// Copyright (c) 2010 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 "webkit/glue/dom_operations.h"

#include <set>

#include "base/compiler_specific.h"
#include "base/string_number_conversions.h"
#include "base/string_split.h"
#include "base/string_util.h"
#include "third_party/WebKit/WebKit/chromium/public/WebAnimationController.h"
#include "third_party/WebKit/WebKit/chromium/public/WebDocument.h"
#include "third_party/WebKit/WebKit/chromium/public/WebElement.h"
#include "third_party/WebKit/WebKit/chromium/public/WebFrame.h"
#include "third_party/WebKit/WebKit/chromium/public/WebInputElement.h"
#include "third_party/WebKit/WebKit/chromium/public/WebNode.h"
#include "third_party/WebKit/WebKit/chromium/public/WebNodeCollection.h"
#include "third_party/WebKit/WebKit/chromium/public/WebNodeList.h"
#include "third_party/WebKit/WebKit/chromium/public/WebString.h"
#include "third_party/WebKit/WebKit/chromium/public/WebVector.h"
#include "third_party/WebKit/WebKit/chromium/public/WebView.h"

using WebKit::WebAnimationController;
using WebKit::WebDocument;
using WebKit::WebElement;
using WebKit::WebFrame;
using WebKit::WebInputElement;
using WebKit::WebNode;
using WebKit::WebNodeCollection;
using WebKit::WebNodeList;
using WebKit::WebString;
using WebKit::WebVector;
using WebKit::WebView;

namespace {

// Structure for storage the unique set of all savable resource links for
// making sure that no duplicated resource link in final result. The consumer
// of the SavableResourcesUniqueCheck is responsible for keeping these pointers
// valid for the lifetime of the SavableResourcesUniqueCheck instance.
struct SavableResourcesUniqueCheck {
  // Unique set of all sub resource links.
  std::set<GURL>* resources_set;
  // Unique set of all frame links.
  std::set<GURL>* frames_set;
  // Collection of all frames we go through when getting all savable resource
  // links.
  std::vector<WebFrame*>* frames;

  SavableResourcesUniqueCheck()
      : resources_set(NULL),
        frames_set(NULL),
        frames(NULL) {}

  SavableResourcesUniqueCheck(std::set<GURL>* resources_set,
      std::set<GURL>* frames_set, std::vector<WebFrame*>* frames)
      : resources_set(resources_set),
        frames_set(frames_set),
        frames(frames) {}
};

// Get all savable resource links from current element. One element might
// have more than one resource link. It is possible to have some links
// in one CSS stylesheet.
void GetSavableResourceLinkForElement(
    const WebElement& element,
    const WebDocument& current_doc,
    SavableResourcesUniqueCheck* unique_check,
    webkit_glue::SavableResourcesResult* result) {

  // Handle frame and iframe tag.
  if (element.hasTagName("iframe") ||
      element.hasTagName("frame")) {
    WebFrame* sub_frame = WebFrame::fromFrameOwnerElement(element);
    if (sub_frame)
      unique_check->frames->push_back(sub_frame);
    return;
  }

  // Check whether the node has sub resource URL or not.
  WebString value =
      webkit_glue::GetSubResourceLinkFromElement(element);
  if (value.isNull())
    return;
  // Get absolute URL.
  GURL u = current_doc.completeURL(value);
  // ignore invalid URL
  if (!u.is_valid())
    return;
  // Ignore those URLs which are not standard protocols. Because FTP
  // protocol does no have cache mechanism, we will skip all
  // sub-resources if they use FTP protocol.
  if (!u.SchemeIs("http") && !u.SchemeIs("https") && !u.SchemeIs("file"))
    return;
  // Ignore duplicated resource link.
  if (!unique_check->resources_set->insert(u).second)
    return;
  result->resources_list->push_back(u);
  // Insert referrer for above new resource link.
  result->referrers_list->push_back(GURL());
}

