/* SPDX-License-Identifier: MIT */
/*
 * konpicture.c
 *
 * Copyright (c) 2026 KonAki
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include "konpicture.h"

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

#define FRAME (1.0f / 60.0f)

/*** helpers ***/

static kon_picture_t *slot(kon_pictures_t *pictures, int id)
{
	if (!pictures || id < 1 || id > KON_PICTURES) return NULL;
	return &pictures->slot[id - 1];
}

static float clampf(float v, float low, float high)
{
	if (!(v >= low)) return low;
	if (v > high) return high;
	return v;
}

static kon_ease_t easeFor(int easing)
{
	switch (easing) {
	case 1: return KON_EASE_IN;
	case 2: return KON_EASE_OUT;
	case 3: return KON_EASE_INOUT;
	default: return KON_EASE_LINEAR;
	}
}

static void glide(kon_tween_t *tween, float to, int frames, int easing)
{
	if (frames <= 0) kon_tweenSet(tween, to);
	else kon_tweenStart(tween, kon_tweenValue(tween), to, (float)frames * FRAME, easeFor(easing));
}

static void dropToned(kon_picture_t *p)
{
	if (p->toned) kon_freeImage(p->toned);
	p->toned = NULL;
}

/*** pictures ***/

void kon_picturesInit(kon_pictures_t *pictures, kon_pictureLoad load, void *user)
{
	memset(pictures, 0, sizeof *pictures);
	pictures->load = load;
	pictures->user = user;
}

void kon_picturesFree(kon_pictures_t *pictures)
{
	int i;

	if (!pictures) return;
	for (i = 0; i < KON_PICTURES; i++) dropToned(&pictures->slot[i]);
	memset(pictures->slot, 0, sizeof pictures->slot);
}

void kon_pictureShow(kon_pictures_t *pictures, int id, const char *name, int origin, int x, int y, int scaleX, int scaleY, int opacity, int blend)
{
	kon_picture_t *p = slot(pictures, id);
	size_t n;

	if (!p) return;
	dropToned(p);
	memset(p, 0, sizeof *p);
	p->shown = 1;
	if (!name) name = "";
	n = strlen(name);
	if (n >= KON_PICTURE_NAME) n = KON_PICTURE_NAME - 1;
	memcpy(p->name, name, n);
	p->name[n] = '\0';
	p->image = pictures->load && p->name[0] ? pictures->load(p->name, pictures->user) : NULL;
	p->origin = origin == 1 ? 1 : 0;
	p->blend = blend >= 0 && blend <= 3 ? blend : 0;
	kon_tweenSet(&p->x, (float)x);
	kon_tweenSet(&p->y, (float)y);
	kon_tweenSet(&p->scaleX, (float)scaleX);
	kon_tweenSet(&p->scaleY, (float)scaleY);
	kon_tweenSet(&p->opacity, clampf((float)opacity, 0.0f, 255.0f));
}

void kon_pictureMove(kon_pictures_t *pictures, int id, int origin, int x, int y, int scaleX, int scaleY, int opacity, int blend, int frames, int easing)
{
	kon_picture_t *p = slot(pictures, id);

	if (!p || !p->shown) return;
	p->origin = origin == 1 ? 1 : 0;
	p->blend = blend >= 0 && blend <= 3 ? blend : 0;
	glide(&p->x, (float)x, frames, easing);
	glide(&p->y, (float)y, frames, easing);
	glide(&p->scaleX, (float)scaleX, frames, easing);
	glide(&p->scaleY, (float)scaleY, frames, easing);
	glide(&p->opacity, clampf((float)opacity, 0.0f, 255.0f), frames, easing);
}

void kon_pictureRotate(kon_pictures_t *pictures, int id, int speed)
{
	kon_picture_t *p = slot(pictures, id);

	if (!p || !p->shown) return;
	p->turn = (float)speed;
}

void kon_pictureTint(kon_pictures_t *pictures, int id, int red, int green, int blue, int gray, int frames)
{
	kon_picture_t *p = slot(pictures, id);

	if (!p || !p->shown) return;
	glide(&p->tone[0], clampf((float)red, -255.0f, 255.0f), frames, 0);
	glide(&p->tone[1], clampf((float)green, -255.0f, 255.0f), frames, 0);
	glide(&p->tone[2], clampf((float)blue, -255.0f, 255.0f), frames, 0);
	glide(&p->tone[3], clampf((float)gray, 0.0f, 255.0f), frames, 0);
}

void kon_pictureErase(kon_pictures_t *pictures, int id)
{
	kon_picture_t *p = slot(pictures, id);

	if (!p) return;
	dropToned(p);
	memset(p, 0, sizeof *p);
}

/*** time ***/

void kon_picturesUpdate(kon_pictures_t *pictures, float dt)
{
	int i, k;

