/* ScummVM - Scumm Interpreter
 * Copyright (C) 2006 The ScummVM project
 *
 * Copyright (C) 1999-2003 Sarien Team
 *
 * 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
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

#include "common/stdafx.h"

#include "agi/agi.h"
#include "agi/text.h"
#include "agi/sprite.h"
#include "agi/graphics.h"
#include "agi/keyboard.h"
#include "agi/menu.h"
#include "agi/savegame.h"

namespace Agi {

#define TICK_SECONDS	20

#ifdef USE_MOUSE
struct mouse mouse;
#endif

volatile uint32 clock_ticks;
volatile uint32 clock_count;

/**
 * Set up new room.
 * This function is called when ego enters a new room.
 * @param n room number
 */
void new_room(int n) {
	struct vt_entry *v;
	int i;

	debugC(4, kDebugLevelMain, "*** room %d ***", n);
	stop_sound();

	i = 0;
	for (v = game.view_table; v < &game.view_table[MAX_VIEWTABLE]; v++) {
		v->entry = i++;
		v->flags &= ~(ANIMATED | DRAWN);
		v->flags |= UPDATE;
		v->step_time = 1;
		v->step_time_count = 1;
		v->cycle_time = 1;
		v->cycle_time_count = 1;
		v->step_size = 1;
	}
	agi_unload_resources();

	game.player_control = true;
	game.block.active = false;
	game.horizon = 36;
	game.vars[V_prev_room] = game.vars[V_cur_room];
	game.vars[V_cur_room] = n;
	game.vars[V_border_touch_obj] = 0;
	game.vars[V_border_code] = 0;
	game.vars[V_ego_view_resource] = game.view_table[0].current_view;

	agi_load_resource(rLOGIC, n);

	/* Reposition ego in the new room */
	switch (game.vars[V_border_touch_ego]) {
	case 1:
		game.view_table[0].y_pos = _HEIGHT - 1;
		break;
	case 2:
		game.view_table[0].x_pos = 0;
		break;
	case 3:
		game.view_table[0].y_pos = HORIZON + 1;
		break;
	case 4:
		game.view_table[0].x_pos = _WIDTH - game.view_table[0].x_size;
		break;
	}

	game.vars[V_border_touch_ego] = 0;
	setflag(F_new_room_exec, true);

	game.exit_all_logics = true;

	write_status();
	write_prompt();
}

static void reset_controllers() {
	int i;

	for (i = 0; i < MAX_DIRS; i++) {
		game.ev_keyp[i].occured = false;
	}
}

static void interpret_cycle() {
	int old_sound, old_score;

	if (game.player_control)
		game.vars[V_ego_dir] = game.view_table[0].direction;
	else
		game.view_table[0].direction = game.vars[V_ego_dir];

	check_all_motions();

	old_score = game.vars[V_score];
	old_sound = getflag(F_sound_on);

	game.exit_all_logics = false;
	while (run_logic(0) == 0 && !game.quit_prog_now) {
		game.vars[V_word_not_found] = 0;
		game.vars[V_border_touch_obj] = 0;
		game.vars[V_border_code] = 0;
		old_score = game.vars[V_score];
		setflag(F_entered_cli, false);
		game.exit_all_logics = false;
		reset_controllers();
	}
	reset_controllers();

	game.view_table[0].direction = game.vars[V_ego_dir];

	if (game.vars[V_score] != old_score || getflag(F_sound_on) != old_sound)
		write_status();

	game.vars[V_border_touch_obj] = 0;
	game.vars[V_border_code] = 0;
	setflag(F_new_room_exec, false);
	setflag(F_restart_game, false);
	setflag(F_restore_just_ran, false);

	if (game.gfx_mode) {
		update_viewtable();
		do_update();
	}
}

/**
 * Update AGI interpreter timer.
 */
void update_timer() {
	clock_count++;
	if (clock_count <= TICK_SECONDS)
		return;

	clock_count -= TICK_SECONDS;

	if (!game.clock_enabled)
		return;

	setvar(V_seconds, getvar(V_seconds) + 1);
	if (getvar(V_seconds) < 60)
		return;

	setvar(V_seconds, 0);
	setvar(V_minutes, getvar(V_minutes) + 1);
	if (getvar(V_minutes) < 60)
		return;

	setvar(V_minutes, 0);
	setvar(V_hours, getvar(V_hours) + 1);
	if (getvar(V_hours) < 24)
		return;

	setvar(V_hours, 0);
	setvar(V_days, getvar(V_days) + 1);
}

static int old_mode = -1;

void new_input_mode(int i) {
	old_mode = game.input_mode;
	game.input_mode = i;
}

void old_input_mode() {
	game.input_mode = old_mode;
}

/* If main_cycle returns false, don't process more events! */
int main_cycle() {
	unsigned int key, kascii;
	struct vt_entry *v = &game.view_table[0];

	poll_timer();		/* msdos driver -> does nothing */
	update_timer();

	if (game.ver == 0) {
		message_box("Warning: game CRC not listed, assuming AGI version 2.917.");
		game.ver = -1;
	}

	key = do_poll_keyboard();

#ifdef USE_MOUSE
	/* In AGI Mouse emulation mode we must update the mouse-related
	 * vars in every interpreter cycle.
	 */
	if (opt.agimouse) {
		game.vars[28] = mouse.x / 2;
		game.vars[29] = mouse.y;
	}
#endif

