#include <string.h>
#include <math.h>
#include <stdio.h>
#include <assert.h>
#include <stdlib.h>

#include "scheme.h"

#include "../any_log.h"

typedef struct {
    effect_t effect;
    unsigned int width;
    cairo_pattern_t *gradient;
} effect_shine_t;

extern double cubic_bezier(double x, double a, double b, double c, double d);

static void effect_shine_post(effect_t *effect, layout_t *layout, cairo_t *cr)
{
    struct timespec now;
    timespec_get(&now, TIME_UTC);

    struct timespec diff = timespec_diff(now, effect->start);
    double t = (double)timespec_to_ms(diff) / timespec_to_ms(effect->info->duration);
    double s = cubic_bezier(t, 0.19, 1.0, 0.22, 1.0);

    effect_shine_t *shine = (effect_shine_t *)effect;

    unsigned int x = layout->x + s * layout->width - shine->width;
    unsigned int y = layout->y;

    cairo_set_operator(cr, CAIRO_OPERATOR_ATOP);
    cairo_set_source(cr, shine->gradient);
    cairo_rectangle(cr, x, y - layout->height / 2, shine->width, layout->height);
    cairo_fill(cr);
}

static effect_t *effect_shine_allocate(const effect_info_t *info)
{
    effect_shine_t *effect = malloc(sizeof(effect_shine_t));
    effect_init((effect_t *)effect, info);

    effect->width = 20;
    effect->gradient = cairo_pattern_create_linear(0, 0, effect->width, 0);
    cairo_pattern_add_color_stop_rgba(effect->gradient, 1, 1, 1, 1, 0.1);
    cairo_pattern_add_color_stop_rgba(effect->gradient, 0.5, 1, 1, 1, 0.8);
    cairo_pattern_add_color_stop_rgba(effect->gradient, 1, 1, 1, 1, 0.1);

    return (effect_t *)effect;
}

static void effect_shine_finalize(effect_shine_t *effect)
{
    cairo_pattern_destroy(effect->gradient);
    free(effect);
}

static bool effect_shine_validate(effect_info_t *info, const effect_scheme_t *scheme)
{
    return true;
}

static const config_entry_t effect_shine_entries[] = {
    { 0 },
};

const effect_scheme_t effect_shine_scheme = {
    .name = "shine",
    .info = {
        .duration = {
            .tv_sec = 0,
            .tv_nsec = 200000000,
        },
        .allocate = effect_shine_allocate,
        .finalize = (effect_finalize_t)effect_shine_finalize,
        .post = effect_shine_post,
    },
    .size = sizeof(unsigned int),
    .entries = effect_shine_entries,
    .validate = effect_shine_validate,
};