/*
 * Josh Holtrop
 * 2008-12-11
 * barebones SDL program
 */

#include <SDL/SDL.h>
#include <mpi.h>
#include <iostream>
using namespace std;

#define PROGNAME "Josh's CS677 Final : MPI Fractal Generator"

bool createWindow(int width, int height,
                  SDL_Surface ** screen, Uint32 ** pixels);
void getSizes(int * rank, int * size, int * nprocs);

int main(int argc, char * argv[])
{
    int width = 800;
    int height = 600;
    int my_rank;
    int world_size;
    int nprocs;

    SDL_Surface * screen;
    Uint32 * pixels;

    MPI_Init(&argc, &argv);
    getSizes(&my_rank, &world_size, &nprocs);

    if (my_rank == 0)
    {
        bool window_success = createWindow(width, height, &screen, &pixels);
        if (window_success)
        {
            for (int y = 0; y < height; y++)
            {
                for (int x = 0; x < width; x++)
                {
                    *pixels++ = (((x * 255 / width) & 0xFF) << 8)
                              + ((y * 255 / height) & 0xFF);
                }
            }
            SDL_UpdateRect(screen, 0, 0, 0, 0);

            bool going = true;
            SDL_Event event;
            while (going && SDL_WaitEvent(&event) != 0)
            {
                switch (event.type)
                {
                    case SDL_QUIT:
                        going = false;
                        break;
                    case SDL_KEYDOWN:
                        if (event.key.keysym.sym == SDLK_q)
                            going = false;
                        break;
                }
            }
        }
    }

    MPI_Finalize();

    return 0;
}

bool createWindow(int width, int height,
                  SDL_Surface ** screen, Uint32 ** pixels)
{
    if (SDL_Init(SDL_INIT_VIDEO))
    {
        cerr << "Failed to initialize SDL!" << endl;
        return false;
    }

    atexit(SDL_Quit);

    if (!(*screen = SDL_SetVideoMode(width, height, 32, 0)))
    {
        cerr << "Failed to set video mode!" << endl;
        return false;
    }
    SDL_WM_SetCaption(PROGNAME, PROGNAME);

    *pixels = (Uint32 *) (*screen)->pixels;

    return true;
}

void getSizes(int * rank, int * size, int * nprocs)
{
    MPI_Comm_rank(MPI_COMM_WORLD, rank);
    MPI_Comm_size(MPI_COMM_WORLD, size);

    *nprocs = sysconf(_SC_NPROCESSORS_CONF);

    int displs[*size];
    int counts[*size];
    for (int i = 0; i < *size; i++)
    {
        displs[i] = i;
        counts[i] = 1;
    }
    int all_nprocs[*size];
    MPI_Gatherv(nprocs, 1, MPI_INT,
                &all_nprocs[0], &counts[0], &displs[0], MPI_INT,
                0, MPI_COMM_WORLD);

    if (*rank == 0)
    {
        int total_nprocs = 0;
        cout << "Number of cores on each MPI node:" << endl;
        for (int i = 0; i < *size; i++)
        {
            cout << all_nprocs[i] << " ";
            total_nprocs += all_nprocs[i];
        }
        cout << endl;
        cout << "Total number of cores: " << total_nprocs << endl;
    }
}