#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "matrix.h"

// TODO Matrix-Funktionen implementieren

Matrix createMatrix(unsigned int rows, unsigned int cols)
{

    if(rows == 0 || cols == 0){
        Matrix matrixNull;
        matrixNull.rows = 0;
        matrixNull.cols = 0;
        matrixNull.buffer = NULL;
        return matrixNull;
    }

    Matrix matrix;
    matrix.rows = rows;
    matrix.cols = cols;
    matrix.buffer = calloc(rows*cols, sizeof(MatrixType));

    if(matrix.buffer == 0){
        printf("Das erstellen der Matrix ist fehlgeschlagen");
        clearMatrix(&matrix);
        return matrix;
    }

    return matrix;
}

void clearMatrix(Matrix *matrix)
{
    matrix->buffer = NULL;
    matrix->rows = 0;
    matrix->cols = 0;
    free(matrix->buffer);
}

void setMatrixAt(MatrixType value, Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
{
    size_t index = rowIdx * matrix.cols + colIdx; //spingt die zeilen * Anzahl der spalten (Eine Zeile = Anzahl der Spalten lang); + springt noch anzahl an spalten bis zur irhctigen Position
    matrix.buffer[index] = value;
}

MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
{
    if(rowIdx > matrix.rows -1 || colIdx > matrix.cols -1){
        return 0;
    }
    size_t index = rowIdx * matrix.cols + colIdx;
    return matrix.buffer[index];
}

Matrix add(const Matrix matrix1, const Matrix matrix2)
{

    if (matrix1.rows != matrix2.rows || matrix1.cols != matrix2.cols) {
        printf("Die Matritzen koennen nicht addiert werden");
        return createMatrix(0,0);
    }

    Matrix matrix = createMatrix(matrix1.rows, matrix1.cols);

    for (int index = 0; index < matrix1.rows * matrix1.cols; index++){
        matrix.buffer[index] = matrix1.buffer[index] + matrix2.buffer[index];
    }

    return matrix;
}

Matrix multiply(const Matrix matrix1, const Matrix matrix2)
{

    if (matrix1.cols != matrix2.rows) {
        printf("Die Matritzen koennen nicht multipliziert werden");
        return createMatrix(0,0);;
    }

    Matrix matrix = createMatrix(matrix1.rows, matrix2.cols);

    int index = 0;
    float wert = 0.0;
    for(int i = 0; i < matrix1.rows * matrix1.cols; i+=matrix1.cols){
        for(int j = 0; j < matrix2.cols; j++){
            for(int k = 0; k < matrix1.cols; k++){
                wert += matrix1.buffer[i+k] * matrix2.buffer[j+k*matrix2.cols];
            }
            matrix.buffer[index] = wert;
            wert = 0.0;
            index++;
        }
    }

    return matrix;
}