module hunt.http.client.Http1ClientConnection;

import hunt.http.client.ClientHttpHandler;
import hunt.http.client.ClientHttp2SessionListener;
import hunt.http.client.HttpClientConnection;
import hunt.http.client.Http1ClientResponseHandler;
import hunt.http.client.Http2ClientConnection;
import hunt.http.client.Http2ClientResponseHandler;
import hunt.http.client.Http2ClientSession;

import hunt.http.codec.http.decode.HttpParser;
import hunt.http.codec.http.encode.HttpGenerator;
import hunt.http.codec.http.frame.SettingsFrame;
import hunt.http.codec.http.model;
import hunt.http.codec.http.stream;
import hunt.http.WebSocketCommon;
import hunt.http.WebSocketConnection;
import hunt.http.codec.websocket.stream.IOState;
import hunt.http.codec.websocket.stream.WebSocketConnectionImpl;

import hunt.http.HttpConnection;
import hunt.http.HttpField;
import hunt.http.HttpFields;
import hunt.http.HttpHeader;
import hunt.http.HttpMethod;
import hunt.http.HttpOptions;
import hunt.http.HttpOutputStream;
import hunt.http.HttpRequest;
import hunt.http.HttpResponse;
import hunt.http.HttpVersion;
import hunt.http.WebSocketPolicy;

import hunt.net.secure.SecureSession;
import hunt.net.Connection;

import hunt.collection;
import hunt.concurrency.Promise;
import hunt.stream;
import hunt.Exceptions;
import hunt.logging;
import hunt.text.Common;
import hunt.text.Codec;

import std.array;
import std.base64;
import std.conv;
import std.random;
import std.socket;

alias HttpProtocol = hunt.http.codec.http.model.Protocol.Protocol;
alias SessionListener = StreamSession.Listener;

// import hunt.http.codec.websocket.model.WebSocketConstants.SPEC_VERSION;

/**
*/
class Http1ClientConnection : AbstractHttp1Connection, HttpClientConnection {

    private Promise!(WebSocketConnection) webSocketConnectionPromise;
    private IncomingFrames incomingFrames;
    private WebSocketPolicy policy;
    private Promise!(HttpClientConnection) http2ConnectionPromise;
    private Http2ClientConnection http2Connection;
    private ClientHttp2SessionListener http2SessionListener;
    private bool upgradeHttp2Complete = false; 
    private bool upgradeWebSocketComplete = false;
    private ResponseHandlerWrap wrap;

    this(HttpOptions config, Connection tcpSession) { // , SecureSession secureSession
        this(config, tcpSession, new ResponseHandlerWrap()); // secureSession, 
    }

    private this(HttpOptions config,
            Connection tcpSession, HttpResponseParsingHandler responseHandler) {

        super(config, tcpSession, null, responseHandler);
        wrap = cast(ResponseHandlerWrap) responseHandler;
        wrap.connection = this;
    }

    override protected HttpParser initHttpParser(HttpOptions config,
            HttpRequestParsingHandler requestHandler, HttpResponseParsingHandler responseHandler) {
        return new HttpParser(responseHandler, config.getMaxRequestHeadLength());
    }

    override HttpConnectionType getConnectionType() {
        return HttpConnectionType.HTTP1;
    }

    // override bool isSecured() {
    //     return super.isSecured();
    // }

    HttpParser getParser() {
        return parser;
    }

    HttpOptions getHttpOptions() {
        return config;
    }

    // dfmt off
    override void upgradeHttp2(HttpRequest request, SettingsFrame settings, 
            Promise!(HttpClientConnection) promise, ClientHttpHandler upgradeHandler,
            ClientHttpHandler http2ResponseHandler) {

        Promise!(Stream) initStream = new Http2ClientResponseHandler.ClientStreamPromise(request, 
            new class DefaultPromise!(HttpOutputStream) {

            override
            bool failed(Throwable x) {
                errorf("Create client output stream exception", x);
                return true;
            }
        });

        Stream.Listener initStreamListener = new Http2ClientResponseHandler(request, http2ResponseHandler, this);
        ClientHttp2SessionListener listener = new class ClientHttp2SessionListener {

            override
            Map!(int, int) onPreface(StreamSession session) {
                return settings.getSettings();
            }