#ifdef USE_CONSOLE
	if (key == KEY_PRIORITY) {
		erase_both();
		debug_.priority = !debug_.priority;
		show_pic();
		blit_both();
		commit_both();
		key = 0;
	}

	if (key == KEY_STATUSLN) {
		debug_.statusline = !debug_.statusline;
		write_status();
		key = 0;
	}
#endif

	/* Click-to-walk mouse interface */
	if (game.player_control && v->flags & ADJ_EGO_XY) {
		v->direction = get_direction(v->x_pos, v->y_pos, v->parm1, v->parm2, v->step_size);

		if (v->direction == 0)
			in_destination(v);
	}

	kascii = KEY_ASCII(key);

	if (!console_keyhandler(key)) {
		if (kascii)
			setvar(V_key, kascii);
		process_key:
		switch (game.input_mode) {
		case INPUT_NORMAL:
			if (!handle_controller(key)) {
				if (key == 0 || !game.input_enabled)
					break;
				handle_keys(key);

				/* if ESC pressed, activate menu before
				 * accept.input from the interpreter cycle
				 * sets the input mode to normal again
				 * (closes: #540856)
				 */
				if (key == KEY_ESCAPE) {
					key = 0;
					goto process_key;
				}

				/* commented out to close bug #438872
				 * if (key) game.keypress = key;
				 */
			}
			break;
		case INPUT_GETSTRING:
			handle_controller(key);
			handle_getstring(key);
			setvar(V_key, 0);	/* clear ENTER key */
			break;
		case INPUT_MENU:
			menu_keyhandler(key);
			console_cycle();
			return false;
		case INPUT_NONE:
			handle_controller(key);
			if (key)
				game.keypress = key;
			break;
		}
	} else {
		if (game.input_mode == INPUT_MENU) {
			console_cycle();
			return false;
		}
	}

	console_cycle();

	if (game.msg_box_ticks > 0)
		game.msg_box_ticks--;

	return true;
}

static int play_game() {
	int ec = err_OK;

	debugC(2, kDebugLevelMain, "initializing...");
	debugC(2, kDebugLevelMain, "game.ver = 0x%x", game.ver);

	stop_sound();
	clear_screen(0);

	game.horizon = HORIZON;
	game.player_control = false;

	setflag(F_logic_zero_firsttime, true);	/* not in 2.917 */
	setflag(F_new_room_exec, true);	/* needed for MUMG and SQ2! */
	setflag(F_sound_on, true);	/* enable sound */
	setvar(V_time_delay, 2);	/* "normal" speed */

	game.gfx_mode = true;
	game.quit_prog_now = false;
	game.clock_enabled = true;
	game.line_user_input = 22;

#ifdef USE_MOUSE
	if (opt.agimouse)
		report("Using AGI Mouse 1.0 protocol\n");
#endif

	report("Running AGI script.\n");

#ifdef USE_CONSOLE
	console.count = 5;
	console_prompt();
#endif

	setflag(F_entered_cli, false);
	setflag(F_said_accepted_input, false);
	game.vars[V_word_not_found] = 0;
	game.vars[V_key] = 0;

	debugC(2, kDebugLevelMain, "Entering main loop");
	do {

		if (!main_cycle())
			continue;

		if (getvar(V_time_delay) == 0 ||
		    (1 + clock_count) % getvar(V_time_delay) == 0) {
			if (!game.has_prompt && game.input_mode == INPUT_NORMAL) {
				write_prompt();
				game.has_prompt = 1;
			} else
			    if (game.has_prompt && game.input_mode == INPUT_NONE) {
				write_prompt();
				game.has_prompt = 0;
			}

			interpret_cycle();

			setflag(F_entered_cli, false);
			setflag(F_said_accepted_input, false);
			game.vars[V_word_not_found] = 0;
			game.vars[V_key] = 0;
		}

		if (game.quit_prog_now == 0xff)
			ec = err_RestartGame;

	} while (game.quit_prog_now == 0);

	stop_sound();

	return ec;
}

int run_game() {
	int i, ec = err_OK;

#ifdef USE_HIRES
	if (opt.cgaemu)
		opt.hires = 0;
#endif

	for (i = 0; i < MAX_DIRS; i++)
		memset(&game.ev_keyp[i], 0, sizeof(struct agi_event));

	/* Execute the game */
	do {
		debugC(2, kDebugLevelMain, "game loop");
		debugC(2, kDebugLevelMain, "game.ver = 0x%x", game.ver);

		if (agi_init() != err_OK)
			break;
		if (ec == err_RestartGame)
			setflag(F_restart_game, true);

		setvar(V_computer, 0);	/* IBM PC (4 = Atari ST) */
		setvar(V_soundgen, 1);	/* IBM PC SOUND */
		setvar(V_monitor, 0x3);	/* EGA monitor */
		setvar(V_max_input_chars, 38);
		game.input_mode = INPUT_NONE;
		game.input_enabled = 0;
		game.has_prompt = 0;

		game.state = STATE_RUNNING;
		ec = play_game();
		game.state = STATE_LOADED;
		agi_deinit();
	} while (ec == err_RestartGame);

	menu_deinit();

	release_image_stack();

	return ec;
}

}                             // End of namespace Agi