/* ScummVM - Scumm Interpreter
 * Copyright (C) 2002-2006 The ScummVM project
 *
 * 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 "base/engine.h"
#include "base/version.h"
#include "common/system.h"
#include "common/util.h"
#include "gui/about.h"
#include "gui/eval.h"
#include "gui/newgui.h"
#include "gui/widget.h"

namespace GUI {

enum {
	kScrollStartDelay = 1500,
	kScrollMillisPerPixel = 60
};

// The following commands can be put at the start of a line (all subject to change):
//   \C, \L, \R  -- set center/left/right alignment
//   \c0 - \c4   -- set a custom color:
//                  0 normal text (green)
//                  1 highlighted text (light green)
//                  2 light border (light gray)
//                  3 dark border (dark gray)
//                  4 background (black)
// TODO: Maybe add a tab/indent feature; that is, make it possible to specify
// an amount by which that line shall be indented (the indent of course would have
// to be considered while performing any word wrapping, too).
//
// TODO: Add different font sizes (for bigger headlines)
// TODO: Allow color change in the middle of a line...
static const char *credits_intro[] = {
"\\C""Copyright (C) 2002-2006 The ScummVM project",
"\\C""http://www.scummvm.org",
"\\C""",
"\\C""LucasArts SCUMM Games (C) LucasArts",
"\\C""Humongous SCUMM Games (C) Humongous",
"\\C""Simon the Sorcerer (C) Adventure Soft",
"\\C""Beneath a Steel Sky (C) Revolution",
"\\C""Broken Sword Games (C) Revolution",
"\\C""Flight of the Amazon Queen (C) John Passfield",
"\\C""and Steve Stamatiadis",
"\\C""Inherit the Earth (C) Wyrmkeep Entertainment",
"\\C""Goblins Games (C) Coktel Vision",
"\\C""The Legend of Kyrandia (C) Westwood Studios",
"\\C""",
"\\C""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.",
"\\C""",
"\\C""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.",
"\\C""",
"\\C""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.",
"\\C"""
};

#include "gui/credits.h"

AboutDialog::AboutDialog()
	: Dialog(10, 20, 300, 174),
	_scrollPos(0), _scrollTime(0), _modifiers(0), _willClose(false) {

	int i;

	const int screenW = g_system->getOverlayWidth();
	const int screenH = g_system->getOverlayHeight();

	xOff = g_gui.evaluator()->getVar("aboutXOff");
	yOff = g_gui.evaluator()->getVar("aboutYOff");
	int outerBorder = g_gui.evaluator()->getVar("aboutOuterBorder");

	_w = screenW - 2 * outerBorder;
	_h = screenH - 2 * outerBorder;

	_lineHeight = g_gui.getFontHeight() + 3;

	// Heuristic to compute 'optimal' dialog width
	int maxW = _w - 2*xOff;
	_w = 0;
	for (i = 0; i < ARRAYSIZE(credits); i++) {
		int tmp = g_gui.getStringWidth(credits[i] + 5);
		if ( _w < tmp && tmp <= maxW) {
			_w = tmp;
		}
	}
	_w += 2*xOff;

	for (i = 0; i < 1; i++)
		_lines.push_back("");

	Common::String version("\\C\\c0""ScummVM ");
	version += gScummVMVersion;
	_lines.push_back(version);

	Common::String date("\\C\\c2""(built on ");
	date += gScummVMBuildDate;
	date += ')';
	_lines.push_back(date);

	Common::String features("\\C\\c2""Supports: ");
	features += gScummVMFeatures;
	addLine(features.c_str());

	_lines.push_back("");

	for (i = 0; i < ARRAYSIZE(credits_intro); i++)
		addLine(credits_intro[i]);

	for (i = 0; i < ARRAYSIZE(credits); i++)
		addLine(credits[i]);

	// Center the dialog
	_x = (screenW - _w) / 2;
	_y = (screenH - _h) / 2;
}

void AboutDialog::addLine(const char *str) {
	// Extract formatting instructions
	Common::String format;
	while (*str == '\\') {
		format += *str++;
		switch (*str) {
		case 'C':
		case 'L':
		case 'R':
			format += *str++;
			break;
		case 'c':
			format += *str++;
			format += *str++;
			break;
		default:
			error("Unknown scroller opcode '%c'\n", *str);
			break;
		}
	}

	if (*str == 0) {
		_lines.push_back(format);
	} else {
		Common::StringList wrappedLines;
		g_gui.getFont().wordWrapText(str, _w - 2 * xOff, wrappedLines);

		for (Common::StringList::const_iterator i = wrappedLines.begin(); i != wrappedLines.end(); ++i) {
			_lines.push_back(format + *i);
		}
	}
}


void AboutDialog::open() {
	_scrollTime = getMillis() + kScrollStartDelay;
	_scrollPos = 0;
	_modifiers = 0;
	_willClose = false;

