/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 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 HOLDER 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 <AK/StringBuilder.h>
#include <LibWeb/HTML/EventNames.h>
#include <LibWeb/HTML/HTMLFormElement.h>
#include <LibWeb/HTML/HTMLInputElement.h>
#include <LibWeb/HTML/SubmitEvent.h>
#include <LibWeb/InProcessWebView.h>
#include <LibWeb/Page/Frame.h>
#include <LibWeb/URLEncoder.h>

namespace Web::HTML {

HTMLFormElement::HTMLFormElement(DOM::Document& document, QualifiedName qualified_name)
    : HTMLElement(document, move(qualified_name))
{
}

HTMLFormElement::~HTMLFormElement()
{
}

void HTMLFormElement::submit_form(RefPtr<HTMLElement> submitter, bool from_submit_binding)
{
    if (cannot_navigate())
        return;

    if (action().is_null()) {
        dbgln("Unsupported form action ''");
        return;
    }

    auto effective_method = method().to_lowercase();

    if (effective_method == "dialog") {
        dbgln("Failed to submit form: Unsupported form method '{}'", method());
        return;
    }

    if (effective_method != "get" && effective_method != "post") {
        effective_method = "get";
    }

    if (!from_submit_binding) {
        if (m_firing_submission_events)
            return;

        m_firing_submission_events = true;

        // FIXME: If the submitter element's no-validate state is false...

        RefPtr<HTMLElement> submitter_button;

        if (submitter != this)
            submitter_button = submitter;

        auto submit_event = SubmitEvent::create(EventNames::submit, submitter_button);
        submit_event->set_bubbles(true);
        submit_event->set_cancelable(true);
        bool continue_ = dispatch_event(submit_event);

        m_firing_submission_events = false;

        if (!continue_)
            return;

        // This is checked again because arbitrary JS may have run when handling submit,
        // which may have changed the result.
        if (cannot_navigate())
            return;
    }

    URL url(document().complete_url(action()));

    if (!url.is_valid()) {
        dbgln("Failed to submit form: Invalid URL: {}", action());
        return;
    }

    if (url.protocol() == "file") {
        if (document().url().protocol() != "file") {
            dbgln("Failed to submit form: Security violation: {} may not submit to {}", document().url(), url);
            return;
        }
        if (effective_method != "get") {
            dbgln("Failed to submit form: Unsupported form method '{}' for URL: {}", method(), url);
            return;
        }
    } else if (url.protocol() != "http" && url.protocol() != "https") {
        dbgln("Failed to submit form: Unsupported protocol for URL: {}", url);
        return;
    }

    Vector<URLQueryParam> parameters;

    for_each_in_subtree_of_type<HTMLInputElement>([&](auto& node) {
        auto& input = downcast<HTMLInputElement>(node);
        if (!input.name().is_null() && (input.type() != "submit" || &input == submitter))
            parameters.append({ input.name(), input.value() });
        return IterationDecision::Continue;
    });

    if (effective_method == "get") {
        url.set_query(urlencode(parameters));
    }

    LoadRequest request;
    request.set_url(url);

    if (effective_method == "post") {
        auto body = urlencode(parameters).to_byte_buffer();
        request.set_method("POST");
        request.set_header("Content-Type", "application/x-www-form-urlencoded");
        request.set_header("Content-Length", String::number(body.size()));
        request.set_body(body);
    }

    if (auto* page = document().page())
        page->load(request);
}

void HTMLFormElement::submit()
{
    submit_form(this, true);
}

}