/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "teenagent/dialog.h"
#include "teenagent/resources.h"
#include "teenagent/scene.h"
#include "teenagent/teenagent.h"

namespace TeenAgent {

void Dialog::show(uint16 dialogNum, Scene *scene, uint16 animation1, uint16 animation2, byte color1, byte color2, byte slot1, byte slot2) {
	uint16 addr = _vm->res->getDialogAddr(dialogNum);
	// WORKAROUND: For Dialog 163, The usage of this in the engine overlaps the previous dialog i.e. the
	// starting offset used is two bytes early, thus implicitly changing the first command of this dialog
	// from NEW_LINE to CHANGE_CHARACTER.
	// FIXME: Unsure if this is correct behaviour or if this is a regression from the original. Check this.
	// Similar issue occurs with Dialog 190 which is used from dialogue stack at 0x7403, rather than start of 0x7405
	// Similar issue occurs with Dialog 0 which is used from dialogue stack at 0x0001, rather than start of 0x0000
	if (dialogNum == 163)
		addr -= 2;
	show(scene, addr, animation1, animation2, color1, color2, slot1, slot2);
}

void Dialog::show(Scene *scene, uint16 addr, uint16 animation1, uint16 animation2, byte color1, byte color2, byte slot1, byte slot2) {
	debugC(0, kDebugDialog, "Dialog::show(%04x, %u:%u, %u:%u)", addr, slot1, animation1, slot2, animation2);
	int n = 0;
	Common::String message;
	byte color = color1;

	if (animation1 != 0) {
		SceneEvent e1(SceneEvent::kPlayAnimation);
		e1.animation = animation1;
		e1.slot = 0xc0 | slot1; //looped, paused
		scene->push(e1);
	}

	if (animation2 != 0) {
		SceneEvent e2(SceneEvent::kPlayAnimation);
		e2.animation = animation2;
		e2.slot = 0xc0 | slot2; //looped, paused
		scene->push(e2);
	}

	while (n < 4) {
		byte c = _vm->res->eseg.get_byte(addr++);
		debugC(1, kDebugDialog, "%02x: %c", c, c > 0x20? c: '.');

		switch (c) {
		case 0:
			++n;
			switch (n) {
			case 1:
				debugC(1, kDebugDialog, "new line\n");
				if (!message.empty())
					message += '\n';
				break;
			case 2:
				debugC(1, kDebugDialog, "displaymessage %s", message.c_str());
				if (color == color2) {
					//pause animation in other slot
					SceneEvent e1(SceneEvent::kPauseAnimation);
					e1.slot = 0x80 | slot1;
					scene->push(e1);

					SceneEvent e2(SceneEvent::kPlayAnimation);
					e2.animation = animation2;
					e2.slot = 0x80 | slot2;
					scene->push(e2);
				} else if (color == color1) {
					//pause animation in other slot
					SceneEvent e2(SceneEvent::kPauseAnimation);
					e2.slot = 0x80 | slot2;
					scene->push(e2);

					SceneEvent e1(SceneEvent::kPlayAnimation);
					e1.animation = animation1;
					e1.slot = 0x80 | slot1;
					scene->push(e1);
				}

				message.trim();
				if (!message.empty()) {
					SceneEvent em(SceneEvent::kMessage);
					em.message = message;
					em.color = color;
					if (color == color1)
						em.slot = slot1;
					if (color == color2)
						em.slot = slot2;
					scene->push(em);
					message.clear();
				}
				break;

			case 3:
				color = (color == color1) ? color2 : color1;
				debugC(1, kDebugDialog, "changing color to %02x", color);
				break;

			default:
				break;
			}
			break;

		case 0xff:
			//FIXME : wait for the next cycle of the animation
			break;

		default:
			message += c;
			n = 0;
			break;
		}
	}

	SceneEvent ec(SceneEvent::kClearAnimations);
	scene->push(ec);
}

uint16 Dialog::pop(Scene *scene, uint16 addr, uint16 animation1, uint16 animation2, byte color1, byte color2, byte slot1, byte slot2) {
	debugC(0, kDebugDialog, "Dialog::pop(%04x, %u:%u, %u:%u)", addr, slot1, animation1, slot2, animation2);
	uint16 next;
	do {
		next = _vm->res->dseg.get_word(addr);
		addr += 2;
	} while (next == 0);
	uint16 next2 = _vm->res->dseg.get_word(addr);
	if (next2 != 0xffff)
		_vm->res->dseg.set_word(addr - 2, 0);
	show(scene, next, animation1, animation2, color1, color2, slot1, slot2);
	return next;
}

} // End of namespace TeenAgent
