/// @file
/// @brief Task2: Structure definitions and function declarations

#pragma once

#include <stddef.h> // size_t

/// @brief Two-dimensional matrix with 'm' rows and 'n' columns.
/// @note: the values ares stored in a contiguous block in memory in row-major layout
/// @note: row-major storage order is used, access of element (i,j) -> data[j + n*i]
struct Matrix {
  double* data; ///< pointer to a dynamically allocated contiguous memory block fitting m*n values
  size_t m;     ///< number of rows (first dimension)
  size_t n;     ///< number of columns (second dimension)
};

/// @brief Initalize a matrix from the values in a buffer
/// @param m first dimension of the matrix
/// @param n second dimension of the matrix
/// @param data contiguous memory holding the values to copy (in row-major format)
struct Matrix matrix_init(size_t m, size_t n, const double* data);

/// @brief Prints a Matrix to the console
/// @param mat Matrix to be printed
void matrix_print(const struct Matrix* mat);

/// @brief Resets a matrix (deallocates memory and sets its size to 0 x 0)
/// @param mat Matrix to be reset
void matrix_clear(struct Matrix* mat);

/// @brief Initializes an matrix with zeros
/// @param m first dimension of the matrix
/// @param n first dimension of the matrix
struct Matrix matrix_zeros(size_t m, size_t n);

/// @brief Initializes a square identity matrix
/// @param n dimension of the identity matrix
struct Matrix matrix_identity(size_t n);

/// @brief Transposes a matrix
/// @param mat Matrix to be transposed
/// @note this function might swap/replace the block of memory owned by the matrix
void matrix_transpose(struct Matrix* mat);

/// @brief Performs a matrix-matrix mutliplication: a*b = c
/// @a first matrix (left factor)
/// @b second matrix (right factor)
/// @c Result of the multiplication is stored in this Matrix:
///    - the dimensions of this matrix must be 'a.m x b.n' when calling this function
///    - the values will be overwritten with the result of the multiplication
void matrix_mult(const struct Matrix* a, const struct Matrix* b, struct Matrix* c);