#include "exports.hpp"
#include "graph.hpp"
#include "graph_powerlaw.hpp"
#include "graph_spectrum.hpp"
#include "switchchain.hpp"
#include <algorithm>
#include <fstream>
#include <iostream>
#include <numeric>
#include <random>
#include <vector>


int main(int argc, char* argv[]) {
    // Simulation parameters
    const int numVerticesMin = 10000;
    const int numVerticesMax = 10000;
    const int numVerticesStep = 1000;

    float tauValues[] = {2.1f, 2.5f, 2.9f};

    auto getMixingTime = [](int n, float tau) {
        return int(100.0f * (50.0f - 5.0f * (tau - 2.0f)) * n);
    };
    auto getMeasurements = [](int n, float tau) {
        (void)n;
        (void)tau;
        return 5000000;
    };

    // Output file
    std::ofstream outfile;
    if (argc >= 2)
        outfile.open(argv[1]);
    else
        outfile.open("graphdata_canonical_creationfreqs.m");
    if (!outfile.is_open()) {
        std::cout << "ERROR: Could not open output file.\n";
        return 1;
    }

    // Output Mathematica-style comment to indicate file contents
    outfile << "(*\n";
    outfile << "n from " << numVerticesMin << " to " << numVerticesMax
            << " step " << numVerticesStep << std::endl;
    outfile << "tauValues: " << tauValues << std::endl;
    outfile << "Canonical degree sequence.\n";
    outfile << "mixingTime: 100 * (50 - 5 (tau - 2)) n\n";
    outfile << "measurements: 5000000\n";
    outfile << "measureSkip: 0\n";
    outfile << "histogram is conditioned on successful switches\n";
    outfile << "data:\n";
    outfile << "1: {n,tau}\n";
    outfile << "2: { {delta1, freq1} , {delta2, freq2} , ... }\n";
    outfile << "3: {successful switches, total attempted switches}\n";
    outfile << "*)" << std::endl;

    // Mathematica does not accept normal scientific notation
    outfile << std::fixed;
    outfile << '{' << '\n';
    bool outputComma = false;

    Graph g;
    for (int numVertices = numVerticesMin; numVertices <= numVerticesMax;
         numVertices += numVerticesStep) {
        for (float tau : tauValues) {
            DegreeSequence ds;
            generateCanonicalPowerlawGraph(numVertices, tau, g, ds);

            SwitchChain chain;
            if (!chain.initialize(g)) {
                std::cerr << "Could not initialize Markov chain.\n";
                return 1;
            }

            std::cout << "Running (n,tau) = (" << numVertices << ',' << tau
                      << "). " << std::flush;

            // Mix
            int mixingTime = getMixingTime(numVertices, tau);
            for (int i = 0; i < mixingTime; ++i) {
                chain.doMove();
            }

            std::cout << "Mixing done. " << std::flush;

            int range = 500;
            // Keep track of [-range, range]
            std::vector<int> frequencies(2*range+1, 0);
            // frequencies[x+range] corresponds to frequency of x
            // clip anything outside of range to range!

            int prevTriangles = chain.g.countTriangles();
            chain.g.getTrackedTriangles() = prevTriangles;

            int movesDone = 0;
            int measurements = getMeasurements(numVertices, tau);
            for (int i = 0; i < measurements; ++i) {
                if (chain.doMove(true)) {
                    ++movesDone;
                    int newTriangles = chain.g.getTrackedTriangles();
                    int diff = newTriangles - prevTriangles;
                    prevTriangles = newTriangles;
                    // Add 'diff' to histogram
                    if (diff < -range)
                        diff = -range;
                    else if (diff > range)
                        diff = range;
                    frequencies[diff+range]++;
                }
            }

            std::cout << "Measuring done. " << std::flush;

            std::vector<std::pair<int, int>> histogram;
            for (int i = -range; i <= range; ++i) {
                histogram.push_back(std::make_pair(i, frequencies[i + range]));
            }

            if (outputComma)
                outfile << ',' << '\n';
            outputComma = true;

            outfile << '{' << '{' << numVertices << ',' << tau << '}';
            outfile << ',' << histogram;
            outfile << ',' << '{' << movesDone << ',' << measurements << '}';
            outfile << '}' << std::flush;

            std::cout << "Output done." << std::endl;
        }
    }
    outfile << '\n' << '}';
    return 0;
}