// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/renderer_host/navigation_entry_restore_context_impl.h"

#include "content/browser/renderer_host/frame_navigation_entry.h"

namespace content {

// static
std::unique_ptr<NavigationEntryRestoreContext>
NavigationEntryRestoreContext::Create() {
  return std::make_unique<NavigationEntryRestoreContextImpl>();
}

NavigationEntryRestoreContextImpl::NavigationEntryRestoreContextImpl() =
    default;
NavigationEntryRestoreContextImpl::~NavigationEntryRestoreContextImpl() =
    default;

void NavigationEntryRestoreContextImpl::AddFrameNavigationEntry(
    FrameNavigationEntry* entry) {
  // Do not track FrameNavigationEntries for the default ISN of 0, since this
  // value can be used for any arbitrary document.
  if (entry->item_sequence_number() == 0) {
    return;
  }
  auto [it, inserted] =
      entries_.try_emplace(Key(entry->item_sequence_number(),
                               entry->frame_unique_name(), entry->url()),
                           entry);
  // The checks here should be consistent with GetFrameNavigationEntry and this
  // is only expected to be called after that function fails to find an entry,
  // so we don't expect there to be an entry for this key already.
  CHECK(inserted, base::NotFatalUntil::M152);
}

FrameNavigationEntry*
NavigationEntryRestoreContextImpl::GetFrameNavigationEntry(
    int64_t item_sequence_number,
    const std::string& unique_name,
    const GURL& url) {
  // Note: Ensure the checks here are consistent with AddFrameNavigationEntry,
  // to satisfy the DCHECK there. See https://crbug.com/1275257.
  if (item_sequence_number == 0)
    return nullptr;
  auto it = entries_.find(Key(item_sequence_number, unique_name, url));
  if (it == entries_.end())
    return nullptr;
  return it->second;
}

bool NavigationEntryRestoreContextImpl::Key::Compare::operator()(
    const Key& x,
    const Key& y) const {
  if (x.item_sequence_number_ != y.item_sequence_number_) {
    return x.item_sequence_number_ > y.item_sequence_number_;
  }
  if (x.unique_name_ != y.unique_name_) {
    return x.unique_name_ > y.unique_name_;
  }
  return x.url_ > y.url_;
}

}  // namespace content