// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/attribution_reporting/os_registration.h"

#include <utility>
#include <vector>

#include "base/check_op.h"
#include "base/metrics/histogram_functions.h"
#include "base/types/expected.h"
#include "components/attribution_reporting/os_registration_error.mojom-shared.h"
#include "net/http/structured_headers.h"
#include "url/gurl.h"

namespace attribution_reporting {

namespace {
using ::attribution_reporting::mojom::OsRegistrationError;
}  // namespace

base::expected<std::vector<OsRegistrationItem>, OsRegistrationError>
ParseOsSourceOrTriggerHeader(std::string_view header) {
  const auto list = net::structured_headers::ParseList(header);
  if (!list) {
    return base::unexpected(OsRegistrationError::kInvalidList);
  }

  return ParseOsSourceOrTriggerHeader(*list);
}

base::expected<std::vector<OsRegistrationItem>, OsRegistrationError>
ParseOsSourceOrTriggerHeader(const net::structured_headers::List& list) {
  std::vector<OsRegistrationItem> items;
  items.reserve(list.size());

  for (const auto& parameterized_member : list) {
    if (parameterized_member.member_is_inner_list) {
      continue;
    }

    CHECK_EQ(parameterized_member.member.size(), 1u);
    const auto& parameterized_item = parameterized_member.member.front();

    if (!parameterized_item.item.is_string()) {
      continue;
    }

    GURL url(parameterized_item.item.GetString());
    if (!url.is_valid()) {
      continue;
    }

    bool debug_reporting = false;
    for (const auto& param : parameterized_member.params) {
      if (param.first == "debug-reporting") {
        if (param.second.is_boolean()) {
          debug_reporting = param.second.GetBoolean();
        }
        break;
      }
    }

    items.emplace_back(std::move(url), debug_reporting);
  }

  base::UmaHistogramCounts100("Conversions.OsRegistrationItemsPerHeader",
                              items.size());

  if (items.empty()) {
    return base::unexpected(OsRegistrationError::kInvalidList);
  }

  return items;
}

}  // namespace attribution_reporting