        };
        upgradeHttp2(request, settings, promise, initStream, initStreamListener, listener, upgradeHandler);
    }

    void upgradeHttp2(HttpRequest request, SettingsFrame settings,
            Promise!(HttpClientConnection) promise, Promise!(Stream) initStream,
            Stream.Listener initStreamListener,
            ClientHttp2SessionListener listener, ClientHttpHandler handler) {
        if (isSecured()) {
            throw new IllegalStateException("The TLS TCP connection must use ALPN to upgrade HTTP2");
        }

        this.http2ConnectionPromise = promise;
        this.http2SessionListener = listener;
        http2Connection = new class Http2ClientConnection {
            this() {
                super(getHttpOptions(), this.outer.getTcpConnection(), http2SessionListener);
            }
            
            override
            protected Http2Session initHttp2Session(HttpOptions config, FlowControlStrategy flowControl,
                                                    StreamSession.Listener listener) {
                return Http2ClientSession.initSessionForUpgradingHTTP2(null, this.outer.getTcpConnection(), generator,
                        listener, flowControl, 3, config.getStreamIdleTimeout(), initStream,
                        initStreamListener);
            }
        };        

        // generate http2 upgrading headers
        request.getFields().add(new HttpField(HttpHeader.CONNECTION, "Upgrade, HTTP2-Settings"));
        request.getFields().add(new HttpField(HttpHeader.UPGRADE, "h2c"));
        if (settings !is null) {
            List!(ByteBuffer) byteBuffers = http2Generator.control(settings);
            if (byteBuffers !is null && byteBuffers.size() > 0) {
                try {
                    // ByteArrayOutputStream ot = new ByteArrayOutputStream();
                    // foreach (ByteBuffer buffer ; byteBuffers) {
                    //     ot.write(BufferUtils.toArray(buffer));
                    // }
                    Appender!(byte[]) ot;
                    foreach (ByteBuffer buffer; byteBuffers) {
                        byte[] bufferArray = BufferUtils.toArray(buffer);
                        // writeln("before1:\t" ~ TypeUtils.toHexString(bufferArray));
                        // writefln("before1:\t%(%02X %)" , bufferArray);
                        ot.put(bufferArray);
                    }
                    byte[] settingsFrame = ot.data; //ot.toByteArray();
                    byte[] settingsPayload = new byte[settingsFrame.length - 9];
                    // System.arraycopy(settingsFrame, 9, settingsPayload, 0, settingsPayload.length);
                    settingsPayload[0 .. settingsPayload.length] = settingsFrame[9 .. 9 + settingsPayload.length];

                    request.getFields().add(new HttpField(HttpHeader.HTTP2_SETTINGS,
                            // Base64Utils.encodeToUrlSafeString(settingsPayload)
                            Base64URL.encode(settingsPayload)));
                } catch (IOException e) {
                    errorf("generate http2 upgrading settings exception", e);
                }
            } else {
                request.getFields().add(new HttpField(HttpHeader.HTTP2_SETTINGS, ""));
            }
        } else {
            request.getFields().add(new HttpField(HttpHeader.HTTP2_SETTINGS, ""));
        }

        send(request, handler);
    }
    // dfmt on

    bool upgradeProtocolComplete(HttpRequest request, HttpResponse response) {
        switch (ProtocolHelper.from(response)) {
        case HttpProtocol.H2: {
                if (http2ConnectionPromise !is null
                        && http2SessionListener !is null && http2Connection !is null) {
                    upgradeHttp2Complete = true;
                    // tcpSession.attachObject(http2Connection);
                    setAttribute(HttpConnection.NAME, http2Connection);
                    http2SessionListener.setConnection(http2Connection);
                    http2Connection.initialize(getHttpOptions(),
                            http2ConnectionPromise, http2SessionListener);
                    return true;
                } else {
                    resetUpgradeProtocol();
                    return false;
                }
            }
        case HttpProtocol.WEB_SOCKET: {
                if (webSocketConnectionPromise !is null && incomingFrames !is null && policy !is null) {
                    upgradeWebSocketComplete = true;
                    WebSocketConnection webSocketConnection = new WebSocketConnectionImpl(
                            getTcpConnection(), incomingFrames, policy, request, response, config);
                    // tcpSession.attachObject(cast(Object) webSocketConnection);
                    setAttribute(HttpConnection.NAME, cast(Object)webSocketConnection);
                    IOState state = webSocketConnection.getIOState();
                    state.onConnected();
                    state.onOpened();
                    webSocketConnectionPromise.succeeded(webSocketConnection);
                    return true;
                } else {
                    resetUpgradeProtocol();
                    return false;
                }
            }
        default:
            resetUpgradeProtocol();
            return false;
        }
    }

