#include "../../include/std/buffer.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

void tsl_buffer_init(TslBuffer *self) {
    self->data = NULL;
    self->size = 0;
    self->capacity = 0;
}

void tsl_buffer_deinit(TslBuffer *self) {
    free(self->data);
}

static int tsl_buffer_ensure_capacity(TslBuffer *self, size_t new_size) {
    void *new_ptr;
    if(new_size <= self->capacity)
        return 1;
    
    if(self->capacity != 0) {
        size_t new_capacity = self->capacity;
        while(new_capacity < new_size) {
            new_capacity <<= 1;
        }
        new_size = new_capacity;
    }
    new_ptr = realloc(self->data, new_size);
    if(!new_ptr) {
        fprintf(stderr, "Error: buffer append failed. Reason: out of memory\n");
        return 0;
    }

    self->data = new_ptr;
    self->capacity = new_size;
    return 1;
}

int tsl_buffer_append(TslBuffer *self, const void *data, size_t size) {
    if(!tsl_buffer_ensure_capacity(self, self->size + size))
        return 0;
    memcpy((char*)self->data + self->size, data, size);
    self->size += size;
    return 1;
}

void tsl_buffer_pop(TslBuffer *self, size_t size) {
    assert(self->size >= size);
    self->size -= size;
}

void* tsl_buffer_begin(TslBuffer *self) {
    return self->data;
}

void* tsl_buffer_end(TslBuffer *self) {
    return (char*)self->data + self->size;
}