	if (!pictures || !(dt > 0.0f)) return;
	if (dt > 0.25f) dt = 0.25f;
	for (i = 0; i < KON_PICTURES; i++) {
		kon_picture_t *p = &pictures->slot[i];

		if (!p->shown) continue;
		kon_tweenStep(&p->x, dt);
		kon_tweenStep(&p->y, dt);
		kon_tweenStep(&p->scaleX, dt);
		kon_tweenStep(&p->scaleY, dt);
		kon_tweenStep(&p->opacity, dt);
		for (k = 0; k < 4; k++) kon_tweenStep(&p->tone[k], dt);
		if (p->turn != 0.0f) {
			p->angle += p->turn * 0.5f * (dt / FRAME) * (3.14159265f / 180.0f);
			if (p->angle > 6.2831853f || p->angle < -6.2831853f) p->angle = fmodf(p->angle, 6.2831853f);
		}
	}
}

int kon_picturesBusy(const kon_pictures_t *pictures)
{
	int i, k;

	if (!pictures) return 0;
	for (i = 0; i < KON_PICTURES; i++) {
		const kon_picture_t *p = &pictures->slot[i];

		if (!p->shown) continue;
		if (!kon_tweenDone(&p->x) || !kon_tweenDone(&p->y) || !kon_tweenDone(&p->scaleX) || !kon_tweenDone(&p->scaleY) || !kon_tweenDone(&p->opacity)) return 1;
		for (k = 0; k < 4; k++) {
			if (!kon_tweenDone(&p->tone[k])) return 1;
		}
	}
	return 0;
}

/*** drawing ***/

static int channel(int v)
{
	return v < 0 ? 0 : v > 255 ? 255 : v;
}

/* the copy of the picture with its tone in it, made again only when the tone has changed */
static const kon_image *tonedImage(kon_picture_t *p)
{
	int tone[4], k, i, count;

	for (k = 0; k < 4; k++) tone[k] = (int)floorf(kon_tweenValue(&p->tone[k]) + 0.5f);
	if (!tone[0] && !tone[1] && !tone[2] && !tone[3]) {
		dropToned(p);
		return p->image;
	}
	if (p->toned && !memcmp(tone, p->tonedFor, sizeof tone) && p->toned->width == p->image->width && p->toned->height == p->image->height) return p->toned;

	if (!p->toned || p->toned->width != p->image->width || p->toned->height != p->image->height) {
		dropToned(p);
		p->toned = kon_createFramebuffer(p->image->width, p->image->height);
		if (!p->toned) return p->image;
	}
	count = p->image->width * p->image->height;
	for (i = 0; i < count; i++) {
		uint32_t c = p->image->data[i];
		int r = (int)((c >> 16) & 255), g = (int)((c >> 8) & 255), b = (int)(c & 255);

		if (tone[3]) {
			int gray = (r * 30 + g * 59 + b * 11) / 100;

			r += (gray - r) * tone[3] / 255;
			g += (gray - g) * tone[3] / 255;
			b += (gray - b) * tone[3] / 255;
		}
		p->toned->data[i] = (c & 0xFF000000u) | (uint32_t)channel(r + tone[0]) << 16 | (uint32_t)channel(g + tone[1]) << 8 | (uint32_t)channel(b + tone[2]);
	}
	memcpy(p->tonedFor, tone, sizeof tone);
	return p->toned;
}

void kon_picturesDraw(kon_pictures_t *pictures, kon_framebuffer_t *fb)
{
	int i;

	if (!pictures || !fb) return;
	for (i = 0; i < KON_PICTURES; i++) {
		kon_picture_t *p = &pictures->slot[i];
		const kon_image *image;
		float sx, sy, alpha;
		kon_rect_t whole;

		if (!p->shown || !p->image || p->image->width <= 0 || p->image->height <= 0) continue;
		alpha = clampf(kon_tweenValue(&p->opacity), 0.0f, 255.0f);
		if (alpha < 0.5f) continue;
		sx = kon_tweenValue(&p->scaleX) / 100.0f;
		sy = kon_tweenValue(&p->scaleY) / 100.0f;
		image = tonedImage(p);
		whole.x = whole.y = 0;
		whole.w = image->width;
		whole.h = image->height;
		kon_drawImageBlend(fb, image, whole, kon_tweenValue(&p->x), kon_tweenValue(&p->y),
			p->origin ? (float)image->width * 0.5f : 0.0f, p->origin ? (float)image->height * 0.5f : 0.0f,
			sx, sy, p->angle, sx == 1.0f && sy == 1.0f && p->angle == 0.0f ? KON_FILTER_NEAREST : KON_FILTER_LINEAR,
			((uint32_t)alpha << 24) | 0x00FFFFFFu, (kon_blend_t)p->blend);
	}
}