#include <librr/memory.h>

bool_t rr_mem_overlap(void *block1, usz_t length1, void *block2, usz_t length2)
{
    // Make block1 always be before block2
    if(block1 > block2)
    {
        void           *block_backup            = block2;
        usz_t           length_backup           = length2;
        block2                  = block1;
        length2                 = length1;
        block1                  = block_backup;
        length1                 = length_backup;
    }
    usz_t           start1                  = (usz_t) block1;
    usz_t           start2                  = (usz_t) block2;
    usz_t           end1                    = start1 + length1;
    usz_t           end2                    = start2 + length2;

    if(end2 > start1)
    {
        if(start2 > end1) return FALSE;
        return TRUE;
    }
    return FALSE;
}

bool_t rr_memequ(void *block1, void *block2, usz_t count)
{
    u8_t           *block1_8            = block1;
    u8_t           *block2_8            = block2;
    for(usz_t index = 0; index < count; ++index)
        if(block1_8[index] != block2_8[index]) return FALSE;
    return TRUE;
}

void  rr_memset(void *destination, usz_t count, u8_t value)
{
    u8_t           *destination_8       = destination;
    for(usz_t index = 0; index < count; ++index)
        destination_8[index] = value;
}

usz_t rr_memrep(void *destination, usz_t num_bytes, void *sequence, usz_t len_sequence)
{
    if(rr_mem_overlap(destination, num_bytes, sequence, len_sequence)) return 0;
    u8_t           *destination_8       = destination;
    u8_t           *sequence_8          = sequence;
    for(usz_t index = 0; index < num_bytes; ++index)
        destination_8[index] = sequence_8[index % len_sequence];
    return (num_bytes / len_sequence)           // How many full repetitions are performed
        + ((num_bytes % len_sequence) != 0);    // One more if a partial repetiton is done
}

void rr_memcopy(void *destination, void *source, usz_t num_bytes)
{
    if(rr_mem_overlap(destination, num_bytes, source, num_bytes)) return;
    u8_t           *destination_8       = destination;
    u8_t           *source_8            = source;
    for(usz_t index = 0; index < num_bytes; ++index)
        destination_8[index]                = source_8[index];
}