// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/renderer/history_serialization.h"

#include <stddef.h>

#include "base/strings/nullable_string16.h"
#include "content/child/web_url_request_util.h"
#include "content/common/page_state_serialization.h"
#include "content/public/common/page_state.h"
#include "content/renderer/history_entry.h"
#include "third_party/WebKit/public/platform/WebData.h"
#include "third_party/WebKit/public/platform/WebFloatPoint.h"
#include "third_party/WebKit/public/platform/WebHTTPBody.h"
#include "third_party/WebKit/public/platform/WebPoint.h"
#include "third_party/WebKit/public/platform/WebString.h"
#include "third_party/WebKit/public/platform/WebVector.h"
#include "third_party/WebKit/public/web/WebHistoryItem.h"
#include "third_party/WebKit/public/web/WebSerializedScriptValue.h"

using blink::WebData;
using blink::WebHTTPBody;
using blink::WebHistoryItem;
using blink::WebSerializedScriptValue;
using blink::WebString;
using blink::WebVector;

namespace content {
namespace {

void ToNullableString16Vector(const WebVector<WebString>& input,
                              std::vector<base::NullableString16>* output) {
  output->reserve(output->size() + input.size());
  for (size_t i = 0; i < input.size(); ++i)
    output->push_back(input[i]);
}

void GenerateFrameStateFromItem(const WebHistoryItem& item,
                                ExplodedFrameState* state) {
  state->url_string = item.urlString();
  state->referrer = item.referrer();
  state->referrer_policy = item.referrerPolicy();
  state->target = item.target();
  if (!item.stateObject().isNull())
    state->state_object = item.stateObject().toString();
  state->scroll_restoration_type = item.scrollRestorationType();
  state->visual_viewport_scroll_offset = item.visualViewportScrollOffset();
  state->scroll_offset = item.scrollOffset();
  state->item_sequence_number = item.itemSequenceNumber();
  state->document_sequence_number =
      item.documentSequenceNumber();
  state->page_scale_factor = item.pageScaleFactor();
  ToNullableString16Vector(item.documentState(), &state->document_state);

  state->http_body.http_content_type = item.httpContentType();
  const WebHTTPBody& http_body = item.httpBody();
  if (!http_body.isNull()) {
    state->http_body.request_body = GetRequestBodyForWebHTTPBody(http_body);
    state->http_body.contains_passwords = http_body.containsPasswordData();
  }
}

void RecursivelyGenerateFrameState(
    HistoryEntry::HistoryNode* node,
    ExplodedFrameState* state,
    std::vector<base::NullableString16>* referenced_files) {
  GenerateFrameStateFromItem(node->item(), state);
  ToNullableString16Vector(node->item().getReferencedFilePaths(),
                           referenced_files);

  std::vector<HistoryEntry::HistoryNode*>& children = node->children();
  state->children.resize(children.size());
  for (size_t i = 0; i < children.size(); ++i) {
    RecursivelyGenerateFrameState(children[i], &state->children[i],
                                  referenced_files);
  }
}

void RecursivelyGenerateHistoryItem(const ExplodedFrameState& state,
                                    HistoryEntry::HistoryNode* node) {
  WebHistoryItem item;
  item.initialize();
  item.setURLString(state.url_string);
  item.setReferrer(state.referrer, state.referrer_policy);
  item.setTarget(state.target);
  if (!state.state_object.is_null()) {
    item.setStateObject(
        WebSerializedScriptValue::fromString(state.state_object));
  }
  item.setDocumentState(state.document_state);
  item.setScrollRestorationType(state.scroll_restoration_type);
  item.setVisualViewportScrollOffset(state.visual_viewport_scroll_offset);
  item.setScrollOffset(state.scroll_offset);
  item.setPageScaleFactor(state.page_scale_factor);

  // These values are generated at WebHistoryItem construction time, and we
  // only want to override those new values with old values if the old values
  // are defined.  A value of 0 means undefined in this context.
  if (state.item_sequence_number)
    item.setItemSequenceNumber(state.item_sequence_number);
  if (state.document_sequence_number)
    item.setDocumentSequenceNumber(state.document_sequence_number);

  item.setHTTPContentType(state.http_body.http_content_type);
  if (state.http_body.request_body != nullptr) {
    item.setHTTPBody(
        GetWebHTTPBodyForRequestBody(state.http_body.request_body));
  }
  node->set_item(item);

  for (size_t i = 0; i < state.children.size(); ++i)
    RecursivelyGenerateHistoryItem(state.children[i], node->AddChild());
}

}  // namespace

PageState HistoryEntryToPageState(HistoryEntry* entry) {
  ExplodedPageState state;
  RecursivelyGenerateFrameState(entry->root_history_node(), &state.top,
                                &state.referenced_files);

  std::string encoded_data;
  EncodePageState(state, &encoded_data);
  return PageState::CreateFromEncodedData(encoded_data);
}

PageState SingleHistoryItemToPageState(const WebHistoryItem& item) {
  ExplodedPageState state;
  ToNullableString16Vector(item.getReferencedFilePaths(),
                           &state.referenced_files);
  GenerateFrameStateFromItem(item, &state.top);

  std::string encoded_data;
  EncodePageState(state, &encoded_data);
  return PageState::CreateFromEncodedData(encoded_data);
}

std::unique_ptr<HistoryEntry> PageStateToHistoryEntry(
    const PageState& page_state) {
  ExplodedPageState state;
  if (!DecodePageState(page_state.ToEncodedData(), &state))
    return std::unique_ptr<HistoryEntry>();

  std::unique_ptr<HistoryEntry> entry(new HistoryEntry());
  RecursivelyGenerateHistoryItem(state.top, entry->root_history_node());

  return entry;
}

}  // namespace content