/*
 *
 * Copyright 2014, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <grpc/support/string.h>

#include <ctype.h>
#include <stddef.h>
#include <string.h>

#include <grpc/support/alloc.h>
#include <grpc/support/port_platform.h>
#include <grpc/support/useful.h>

char *gpr_strdup(const char *src) {
  char *dst;
  size_t len;

  if (!src) {
    return NULL;
  }

  len = strlen(src) + 1;
  dst = gpr_malloc(len);

  memcpy(dst, src, len);

  return dst;
}

typedef struct {
  size_t capacity;
  size_t length;
  char *data;
} hexout;

static hexout hexout_create() {
  hexout r = {0, 0, NULL};
  return r;
}

static void hexout_append(hexout *out, char c) {
  if (out->length == out->capacity) {
    out->capacity = GPR_MAX(8, 2 * out->capacity);
    out->data = gpr_realloc(out->data, out->capacity);
  }
  out->data[out->length++] = c;
}

char *gpr_hexdump(const char *buf, size_t len, gpr_uint32 flags) {
  static const char hex[16] = "0123456789abcdef";
  hexout out = hexout_create();

  const gpr_uint8 *const beg = (const gpr_uint8 *)buf;
  const gpr_uint8 *const end = beg + len;
  const gpr_uint8 *cur;

  for (cur = beg; cur != end; ++cur) {
    if (cur != beg) hexout_append(&out, ' ');
    hexout_append(&out, hex[*cur >> 4]);
    hexout_append(&out, hex[*cur & 0xf]);
  }

  if (flags & GPR_HEXDUMP_PLAINTEXT) {
    cur = beg;
    if (len) hexout_append(&out, ' ');
    hexout_append(&out, '\'');
    for (cur = beg; cur != end; ++cur) {
      hexout_append(&out, isprint(*cur) ? *cur : '.');
    }
    hexout_append(&out, '\'');
  }

  hexout_append(&out, 0);

  return out.data;
}

int gpr_parse_bytes_to_uint32(const char *buf, size_t len, gpr_uint32 *result) {
  gpr_uint32 out = 0;
  gpr_uint32 new;
  size_t i;

  if (len == 0) return 0; /* must have some bytes */

  for (i = 0; i < len; i++) {
    if (buf[i] < '0' || buf[i] > '9') return 0; /* bad char */
    new = 10 * out + (buf[i] - '0');
    if (new < out) return 0; /* overflow */
    out = new;
  }

  *result = out;
  return 1;
}