//
//  VoxelModel.cpp
//  OpenSpades
//
//  Created by yvt on 7/15/13.
//  Copyright (c) 2013 yvt.jp. All rights reserved.
//

#include "VoxelModel.h"
#include "Exception.h"
#include <algorithm>
#include <vector>
#include "Debug.h"

namespace spades {
	VoxelModel::VoxelModel(int w, int h, int d) {
		SPADES_MARK_FUNCTION();
		
		width = w;
		height = h;
		depth = d;
		if(d > 64){
			SPRaise("Voxel model with depth > 64 is not supported.");
		}
		
		solidBits = new uint64_t[w * h];
		colors = new uint32_t[w * h * d];
		
		std::fill(solidBits, solidBits + w * h, 0);
		
	}
	VoxelModel::~VoxelModel() {
		SPADES_MARK_FUNCTION();
		
		delete[] solidBits;
		delete[] colors;
	}
	
	struct KV6Block {
		uint32_t color;
		uint16_t zPos;
		uint8_t visFaces;
		uint8_t lighting;
	};
	
	struct KV6Header {
		uint32_t xsiz, ysiz, zsiz;
		float xpivot, ypivot, zpivot;
		uint32_t blklen;
	};
	static uint32_t swapColor(uint32_t col ){
		union {
			uint8_t bytes[4];
			uint32_t c;
		} u;
		u.c = col;
		std::swap(u.bytes[0], u.bytes[2]);
		return (u.c & 0xffffff);
	}
	
	
	VoxelModel *VoxelModel::LoadKV6(spades::IStream *stream) {
		SPADES_MARK_FUNCTION();
		
		if(stream->Read(4) != "Kvxl"){
			SPRaise("Invalid magic");
		}
		
		KV6Header header;
		if(stream->Read(&header, sizeof(header)) < sizeof(header)){
			SPRaise("File truncated: failed to read header");
		}
		
		std::vector<KV6Block> blkdata;
		blkdata.resize(header.blklen);
		
		if(stream->Read(blkdata.data(), sizeof(KV6Block) * header.blklen) <
		   sizeof(KV6Block) * header.blklen){
			SPRaise("File truncated: failed to read blocks");
		}
		
		std::vector<uint32_t> xoffset;
		xoffset.resize(header.xsiz);
		
		if(stream->Read(xoffset.data(), sizeof(uint32_t) * header.xsiz) <
		   sizeof(uint32_t) * header.xsiz){
			SPRaise("File truncated: failed to read xoffset");
		}
		
		std::vector<uint16_t> xyoffset;
		xyoffset.resize(header.xsiz * header.ysiz);
		
		if(stream->Read(xyoffset.data(), sizeof(uint16_t) * header.xsiz * header.ysiz) <
		   sizeof(uint16_t) * header.xsiz * header.ysiz){
			SPRaise("File truncated: failed to read xyoffset");
		}
		
		// validate: zpos < depth
		for(size_t i = 0; i < blkdata.size(); i++)
			if(blkdata[i].zPos >= header.zsiz)
				SPRaise("File corrupted: blkData[i].zPos >= header.zsiz");
		
		// validate sum(xyoffset) = blkLen
		{
			uint64_t ttl = 0;
			for(size_t i = 0; i < xyoffset.size(); i++){
				ttl += (uint32_t)xyoffset[i];
			}
			if(ttl != (uint64_t)blkdata.size())
				SPRaise("File corrupted: sum(xyoffset) != blkdata.size()");
		}
		
		VoxelModel *model = new VoxelModel(header.xsiz, header.ysiz, header.zsiz);
		model->SetOrigin(MakeVector3(-header.xpivot,
									 -header.ypivot,
									 -header.zpivot));
		try{
			int pos = 0;
			for(int x = 0; x < (int)header.xsiz; x++)
				for(int y = 0; y < (int)header.ysiz; y++){
					int spanBlocks = (int)xyoffset[x *header.ysiz + y];
					int lastZ = -1;
					//printf("pos: %d, (%d, %d): %d\n",
					//	   pos, x, y, spanBlocks);
					while(spanBlocks--){
						const KV6Block& b = blkdata[pos];
						//printf("%d, %d, %d: %d, %d\n", x, y, b.zPos,
						//	   b.visFaces, b.lighting);
						if(model->IsSolid(x, y, b.zPos)){
							SPRaise("Duplicate voxel (%d, %d, %d)",
									x, y, b.zPos);
						}
						if(b.zPos <= lastZ){
							SPRaise("Not Z-sorted");
						}
						lastZ = b.zPos;
						model->SetSolid(x, y, b.zPos,
										swapColor(b.color));
						pos++;
					}
				}
			
			SPAssert(pos == blkdata.size());
			
			return model;
		}catch(...){
			delete model;
			throw;
		}
	}
	
}