/*
 * SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 * SPDX-License-Identifier: Apache-2.0
 */
#pragma once

// Configuration helpers shared by the ANN and clustering benchmarks. Unlike benchmark_utils.hpp,
// this header does not depend on Google Benchmark, so configuration code can include it alone.

#include <nlohmann/json.hpp>

#include <cstddef>
#include <optional>
#include <sstream>
#include <stdexcept>
#include <string>
#include <tuple>
#include <vector>

namespace cuvs::bench {

using kv_series = std::vector<std::tuple<std::string, std::vector<nlohmann::json>>>;

/**
 * Parse one `--override_kv=<key>:<value1>[:<value2>...]` argument, whose values are JSON, and
 * append it to `out`. Throws std::invalid_argument on malformed input.
 */
inline void parse_override_kv(const std::string& arg, kv_series& out)
{
  std::vector<std::string> tokens;
  std::string token;
  std::istringstream iss(arg);
  while (std::getline(iss, token, ':')) {
    if (!token.empty()) { tokens.push_back(token); }
  }
  if (tokens.size() < 2) {
    throw std::invalid_argument("Invalid --override_kv=" + arg +
                                ", expected <key>:<value1>[:<value2>...]");
  }
  std::vector<nlohmann::json> vals{};
  for (std::size_t j = 1; j < tokens.size(); j++) {
    try {
      vals.push_back(nlohmann::json::parse(tokens[j]));
    } catch (const nlohmann::json::parse_error&) {
      throw std::invalid_argument("Invalid --override_kv value '" + tokens[j] +
                                  "', expected JSON (quote strings: '\"" + tokens[j] + "\"')");
    }
  }
  out.emplace_back(tokens[0], vals);
}

/** Data type of a dataset file, inferred from its extension; nullopt if it is not recognized. */
inline auto dtype_from_filename(const std::string& filename) -> std::optional<std::string>
{
  auto ends_with = [&](const std::string& suffix) {
    return filename.size() > suffix.size() &&
           filename.compare(filename.size() - suffix.size(), suffix.size(), suffix) == 0;
  };
  if (ends_with("f16bin") || ends_with("fp16.fbin")) { return "half"; }
  if (ends_with("fbin")) { return "float"; }
  if (ends_with("u8bin")) { return "uint8"; }
  if (ends_with("i8bin")) { return "int8"; }
  return std::nullopt;
}

}  // namespace cuvs::bench