#include "../../include/std/buffer.h"
#include "../../include/std/alloc.h"
#include "../../include/std/mem.h"
#include "../../include/std/scoped_allocator.h"
#include <assert.h>

int buffer_init(Buffer *self, struct ScopedAllocator *allocator) {
    self->data = NULL;
    self->size = 0;
    self->capacity = 0;
    if(allocator)
        return scoped_allocator_add_buffer(allocator, self);
    return 0;
}

static CHECK_RESULT int buffer_ensure_capacity(Buffer *self, usize new_capacity) {
    usize capacity;
    void *new_mem;
    int alloc_result;

    if(self->capacity >= new_capacity)
        return BUFFER_OK;
    
    capacity = self->capacity;
    if(capacity == 0) {
        capacity = new_capacity;
    } else {
        while(capacity < new_capacity) {
            capacity *= 1.5;
        }
    }

    alloc_result = am_realloc(self->data, capacity, &new_mem);
    if(alloc_result != ALLOC_OK)
        return BUFFER_ALLOC_FAIL;
    
    self->data = new_mem;
    self->capacity = capacity;
    return BUFFER_OK;
}

int buffer_append(Buffer *self, const void *data, usize size) {
    return_if_error(buffer_ensure_capacity(self, self->size + size));
    if(data)
        am_memcpy(self->data + self->size, data, size);
    self->size += size;
    return BUFFER_OK; 
}

void* buffer_get(Buffer *self, usize index, usize type_size) {
    usize real_index;
    real_index = index * type_size;
    assert(real_index < self->size);
    return &self->data[real_index];
}

int buffer_pop(Buffer *self, void *data, usize size) {
    if(size > self->size)
        return -1;
    am_memcpy(data, &self->data[self->size - size], size);
    self->size -= size;
    return 0;
}

void* buffer_start(Buffer *self) {
    return self->data;
}

void *buffer_end(Buffer *self) {
    return self->data + self->size;
}

usize __buffer_get_size(Buffer *self, usize type_size) {
    assert(type_size != 0);
    return self->size / type_size;
}