#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <math.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <values.h>
#include <unistd.h>
#include <wchar.h>

#include "ply-animation.h"
#include "ply-event-loop.h"
#include "ply-array.h"
#include "ply-logger.h"
#include "ply-image.h"
#include "ply-pixel-buffer.h"
#include "ply-utils.h"

#include <linux/kd.h>

#ifndef FRAMES_PER_SECOND
#define FRAMES_PER_SECOND 30
#endif

struct _ply_animation
{
        ply_array_t         *frames;
        ply_event_loop_t    *loop;
        char                *image_dir;
        char                *frames_prefix;

        ply_pixel_display_t *display;
        ply_trigger_t       *stop_trigger;

        int                  frame_number;
        long                 x, y;
        long                 width, height;
        double               start_time, previous_time, now;
        uint32_t             is_stopped : 1;
        uint32_t             stop_requested : 1;
};

static void ply_animation_stop_now (ply_animation_t *animation);


ply_animation_t *
ply_animation_new (const char *image_dir,
                   const char *frames_prefix)
{
        ply_animation_t *animation;

        assert (image_dir != NULL);
        assert (frames_prefix != NULL);

        animation = calloc (1, sizeof(ply_animation_t));

        animation->frames = ply_array_new (PLY_ARRAY_ELEMENT_TYPE_POINTER);
        animation->frames_prefix = strdup (frames_prefix);
        animation->image_dir = strdup (image_dir);
        animation->frame_number = 0;
        animation->is_stopped = true;
        animation->stop_requested = false;
        animation->width = 0;
        animation->height = 0;

        return animation;
}

static void
ply_animation_remove_frames (ply_animation_t *animation)
{
        int i;
        ply_pixel_buffer_t **frames;

        frames = (ply_pixel_buffer_t **) ply_array_steal_pointer_elements (animation->frames);
        for (i = 0; frames[i] != NULL; i++) {
                ply_pixel_buffer_free (frames[i]);
        }
        free (frames);
}

void
ply_animation_free (ply_animation_t *animation)
{
        if (animation == NULL)
                return;

        if (!animation->is_stopped)
                ply_animation_stop_now (animation);

        ply_animation_remove_frames (animation);
        ply_array_free (animation->frames);

        free (animation->frames_prefix);
        free (animation->image_dir);
        free (animation);
}

static bool
animate_at_time (ply_animation_t *animation,
                 double           time)
{
        int number_of_frames;
        ply_pixel_buffer_t *const *frames;
        ply_rectangle_t frame_area;
        bool should_continue;

        number_of_frames = ply_array_get_size (animation->frames);

        if (number_of_frames == 0)
                return false;

        should_continue = true;

        if (animation->frame_number > number_of_frames - 1) {
                ply_trace ("reached last frame of animation");
                return false;
        }

        if (animation->stop_requested) {
                ply_trace ("stopping animation in the middle of sequence");
                should_continue = false;
        }

        frames = (ply_pixel_buffer_t *const *) ply_array_get_pointer_elements (animation->frames);
        ply_pixel_buffer_get_size (frames[animation->frame_number], &frame_area);

        ply_pixel_display_draw_area (animation->display,
                                     animation->x, animation->y,
                                     frame_area.width,
                                     frame_area.height);

        animation->frame_number++;

        return should_continue;
}

static void
on_timeout (ply_animation_t *animation)
{
        double sleep_time;
        bool should_continue;

        animation->previous_time = animation->now;
        animation->now = ply_get_timestamp ();

        should_continue = animate_at_time (animation,
                                           animation->now - animation->start_time);

        sleep_time = 1.0 / FRAMES_PER_SECOND;
        sleep_time = MAX (sleep_time - (ply_get_timestamp () - animation->now),
                          0.005);

        if (!should_continue) {
                if (animation->stop_trigger != NULL) {
                        ply_trace ("firing off stop trigger");
                        ply_trigger_pull (animation->stop_trigger, NULL);
                        animation->stop_trigger = NULL;
                }
        } else {
                ply_event_loop_watch_for_timeout (animation->loop,
                                                  sleep_time,
                                                  (ply_event_loop_timeout_handler_t)
                                                  on_timeout, animation);
        }
}

static bool
ply_animation_add_frame (ply_animation_t *animation,
                         const char      *filename)
{
        ply_image_t *image;
        ply_pixel_buffer_t *frame;

        image = ply_image_new (filename);

        if (!ply_image_load (image)) {
                ply_image_free (image);
                return false;
        }

        frame = ply_image_convert_to_pixel_buffer (image);

        ply_array_add_pointer_element (animation->frames, frame);