    private void resetUpgradeProtocol() {
        if (http2ConnectionPromise !is null) {
            http2ConnectionPromise.failed(new IllegalStateException("upgrade h2 failed"));
            http2ConnectionPromise = null;
        }
        http2SessionListener = null;
        http2Connection = null;
        if (webSocketConnectionPromise !is null) {
            webSocketConnectionPromise.failed(
                    new IllegalStateException("The websocket handshake failed"));
            webSocketConnectionPromise = null;
        }
        incomingFrames = null;
        policy = null;
    }

    override void upgradeWebSocket(HttpRequest request, WebSocketPolicy policy,
            Promise!(WebSocketConnection) promise,
            ClientHttpHandler upgradeHandler, IncomingFrames incomingFrames) {
        assert(HttpMethod.GET.asString() == request.getMethod(),
                "The method of the request MUST be GET in the websocket handshake.");

        assert(policy.getBehavior() == WebSocketBehavior.CLIENT,
                "The websocket behavior MUST be client");

        request.getFields().put(HttpHeader.SEC_WEBSOCKET_VERSION,
                WebSocketConstants.SPEC_VERSION.to!string());
        request.getFields().put(HttpHeader.UPGRADE, "websocket");
        request.getFields().put(HttpHeader.CONNECTION, "Upgrade");
        request.getFields().put(HttpHeader.SEC_WEBSOCKET_KEY, genRandomKey());
        webSocketConnectionPromise = promise;
        this.incomingFrames = incomingFrames;
        this.policy = policy;
        send(request, upgradeHandler);
    }

    private string genRandomKey() {
        byte[] bytes = new byte[16];
        // ThreadLocalRandom.current().nextBytes(bytes);
        auto rnd = Random(2018);
        for (int i; i < bytes.length; i++)
            bytes[i] = cast(byte) uniform(byte.min, byte.max, rnd);
        return cast(string)(B64Code.encode(bytes));
    }

    override HttpOutputStream sendRequestWithContinuation(HttpRequest request, ClientHttpHandler handler) {
        request.getFields().put(HttpHeader.EXPECT, HttpHeaderValue.CONTINUE);
        HttpOutputStream outputStream = getHttpOutputStream(request, handler);
        try {
            outputStream.commit();
        } catch (IOException e) {
            errorf("client generates the HTTP message exception", e);
        }
        return outputStream;
    }

    override void send(HttpRequest request, ClientHttpHandler handler) {
        try {
            version (HUNT_HTTP_DEBUG) tracef("client request and does not send data");
            HttpOutputStream output = getHttpOutputStream(request, handler);
            output.close();
        } catch (Exception e) {
            errorf("client generates the HTTP message exception", e);
        }
    }

    override void send(HttpRequest request, ByteBuffer buffer, ClientHttpHandler handler) {
        try {
            HttpOutputStream output = getHttpOutputStream(request, handler);
            if (buffer !is null) {
                output.writeWithContentLength(buffer);
            }
        } catch (IOException e) {
            errorf("client generates the HTTP message exception", e);
        }
    }

    override void send(HttpRequest request, ByteBuffer[] buffers, ClientHttpHandler handler) {
        try {
            HttpOutputStream output = getHttpOutputStream(request, handler);
            if (buffers !is null) {
                output.writeWithContentLength(buffers);
            }
        } catch (IOException e) {
            errorf("client generates the HTTP message exception", e);
        }
    }

    override void send(HttpRequest request, Promise!(HttpOutputStream) promise,
            ClientHttpHandler handler) {
        promise.succeeded(getHttpOutputStream(request, handler));
    }

    override HttpOutputStream getHttpOutputStream(HttpRequest request, ClientHttpHandler handler) {
        Http1ClientResponseHandler http1ClientResponseHandler = 
            new Http1ClientResponseHandler(handler);
        checkWrite(request, http1ClientResponseHandler);
        http1ClientResponseHandler.outputStream = new Http1ClientRequestOutputStream(this,
                wrap.writing.request);
        return http1ClientResponseHandler.outputStream;
    }

    private void checkWrite(HttpRequest request, Http1ClientResponseHandler handler) {
        assert(request, "The http client request is null.");
        assert(handler, "The http1 client response handler is null.");
        assert(isOpen(), "The current connection " ~ getId()
                .to!string ~ " has been closed.");
        assert(!upgradeHttp2Complete, "The current connection " ~ getId()
                .to!string ~ " has upgraded HTTP2.");
        assert(!upgradeWebSocketComplete, "The current connection " ~ getId()
                .to!string ~ " has upgraded WebSocket.");

        if (wrap.writing is null) {
            wrap.writing = handler;
            HttpFields headerFields = request.getFields();
            
            if(!headerFields.contains(HttpHeader.HOST)) {
                headerFields.put(HttpHeader.HOST, request.getURI.getHost());
            }
            handler.connection = this;
            handler.request = request;
            handler.onReady();
        } else {
            throw new WritePendingException("");
        }
    }

    override void close() {
        if (isOpen()) {
            super.close();
        }
    }

