/*
 *  Copyright (C) 2018  Vito Caputo - <vcaputo@pengaru.com>
 *
 *  This program is free software: you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License version 3 as published
 *  by the Free Software Foundation.
 *
 *  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, see <http://www.gnu.org/licenses/>.
 */

#include <assert.h>
#include <SDL.h>
#include <SDL_mixer.h>
#include <math.h>

#include "aabb.h"
#include "macros.h"
#include "whale.h"
#include "stage.h"
#include "svg-node.h"

/* the opening credits */

void whale_credits_event(whale_t *whale, SDL_Event *ev)
{
	/* no events handled in credits, their brief */
}

typedef enum credits_fsm_t {
	CREDITS_FSM_FADEOUT,
	CREDITS_FSM_FADEIN,
	CREDITS_FSM_PLANETS_FADEOUT,
	CREDITS_FSM_CREDITS_FADEOUT,
} credits_fsm_t;

void whale_credits_update(whale_t *whale)
{
	static stage_node_t	*bobby, *crater, *planets, *credits;
	static unsigned		initialized;
	static credits_fsm_t	state;
	Uint32			now = whale_ticks(whale, WHALE_TICKS_TIMER);
	stage_t			*stage = whale_get_stage(whale);

	if (!initialized) {
		whale_ticks_reset(whale, WHALE_TICKS_TIMER);	/* get ticks approximately aligned with credits start */

		bobby = stage_node_lookup_name(stage, "bobby");
		fatal_if(!bobby, "Unable to lookup whale node");

		crater = stage_node_lookup_name(stage, "crater");
		fatal_if(!crater, "Unable to lookup crater node");
		
		planets = stage_node_lookup_name(stage, "planets");
		fatal_if(!crater, "Unable to lookup planets node");

		credits = svg_node_new_file(stage, "credits", "assets/credits.svg", 0, (aabb_t){{-.8f, -.8f}, {.8f, .8f}});
		fatal_if(!credits, "Unable to load credits svg");

		now = whale_ticks(whale, WHALE_TICKS_TIMER);

		initialized = 1;
	}


	switch (state) {
	case CREDITS_FSM_FADEOUT:
		if (now < 2000) {
			float	t = 1.0f - ((float)now) * (1.0f / 2000.0f);

			stage_node_set_alpha(stage, bobby, t);
			stage_node_set_alpha(stage, crater, t);
		} else {
			stage_node_free(stage, bobby);
			stage_node_free(stage, crater);
			stage_node_set_active(stage, credits);
			state++;
		}
		break;

	case CREDITS_FSM_FADEIN:
		if (now < 4000) {
			stage_node_set_alpha(stage, planets, 1.0f - ((float)(now - 2000)) * (1.0f / 15000.0f));
			stage_node_set_alpha(stage, credits, ((float)(now - 2000)) * (1.0f / 2000.0f));
		} else {
			stage_node_set_alpha(stage, credits, 1.0f);
			state++;
		}
		break;

	case CREDITS_FSM_PLANETS_FADEOUT:
		if (now < 17000) {
			stage_node_set_alpha(stage, planets, 1.0f - ((float)(now - 2000)) * (1.0f / 15000.0f));
		} else {
			stage_node_free(stage, planets);
			state++;
		}
		break;

	case CREDITS_FSM_CREDITS_FADEOUT:
		if (now < 20000) {
			stage_node_set_alpha(stage, credits, 1.0f - ((float)(now - 17000)) * (1.0f / 3000.0f));
		} else {
			stage_node_free(stage, credits);
			exit(0);
		}
		break;

	default:
		assert(0);
	}

	if (!Mix_PlayingMusic() || now > 20000)
		exit(0);
}