// EvalStats.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"

#include <string>
#include <vector>
#include <istream>
#include <iostream>
#include <fstream>


using namespace std;

/** This is a small function which takes two log files and computes the
	difference in percent of the weighted render cost.
*/


struct RenderStats 
{
	float mRenderCost;
	float mAvgRenderCost;
};


typedef vector<RenderStats> StatsContainer;


enum {NO_TAG, RENDER_COST, AVG_RENDER_COST};


bool extractRenderStats(ifstream &file, StatsContainer &renderStats)
{
	if (!file.is_open())
		return false;
		
	string buf;

	int currentTag = NO_TAG;
	
	while (!(getline(file, buf)).eof())
	{
		//cout << "buf: " << buf << endl;

		if (buf[0] == '#')
		{
			char entry[50];	

			sscanf(buf.c_str(), "#%s", entry);
			
			// new entry
			if (strcmp(entry, "Pass") == 0)
			{
				//cout << "\nnew render stat " << endl;
				renderStats.push_back(RenderStats());
			}
			else if (strcmp(entry, "TotalRenderCost") == 0)
			{
				currentTag = RENDER_COST;
			}
			else if (strcmp(entry, "AvgRenderCost") == 0)
			{
				currentTag = AVG_RENDER_COST;
			}
		}
		else
		{
			float val;
			sscanf(buf.c_str(), "%f", &val);
			
			switch (currentTag)
			{
			case RENDER_COST:
				//cout << "render cost: " << val << endl;
                renderStats.back().mRenderCost = val;
				break;
			case AVG_RENDER_COST:
				//cout << "avg render cost: " << val << endl;
				renderStats.back().mAvgRenderCost = val;
				break;
			default:
				break;
			}
			
			currentTag = NO_TAG;
		}
	}

	return true;
}



void ComputeStats(ofstream &statsOut, 
				  const RenderStats &firstStats, 
				  const RenderStats &currentStats, 
				  const int index)
{
	float denom = firstStats.mRenderCost ? firstStats.mRenderCost : 0.000001f;
	float costRatio = currentStats.mRenderCost / denom;
			
	denom = firstStats.mAvgRenderCost ? firstStats.mAvgRenderCost : 0.000001f;
	float avgCostRatio = currentStats.mAvgRenderCost / denom;

	statsOut << "#ViewCells\n" << index + 1 << endl
			 //<< "#TotalRenderCostGain\n" << 100.0f - costRatio * 100.0f << endl
			 //<< "#AvgRenderCostGain\n" << 100.0f - avgCostRatio * 100.0f << endl << endl;
			 << "#TotalRenderCostGain\n" << 100.0f * costRatio - 100.0f<< endl
			 << "#AvgRenderCostGain\n" << 100.0f * avgCostRatio -100.0f << endl << endl;
}



int _tmain(int argc, _TCHAR* argv[])
{
	vector<StatsContainer> renderStats;
	
	if (argc < 3)
	{
		cerr << "arguments missing. Usage: input1 input2 ... intputn" << endl;
		exit(1);
	}

	vector<string> outFilenames;

	// read input files from command line
	for (int i = 1; i < argc; ++ i)
	{
		StatsContainer currentStats;
      
		ifstream file(argv[i]);

		// extract the render cost
		cout << "extracting render cost of file " << argv[i] << endl;
		cout.flush();

		extractRenderStats(file, currentStats);
		renderStats.push_back(currentStats);

		// create output file name
		string fn = argv[i];
		
		string::size_type pos = fn.find(".log", 0);
		fn.erase(pos, 4);
		//sscanf(argv[i], "%s.log", fn);
		string outFilename = string(fn) + string("-ratio.log");

		outFilenames.push_back(outFilename);
	}

	//statsOut << "rc1 size: " << (int)renderCosts1.size() << " " << (int)renderCosts2.size() << endl << endl;
	vector<StatsContainer>::const_iterator it = renderStats.begin(), it_end = renderStats.end();
	vector<string>::const_iterator sit, sit_end = outFilenames.end();

	sit = outFilenames.begin();
	
	// compare all values with this vector
	StatsContainer &firstStats = renderStats[0];

	// don't compare with itself
	++ it;
	++ sit;

	for (it; it != it_end; ++ it)
	{
		cout << "writing output to file " << *sit << endl;
		ofstream statsOut((*sit).c_str());
		++ sit;

		// compute size of output vector
		const int n = min((int)firstStats.size(), (int)(*it).size());
	
		for (int i = 0; i < n; ++ i)
		{
			ComputeStats(statsOut, firstStats[i], (*it)[i], i);
		}
		
		statsOut.close();
	}

	return 0;
}