/*
  Copyright 2011 David Robillard <http://drobilla.net>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

#ifndef SERD_INTERNAL_H
#define SERD_INTERNAL_H

#include <assert.h>
#include <stdlib.h>

#include "serd/serd.h"

/** A dynamic stack in memory. */
typedef struct {
	uint8_t* buf;       ///< Stack memory
	size_t   buf_size;  ///< Allocated size of buf (>= size)
	size_t   size;      ///< Conceptual size of stack in buf
} SerdStack;

/** An offset to start the stack at. Note 0 is reserved for NULL. */
#define SERD_STACK_BOTTOM sizeof(void*)

static inline SerdStack
serd_stack_new(size_t size)
{
	SerdStack stack;
	stack.buf       = malloc(size);
	stack.buf_size  = size;
	stack.size      = SERD_STACK_BOTTOM;
	return stack;
}

static inline bool
serd_stack_is_empty(SerdStack* stack)
{
	return stack->size <= SERD_STACK_BOTTOM;
}

static inline void
serd_stack_free(SerdStack* stack)
{
	free(stack->buf);
	stack->buf      = NULL;
	stack->buf_size = 0;
	stack->size     = 0;
}

static inline uint8_t*
serd_stack_push(SerdStack* stack, size_t n_bytes)
{
	const size_t new_size = stack->size + n_bytes;
	if (stack->buf_size < new_size) {
		stack->buf_size *= 2;
		stack->buf = realloc(stack->buf, stack->buf_size);
	}
	uint8_t* const ret = (stack->buf + stack->size);
	stack->size = new_size;
	return ret;
}

static inline void
serd_stack_pop(SerdStack* stack, size_t n_bytes)
{
	assert(stack->size >= n_bytes);
	stack->size -= n_bytes;
}

/** Return true if @a c lies within [min...max] (inclusive) */
static inline bool
in_range(const uint8_t c, const uint8_t min, const uint8_t max)
{
	return (c >= min && c <= max);
}

/** RFC2234: ALPHA := %x41-5A / %x61-7A  ; A-Z / a-z */
static inline bool
is_alpha(const uint8_t c)
{
	return in_range(c, 'A', 'Z') || in_range(c, 'a', 'z');
}

/** RFC2234: DIGIT ::= %x30-39  ; 0-9 */
static inline bool
is_digit(const uint8_t c)
{
	return in_range(c, '0', '9');
}

#endif  // SERD_INTERNAL_H