/*

 * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.io.IOException;

import java.net.InetSocketAddress;

import java.net.Proxy;

import java.net.ProxySelector;

import java.net.URI;

import java.security.AccessControlContext;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.time.Duration;

import java.util.List;

import java.util.Locale;

import java.util.Optional;

class HttpRequestImpl extends HttpRequest implements WebSocketRequest {

    private final HttpHeaders userHeaders;

    private final HttpHeadersImpl systemHeaders;

    private final URI uri;

    private volatile Proxy proxy; // ensure safe publishing

    private final InetSocketAddress authority; // only used when URI not specified

    private final String method;

    final BodyPublisher requestPublisher;

    final boolean secure;

    final boolean expectContinue;

    private volatile boolean isWebSocket;

    private volatile AccessControlContext acc;

    private final Duration timeout;  // may be null

    private final Optional<HttpClient.Version> version;

    private static String userAgent() {

        PrivilegedAction<String> pa = () -> System.getProperty("java.version");

        String version = AccessController.doPrivileged(pa);

        return "Java-http-client/" + version;

    }

    /** The value of the User-Agent header for all requests sent by the client. */

    public static final String USER_AGENT = userAgent();

    /**

     * Creates an HttpRequestImpl from the given builder.

     */

    public HttpRequestImpl(HttpRequestBuilderImpl builder) {

        String method = builder.method();

        this.method = method == null ? "GET" : method;

        this.userHeaders = ImmutableHeaders.of(builder.headers().map(), ALLOWED_HEADERS);

        this.systemHeaders = new HttpHeadersImpl();

        this.uri = builder.uri();

        assert uri != null;

        this.proxy = null;

        this.expectContinue = builder.expectContinue();

        this.secure = uri.getScheme().toLowerCase(Locale.US).equals("https");

        this.requestPublisher = builder.bodyPublisher();  // may be null

        this.timeout = builder.timeout();

        this.version = builder.version();

        this.authority = null;

    }

    /**

     * Creates an HttpRequestImpl from the given request.

     */

    public HttpRequestImpl(HttpRequest request, ProxySelector ps, AccessControlContext acc) {

        String method = request.method();

        this.method = method == null ? "GET" : method;

        this.userHeaders = request.headers();

        if (request instanceof HttpRequestImpl) {

            this.systemHeaders = ((HttpRequestImpl) request).systemHeaders;

            this.isWebSocket = ((HttpRequestImpl) request).isWebSocket;

        } else {

            this.systemHeaders = new HttpHeadersImpl();

        }

        this.systemHeaders.setHeader("User-Agent", USER_AGENT);

        this.uri = request.uri();

        if (isWebSocket) {

            // WebSocket determines and sets the proxy itself

            this.proxy = ((HttpRequestImpl) request).proxy;

        } else {

            if (ps != null)

                this.proxy = retrieveProxy(ps, uri);

            else

                this.proxy = null;

        }

        this.expectContinue = request.expectContinue();

        this.secure = uri.getScheme().toLowerCase(Locale.US).equals("https");

        this.requestPublisher = request.bodyPublisher().orElse(null);

        if (acc != null && requestPublisher instanceof RequestPublishers.FilePublisher) {

            // Restricts the file publisher with the senders ACC, if any

            ((RequestPublishers.FilePublisher)requestPublisher).setAccessControlContext(acc);

        }

        this.timeout = request.timeout().orElse(null);

        this.version = request.version();

        this.authority = null;

    }

    /** Creates a HttpRequestImpl using fields of an existing request impl. */

    public HttpRequestImpl(URI uri,

                           String method,

                           HttpRequestImpl other) {

        this.method = method == null? "GET" : method;

        this.userHeaders = other.userHeaders;

        this.isWebSocket = other.isWebSocket;

        this.systemHeaders = other.systemHeaders;

        this.uri = uri;

        this.proxy = other.proxy;

        this.expectContinue = other.expectContinue;

        this.secure = uri.getScheme().toLowerCase(Locale.US).equals("https");

        this.requestPublisher = other.requestPublisher;  // may be null

        this.acc = other.acc;

        this.timeout = other.timeout;

        this.version = other.version();

        this.authority = null;

    }

    /* used for creating CONNECT requests  */

    HttpRequestImpl(String method, InetSocketAddress authority, HttpHeaders headers) {

        // TODO: isWebSocket flag is not specified, but the assumption is that

        // such a request will never be made on a connection that will be returned

        // to the connection pool (we might need to revisit this constructor later)

        assert "CONNECT".equalsIgnoreCase(method);

        this.method = method;

        this.systemHeaders = new HttpHeadersImpl();

        this.userHeaders = ImmutableHeaders.of(headers);

        this.uri = URI.create("socket://" + authority.getHostString() + ":"

                              + Integer.toString(authority.getPort()) + "/");

        this.proxy = null;

        this.requestPublisher = null;

        this.authority = authority;

        this.secure = false;

        this.expectContinue = false;

        this.timeout = null;

        // The CONNECT request sent for tunneling is only used in two cases:

        //   1. websocket, which only supports HTTP/1.1

        //   2. SSL tunneling through a HTTP/1.1 proxy

        // In either case we do not want to upgrade the connection to the proxy.

