#include "graph.h"
#include "debug.h"
#include <cmath>

using std::abs;

int Graph::MAX_MOVE_DISTANCE = 100;

Graph::Graph()
{
    current_vertex = NULL;
}

Graph::~Graph()
{
    for (list<Vertex*>::iterator cursor = vertices.begin();
	 cursor != vertices.end(); cursor++)
    {
	Vertex* v = *cursor;
	delete v;
    }
}

bool Graph::vertex_present(int x, int y, int size)
{
    int delta = size / 2;

    int x_min = x - delta;
    int x_max = x + delta;
    int y_min = y - delta;
    int y_max = y + delta;

    for (list<Vertex*>::iterator cursor = vertices.begin();
	 cursor != vertices.end(); cursor++)
    {
	Vertex v = *(*cursor);
	if (((x_min >= v.x_min && x_min <= v.x_max) &&
	     ((y_min >= v.y_min && y_min <= v.y_max) ||
	      (y_max >= v.y_min && y_max <= v.y_max))) ||
	    ((x_max >= v.x_min && x_max <= v.x_max) &&
	     ((y_min >= v.y_min && y_min <= v.y_max) ||
	      (y_max >= v.y_min && y_max <= v.y_max))))
	{
#ifdef DEBUG
    cerr << "debug: Graph::vertex_present(): vertex present at x=" << v.x << ", y=" << v.y << "\n";
#endif
	    return true;
	}
    }

	return false;
}


void Graph::do_vertex(int x, int y, int size)
{
    if (vertex_present(x, y, size)) select_vertex(x, y);
    else add_vertex(x, y, size);
}


void Graph::select_vertex(int x, int y)
{
    for (list<Vertex*>::iterator cursor = vertices.begin();
	 cursor != vertices.end(); cursor++)
    {
	Vertex* v = *cursor;
	if (x >= v->x_min && x <= v->x_max && y >= v->y_min && y <= v->y_max)
	{
	    current_vertex = v;
	    return;
	}
    }
}


void Graph::add_vertex(int x, int y, int size)
{
    if (current_vertex != NULL &&
	(Vertex::distance(*current_vertex, Vertex(x, y)) > MAX_MOVE_DISTANCE))
	return;

    Vertex* v = new Vertex(x, y);
    v->x_min = x - size/2;
    v->x_max = x + size/2;
    v->y_min = y - size/2;
    v->y_max = y + size/2;

    if (vertex_present(v->x, v->y, 25)) return;

    vertices.push_back(v);

    if (current_vertex == NULL)
    {
	current_vertex = v;
	return;
    }

    Edge e;
    e.a = current_vertex;
    e.b = v;
    edges.push_back(e);
    current_vertex = v;
}


float Vertex::distance(Vertex a, Vertex b)
{
    float dy = abs(static_cast<float>(b.y) - a.y);
    float dx = abs(static_cast<float>(b.x) - a.x);
    return sqrt(dy*dy + dx*dx);
}