/*

 * Copyright (C) 2009 Google Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are

 * met:

 *

 *     * Redistributions of source code must retain the above copyright

 * notice, this list of conditions and the following disclaimer.

 *     * Redistributions in binary form must reproduce the above

 * copyright notice, this list of conditions and the following disclaimer

 * in the documentation and/or other materials provided with the

 * distribution.

 *     * Neither the name of Google Inc. nor the names of its

 * contributors may be used to endorse or promote products derived from

 * this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "config.h"

#include "WebSearchableFormData.h"

#include "Document.h"

#include "FormDataBuilder.h"

#include "FormDataList.h"

#include "Frame.h"

#include "HTMLFormControlElement.h"

#include "HTMLFormElement.h"

#include "HTMLInputElement.h"

#include "HTMLNames.h"

#include "HTMLOptionElement.h"

#include "HTMLOptionsCollection.h"

#include "HTMLSelectElement.h"

#include "TextEncoding.h"

#include "WebFormElement.h"

using namespace WebCore;

namespace {

// Gets the encoding for the form.

void GetFormEncoding(const HTMLFormElement* form, TextEncoding* encoding)

{

    String str(form->getAttribute(HTMLNames::accept_charsetAttr));

    str.replace(',', ' ');

    Vector<String> charsets;

    str.split(' ', charsets);

    for (Vector<String>::const_iterator i(charsets.begin()); i != charsets.end(); ++i) {

        *encoding = TextEncoding(*i);

        if (encoding->isValid())

            return;

    }

    const Frame* frame = form->document()->frame();

    *encoding = frame ? TextEncoding(frame->loader()->writer()->encoding()) : Latin1Encoding();

}

// Returns true if the submit request results in an HTTP URL.

bool IsHTTPFormSubmit(const HTMLFormElement* form)

{

    String action(form->action());

    return form->document()->frame()->loader()->completeURL(action.isNull() ? "" : action).protocol() == "http";

}

// If the form does not have an activated submit button, the first submit

// button is returned.

HTMLFormControlElement* GetButtonToActivate(HTMLFormElement* form)

{

    HTMLFormControlElement* firstSubmitButton = 0;

    // FIXME: Consider refactoring this code so that we don't call form->associatedElements() twice.

    for (Vector<HTMLFormControlElement*>::const_iterator i(form->associatedElements().begin()); i != form->associatedElements().end(); ++i) {

      HTMLFormControlElement* formElement = *i;

      if (formElement->isActivatedSubmit())

          // There's a button that is already activated for submit, return 0.

          return 0;

      if (!firstSubmitButton && formElement->isSuccessfulSubmitButton())

          firstSubmitButton = formElement;

    }

    return firstSubmitButton;

}

// Returns true if the selected state of all the options matches the default

// selected state.

bool IsSelectInDefaultState(const HTMLSelectElement* select)

{

    const Vector<Element*>& listItems = select->listItems();

    if (select->multiple() || select->size() > 1) {

        for (Vector<Element*>::const_iterator i(listItems.begin()); i != listItems.end(); ++i) {

            if (!(*i)->hasLocalName(HTMLNames::optionTag))

                continue;

            const HTMLOptionElement* optionElement = static_cast<const HTMLOptionElement*>(*i);

            if (optionElement->selected() != optionElement->defaultSelected())

                return false;

        }

        return true;

    }

    // The select is rendered as a combobox (called menulist in WebKit). At

    // least one item is selected, determine which one.

    const HTMLOptionElement* initialSelected = 0;

    for (Vector<Element*>::const_iterator i(listItems.begin()); i != listItems.end(); ++i) {

        if (!(*i)->hasLocalName(HTMLNames::optionTag))

            continue;

        const HTMLOptionElement* optionElement = static_cast<const HTMLOptionElement*>(*i);

        if (optionElement->defaultSelected()) {

            // The page specified the option to select.

            initialSelected = optionElement;

            break;

        }

        if (!initialSelected)

            initialSelected = optionElement;

    }

    return initialSelected ? initialSelected->selected() : true;

}

// Returns true if the form element is in its default state, false otherwise.

