/*
   ui/scrollpane.cc
   This file is part of the Osirion project and is distributed under
   the terms of the GNU General Public License version 2
*/

#include <cmath>

#include "ui/scrollpane.h"
#include "render/text.h"
#include "render/gl.h"

namespace ui
{

ScrollPane::ScrollPane(Widget *parent, ui::Text &text) : Widget(parent), scrollpane_text(text)
{
	set_label("scrollpane");
	set_alignment(AlignBottom);
	scrollpane_scroll = 0;
	scrollpane_offset = 1;
}

ScrollPane::~ScrollPane()
{
}

void ScrollPane::set_alignment(const unsigned int alignment)
{
	scrollpane_alignment = alignment;
}

void ScrollPane::set_scroll(const int scroll)
{
	scrollpane_scroll = scroll;

	if (scrollpane_scroll > (int) scrollpane_text.size())
		scrollpane_scroll = (int) scrollpane_text.size();
	else if (scrollpane_scroll < 0)
		scrollpane_scroll = 0;
}

void ScrollPane::inc_scroll(const int scroll)
{
	scrollpane_scroll += scroll;

	if (scrollpane_scroll > (int) scrollpane_text.size())
		scrollpane_scroll = (int) scrollpane_text.size();
	else if (scrollpane_scroll < 0)
		scrollpane_scroll = 0;
}

void ScrollPane::dec_scroll(const int scroll)
{
	scrollpane_scroll -= scroll;

	if (scrollpane_scroll > (int) scrollpane_text.size())
		scrollpane_scroll = (int) scrollpane_text.size();
	else if (scrollpane_scroll < 0)
		scrollpane_scroll = 0;
}

void ScrollPane::set_offset(const int offset)
{
	scrollpane_offset = offset;
}

bool ScrollPane::on_mousewheel(const math::Vector2f & direction)
{
	// number of lines to scroll
	int alignmentmodifier =( (alignment() & AlignTop) == AlignTop) ? -1 : 1;
	
	if (direction.y() > 0 )
	{
		inc_scroll(alignmentmodifier * scrollpane_offset);
		return true;
	} else if (direction.y() < 0 ) 
	{
		dec_scroll(alignmentmodifier * scrollpane_offset);
		return true;
	}
	
	return false;
}

void ScrollPane::draw()
{
	render::Text::setfont(font()->name().c_str(), font()->width(), font()->height());
	gl::enable(GL_TEXTURE_2D);

	// text size
	int text_height = (int) floorf(height() / font()->height());
	int text_width = (int) floorf(width() / font()->width());

	// validate scroll position
	if (scrollpane_scroll > (int) scrollpane_text.size())
		scrollpane_scroll = (int) scrollpane_text.size();
	else if (scrollpane_scroll < 0)
		scrollpane_scroll = 0;
	
	int bottom = 0;
	int current_line = 0;
	
	if ((alignment() & AlignTop) == AlignTop) {
		bottom = text_height + (int) scrollpane_scroll;
	} else {
		bottom = (int) scrollpane_text.size() - scrollpane_scroll;
	}
	
	ui::Text lines;
	for (ui::Text::const_iterator it = scrollpane_text.begin(); it != scrollpane_text.end() && current_line < bottom; it++) {
		if (current_line >= bottom - text_height) {
			std::string linedata(*it);
			linedata += '\n';

			std::string word;
			size_t word_length = 0;

			std::string line;
			size_t line_length = 0;

			const char *c = linedata.c_str();
			char pen = 'N';
			char wordpen = 'N';

			while (*c) {

				// color code
				if (aux::is_color_code(c)) {
					c++;
					pen = *c;
					word += '^';
					word += pen;
				}

				// new word, wrap if necessary
				else if ((*c == '\n') || (*c == ' ')) {

					if (line_length + word_length > (size_t) text_width) {
						if (line.size()) {
							lines.push_back(line);
							line.clear();
							line += '^';
							line += wordpen;
							line_length = 0;
						}
					}

					line.append(word);
					line_length += word_length;

					word.clear();
					word_length = 0;
					wordpen = pen;

					// new line
					if (*c == '\n') {
						lines.push_back(line);
						line.clear();
						line_length = 0;
						pen = 'N';
						wordpen = 'N';
						// new word
					} else if (*c == ' ') {
						line += ' ';
						line_length++;
					}
				}

				// new character
				else {
					word += *c;
					word_length++;

					if (word_length == (size_t) text_width) {
						if (line.size()) {
							lines.push_back(line);
							line.clear();
							line += '^';
							line += wordpen;
							line_length = 0;
						}

						line.append(word);
						line_length = word_length;

						word.clear();
						word_length = 0;
						wordpen = pen;
					}
				}

				c++;
			}

		}
		current_line++;
	}

	gl::color(palette()->text());
	const math ::Vector2f gl(global_location());
	float y = 0;

	if ((alignment() & AlignTop) == AlignTop) {
		for (ui::Text::iterator it = lines.begin(); (y + font()->height() < height()) && (it != lines.end()); it++) {
			render::Text::draw(gl.x(), gl.y() + y, (*it));
			y += font()->height();
		}
	} else {
		y = height() - font()->height();
		for (ui::Text::reverse_iterator rit = lines.rbegin(); (y >= 0) && (rit != lines.rend()); ++rit) {
			render::Text::draw(gl.x(), gl.y() + y, (*rit));
			y -= font()->height();
		}
	}
	gl::disable(GL_TEXTURE_2D);
}

}