/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include "src/core/lib/slice/slice_string_helpers.h"

#include <string.h>

#include <grpc/support/log.h>

#include "src/core/lib/slice/slice_internal.h"
#include "src/core/lib/support/string.h"

char *grpc_dump_slice(grpc_slice s, uint32_t flags) {
  return gpr_dump((const char *)GRPC_SLICE_START_PTR(s), GRPC_SLICE_LENGTH(s),
                  flags);
}

/** Finds the initial (\a begin) and final (\a end) offsets of the next
 * substring from \a str + \a read_offset until the next \a sep or the end of \a
 * str.
 *
 * Returns 1 and updates \a begin and \a end. Returns 0 otherwise. */
static int slice_find_separator_offset(const grpc_slice str, const char *sep,
                                       const size_t read_offset, size_t *begin,
                                       size_t *end) {
  size_t i;
  const uint8_t *str_ptr = GRPC_SLICE_START_PTR(str) + read_offset;
  const size_t str_len = GRPC_SLICE_LENGTH(str) - read_offset;
  const size_t sep_len = strlen(sep);
  if (str_len < sep_len) {
    return 0;
  }

  for (i = 0; i <= str_len - sep_len; i++) {
    if (memcmp(str_ptr + i, sep, sep_len) == 0) {
      *begin = read_offset;
      *end = read_offset + i;
      return 1;
    }
  }
  return 0;
}

void grpc_slice_split(grpc_slice str, const char *sep, grpc_slice_buffer *dst) {
  const size_t sep_len = strlen(sep);
  size_t begin, end;

  GPR_ASSERT(sep_len > 0);

  if (slice_find_separator_offset(str, sep, 0, &begin, &end) != 0) {
    do {
      grpc_slice_buffer_add_indexed(dst, grpc_slice_sub(str, begin, end));
    } while (slice_find_separator_offset(str, sep, end + sep_len, &begin,
                                         &end) != 0);
    grpc_slice_buffer_add_indexed(
        dst, grpc_slice_sub(str, end + sep_len, GRPC_SLICE_LENGTH(str)));
  } else { /* no sep found, add whole input */
    grpc_slice_buffer_add_indexed(dst, grpc_slice_ref_internal(str));
  }
}

bool grpc_parse_slice_to_uint32(grpc_slice str, uint32_t *result) {
  return gpr_parse_bytes_to_uint32((const char *)GRPC_SLICE_START_PTR(str),
                                   GRPC_SLICE_LENGTH(str), result) != 0;
}
