#include <stdio.h>
#include <string.h>
#include <sstream>
#include <iostream>
#include <fstream>
#include <vector>
#include <tuple>
#include <cmath>
#include <numeric>  
#include <map>
#include <algorithm>
#include <filesystem>
#include <unistd.h> 

#include <bits/stdc++.h> 
#include <iostream> 
#include <sys/stat.h> 
#include <sys/types.h> 

#include "rawls.h"

struct Point {
    unsigned x;
    unsigned y;
};

struct Tile {
    Point p1;
    Point p2;
};

std::vector<std::string> split(const std::string& s, char delimiter)
{
   std::vector<std::string> tokens;
   std::string token;
   std::istringstream tokenStream(s);
   while (std::getline(tokenStream, token, delimiter))
   {
      tokens.push_back(token);
   }
   return tokens;
}

void writeProgress(float progress, bool moveUp = false){
    int barWidth = 200;

    if (moveUp){
        // move up line
        std::cout << "\e[A";
        std::cout.flush();
    }

    std::cout << "[";
    int pos = barWidth * progress;
    for (int i = 0; i < barWidth; ++i) {
        if (i < pos) std::cout << "=";
        else if (i == pos) std::cout << ">";
        else std::cout << " ";
    }
    std::cout << "] " << int(progress * 100.0) << " %\r";
    std::cout.flush();
}

float getEstimator(std::string estimator, std::vector<float> values) {

    if (estimator == "median") {
        
        std::sort(values.begin(), values.end());

        unsigned size = values.size();

        if (size % 2 == 0)
        {
            return (values[size / 2 - 1] + values[size / 2]) / 2;
        }
        else 
        {
            return values[size / 2];
        }
    } else if (estimator == "mean") {

        return std::accumulate(values.begin(), values.end(), 0.0) / values.size(); 

    } else if (estimator == "var") {
        // Calculate the mean
        const float mean = std::accumulate(values.begin(), values.end(), 0.0) / values.size();

        // Now calculate the variance
        auto variance_func = [&mean](float accumulator, const float& val) {
            return accumulator + pow(val - mean, 2);
        };

        return std::accumulate(values.begin(), values.end(), 0.0, variance_func) / values.size();

    } else if (estimator == "std") {

        return sqrt(getEstimator("var", values));

    } else if (estimator == "skewness") {

        unsigned size = values.size();

        float mean = getEstimator("mean", values);
        float std = getEstimator("std", values);

        // Now calculate the sum of pow 3
        auto order3_func = [&mean, &std](float accumulator, const float& val) {
            return accumulator + pow((val - mean) / std, 3);
        };

        float order3 = std::accumulate(values.begin(), values.end(), 0.0, order3_func);

        return order3 / size;

    } else if (estimator == "kurtosis") {
        
        unsigned size = values.size();

        float mean = getEstimator("mean", values);
        float std = getEstimator("std", values);

        // Now calculate the sum of pow 4
        auto order4_func = [&mean, &std](float accumulator, const float& val) {
            return accumulator + pow((val - mean) / std, 4);
        };

        float order4 = std::accumulate(values.begin(), values.end(), 0.0, order4_func);

        return order4 / size;

    } else if (estimator == "mode") {

        std::vector<float> pvalues;

        for (unsigned i = 0; i < values.size(); i++){
            pvalues.push_back(roundf(values.at(i) * 100) / 100.0);
        }

        typedef std::map<float,unsigned int> CounterMap;
        CounterMap counts;
        for (int i = 0; i < pvalues.size(); ++i)
        {
            CounterMap::iterator it(counts.find(pvalues[i]));
            if (it != counts.end()){
                it->second++;   
            } else {
                counts[pvalues[i]] = 1;
            }
        }

        // Create a map iterator and point to beginning of map
        std::map<float, unsigned int>::iterator it = counts.begin();
        unsigned noccurences = 0;
        float modeValue = 0.;
        // Iterate over the map using Iterator till end.
        while (it != counts.end())
        {
            // Accessing KEY from element pointed by it.
            float potentialMode = it->first;
            // Accessing VALUE from element pointed by it.
            unsigned count = it->second;

            if (count > noccurences) {
                noccurences = count;
                modeValue = potentialMode;
            }

            // Increment the Iterator to point to next entry
            it++;
        }

        return modeValue;
    }

    // by default
    return 0.;
}

int main(int argc, char *argv[]){

    std::string folderName;
    std::vector<std::string> estimators = {"median", "var", "std", "skewness", "kurtosis", "mode"};
    unsigned blockHeight;
    unsigned blockWidth;
    std::string outputFolder;

    for (int i = 1; i < argc; ++i) {
        if (!strcmp(argv[i], "--folder") || !strcmp(argv[i], "-folder")) {
            folderName = argv[++i];
        } else if (!strcmp(argv[i], "--bwidth") || !strcmp(argv[i], "-bwidth")) {
            blockHeight = atoi(argv[++i]);
        } else if (!strcmp(argv[i], "--bheight") || !strcmp(argv[i], "-bheight")) {
            blockWidth = atoi(argv[++i]);
        } else if (!strcmp(argv[i], "--output") || !strcmp(argv[i], "-output")) {
            outputFolder = argv[++i];
        }
    }