// Get all savable resource links from current WebFrameImpl object pointer.
void GetAllSavableResourceLinksForFrame(WebFrame* current_frame,
    SavableResourcesUniqueCheck* unique_check,
    webkit_glue::SavableResourcesResult* result,
    const char** savable_schemes) {
  // Get current frame's URL.
  GURL current_frame_url = current_frame->url();

  // If url of current frame is invalid, ignore it.
  if (!current_frame_url.is_valid())
    return;

  // If url of current frame is not a savable protocol, ignore it.
  bool is_valid_protocol = false;
  for (int i = 0; savable_schemes[i] != NULL; ++i) {
    if (current_frame_url.SchemeIs(savable_schemes[i])) {
      is_valid_protocol = true;
      break;
    }
  }
  if (!is_valid_protocol)
    return;

  // If find same frame we have recorded, ignore it.
  if (!unique_check->frames_set->insert(current_frame_url).second)
    return;

  // Get current using document.
  WebDocument current_doc = current_frame->document();
  // Go through all descent nodes.
  WebNodeCollection all = current_doc.all();
  // Go through all node in this frame.
  for (WebNode node = all.firstItem(); !node.isNull();
       node = all.nextItem()) {
    // We only save HTML resources.
    if (!node.isElementNode())
      continue;
    WebElement element = node.to<WebElement>();
    GetSavableResourceLinkForElement(element,
                                     current_doc,
                                     unique_check,
                                     result);
  }
}

}  // namespace

namespace webkit_glue {

WebString GetSubResourceLinkFromElement(const WebElement& element) {
  const char* attribute_name = NULL;
  if (element.hasTagName("img") ||
      element.hasTagName("script")) {
    attribute_name = "src";
  } else if (element.hasTagName("input")) {
    const WebInputElement input = element.toConst<WebInputElement>();
    if (input.isImageButton()) {
      attribute_name = "src";
    }
  } else if (element.hasTagName("body") ||
             element.hasTagName("table") ||
             element.hasTagName("tr") ||
             element.hasTagName("td")) {
    attribute_name = "background";
  } else if (element.hasTagName("blockquote") ||
             element.hasTagName("q") ||
             element.hasTagName("del") ||
             element.hasTagName("ins")) {
    attribute_name = "cite";
  } else if (element.hasTagName("link")) {
    // If the link element is not linked to css, ignore it.
    if (LowerCaseEqualsASCII(element.getAttribute("type"), "text/css")) {
      // TODO(jnd): Add support for extracting links of sub-resources which
      // are inside style-sheet such as @import, url(), etc.
      // See bug: http://b/issue?id=1111667.
      attribute_name = "href";
    }
  }
  if (!attribute_name)
    return WebString();
  WebString value = element.getAttribute(WebString::fromUTF8(attribute_name));
  // If value has content and not start with "javascript:" then return it,
  // otherwise return NULL.
  if (!value.isNull() && !value.isEmpty() &&
      !StartsWithASCII(value.utf8(), "javascript:", false))
    return value;

  return WebString();
}

// Get all savable resource links from current webview, include main
// frame and sub-frame
bool GetAllSavableResourceLinksForCurrentPage(WebView* view,
    const GURL& page_url, SavableResourcesResult* result,
    const char** savable_schemes) {
  WebFrame* main_frame = view->mainFrame();
  if (!main_frame)
    return false;

  std::set<GURL> resources_set;
  std::set<GURL> frames_set;
  std::vector<WebFrame*> frames;
  SavableResourcesUniqueCheck unique_check(&resources_set,
                                           &frames_set,
                                           &frames);

  GURL main_page_gurl(main_frame->url());

  // Make sure we are saving same page between embedder and webkit.
  // If page has being navigated, embedder will get three empty vector,
  // which will make the saving page job ended.
  if (page_url != main_page_gurl)
    return true;

  // First, process main frame.
  frames.push_back(main_frame);

  // Check all resource in this page, include sub-frame.
  for (int i = 0; i < static_cast<int>(frames.size()); ++i) {
    // Get current frame's all savable resource links.
    GetAllSavableResourceLinksForFrame(frames[i], &unique_check, result,
                                       savable_schemes);
  }

