#include "TbirdUvSynth.h"
using namespace CCS;

const int TbirdUvSynth::NUM_TBIRD_UVS = 4;

bool TbirdUvSynth::addVisitedFace(Face* f)
{
	pair<set<Face*>::iterator, bool> stat = visitedFaces.insert(f);

	bool wasntAlreadyThere = stat.second;
	return wasntAlreadyThere;
}

/*
 * Returns the tbird UV number that the neighbor (an edge nbor)
 * should start with if the current face starts at vertStart
 * at the shared edge.
 */
int TbirdUvSynth::getStartUvForNbor(int vertStart)
{
	switch(vertStart)
	{
		case 0: return 0;
		case 1: return 3;
		case 2: return 2;
		case 3: return 1;
		default:
				__ERROR__("bad vertstart for tbird UV: " << vertStart);
				exit(1);
				return -1;
	}
}

/*
 * The main recursive func
 */
void TbirdUvSynth::synthUVs(Face* f, Vertex* startVert, int startUvNum)
{

	if(addVisitedFace(f)) {
		// This hasn't been synth'd yet - do it!
		
		if(f->edgeUses.size() != NUM_TBIRD_UVS) {
			__ERROR__("tried to syth tbird UVs over a face that has "
					<< f->edgeUses.size() << " verts!  It should only have " 
					<< NUM_TBIRD_UVS << " verts..");
			exit(1);
		}

		f->txtr = this->tbirdTxtr;

		// first, obtain the UVs iterator that corresponds
		// to the given startVert
		list<UVs>::iterator uv_iter;
	   	list<EdgeUse>::iterator eu_iter;
		f->getItersForVert(startVert, eu_iter, uv_iter);

		__STAT__("starting face at vert " << startVert->p << " with UV num " << startUvNum);

		int uvNum = startUvNum;

		for(int count = 0; count < NUM_TBIRD_UVS; ++count) {
			// set the UV!
			*uv_iter = this->tbirdUVs[uvNum];

			// recursively do the current nbor
			Face *nbor = (*eu_iter).getSharingFace();
			Vertex *nborStart = (*eu_iter).getUseStart();
			if(nbor != NULL) {
				synthUVs(nbor, nborStart, getStartUvForNbor(uvNum));
			}
			else {
				__WARN__("non-closed mesh given!");
			}

			// advance uv iter and uvNum, cyclically
			uvNum = (uvNum + 1) % NUM_TBIRD_UVS;

			++uv_iter;
			++eu_iter;
			if(uv_iter == f->uvs.end()) {
				// wrap!
				uv_iter = f->uvs.begin();
				eu_iter = f->edgeUses.begin();
			}
		}
	}
	else {
		// don't do jack
	}
}

TbirdUvSynth::TbirdUvSynth()
{
	// set UVs
	this->tbirdUVs.clear();
	this->tbirdUVs.resize(NUM_TBIRD_UVS);
	this->tbirdUVs[0] = UVs(0,0);
	this->tbirdUVs[1] = UVs(1,0);
	this->tbirdUVs[2] = UVs(1,1);
	this->tbirdUVs[3] = UVs(0,1);

	tbirdTxtr = NULL;
	visitedFaces.clear();
}

void TbirdUvSynth::synth(Mesh *mesh, TiffImage *txtr)
{
	tbirdTxtr = txtr;
	visitedFaces.clear();

	Face *firstFace = mesh->faces.front();
	Vertex *firstVert = firstFace->edgeUses.front().getUseStart();

	synthUVs(firstFace, firstVert, 0);
}