	Dialog::open();
}

void AboutDialog::close() {
	Dialog::close();
}

void AboutDialog::drawDialog() {
	g_gui.theme()->setDrawArea(Common::Rect(_x, _y, _x+_w, _y+_h));
	Dialog::drawDialog();

	// Draw text
	// TODO: Add a "fade" effect for the top/bottom text lines
	// TODO: Maybe prerender all of the text into another surface,
	//       and then simply compose that over the screen surface
	//       in the right way. Should be even faster...
	const int firstLine = _scrollPos / _lineHeight;
	const int lastLine = MIN((_scrollPos + _h) / _lineHeight + 1, (uint32)_lines.size());
	// FIXME: There's some confusion here about the meaning of 'yOff'.
	//        The setDrawArea call above makes it possible to render text
	//        vertically from _y to _y+_h, while the line below assumes text
	//        is drawn from _y+yOff down. This causes leftover pixels
	//        the top while scrolling.
	int y = _y + yOff - (_scrollPos % _lineHeight);

	for (int line = firstLine; line < lastLine; line++) {
		const char *str = _lines[line].c_str();
		Theme::kTextAlign align = Theme::kTextAlignCenter;
		Theme::kState state = Theme::kStateEnabled;
		while (str[0] == '\\') {
			switch (str[1]) {
			case 'C':
				align = Theme::kTextAlignCenter;
				break;
			case 'L':
				align = Theme::kTextAlignLeft;
				break;
			case 'R':
				align = Theme::kTextAlignRight;
				break;
			case 'c':
				switch (str[2]) {
				case '0':
					state = Theme::kStateEnabled;
					break;
				case '1':
					state = Theme::kStateHighlight;
					break;
				case '2':
					state = Theme::kStateDisabled;
					break;
				case '3':
					warning("Need state for color 3");
					// color = g_gui._shadowcolor;
					break;
				case '4':
					warning("Need state for color 4");
					// color = g_gui._bgcolor;
					break;
				default:
					error("Unknown color type '%c'", str[2]);
				}
				str++;
				break;
			default:
				error("Unknown scroller opcode '%c'\n", str[1]);
				break;
			}
			str += 2;
		}
		// Trim leading whitespaces if center mode is on
		if (align == Theme::kTextAlignCenter)
			while (*str && *str == ' ')
				str++;

		g_gui.theme()->drawText(Common::Rect(_x + xOff, y, _x + _w - xOff, y + g_gui.theme()->getFontHeight()), str, state, align, false, 0, false);
		y += _lineHeight;
	}
	g_gui.theme()->resetDrawArea();
}

void AboutDialog::handleTickle() {
	const uint32 t = getMillis();
	int scrollOffset = ((int)t - (int)_scrollTime) / kScrollMillisPerPixel;
	if (scrollOffset > 0) {
		// Scroll faster when shift is pressed
		if (_modifiers & OSystem::KBD_SHIFT)
			scrollOffset *= 4;
		// Reverse scrolling when alt is pressed
		if (_modifiers & OSystem::KBD_ALT)
			scrollOffset *= -1;
		_scrollPos += scrollOffset;
		_scrollTime = t;

		if (_scrollPos < 0) {
			_scrollPos = 0;
		} else if ((uint32)_scrollPos > _lines.size() * _lineHeight) {
			_scrollPos = 0;
			_scrollTime += kScrollStartDelay;
		}
		drawDialog();
	}
}

void AboutDialog::handleMouseUp(int x, int y, int button, int clickCount) {
	// Close upon any mouse click
	close();
}

void AboutDialog::handleKeyDown(uint16 ascii, int keycode, int modifiers) {
	_modifiers = modifiers;
	if (ascii)
		_willClose = true;
}

void AboutDialog::handleKeyUp(uint16 ascii, int keycode, int modifiers) {
	_modifiers = modifiers;
	if (ascii && _willClose)
		close();
}

void AboutDialog::handleScreenChanged() {
	Dialog::handleScreenChanged();
	const int screenW = g_system->getOverlayWidth();
	const int screenH = g_system->getOverlayHeight();

	xOff = g_gui.evaluator()->getVar("aboutXOff");
	yOff = g_gui.evaluator()->getVar("aboutYOff");
	int outerBorder = g_gui.evaluator()->getVar("aboutOuterBorder");

	_w = screenW - 2 * outerBorder;
	_h = screenH - 2 * outerBorder;

	_lineHeight = g_gui.getFontHeight() + 3;

	// Heuristic to compute 'optimal' dialog width
	int maxW = _w - 2*xOff;
	_w = 0;
	for (int i = 0; i < ARRAYSIZE(credits); i++) {
		int tmp = g_gui.getStringWidth(credits[i] + 5);
		if ( _w < tmp && tmp <= maxW) {
			_w = tmp;
		}
	}
	_w += 2*xOff;

	_lineHeight = g_gui.getFontHeight() + 3;

	_x = (screenW - _w) / 2;
	_y = (screenH - _h) / 2;
}

} // End of namespace GUI