        animation->width = MAX (animation->width, (long) ply_pixel_buffer_get_width (frame));
        animation->height = MAX (animation->height, (long) ply_pixel_buffer_get_height (frame));

        return true;
}

static bool
ply_animation_add_frames (ply_animation_t *animation)
{
        struct dirent **entries;
        int number_of_entries;
        int number_of_frames;
        int i;
        bool load_finished;

        entries = NULL;

        number_of_entries = scandir (animation->image_dir, &entries, NULL, versionsort);

        if (number_of_entries <= 0)
                return false;

        load_finished = false;
        for (i = 0; i < number_of_entries; i++) {
                if (strncmp (entries[i]->d_name,
                             animation->frames_prefix,
                             strlen (animation->frames_prefix)) == 0
                    && (strlen (entries[i]->d_name) > 4)
                    && strcmp (entries[i]->d_name + strlen (entries[i]->d_name) - 4, ".png") == 0) {
                        char *filename;

                        filename = NULL;
                        asprintf (&filename, "%s/%s", animation->image_dir, entries[i]->d_name);

                        if (!ply_animation_add_frame (animation, filename))
                                goto out;

                        free (filename);
                }

                free (entries[i]);
                entries[i] = NULL;
        }

        number_of_frames = ply_array_get_size (animation->frames);
        if (number_of_frames == 0) {
                ply_trace ("%s directory had no files starting with %s",
                           animation->image_dir, animation->frames_prefix);
                goto out;
        } else {
                ply_trace ("animation has %d frames", number_of_frames);
        }

        load_finished = true;

out:
        if (!load_finished) {
                ply_animation_remove_frames (animation);

                while (i < number_of_entries) {
                        free (entries[i]);
                        i++;
                }
        }
        free (entries);

        return ply_array_get_size (animation->frames) > 0;
}

bool
ply_animation_load (ply_animation_t *animation)
{
        if (ply_array_get_size (animation->frames) != 0) {
                ply_animation_remove_frames (animation);
                ply_trace ("reloading animation with new set of frames");
        } else {
                ply_trace ("loading frames for animation");
        }

        if (!ply_animation_add_frames (animation))
                return false;

        return true;
}

bool
ply_animation_start (ply_animation_t     *animation,
                     ply_pixel_display_t *display,
                     ply_trigger_t       *stop_trigger,
                     long                 x,
                     long                 y)
{
        assert (animation != NULL);

        if (!animation->is_stopped)
                return true;

        ply_trace ("starting animation");

        animation->loop = ply_event_loop_get_default ();
        animation->display = display;
        animation->stop_trigger = stop_trigger;
        animation->is_stopped = false;
        animation->stop_requested = false;

        animation->x = x;
        animation->y = y;

        animation->start_time = ply_get_timestamp ();

        ply_event_loop_watch_for_timeout (animation->loop,
                                          1.0 / FRAMES_PER_SECOND,
                                          (ply_event_loop_timeout_handler_t)
                                          on_timeout, animation);

        return true;
}

static void
ply_animation_stop_now (ply_animation_t *animation)
{
        animation->is_stopped = true;

        ply_trace ("stopping animation now");

        if (animation->loop != NULL) {
                ply_event_loop_stop_watching_for_timeout (animation->loop,
                                                          (ply_event_loop_timeout_handler_t)
                                                          on_timeout, animation);
                animation->loop = NULL;
        }

        animation->display = NULL;
}

void
ply_animation_stop (ply_animation_t *animation)
{
        if (animation->is_stopped) {
                ply_trace ("animation already stopped, ignoring stop request");
                return;
        }

        if (animation->stop_trigger == NULL) {
                ply_animation_stop_now (animation);
                return;
        }

        ply_trace ("stopping animation next time through the loop");
        animation->stop_requested = true;
}

bool
ply_animation_is_stopped (ply_animation_t *animation)
{
        return animation->is_stopped;
}

void
ply_animation_draw_area (ply_animation_t    *animation,
                         ply_pixel_buffer_t *buffer,
                         long                x,
                         long                y,
                         unsigned long       width,
                         unsigned long       height)
{
        ply_pixel_buffer_t *const *frames;
        int number_of_frames;
        int frame_index;

        if (animation->is_stopped)
                return;

        number_of_frames = ply_array_get_size (animation->frames);
        frame_index = MIN (animation->frame_number, number_of_frames - 1);

        frames = (ply_pixel_buffer_t *const *) ply_array_get_pointer_elements (animation->frames);
        ply_pixel_buffer_fill_with_buffer (buffer,
                                           frames[frame_index],
                                           animation->x, animation->y);
}

long
ply_animation_get_width (ply_animation_t *animation)
{
        return animation->width;
}

long
ply_animation_get_height (ply_animation_t *animation)
{
        return animation->height;
}