#include "common.h"

void *my_malloc(size_t size) {
    void *ptr = malloc(size);
    if (ptr == NULL) {
        printf("Memory allocation unsuccessful.\n");
        exit(EXIT_FAILURE);
    }
    return ptr;
}

void *my_calloc(size_t nitems, size_t size) {
    void *ptr = calloc(nitems, size);
    if (ptr == NULL) {
        printf("Memory allocation with initialisation unsuccessful.\n");
        exit(EXIT_FAILURE);
    }
    return ptr;
}


void *my_realloc(void *ptr, size_t size) {
    void *temp = realloc(ptr, size);
    if (temp == NULL) {
        printf("Insufficient memory; can't add more items.\n");
        exit(EXIT_FAILURE);
    }
    return temp;
}


FILE *my_fopen(const char *filename, const char *mode) {
    FILE *file = fopen(filename, mode);
    if (file == NULL) {
        printf("File %s could not be opened.\n", filename);
        exit(EXIT_FAILURE);
    }
    return file;
}

void *buffer_grow(void *ptr, int numCount, int *sizeBufferTotal) {
    // Grow the buffer exponentially when needed
    if (numCount == *sizeBufferTotal) {
        *sizeBufferTotal *= GROWTH_FACTOR;
        ptr = my_realloc(ptr, *sizeBufferTotal * sizeof(int));
    }
    return ptr;
}

bool check_parallel_worth(int numProcesses, int numCount, int limit) {
    if (numProcesses > numCount / limit) {
        //printf("*********************************************************************************\n");
        printf("The number of processes if greater than number of parallel computations required!\n");
        //printf("*********************************************************************************\n\n");
        exit(EXIT_FAILURE);
    }
    return true;
}

void spread_evenly(int numProcesses, int numCount, int multiplier, int **arrBlockIndices, int **arrBlockSizes) {
    int numBlockIndex = 0;
    int numRemainder = numCount % numProcesses;

    *arrBlockSizes = my_malloc(numProcesses * sizeof(int));
    *arrBlockIndices = my_malloc(numProcesses * sizeof(int));

    for (int i = 0; i < numProcesses; i++) {
        int numBlockSize = numCount / numProcesses;
        if (numRemainder > 0) {
            numBlockSize++;
            numRemainder--;
        }
        numBlockSize *= multiplier;
        (*arrBlockSizes)[i] = numBlockSize;

        int arrBlockData[NUM_CODES];
        arrBlockData[CODE_SIZE] = numBlockSize; 
        arrBlockData[CODE_INDEX] = numBlockIndex; 

        //printf("size[%d] = %d\tindex[%d] = %d\n", i, numBlockSize, i, numBlockIndex);

        (*arrBlockIndices)[i] = numBlockIndex;
        numBlockIndex += numBlockSize;


        // Send every process starting index of 1D represented matrix and number of 
        // succeding indices to calculate transposition
        MPI_Send(arrBlockData, NUM_CODES, MPI_INT, i, 1, MPI_COMM_WORLD); 

        //(*ptrFciLoopEnd)(&numBlockSize, i);
        //MPI_Send(&arrBlockSizes[i], 1, MPI_INT, i, 1, MPI_COMM_WORLD); 
    }
}

void *read_matrix_file(const char *filename, int *numCols, int *numCount) {
    // To avoid aggresive buffer growth at the beggining of the sequence
    int sizeBufferTotal = INIT_BUFFER_SIZE;
    // Allocate enough memory for initial buffer
    int *ptr = my_malloc(sizeBufferTotal * sizeof(int));
    // Open the file with input data
    FILE *ptrFile = my_fopen(filename, "r");

    // Read line by line until the end of file
    // TODO: remove the MAX_LINE_LENGTH limitation of strBuffer
    char *ptrBuffer, strBuffer[MAX_LINE_LENGTH];
    while (fgets(strBuffer, sizeof strBuffer, ptrFile) != 0) {
        // Store the pointer
        ptrBuffer = strBuffer;
        *numCols = 0;
        int numValue;
        // Read untill newline
        while (*ptrBuffer != '\n') {
            // Grow buffer when needed
            ptr = buffer_grow(ptr, *numCount, &sizeBufferTotal);
            // Convert string to base 10
            numValue = strtol(ptrBuffer, &ptrBuffer, 10);
            // Store the number read in memory
            ptr[*numCount] = numValue;
            *numCount = *numCount + 1;
            *numCols = *numCols + 1;
        }
    }
    
    fclose(ptrFile);

    return ptr;
}

int transpose_index(int index, int rows, int cols) {
    //return ((rows * index) / (cols * rows)) + ((rows * index) % (cols * rows));
    //return (index / cols) + rows * (index % cols);
    return (index / rows) + cols * (index % rows);
}