/*
Copyright (c) 2013 Andrey Penechko

Boost Software License - Version 1.0 - August 17th, 2003

Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license the "Software" to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
do so, all subject to the following:

The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/

module anchovy.gui.textline;

import anchovy.gui;
public import anchovy.graphics.texrectarray;
import anchovy.graphics.interfaces.irenderer;
import anchovy.graphics.font.fontmanager;

class TextLine
{

public:

	this()
	{
		_text = "";
	}

	void font(Font newFont) @property
	{
		if (newFont is null) return;
		_font = newFont;
		if (!_isInited || newFont != _font)
			init();
	}

	Font font() @property
	{
		return _font;
	}

	bool isInited() @property
	{
		return _isInited;
	}
	
	void update()
	{
		if (text.length == 0 || !_isInited) return;
		if (_isDirty)
		{
			_geometry.load;
			_isDirty = false;
		}
	}

	uint width() @property
	{
		return _width;
	}

	uint height() @property
	{
		return _height;
	}

	ivec2 size() @property
	{
		return ivec2(_width, _height);
	}

	TexRectArray geometry() @property
	{
		return _geometry;
	}

	dstring text() @property
	{
		return _text;
	}

	dstring text(in string newText) @property
	{
		return text = to!dstring(newText);
	}

	dstring text(in dstring newText) @property
	{
		if (_text == newText)
		{
			return _text;
		}

		_text = newText;
		if (!_isInited) return _text;

		_geometry.vertieces = null;
		_cursorX = 0;
		
		appendGlyphs(_text, _font);
		_isDirty = true;

		return _text;
	}

	string fontName() @property
	{
		return _fontName;
	}

	void fontName(string newFontName) @property
	{
		_fontName = newFontName;
	}

	///Supports chaining
	TextLine append(in string text)
	{
		return append(to!dstring(text));
	}

	TextLine append(in dstring text)
	{
		appendGlyphs(_text, _font);
		_isDirty = true;
		return this;
	}

protected:

	void init()
	{
		_geometry = new TexRectArray;
		_height = _font.size;
		appendGlyphs(_text, _font);
		_isInited = true;
	}

	void appendGlyphs(in dstring text, Font font)
	{
		foreach(dchar chr; text)
		{
			Glyph* glyph = font.getGlyph(chr);
			if (glyph !is null && chr == '\t')
			{
				_cursorX += glyph.metrics.advanceX * _tabSize;
				continue;
			}
			if (glyph is null) glyph = font.getGlyph('?');
			
			int x  =  glyph.metrics.offsetX + _cursorX;
			int y  =  font.verticalOffset - glyph.metrics.offsetY;
			int w  =  glyph.metrics.width;
			int h  =  glyph.metrics.height;
			int tx =  glyph.atlasPosition.x;
			int ty =  glyph.atlasPosition.y;
			
			//whitespace
			if (w == 0 || h == 0)
			{
				_cursorX += glyph.metrics.advanceX;
				continue;
			}

			_geometry.appendQuad(Rect(x, y, w, h), Rect(tx, ty, w, h));
			_cursorX += glyph.metrics.advanceX;
		}

		_width = _cursorX;
	}

protected:
	uint _width;
	uint _height;
	dstring _text;
	bool _isInited = false;
	
	TexRectArray _geometry;
	uint _cursorX;
	bool _isDirty = true;
	
	Font _font;
	string _fontName;
	
	ubyte _tabSize = 4;
}