#pragma once

#include <stdlib.h>
#include <stdbool.h>
#include <string.h>

#define SVIEW_LIT(S) ((void)(S "LITERAL_CHECK"), (str_view_t) { S, sizeof(S) - 1 })
#define SVIEW_NULL ((str_view_t) { NULL, 0 })
#define SBUF_NULL ((str_buf_t) { NULL, 0 })
#define SBUF_SCOPED(NAME) str_buf_t NAME __attribute__((cleanup(sb_free))) = SB_NULL

#define SVIEW_PRI "%.*s"
#define SVIEW_PRI_ARGS(S) (int)((S).len), (S).ptr

// String which is:
// - Not owned
// - Not necessarily heap-allocated
// - Not necessarily nul-terminated
typedef struct {
  const char *ptr;
  size_t len;
} str_view_t;

// String which is:
// - Owned
// - Heap-allocated
// - Nul-terminated
// The length does not include the nul terminator.
typedef struct {
  char *ptr;
  size_t len;
} str_buf_t;

static inline bool sview_is_null(str_view_t s) {
  return !s.ptr;
}

static inline bool sview_is_empty(str_view_t s) {
  return !s.len;
}

static inline bool sbuf_is_null(str_buf_t buf) {
  return !buf.ptr;
}

static inline bool sbuf_is_empty(str_buf_t buf) {
  return !buf.len;
}

static inline str_view_t sview_from_parts(const char *ptr, size_t len) {
  return (str_view_t) { ptr, len };
}

static inline str_view_t sview_from_cstr(const char *ptr, size_t maxlen) {
  size_t len;

  len = strnlen(ptr, maxlen);
  return sview_from_parts(ptr, len);
}

static inline str_view_t sview_from_cstr_unbounded(const char *ptr) {
  size_t len = strlen(ptr);
  return sview_from_parts(ptr, len);
}

static inline bool sview_eq(str_view_t s1, str_view_t s2) {
  return (s1.len == s2.len) && ((!s1.ptr || !s2.ptr)
    ? (s1.ptr == s2.ptr)
    : !memcmp(s1.ptr, s2.ptr, s1.len));
}

static inline str_view_t sview_substr(str_view_t s, size_t start, size_t end) {
  if ((start > end) || (start > s.len) || (end > s.len))
    return SVIEW_NULL;
  return sview_from_parts(s.ptr + start, end - start);
}

static inline str_view_t sbuf_view(str_buf_t buf) {
  return sview_from_parts(buf.ptr, buf.len);
}

str_buf_t sbuf_from_sview(str_view_t s);

static inline void sbuf_free(str_buf_t *buf) {
  free(buf->ptr);
  buf->ptr = NULL;
  buf->len = 0;
}