#include "geom.h"
#include "getmatrix.h"
#include "jacsolve.h"
#include "userset.h"
#include "vdop.h"

#include <cassert>
#include <chrono>           // timing
#include <cmath>
#include <iostream>
#include <omp.h>
using namespace std;
using namespace std::chrono;  // timing


int main(int argc, char **argv )
{
    // generating the mesh
    Mesh const mesh_c("../generate_mesh/coffee_cup.txt", "../generate_mesh/coffee_cup_sd.txt");
    bool ba = mesh_c.checkObtuseAngles();
    if (ba) cout << "mesh corrected" << endl;
    //mesh_c.DebugEdgeBased();

    //gMesh_Hierarchy ggm(mesh_c, nrefine);
    //const Mesh &mesh = ggm.finest();
    //mesh.Debug();
    //mesh_c.DebugEdgeBased();

    // ##########################################
    // Assembling
    // ##########################################

    // Initializing FEM matrix !pattern! (only zero entries now)
    FEM_Matrix SK(mesh_c);                                    // CRS matrix
    //SK.writeBinary("sparseMatrix.bin");
    //SK.Debug();

    vector<double> fv(SK.Nrows(), 0.0);                    
    SK.CalculateRHS(fv, [](double x, double y) {return 0;});  // r.h.s.

    SK.CalculateLaplace_mult(fv);                             // stiffness matrix
    SK.AddMass_mult(fv);                                      // mass matrix
    SK.ApplyRobinBC_mult(fv, 18.0);                           // apply Robin bnd

    SK.CheckRowSum();
    SK.CheckMatrix();

    // ##########################################
    // Timestepping
    // ##########################################

    double dt = 1.0;            // time step
    int steps = 100;            // number of time iterations

    // Initialize temperature
    vector<double> uv(SK.Nrows(), 0.0);    // temperature
    mesh_c.Init_Solution_mult(uv, 0, [](double x, double y) -> double { return 18; });    // mug
    mesh_c.Init_Solution_mult(uv, 1, [](double x, double y) -> double { return 80; });    // fluid
    mesh_c.Init_Solution_mult(uv, 2, [](double x, double y) -> double { return 18; });    // air

    for (int i = 0; i < steps; ++i)
    {
        // TODO        
    }

    auto t3 = system_clock::now(); // start timer
    //JacobiSolve(SK, fv, uv );          // solve the system of equations
    auto t4 = system_clock::now();  // stop timer

    auto duration = duration_cast<microseconds>(t4 - t3);        // duration in microseconds
    double t_diff = static_cast<double>(duration.count()) / 1e6; // overall duration in seconds
    cout << "JacobiSolve: timing in sec. : " << t_diff << endl;


    mesh_c.Visualize(uv);

    return 0;
}