/* 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.
 *
 * $Header$
 */

#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/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""",
"\\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();

	int outerBorder;

	if (screenW >= 400 && screenH >= 300) {
		xOff = 8;
		yOff = 5;
		outerBorder = 80;
	} else {
		xOff = 3;
		yOff = 2;
		outerBorder = 10;
	}

	_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;
	_canvas.pixels = NULL;

	Dialog::open();
}

void AboutDialog::close() {
	free(_canvas.pixels);
	Dialog::close();
}

void AboutDialog::drawDialog() {
	if (!_canvas.pixels) {
		// Blend over the background. Since we can't afford to do that
		// every time the text is updated (it's horribly CPU intensive)
		// we do it just once and then use a copy of the result as our
		// static background for the remainder of the credits.
		g_gui.blendRect(_x, _y, _w, _h, g_gui._bgcolor);
		g_gui.copyToSurface(&_canvas, _x, _y, _w, _h);
	}

	g_gui.drawSurface(_canvas, _x, _y);

	// 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());
	int y = _y + yOff - (_scrollPos % _lineHeight);

	for (int line = firstLine; line < lastLine; line++) {
		const char *str = _lines[line].c_str();
		Graphics::TextAlignment align = Graphics::kTextAlignCenter;
		OverlayColor color = g_gui._textcolor;
		while (str[0] == '\\') {
			switch (str[1]) {
			case 'C':
				align = Graphics::kTextAlignCenter;
				break;
			case 'L':
				align = Graphics::kTextAlignLeft;
				break;
			case 'R':
				align = Graphics::kTextAlignRight;
				break;
			case 'c':
				switch (str[2]) {
				case '0':
					color = g_gui._textcolor;
					break;
				case '1':
					color = g_gui._textcolorhi;
					break;
				case '2':
					color = g_gui._color;
					break;
				case '3':
					color = g_gui._shadowcolor;
					break;
				case '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 == Graphics::kTextAlignCenter)
			while (*str && *str == ' ')
				str++;

		g_gui.drawString(str, _x + xOff, y, _w - 2 * xOff, color, align, 0, false);
		y += _lineHeight;
	}

	// Draw a border
	g_gui.box(_x, _y, _w, _h, g_gui._color, g_gui._shadowcolor);

	// Finally blit it all to the screen
	g_gui.addDirtyRect(_x, _y, _w, _h);
}


void AboutDialog::handleTickle() {
	// We're in the process of doing a full redraw to re-create the
	// background image for the text. That means we need to wait for the
	// GUI itself to clear the overlay and call drawDialog() in all of the
	// dialogs, otherwise we'll only redraw this one and it'll still have
	// the remains of the old image, including the text that was on it.
	if (!_canvas.pixels)
		return;

	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::handleScreenChanged() {
	// The screen has changed. That means the overlay colors in the canvas
	// may no longer be correct. Reset it, and issue a full redraw.
	// TODO: We could check if the bit format has changed, like we do in
	// the MPEG player.
	free(_canvas.pixels);
	_canvas.pixels = NULL;
	draw();
}

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();
}


} // End of namespace GUI