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#include "config.h"
#include "WebSocketServer.h"

#include "CommandResult.h"
#include "Logging.h"
#include "Session.h"
#include "WebDriverService.h"
#include <algorithm>
#include <optional>
#include <ranges>
#include <wtf/JSONValues.h>
#include <wtf/UUID.h>
#include <wtf/text/MakeString.h>
#include <wtf/text/WTFString.h>

namespace WebDriver {

WebSocketServer::WebSocketServer(WebSocketMessageHandler& messageHandler)
    : m_messageHandler(messageHandler)
{
}

void WebSocketServer::addStaticConnection(WebSocketMessageHandler::Connection&& connection)
{
    m_staticConnections.push_back(WTFMove(connection));
}

void WebSocketServer::addConnection(WebSocketMessageHandler::Connection&& connection, const String& sessionId)
{
    m_connectionToSession.add(WTFMove(connection), sessionId);
}

bool WebSocketServer::isStaticConnection(const WebSocketMessageHandler::Connection& connection)
{
    return std::ranges::count(m_staticConnections, connection);
}

void WebSocketServer::removeStaticConnection(const WebSocketMessageHandler::Connection& connection)
{
    m_staticConnections.erase(std::ranges::find(m_staticConnections, connection));
}

void WebSocketServer::removeConnection(const WebSocketMessageHandler::Connection& connection)
{
    auto it = m_connectionToSession.find(connection);
    if (it != m_connectionToSession.end())
        m_connectionToSession.remove(it);
}

String WebSocketServer::sessionID(const WebSocketMessageHandler::Connection& connection) const
{
    for (const auto& pair : m_connectionToSession) {
        if (pair.key == connection)
            return pair.value;
    }

    return { };
}

std::optional<WebSocketMessageHandler::Connection> WebSocketServer::connection(const String& sessionId)
{
    for (auto& pair : m_connectionToSession) {
        if (pair.value == sessionId)
            return pair.key;
    }

    return { };
}

String WebSocketServer::getSessionID(const String& resource)
{
    // https://w3c.github.io/webdriver-bidi/#get-a-session-id-for-a-websocket-resource

    constexpr auto sessionPrefix = "/session/"_s;
    if (!resource.startsWith(sessionPrefix))
        return nullString();

    auto sessionId = resource.substring(sessionPrefix.length());
    auto uuid = WTF::UUID::parse(sessionId);
    if (!uuid || !uuid->isValid())
        return nullString();

    return sessionId;
}

RefPtr<WebSocketListener> WebSocketServer::startListening(const String& sessionId)
{
    // https://w3c.github.io/webdriver-bidi/#start-listening-for-a-websocket-connection
    // FIXME Add more listeners when start supporting multiple sessions
    auto resourceName = getResourceName(sessionId);
    m_listener->resources.push_back(resourceName);
    return m_listener;
}

String WebSocketServer::getResourceName(const String& sessionId)
{
    // https://w3c.github.io/webdriver-bidi/#construct-a-websocket-resource-name
    if (sessionId.isNull())
        return "/session"_s;

    return makeString("/session/"_s, sessionId);
}

String WebSocketServer::getWebSocketURL(const RefPtr<WebSocketListener> listener, const String& sessionId)
{
    // https://w3c.github.io/webdriver-bidi/#construct-a-websocket-url
    // FIXME: Support secure flag
    // https://bugs.webkit.org/show_bug.cgi?id=280680

    auto resourceName = getResourceName(sessionId);

    auto host = listener->host;
    if (host == "all"_s)
        host = "localhost"_s;

    return makeString("ws://"_s, host, ":"_s, String::number(listener->port), resourceName);
}

void WebSocketServer::removeResourceForSession(const String& sessionId)
{
    auto resourceName = getResourceName(sessionId);
    std::erase(m_listener->resources, resourceName);
}

WebSocketMessageHandler::Message WebSocketMessageHandler::Message::fail(CommandResult::ErrorCode errorCode, std::optional<Connection> connection, std::optional<String> errorMessage, std::optional<int> commandId)
{
    auto reply = JSON::Object::create();

    if (commandId)
        reply->setInteger("id"_s, *commandId);

    if (errorMessage)
        reply->setString("message"_s, *errorMessage);

    reply->setString("error"_s, CommandResult::errorCodeToString(errorCode));
    reply->setString("type"_s, "error"_s);

    return { (connection ? (*connection) : nullptr), reply->toJSONString().utf8() };
}

WebSocketMessageHandler::Message WebSocketMessageHandler::Message::reply(const String& type, unsigned id, Ref<JSON::Value>&& result)
{
    auto reply = JSON::Object::create();
    reply->setString("type"_s, type);
    reply->setInteger("id"_s, id);

    if (auto resultObject = result->asObject())
        reply->setObject("result"_s, resultObject.releaseNonNull());
    else
        reply->setObject("result"_s, JSON::Object::create());

    // Connection will be set when sending the message back to the client, from the incoming message.
    return { nullptr, reply->toJSONString().utf8() };
}

std::optional<Command> Command::fromData(const char* data, size_t dataLength)
{
    auto messageValue = JSON::Value::parseJSON(String::fromUTF8(std::span<const char>(data, dataLength)));
    if (!messageValue)
        return std::nullopt;

    auto messageObject = messageValue->asObject();
    if (!messageObject)
        return std::nullopt;

    auto id = messageObject->getString("id"_s);
    if (!id)
        return std::nullopt;

    auto method = messageObject->getString("method"_s);
    if (!method)
        return std::nullopt;

    auto params = messageObject->getObject("params"_s);
    if (!params)
        return std::nullopt;

    Command command {
        .id = id,
        .method = method,
        .parameters = params
    };

    return command;
}

void WebSocketServer::sendMessage(const String& sessionId, const String& message)
{
    auto connection = this->connection(sessionId);
    if (!connection) {
        RELEASE_LOG_ERROR(WebDriverBiDi, "No connection found for session %s when trying to send message: %s", sessionId.utf8().data(), message.utf8().data());
        return;
    }
    sendMessage(*connection, message);
}

void WebSocketServer::sendErrorResponse(const String& sessionId, std::optional<unsigned> commandId, CommandResult::ErrorCode errorCode, const String& errorMessage, std::optional<String> stacktrace)
{
    auto connection = this->connection(sessionId);
    if (!connection) {
        RELEASE_LOG_ERROR(WebDriverBiDi, "No connection found for session %s when trying to send error response", sessionId.utf8().data());
        return;
    }
    sendErrorResponse(*connection, commandId, errorCode, errorMessage, stacktrace);
}

void WebSocketServer::sendErrorResponse(WebSocketMessageHandler::Connection connection, std::optional<unsigned> commandId, CommandResult::ErrorCode errorCode, const String& errorMessage, std::optional<String> stacktrace)
{
    auto errorObject = JSON::Object::create();

    errorObject->setString("type"_s, "error"_s);
    errorObject->setString("error"_s, CommandResult::errorCodeToString(errorCode));
    errorObject->setString("message"_s, errorMessage);
    if (commandId)
        errorObject->setInteger("id"_s, *commandId); // FIXME change to JSON::Value
    if (stacktrace)
        errorObject->setString("stacktrace"_s, *stacktrace);

    sendMessage(connection, errorObject->toJSONString());
}


} // namespace WebDriver