    std::vector<std::string> imagesPath;

    for (const auto & entry : std::filesystem::directory_iterator(folderName)){
        std::string imageName = entry.path().string();
        if (rawls::HasExtension(imageName, ".rawls") || rawls::HasExtension(imageName, ".rawls_20")){
            imagesPath.push_back(imageName);
        }
    }

    std::sort(imagesPath.begin(), imagesPath.end());

    std::tuple<unsigned, unsigned, unsigned> data = rawls::getDimensionsRAWLS(imagesPath.at(0));

    unsigned outputWidth = std::get<0>(data);
    unsigned outputHeight = std::get<1>(data);
    unsigned nbChanels = std::get<2>(data);

    std::vector<float*> outputBuffers;
    // new buffer size as new output buffer image (default 3 channels)

    for (int i = 0; i < estimators.size(); i++)
        outputBuffers.push_back(new float[outputHeight * outputWidth * nbChanels]);

    // get all tiles to apply
    unsigned nWidth = ceil(outputWidth / (float)blockWidth);
    unsigned nHeight = ceil(outputHeight / (float)blockHeight);

    std::vector<Tile> tiles;

    for (unsigned i = 0; i < nWidth; i++) {
        for (unsigned j = 0; j < nHeight; j++) {

            unsigned x1 = i * blockWidth;
            unsigned y1 = j * blockHeight;

            unsigned x2 = i * blockWidth + blockWidth;
            unsigned y2 = j * blockHeight + blockHeight;

            x2 = x2 > outputWidth ? outputWidth: x2;
            y2 = y2 > outputHeight ? outputHeight: y2;
            
            Point p1 = {x1, y1};
            Point p2 = {x2, y2};

            Tile tile = {p1, p2};
            tiles.push_back(tile);
        }
    }

    unsigned nsamples = imagesPath.size();
    unsigned nloop = tiles.size() * nsamples;
    unsigned nloopCounter = 0;

    for (unsigned t_index = 0; t_index < tiles.size(); t_index++){

        Tile tile = tiles.at(t_index);

        //std::cout << "Tile: (" << tile.p1.x << ", " << tile.p1.y << ")" << " => " << "(" << tile.p2.x << ", " << tile.p2.y << ")" << std::endl;

        unsigned nvalues = (tile.p2.x - tile.p1.x) * (tile.p2.y - tile.p1.y) * 3;

        std::vector<std::vector<float>> rgbValues(nvalues);

        for (unsigned i = 0; i < nsamples; i++) {
            
            try {
                
                float* RGBpixels = rawls::getPixelsRAWLS(imagesPath.at(i));

                unsigned index = 0;
                for (int y = tile.p1.y; y < tile.p2.y; ++y) {
                    for (int x = tile.p1.x; x < tile.p2.x; ++x) {
            
                        rgbValues.at(index).push_back(RGBpixels[3 * (y * outputWidth + x) + 0]);
                        rgbValues.at(index + 1).push_back(RGBpixels[3 * (y * outputWidth + x) + 1]);
                        rgbValues.at(index + 2).push_back(RGBpixels[3 * (y * outputWidth + x) + 2]);

                        index += 3;
                    
                    }
                }

                delete RGBpixels;

            } catch(std::exception& e){
                std::cout << "Error occurs when reading file" << std::endl;
            }

            // display progress
            nloopCounter += 1;
            writeProgress(nloopCounter / (float)nloop);
        }


        for (int i = 0; i < outputBuffers.size(); i++) {
        
            // extract stat and add predicted value into output buffer
            unsigned index = 0;

            for (int y = tile.p1.y; y < tile.p2.y; ++y) {
                for (int x = tile.p1.x; x < tile.p2.x; ++x) {
                    
                    outputBuffers.at(i)[3 * (y * outputWidth + x) + 0] = getEstimator(estimators.at(i), rgbValues.at(index + 0));
                    outputBuffers.at(i)[3 * (y * outputWidth + x) + 1] = getEstimator(estimators.at(i), rgbValues.at(index + 1));
                    outputBuffers.at(i)[3 * (y * outputWidth + x) + 2] = getEstimator(estimators.at(i), rgbValues.at(index + 2));

                    index += 3;
                }
            }
        }
    }

    // Save here new rawls image
    std::string comments = rawls::getCommentsRAWLS(imagesPath.at(0));

    // create outputs directory
    mkdir(outputFolder.c_str(), 0755);

    auto elements = split(folderName, '/');
    std::string sceneName = elements.at(elements.size() - 1);

    mkdir((outputFolder + "/" + sceneName).c_str(), 0755);

    for (int i = 0; i < outputBuffers.size(); i++) {

        // construct specific outfile name
        std::string outputfile = outputFolder + "/" + sceneName + "/" + sceneName + "_" + estimators.at(i) + ".rawls";
        bool success = rawls::saveAsRAWLS(outputWidth, outputHeight, nbChanels, comments, outputBuffers.at(i), outputfile);

        if (success) {
            std::cout << "New image saved into " << outputfile << std::endl;
        }
        else
        {
            std::cout << "Error while saving current image " << outputfile << std::endl;
        }

        delete outputBuffers[i];
    }

}