#include "nr.h"
#include "nrutil.h"
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "matutil.h"

void try_gaussj(JMatrixData* data) {
    printf("gauss-jordan method:\n");
    gaussj(data->a, data->m, data->b, 1);
    print_matrix(data->m, 1, data->b);
}

void try_lu(JMatrixData* data) {
    printf("LU Decomposition:\n");
    
    int* indx = calloc(data->m + 1, sizeof(int));
    float* d = calloc(data->m + 1, sizeof(float));
    ludcmp(data->a, data->m, indx, d);

    print_matrix(data->m, data->n, data->a);
    
    printf("index: ");
    print_vector_int(data->m, indx);
    printf("d: ");
    print_vector_float(data->m, d);

    printf("solution:\n");
    float * b = calloc(data->m + 1, sizeof(float));
    int i;
    for (i = 1; i <= data->m; i++) {
        b[i] = data->b[i][1];
    }
    lubksb(data->a, data->m, indx, b);
    for (i = 1; i <= data->m; i++) {
        printf("%6.2f ", b[i]);
    }
    free(indx);
    free(d);

}

void processMatrix(JMatrixData* data) {
    printf("-----------------------------\n");
    printf("matrix data A:\n");
    print_matrix(data->m, data->n, data->a);
    printf("matrix data b:\n");
    print_matrix(data->m, 1, data->b);
    printf("-----------------------------\n");
    
    pid_t pid = fork();
    if (pid < 0) {
        printf("process 실행 실패\n");
        return;
    } else if (pid == 0) {
        printf("created process for gauss-jordan method\n");
        printf("-----------------------------\n");
        JMatrixData* copied = new_jmatdata(data->m, data->n);
        copy_jmatdata(data, copied);
        try_gaussj(copied);
        free_jmatdata(copied);
        printf("-----------------------------\n");
        exit(0);
    }

    wait(NULL);
    pid = fork();
    if (pid < 0) {
        printf("process 실행 실패\n");
        return;
    } else if (pid == 0) {
        printf("created process for LU Decomposition\n");
        printf("-----------------------------\n");
        JMatrixData* copied = new_jmatdata(data->m, data->n);
        copy_jmatdata(data, copied);
        try_lu(copied);
        free_jmatdata(copied);
        printf("-----------------------------\n");
        exit(0);

    }
    wait(NULL);
}

JMatrixData*readDataFrom(char *filename) {
    FILE *fp = fopen(filename, "r");

    if (fp == NULL) {
        printf("Error opening file");
        exit(1);
    }

    int m, n;
    fscanf(fp, "%d", &m);
    fscanf(fp, "%d", &n);

    JMatrixData*data = new_jmatdata(m, n);

    int i, j;
    for (i = 1; i <= data->m; i++) {
        for (j = 1; j <= data->n; j++) {
            fscanf(fp, "%f", &data->a[i][j]);
        }
    }

    for (i = 1; i <= data->m; i++) {
        fscanf(fp, "%f", &data->b[i][1]);
    }

    fclose(fp);
    return data;
}

int main() {
    int m, n;
    int i, j;

    
    const char *filenames[] = {
            "lineq1.dat", "lineq2.dat", "lineq3.dat"};
    pid_t pid;
    for (i = 0; i < 3; i++) {
        pid = fork();
        if (pid < 0) {
            printf("process 실행 실패\n");
            return 2;
        } else if (pid == 0) {
            printf("=================================\n");
            printf("data from %s:\n", filenames[i]);
            JMatrixData* data = readDataFrom(filenames[i]);
            processMatrix(data);
            printf("end for %s\n", filenames[i]);
            exit(0);
        }
        wait(NULL);
    }



    printf("end\n");
    
    return 0;
}