#include "dynamic_buffer.h"

int DynamicBuffer_Reserve(DynamicBuffer* o, size_t new_capacity)
{
    int succ = 0;

    if (o->capacity < new_capacity)
    {
        void* tmp_buffer = realloc(o->buffer, new_capacity);

        if (tmp_buffer == NULL)
        {
            goto func_end;
        }

        o->capacity = new_capacity;
        o->buffer = tmp_buffer;
    }

    succ = 1;

func_end:

    return succ;
}

int DynamicBuffer_ResetBuffer(DynamicBuffer* o, size_t position)
{
    int succ = 0;

    /// position should never larger than buffer size!
    assert(position <= o->size);

    if (position > o->size)
    {
        printf("[E] Failed to reset buffer: position is larger than buffer size!");
        goto func_end;
    }

    if (position != o->size)
    {
        memmove(o->buffer, (uint8_t *)o->buffer + position, o->size - position);
    }

    o->size -= position;

    succ = 1;

func_end:

    return succ;
}

int DynamicBuffer_Resize(DynamicBuffer* o, size_t new_size)
{
    if (o->size <= new_size)
    {
        o->size = new_size;
        return 1;
    }

    if (!DynamicBuffer_Reserve(o, new_size))
    {
        return 0;
    }

    o->size = new_size;

    return 1;
}

/// FIXME(anjingyu): Assume never overflow!
void DynamicBuffer_Append(DynamicBuffer* o, const void* buffer, size_t size)
{
    size_t new_size = o->capacity;

    while (o->size + size > new_size)
    {
        new_size <<= 1;
    }

    DynamicBuffer_Reserve(o, new_size);

    memmove(o->buffer + o->size, buffer, size);
    o->size += size;
}