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

#include <stdio.h>

// TODO Matrix-Funktionen implementieren

Matrix createMatrix(unsigned int rows, unsigned int cols)
{
    Matrix matrix = {NULL,rows,cols};
    if(rows != 0 && cols != 0){
        matrix.buffer = calloc(rows * cols, sizeof(MatrixType));
        if(matrix.buffer == NULL){
        matrix.rows = 0;
        matrix.cols = 0; // alternativ Programm beenden mit exit -> so einfach dimensionslos
    }
    }else{
        matrix.rows = 0;
        matrix.cols = 0;
    }
    
    return matrix;
}

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

void setMatrixAt(MatrixType value, Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
{
    if(matrix.rows > rowIdx && matrix.cols > colIdx){
        matrix.buffer[colIdx + rowIdx * matrix.cols] = value;
    }
}

MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
{
    if(matrix.rows > rowIdx && matrix.cols > colIdx){
        return matrix.buffer[colIdx + rowIdx * matrix.cols];
    }else{
        return UNDEFINED_MATRIX_VALUE;
    }
    
}

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

    if(matrix1.rows == matrix2.rows && matrix1.cols == matrix2.cols){
        Matrix resultMatrix = createMatrix(matrix1.rows,matrix1.cols);
        for(int i = 0; i < matrix1.rows * matrix1.cols; i++){
            resultMatrix.buffer[i] = matrix1.buffer[i] + matrix2.buffer[i];
        }
        return resultMatrix;
    }else if(matrix1.rows == matrix2.rows && matrix1.cols == 1){ // Matrix1 ist Vektor
        Matrix resultMatrix = createMatrix(matrix1.rows,matrix2.cols);
        for(int i = 0; i < matrix2.cols; i++){
            for(int j = 0; j < matrix1.rows; j++){
                resultMatrix.buffer[i + j * matrix2.cols]= matrix2.buffer[i + j * matrix2.cols] + matrix1.buffer[j];
            }
        }
        return resultMatrix;
    }else if(matrix1.rows == matrix2.rows && matrix2.cols == 1){ // Matrix ist Vektor
        Matrix resultMatrix = createMatrix(matrix1.rows,matrix1.cols);
        for(int i = 0; i < matrix1.cols; i++){
            for(int j = 0; j < matrix1.rows; j++){
                resultMatrix.buffer[i + j * matrix1.cols]= matrix1.buffer[i + j * matrix1.cols] + matrix2.buffer[j];
            }
        }
        return resultMatrix;
    }else{
        Matrix emptyMatrix = {NULL,0,0};
        return emptyMatrix;
    }










}

Matrix multiply(const Matrix matrix1, const Matrix matrix2)
{
    Matrix resultMatrix = createMatrix(matrix1.rows,matrix2.cols);
    
    if(matrix1.cols == matrix2.rows){
        unsigned int commonDimension = matrix1.cols;

        for(int i = 0; i < resultMatrix.rows; i++){
            
            for(int j = 0; j < resultMatrix.cols; j++){
                MatrixType entry = 0;
                
                for(int k = 0; k < commonDimension; k++){
                    entry += (matrix1.buffer[k + i * matrix1.cols] * matrix2.buffer[j + k * matrix2.cols]);
                }

                resultMatrix.buffer[j + i * resultMatrix.cols] = entry;
            }
        } 

        return resultMatrix;
    }else{
        clearMatrix(&resultMatrix);
        return resultMatrix;
    }



    
}