#include <algorithm>
#include <iostream>

#include <glibmm.h>

#include "labpangorenderer.h"

#include "surface.h"
#include "log.h"

#include "freetypeview.h"


FreeTypeView::FreeTypeView():
	p0(new View::Point( Vector2(0, 0) )),
	px(new View::Point( Vector2(1, 0) )),
	py(new View::Point( Vector2(0, 1) )),
	bounds_p0(new View::Point( Vector2(-2, -2) )),
	bounds_p1(new View::Point( Vector2( 2,  2) ))
{
	prev_p0 = p0->position;
	transform *= Matrix().scaling(Vector2(50, 50));
	points.push_back(p0);
	points.push_back(px);
	points.push_back(py);
	points.push_back(bounds_p0);
	points.push_back(bounds_p1);
	
	set_size_request(400, 400);
	
	params.family = "DjVu";
	params.bold = false;
	params.italic = false;
	params.size = 12;

	params.spacing = Vector2(3, 2);
	
	params.hinting = false;
	params.antialiasing = true;
	
	params.matrix = Matrix().translation(Vector2(15.5, 18.4));
	params.color = Color(1, 1, 0, 1);

	params.text =
		"Lorem ipsum dolor sit amet, consectetur adipisici elit,"
		"sed eiusmod tempor incidunt ut labore et dolore magna aliqua."
		"Ut enim ad minim veniam, quis nostrud exercitation ullamco "
		"laboris nisi ut aliquid ex ea commodi consequat. Quis aute iure"
		"reprehenderit in voluptate velit esse cillum dolore eu fugiat "
		"nulla pariatur. Excepteur sint obcaecat cupiditat non proident, "
		"sunt in culpa qui officia deserunt mollit anim id est laborum.";
	//params.text = "1\n2\n3\n";
	
	params.alignment = -1;
	params.justify = false;
	params.wrap_width = 600;
	params.alignment_by_origin = true;
	
	params.origin = Vector2(0.25, 0.8);
	
	Glib::signal_timeout().connect(
		sigc::mem_fun(*this, &FreeTypeView::on_timeout),
		50,
		Glib::PRIORITY_DEFAULT_IDLE );
}

FreeTypeView::~FreeTypeView()
	{ }

bool
FreeTypeView::on_timeout() {
	if (!is_visible()) return false;
	p0->position.x += 0.001;
	point_motion(p0);
	return true;
}
	
void
FreeTypeView::update_surface() {
	this->surface.clear();
	
	Matrix to_pixels = transform_to_pixels();
	
	Matrix in_matrix(
		Vector3(px->position - p0->position)/50,
		Vector3(py->position - p0->position)/50,
		Vector3(p0->position, 1) );
	params.matrix = transform_to_pixels() * in_matrix;
	
	Pair2 bounds = to_pixels.transform_bounds(
		  Pair2(bounds_p0->position)
		.expand(bounds_p1->position) );
	
	const int width = get_allocated_width();
	const int height = get_allocated_height();
	bounds &= Pair2(Vector2(), Vector2(width, height));
	if (bounds.empty())
		return;

	IntPair2 int_bounds = IntPair2( IntVector2( (int)floor(bounds.p0.x + real_precision),
												(int)floor(bounds.p0.y + real_precision) ),
									IntVector2( (int)ceil(bounds.p1.x - real_precision),
												(int)ceil(bounds.p1.y - real_precision) ))
						& IntPair2( IntVector2(),
									IntVector2(width, height) );
	if (int_bounds.empty())
		return;
	
	const Vector2 spacing(
		params.spacing.x > real_precision ? params.spacing.x : 1,
		params.spacing.y > real_precision ? params.spacing.y : 1 );

	const Vector2 origin(
		clamp(params.origin.x, 0, 1),
		clamp(params.origin.y, 0, 1) );
	
	Matrix matrix = params.matrix;
	Matrix2 glyph_matrix(
		matrix.row_x().vec2(),
		matrix.row_y().vec2() );
	matrix *= Matrix().scaling(spacing);
	Matrix bbox_check_matrix =
		  params.matrix
		* Matrix().scaling(
			Vector2( std::max(Real(1), spacing.x),
					 std::max(Real(1), spacing.y) ));

	if (fabs(glyph_matrix.det()) <= real_precision_sqr)
		return;

	const Real size = params.size;
	const Real wrap_width = params.wrap_width;
	
	// init
	PangoFontMap *font_map = lab_pango_font_map_new(params.hinting, params.antialiasing);
	PangoContext *context = pango_font_map_create_context(font_map);
	
	// load font
	PangoFontDescription *font_desc = pango_font_description_new();
	pango_font_description_set_family(font_desc, params.family.c_str());
	pango_font_description_set_weight(font_desc, params.bold ? PANGO_WEIGHT_BOLD : PANGO_WEIGHT_NORMAL);
	pango_font_description_set_style(font_desc, params.italic ? PANGO_STYLE_ITALIC : PANGO_STYLE_NORMAL);
	pango_font_description_set_absolute_size(font_desc, size * PANGO_SCALE);
	PangoFont *font = pango_context_load_font(context, font_desc);
	