        // What we want to possibly upgrade is the tunneled connection to the

        // target server (so not the CONNECT request itself)

        this.version = Optional.of(HttpClient.Version.HTTP_1_1);

    }

    final boolean isConnect() {

        return "CONNECT".equalsIgnoreCase(method);

    }

    /**

     * Creates a HttpRequestImpl from the given set of Headers and the associated

     * "parent" request. Fields not taken from the headers are taken from the

     * parent.

     */

    static HttpRequestImpl createPushRequest(HttpRequestImpl parent,

                                             HttpHeadersImpl headers)

        throws IOException

    {

        return new HttpRequestImpl(parent, headers);

    }

    // only used for push requests

    private HttpRequestImpl(HttpRequestImpl parent, HttpHeadersImpl headers)

        throws IOException

    {

        this.method = headers.firstValue(":method")

                .orElseThrow(() -> new IOException("No method in Push Promise"));

        String path = headers.firstValue(":path")

                .orElseThrow(() -> new IOException("No path in Push Promise"));

        String scheme = headers.firstValue(":scheme")

                .orElseThrow(() -> new IOException("No scheme in Push Promise"));

        String authority = headers.firstValue(":authority")

                .orElseThrow(() -> new IOException("No authority in Push Promise"));

        StringBuilder sb = new StringBuilder();

        sb.append(scheme).append("://").append(authority).append(path);

        this.uri = URI.create(sb.toString());

        this.proxy = null;

        this.userHeaders = ImmutableHeaders.of(headers.map(), ALLOWED_HEADERS);

        this.systemHeaders = parent.systemHeaders;

        this.expectContinue = parent.expectContinue;

        this.secure = parent.secure;

        this.requestPublisher = parent.requestPublisher;

        this.acc = parent.acc;

        this.timeout = parent.timeout;

        this.version = parent.version;

        this.authority = null;

    }

    @Override

    public String toString() {

        return (uri == null ? "" : uri.toString()) + " " + method;

    }

    @Override

    public HttpHeaders headers() {

        return userHeaders;

    }

    InetSocketAddress authority() { return authority; }

    void setH2Upgrade(Http2ClientImpl h2client) {

        systemHeaders.setHeader("Connection", "Upgrade, HTTP2-Settings");

        systemHeaders.setHeader("Upgrade", "h2c");

        systemHeaders.setHeader("HTTP2-Settings", h2client.getSettingsString());

    }

    @Override

    public boolean expectContinue() { return expectContinue; }

    /** Retrieves the proxy, from the given ProxySelector, if there is one. */

    private static Proxy retrieveProxy(ProxySelector ps, URI uri) {

        Proxy proxy = null;

        List<Proxy> pl = ps.select(uri);

        if (!pl.isEmpty()) {

            Proxy p = pl.get(0);

            if (p.type() == Proxy.Type.HTTP)

                proxy = p;

        }

        return proxy;

    }

    InetSocketAddress proxy() {

        if (proxy == null || proxy.type() != Proxy.Type.HTTP

                || method.equalsIgnoreCase("CONNECT")) {

            return null;

        }

        return (InetSocketAddress)proxy.address();

    }

    boolean secure() { return secure; }

    @Override

    public void setProxy(Proxy proxy) {

        assert isWebSocket;

        this.proxy = proxy;

    }

    @Override

    public void isWebSocket(boolean is) {

        isWebSocket = is;

    }

    boolean isWebSocket() {

        return isWebSocket;

    }

    @Override

    public Optional<BodyPublisher> bodyPublisher() {

        return requestPublisher == null ? Optional.empty()

                                        : Optional.of(requestPublisher);

    }

    /**

     * Returns the request method for this request. If not set explicitly,

     * the default method for any request is "GET".

     */

    @Override

    public String method() { return method; }

    @Override

    public URI uri() { return uri; }

    @Override

    public Optional<Duration> timeout() {

        return timeout == null ? Optional.empty() : Optional.of(timeout);

    }

    HttpHeaders getUserHeaders() { return userHeaders; }

    HttpHeadersImpl getSystemHeaders() { return systemHeaders; }

    @Override

    public Optional<HttpClient.Version> version() { return version; }

    void addSystemHeader(String name, String value) {

        systemHeaders.addHeader(name, value);

    }

    @Override

    public void setSystemHeader(String name, String value) {

        systemHeaders.setHeader(name, value);

    }

    InetSocketAddress getAddress() {

        URI uri = uri();

        if (uri == null) {

            return authority();

        }

        int p = uri.getPort();

        if (p == -1) {

            if (uri.getScheme().equalsIgnoreCase("https")) {

                p = 443;

            } else {

                p = 80;

            }

        }

        final String host = uri.getHost();

        final int port = p;

        if (proxy() == null) {

            PrivilegedAction<InetSocketAddress> pa = () -> new InetSocketAddress(host, port);

            return AccessController.doPrivileged(pa);

        } else {

            return InetSocketAddress.createUnresolved(host, port);

        }

    }

}