// The default state is the state of the form element on initial load of the

// page, and varies depending upon the form element. For example, a checkbox is

// in its default state if the checked state matches the defaultChecked state.

bool IsInDefaultState(const HTMLFormControlElement* formElement)

{

    if (formElement->hasTagName(HTMLNames::inputTag)) {

        const HTMLInputElement* inputElement = static_cast<const HTMLInputElement*>(formElement);

        if (inputElement->inputType() == HTMLInputElement::CHECKBOX || inputElement->inputType() == HTMLInputElement::RADIO)

            return inputElement->checked() == inputElement->defaultChecked();

    } else if (formElement->hasTagName(HTMLNames::selectTag))

        return IsSelectInDefaultState(static_cast<const HTMLSelectElement*>(formElement));

    return true;

}

// If form has only one text input element, return true. If a valid input

// element is not found, return false. Additionally, the form data for all

// elements is added to enc_string and the encoding used is set in

// encoding_name.

bool HasSuitableTextElement(const HTMLFormElement* form, Vector<char>* encodedString, String* encodingName)

{

    TextEncoding encoding;

    GetFormEncoding(form, &encoding);

    if (!encoding.isValid()) {

        // Need a valid encoding to encode the form elements.

        // If the encoding isn't found webkit ends up replacing the params with

        // empty strings. So, we don't try to do anything here.

        return 0;

    }

    *encodingName = encoding.name();

    HTMLInputElement* textElement = 0;

    // FIXME: Consider refactoring this code so that we don't call form->associatedElements() twice.

    for (Vector<HTMLFormControlElement*>::const_iterator i(form->associatedElements().begin()); i != form->associatedElements().end(); ++i) {

        HTMLFormControlElement* formElement = *i;

        if (formElement->disabled() || formElement->name().isNull())

            continue;

        if (!IsInDefaultState(formElement) || formElement->hasTagName(HTMLNames::textareaTag))

            return 0;

        bool isTextElement = false;

        if (formElement->hasTagName(HTMLNames::inputTag)) {

            switch (static_cast<const HTMLInputElement*>(formElement)->inputType()) {

            case HTMLInputElement::TEXT:

            case HTMLInputElement::ISINDEX:

                isTextElement = true;

                break;

            case HTMLInputElement::PASSWORD:

                // Don't store passwords! This is most likely an https anyway.

                // Fall through.

            case HTMLInputElement::FILE:

                // Too big, don't try to index this.

                return 0;

            default:

                // All other input types are indexable.

                break;

            }

      }

      FormDataList dataList(encoding);

      if (!formElement->appendFormData(dataList, false))

          continue;

      const BlobItemList& items = dataList.items();

      if (isTextElement && !items.isEmpty()) {

          if (textElement) {

              // The auto-complete bar only knows how to fill in one value.

              // This form has multiple fields; don't treat it as searchable.

              return false;

          }

          textElement = static_cast<HTMLInputElement*>(formElement);

      }

      for (BlobItemList::const_iterator j(items.begin()); j != items.end(); ++j) {

          const StringBlobItem* item = (*j)->toStringBlobItem();

          ASSERT(item);

          // Handle ISINDEX / <input name=isindex> specially, but only if it's

          // the first entry.

          if (!encodedString->isEmpty() || item->cstr() != "isindex") {

              if (!encodedString->isEmpty())

                  encodedString->append('&');

              FormDataBuilder::encodeStringAsFormData(*encodedString, item->cstr());

              encodedString->append('=');

          }

          ++j;

          if (formElement == textElement)

              encodedString->append("{searchTerms}", 13);

          else

              FormDataBuilder::encodeStringAsFormData(*encodedString, item->cstr());

      }

    }

    return textElement;

}

} // namespace

namespace WebKit {

WebSearchableFormData::WebSearchableFormData(const WebFormElement& form)

{

    RefPtr<HTMLFormElement> formElement = form.operator PassRefPtr<HTMLFormElement>();

    const Frame* frame = formElement->document()->frame();

    if (!frame)

        return;

    // Only consider forms that GET data and the action targets an http page.

    if (equalIgnoringCase(formElement->getAttribute(HTMLNames::methodAttr), "post") || !IsHTTPFormSubmit(formElement.get()))

        return;

    HTMLFormControlElement* firstSubmitButton = GetButtonToActivate(formElement.get());

    if (firstSubmitButton) {

        // The form does not have an active submit button, make the first button

        // active. We need to do this, otherwise the URL will not contain the

        // name of the submit button.

        firstSubmitButton->setActivatedSubmit(true);

    }

    Vector<char> encodedString;

    String encoding;

    bool hasElement = HasSuitableTextElement(formElement.get(), &encodedString, &encoding);

    if (firstSubmitButton)

        firstSubmitButton->setActivatedSubmit(false);

    if (!hasElement) {

        // Not a searchable form.

        return;

    }

    String action(formElement->action());

    KURL url(frame->loader()->completeURL(action.isNull() ? "" : action));

    RefPtr<FormData> formData = FormData::create(encodedString);

    url.setQuery(formData->flattenToString());

    m_url = url;

    m_encoding = encoding;

}

} // namespace WebKit