#pragma once
#include "graph.hpp"
#include "powerlaw.hpp"
#include <algorithm>
#include <iostream>

template <typename RNG>
void generatePowerlawGraph(int n, float tau, Graph& g, DegreeSequence& ds,
                           RNG& rng) {
    ds.resize(n);
    powerlaw_distribution degDist(tau, 1, n);

    // Generate a graph
    // might require multiple tries
    for (int i = 1;; ++i) {
        std::generate(ds.begin(), ds.end(),
                      [&degDist, &rng] { return degDist(rng); });
        // First check if the sum is even
        unsigned int sum = std::accumulate(ds.begin(), ds.end(), 0);
        if (sum % 2)
            continue;

        if (g.createFromDegreeSequence(ds))
            break;

        // When 10 tries have not worked, output a warning
        if (i % 10 == 0) {
            std::cerr << "Warning: could not create graph from "
                         "degree sequence. Trying again...\n";
        }
    }
}

void generateCanonicalPowerlawGraph(int n, float tau, Graph &g,
                                    DegreeSequence &ds) {
    ds.resize(n);
    powerlaw_distribution degDist(tau, 1, n);
    degDist.getFixedDistribution(n, ds.begin());

    unsigned int sum = std::accumulate(ds.begin(), ds.end(), 0);
    if (sum % 2)
        ds.back()++;

    if (g.createFromDegreeSequence(ds))
        return;
    g.reset(n);
    std::cerr << "ERROR: Canonical ds is not graphical" << std::endl;
}