    // override bool isClosed() {
    //     return !isOpen();
    // }

    // override 
    bool isOpen() {
        version (HUNT_HTTP_DEBUG) {
            tracef("Connection status: isOpen=%s, upgradeHttp2Complete=%s, upgradeWebSocketComplete=%s",
                    getTcpConnection().isConnected(), upgradeHttp2Complete, upgradeWebSocketComplete);
        }
        return getTcpConnection().isConnected() && !upgradeHttp2Complete && !upgradeWebSocketComplete;
    }

    bool getUpgradeHttp2Complete() {
        return upgradeHttp2Complete;
    }

    bool getUpgradeWebSocketComplete() {
        return upgradeWebSocketComplete;
    }
}

/**
*/
private class ResponseHandlerWrap : HttpResponseParsingHandler {

    private Http1ClientResponseHandler writing; // = new AtomicReference<)();
    private int status;
    private string reason;
    private Http1ClientConnection connection;

    void badMessage(BadMessageException failure) {
        badMessage(failure.getCode(), failure.getReason());
    }

    override void earlyEOF() {
        Http1ClientResponseHandler h = writing;
        if (h !is null) {
            h.earlyEOF();
        } else {
            IOUtils.close(connection);
        }

        writing = null;
    }

    override void parsedHeader(HttpField field) {
        writing.parsedHeader(field);
    }

    override bool headerComplete() {
        return writing.headerComplete();
    }

    override bool content(ByteBuffer item) {
        return writing.content(item);
    }

    override bool contentComplete() {
        return writing.contentComplete();
    }

    override void parsedTrailer(HttpField field) {
        writing.parsedTrailer(field);
    }

    override bool messageComplete() {
        if (status == 100 && "Continue".equalsIgnoreCase(reason)) {
            tracef("client received the 100 Continue response");
            connection.getParser().reset();
            return true;
        } else {
            auto r = writing.messageComplete();
            writing = null;
            return r;
        }
    }

    override void badMessage(int status, string reason) {
        Http1ClientResponseHandler h = writing;
        writing = null;
        if (h !is null) {
            h.badMessage(status, reason);
        } else {
            IOUtils.close(connection);
        }
    }

    override int getHeaderCacheSize() {
        return 1024;
    }

    override bool startResponse(HttpVersion ver, int status, string reason) {
        this.status = status;
        this.reason = reason;
        return writing.startResponse(ver, status, reason);
    }

}

/** 
 * 
 */
class Http1ClientRequestOutputStream : AbstractHttp1OutputStream {
    private Http1ClientConnection connection;
    private HttpGenerator httpGenerator;

    private this(Http1ClientConnection connection, HttpRequest request) {
        super(request, true);
        this.connection = connection;
        httpGenerator = new HttpGenerator();
    }


    override protected void generateHttpMessageSuccessfully() {
        version(HUNT_DEBUG) tracef("client session %s generates the HTTP message completely", connection.getId());
    }

    override protected void generateHttpMessageExceptionally(HttpGenerator.Result actualResult,
            HttpGenerator.State actualState, HttpGenerator.Result expectedResult,
            HttpGenerator.State expectedState) {
        errorf("http1 generator error, actual: [%s, %s], expected: [%s, %s]",
                actualResult, actualState, expectedResult, expectedState);
        throw new IllegalStateException("client generates http message exception.");
    }

    override protected ByteBuffer getHeaderByteBuffer() {
        return BufferUtils.allocate(connection.getHttpOptions().getMaxRequestHeadLength());
    }

    override protected ByteBuffer getTrailerByteBuffer() {
        return BufferUtils.allocate(connection.getHttpOptions()
                .getMaxRequestTrailerLength());
    }

    override protected Connection getSession() {
        return connection.getTcpConnection();
    }

    override protected HttpGenerator getHttpGenerator() {
        return httpGenerator;
    }
}