  // Since frame's src can also point to sub-resources link, so it is possible
  // that some URLs in frames_list are also in resources_list. For those
  // URLs, we will remove it from frame_list, only keep them in resources_list.
  for (std::set<GURL>::iterator it = frames_set.begin();
       it != frames_set.end(); ++it) {
    // Append unique frame source to savable frame list.
    if (resources_set.find(*it) == resources_set.end())
      result->frames_list->push_back(*it);
  }

  return true;
}

// Sizes a single size (the width or height) from a 'sizes' attribute. A size
// matches must match the following regex: [1-9][0-9]*.
static int ParseSingleIconSize(const string16& text) {
  // Size must not start with 0, and be between 0 and 9.
  if (text.empty() || !(text[0] >= L'1' && text[0] <= L'9'))
    return 0;
  // Make sure all chars are from 0-9.
  for (size_t i = 1; i < text.length(); ++i) {
    if (!(text[i] >= L'0' && text[i] <= L'9'))
      return 0;
  }
  int output;
  if (!base::StringToInt(text, &output))
    return 0;
  return output;
}

// Parses an icon size. An icon size must match the following regex:
// [1-9][0-9]*x[1-9][0-9]*.
// If the input couldn't be parsed, a size with a width/height < 0 is returned.
static gfx::Size ParseIconSize(const string16& text) {
  std::vector<string16> sizes;
  base::SplitStringDontTrim(text, L'x', &sizes);
  if (sizes.size() != 2)
    return gfx::Size();

  return gfx::Size(ParseSingleIconSize(sizes[0]),
                   ParseSingleIconSize(sizes[1]));
}

WebApplicationInfo::WebApplicationInfo() {}

WebApplicationInfo::~WebApplicationInfo() {}

bool ParseIconSizes(const string16& text,
                    std::vector<gfx::Size>* sizes,
                    bool* is_any) {
  *is_any = false;
  std::vector<string16> size_strings;
  SplitStringAlongWhitespace(text, &size_strings);
  for (size_t i = 0; i < size_strings.size(); ++i) {
    if (EqualsASCII(size_strings[i], "any")) {
      *is_any = true;
    } else {
      gfx::Size size = ParseIconSize(size_strings[i]);
      if (size.width() <= 0 || size.height() <= 0)
        return false;  // Bogus size.
      sizes->push_back(size);
    }
  }
  if (*is_any && !sizes->empty()) {
    // If is_any is true, it must occur by itself.
    return false;
  }
  return (*is_any || !sizes->empty());
}

static void AddInstallIcon(const WebElement& link,
                           std::vector<WebApplicationInfo::IconInfo>* icons) {
  WebString href = link.getAttribute("href");
  if (href.isNull() || href.isEmpty())
    return;

  // Get complete url.
  GURL url = link.document().completeURL(href);
  if (!url.is_valid())
    return;

  if (!link.hasAttribute("sizes"))
    return;

  bool is_any = false;
  std::vector<gfx::Size> icon_sizes;
  if (!ParseIconSizes(link.getAttribute("sizes"), &icon_sizes, &is_any) ||
      is_any ||
      icon_sizes.size() != 1) {
    return;
  }
  WebApplicationInfo::IconInfo icon_info;
  icon_info.width = icon_sizes[0].width();
  icon_info.height = icon_sizes[0].height();
  icon_info.url = url;
  icons->push_back(icon_info);
}

void GetApplicationInfo(WebView* view, WebApplicationInfo* app_info) {
  WebFrame* main_frame = view->mainFrame();
  if (!main_frame)
    return;

  WebDocument doc = main_frame->document();
  if (doc.isNull())
    return;

  WebElement head = main_frame->document().head();
  if (head.isNull())
    return;