	// create layout
	PangoLayout *layout = pango_layout_new(context);
	pango_layout_set_font_description(layout, font_desc);
	pango_layout_set_wrap(layout, PANGO_WRAP_WORD_CHAR);
	pango_layout_set_width(layout, wrap_width  > real_precision ? (int)round(wrap_width *PANGO_SCALE) : -1);
	pango_layout_set_alignment(layout,
		params.alignment < 0 ? PANGO_ALIGN_LEFT :
		params.alignment > 0 ? PANGO_ALIGN_RIGHT : PANGO_ALIGN_CENTER );
	pango_layout_set_justify(layout, params.justify);
	pango_layout_set_text(layout, params.text.c_str(), (int)params.text.size());
	
	// move origin
	PangoRectangle ink_rect, rect;
	pango_layout_get_extents(layout, &ink_rect, &rect);
	const Vector2 offset_to_origin(
		(rect.x + rect.width)/Real(PANGO_SCALE) * origin.x,
		(rect.y + rect.height)/Real(PANGO_SCALE) * origin.y );
	matrix *= Matrix().translation(-offset_to_origin);

	bbox_check_matrix *= Matrix().translation(-offset_to_origin)
					   * Matrix().scaling(Vector2(Real(1)/PANGO_SCALE, Real(1)/PANGO_SCALE));
	const Pair2 dst_rect = bbox_check_matrix.transform_bounds(
		Pair2( Vector2( ink_rect.x, ink_rect.y),
			   Vector2( ink_rect.x + ink_rect.width,
					    ink_rect.y + ink_rect.height) ).inflate(Vector2(2, 2)) );
	
	if (!(bounds & dst_rect).empty()) {
		// create renderer
		DataSurface surface(width, height);
		LabPangoRendererParams rp;
		rp.surface      = &surface;
		rp.bounds       = IntPair2( IntVector2( (int)floor(bounds.p0.x + real_precision),
												(int)floor(bounds.p0.y + real_precision) ),
									IntVector2( (int)ceil(bounds.p1.x - real_precision),
												(int)ceil(bounds.p1.y - real_precision) ))
						& IntPair2( IntVector2(),
									IntVector2(width, height) );
		rp.matrix       = matrix;
		rp.glyph_matrix = glyph_matrix;
		rp.color        = params.color;
		rp.hinting      = params.hinting;
		rp.antialiasing = params.antialiasing;
		PangoRenderer *renderer = lab_pango_renderer_new(&rp);
		
		// render line by line
		pango_renderer_activate(renderer);
		PangoLayoutIter *iter = pango_layout_get_iter(layout);
		do {
			PangoRectangle line_ink_rect, line_rect;
			pango_layout_iter_get_line_extents(iter, &line_ink_rect, &line_rect);
			int x = params.alignment_by_origin
				? (int)round((rect.x + rect.width - line_rect.width)*origin.x)
				: line_rect.x;
			int dx = x - line_rect.x;
				
			const Pair2 dst_line_rect = bbox_check_matrix.transform_bounds(
				Pair2( Vector2( line_ink_rect.x + dx,
							    line_ink_rect.y ),
					   Vector2( line_ink_rect.x + dx + line_ink_rect.width,
								line_ink_rect.y + line_ink_rect.height) ).inflate(Vector2(2, 2)) );

			if (!(bounds & dst_line_rect).empty()) {
				int baseline = pango_layout_iter_get_baseline(iter);
				PangoLayoutLine *line = pango_layout_iter_get_line_readonly(iter);
				pango_renderer_draw_layout_line(renderer, line, x, baseline);
			}
		} while(pango_layout_iter_next_line(iter));
		pango_layout_iter_free(iter);
		pango_renderer_deactivate(renderer);

		g_object_unref(renderer);

		this->surface = surface.to_cairo_surface(true);
	}
	
	// free pango
	pango_font_description_free(font_desc);
	g_object_unref(layout);
	g_object_unref(font);
	g_object_unref(context);
	g_object_unref(font_map);
}

void
FreeTypeView::on_point_motion(const View::PointPtr &point) {
	if (point == p0) {
		px->position += p0->position - prev_p0;
		py->position += p0->position - prev_p0;
		prev_p0 = p0->position;
	}
	queue_draw();
}

void
FreeTypeView::on_draw_view(const Cairo::RefPtr<Cairo::Context> &context) {
	update_surface();

	const Real ps = get_pixel_size();

	context->save();
	context->set_line_width(ps);

	// draw transform
	context->set_source_rgba(0, 0, 1, 1);
	context->move_to(px->position.x, px->position.y);
	context->line_to(p0->position.x, p0->position.y);
	context->line_to(py->position.x, py->position.y);
	context->stroke();

	// draw bounds
	context->set_source_rgba(0, 0, 1, 1);
	context->move_to(bounds_p0->position.x, bounds_p0->position.y);
	context->line_to(bounds_p1->position.x, bounds_p0->position.y);
	context->line_to(bounds_p1->position.x, bounds_p1->position.y);
	context->line_to(bounds_p0->position.x, bounds_p1->position.y);
	context->close_path();
	context->stroke();

	if (surface) {
		context->save();
		context->transform(transform_from_pixels().to_cairo());
		context->set_source(surface, 0, 0);
		context->paint();
		context->restore();
	}
	context->restore();
}