  WebNodeList children = head.childNodes();
  for (unsigned i = 0; i < children.length(); ++i) {
    WebNode child = children.item(i);
    if (!child.isElementNode())
      continue;
    WebElement elem = child.to<WebElement>();

    if (elem.hasTagName("link")) {
      std::string rel = elem.getAttribute("rel").utf8();
      // "rel" attribute may use either "icon" or "shortcut icon".
      // see also
      //   <http://en.wikipedia.org/wiki/Favicon>
      //   <http://dev.w3.org/html5/spec/Overview.html#rel-icon>
      if (LowerCaseEqualsASCII(rel, "icon") ||
          LowerCaseEqualsASCII(rel, "shortcut icon"))
        AddInstallIcon(elem, &app_info->icons);
    } else if (elem.hasTagName("meta") && elem.hasAttribute("name")) {
      std::string name = elem.getAttribute("name").utf8();
      WebString content = elem.getAttribute("content");
      if (name == "application-name") {
        app_info->title = content;
      } else if (name == "description") {
        app_info->description = content;
      } else if (name == "application-url") {
        std::string url = content.utf8();
        GURL main_url = main_frame->url();
        app_info->app_url = main_url.is_valid() ?
            main_url.Resolve(url) : GURL(url);
        if (!app_info->app_url.is_valid())
          app_info->app_url = GURL();
      }
    }
  }
}

bool PauseAnimationAtTimeOnElementWithId(WebView* view,
                                         const std::string& animation_name,
                                         double time,
                                         const std::string& element_id) {
  WebFrame* web_frame = view->mainFrame();
  if (!web_frame)
    return false;

  WebAnimationController* controller = web_frame->animationController();
  if (!controller)
    return false;

  WebElement element =
    web_frame->document().getElementById(WebString::fromUTF8(element_id));
  if (element.isNull())
    return false;
  return controller->pauseAnimationAtTime(element,
                                          WebString::fromUTF8(animation_name),
                                          time);
}

bool PauseTransitionAtTimeOnElementWithId(WebView* view,
                                          const std::string& property_name,
                                          double time,
                                          const std::string& element_id) {
  WebFrame* web_frame = view->mainFrame();
  if (!web_frame)
    return false;

  WebAnimationController* controller = web_frame->animationController();
  if (!controller)
    return false;

  WebElement element =
      web_frame->document().getElementById(WebString::fromUTF8(element_id));
  if (element.isNull())
    return false;
  return controller->pauseTransitionAtTime(element,
                                           WebString::fromUTF8(property_name),
                                           time);
}

bool ElementDoesAutoCompleteForElementWithId(WebView* view,
                                             const std::string& element_id) {
  WebFrame* web_frame = view->mainFrame();
  if (!web_frame)
    return false;

  WebElement element = web_frame->document().getElementById(
      WebString::fromUTF8(element_id));
  if (element.isNull() || !element.hasTagName("input"))
    return false;

  WebInputElement input_element = element.to<WebInputElement>();
  return input_element.autoComplete();
}

int NumberOfActiveAnimations(WebView* view) {
  WebFrame* web_frame = view->mainFrame();
  if (!web_frame)
    return -1;

  WebAnimationController* controller = web_frame->animationController();
  if (!controller)
    return -1;

  return controller->numberOfActiveAnimations();
}

void GetMetaElementsWithAttribute(WebDocument* document,
                                  const string16& attribute_name,
                                  const string16& attribute_value,
                                  std::vector<WebElement>* meta_elements) {
  DCHECK(document);
  DCHECK(meta_elements);
  meta_elements->clear();
  WebElement head = document->head();
  if (head.isNull() || !head.hasChildNodes())
    return;

  WebNodeList children = head.childNodes();
  for (size_t i = 0; i < children.length(); ++i) {
    WebNode node = children.item(i);
    if (!node.isElementNode())
      continue;
    WebElement element = node.to<WebElement>();
    if (!element.hasTagName("meta"))
      continue;
    WebString value = element.getAttribute(attribute_name);
    if (value.isNull() || value != attribute_value)
      continue;
    meta_elements->push_back(element);
  }
}

}  // webkit_glue