/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
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package org.apache.http.client.methods;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import org.apache.http.Consts;
import org.apache.http.Header;
import org.apache.http.HeaderIterator;
import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpRequest;
import org.apache.http.NameValuePair;
import org.apache.http.ProtocolVersion;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.entity.ContentType;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.message.HeaderGroup;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.Args;

Builder for HttpUriRequest instances. 
 Please note that this class treats parameters differently depending on composition of the request: if the request has a content entity explicitly set with setEntity(HttpEntity) or it is not an entity enclosing method (such as POST or PUT), parameters will be added to the query component of the request URI. Otherwise, parameters will be added as a URL encoded entity. 
Since:
4.3/**
 * Builder for {@link HttpUriRequest} instances.
 * <p>
 * Please note that this class treats parameters differently depending on composition
 * of the request: if the request has a content entity explicitly set with
 * {@link #setEntity(org.apache.http.HttpEntity)} or it is not an entity enclosing method
 * (such as POST or PUT), parameters will be added to the query component of the request URI.
 * Otherwise, parameters will be added as a URL encoded {@link UrlEncodedFormEntity entity}.
 * </p>
 *
 * @since 4.3
 */
public class RequestBuilder {

    private String method;
    private Charset charset;
    private ProtocolVersion version;
    private URI uri;
    private HeaderGroup headerGroup;
    private HttpEntity entity;
    private List<NameValuePair> parameters;
    private RequestConfig config;

    RequestBuilder(final String method) {
        super();
        this.charset = Consts.UTF_8;
        this.method = method;
    }

    RequestBuilder(final String method, final URI uri) {
        super();
        this.method = method;
        this.uri = uri;
    }

    RequestBuilder(final String method, final String uri) {
        super();
        this.method = method;
        this.uri = uri != null ? URI.create(uri) : null;
    }

    RequestBuilder() {
        this(null);
    }

    public static RequestBuilder create(final String method) {
        Args.notBlank(method, "HTTP method");
        return new RequestBuilder(method);
    }

    public static RequestBuilder get() {
        return new RequestBuilder(HttpGet.METHOD_NAME);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder get(final URI uri) {
        return new RequestBuilder(HttpGet.METHOD_NAME, uri);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder get(final String uri) {
        return new RequestBuilder(HttpGet.METHOD_NAME, uri);
    }

    public static RequestBuilder head() {
        return new RequestBuilder(HttpHead.METHOD_NAME);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder head(final URI uri) {
        return new RequestBuilder(HttpHead.METHOD_NAME, uri);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder head(final String uri) {
        return new RequestBuilder(HttpHead.METHOD_NAME, uri);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder patch() {
        return new RequestBuilder(HttpPatch.METHOD_NAME);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder patch(final URI uri) {
        return new RequestBuilder(HttpPatch.METHOD_NAME, uri);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder patch(final String uri) {
        return new RequestBuilder(HttpPatch.METHOD_NAME, uri);
    }

    public static RequestBuilder post() {
        return new RequestBuilder(HttpPost.METHOD_NAME);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder post(final URI uri) {
        return new RequestBuilder(HttpPost.METHOD_NAME, uri);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder post(final String uri) {
        return new RequestBuilder(HttpPost.METHOD_NAME, uri);
    }

    public static RequestBuilder put() {
        return new RequestBuilder(HttpPut.METHOD_NAME);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder put(final URI uri) {
        return new RequestBuilder(HttpPut.METHOD_NAME, uri);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder put(final String uri) {
        return new RequestBuilder(HttpPut.METHOD_NAME, uri);
    }

    public static RequestBuilder delete() {
        return new RequestBuilder(HttpDelete.METHOD_NAME);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder delete(final URI uri) {
        return new RequestBuilder(HttpDelete.METHOD_NAME, uri);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder delete(final String uri) {
        return new RequestBuilder(HttpDelete.METHOD_NAME, uri);
    }

    public static RequestBuilder trace() {
        return new RequestBuilder(HttpTrace.METHOD_NAME);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder trace(final URI uri) {
        return new RequestBuilder(HttpTrace.METHOD_NAME, uri);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder trace(final String uri) {
        return new RequestBuilder(HttpTrace.METHOD_NAME, uri);
    }

    public static RequestBuilder options() {
        return new RequestBuilder(HttpOptions.METHOD_NAME);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder options(final URI uri) {
        return new RequestBuilder(HttpOptions.METHOD_NAME, uri);
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public static RequestBuilder options(final String uri) {
        return new RequestBuilder(HttpOptions.METHOD_NAME, uri);
    }

    public static RequestBuilder copy(final HttpRequest request) {
        Args.notNull(request, "HTTP request");
        return new RequestBuilder().doCopy(request);
    }

    private RequestBuilder doCopy(final HttpRequest request) {
        if (request == null) {
            return this;
        }
        method = request.getRequestLine().getMethod();
        version = request.getRequestLine().getProtocolVersion();

        if (headerGroup == null) {
            headerGroup = new HeaderGroup();
        }
        headerGroup.clear();
        headerGroup.setHeaders(request.getAllHeaders());

        parameters = null;
        entity = null;

        if (request instanceof HttpEntityEnclosingRequest) {
            final HttpEntity originalEntity = ((HttpEntityEnclosingRequest) request).getEntity();
            final ContentType contentType = ContentType.get(originalEntity);
            if (contentType != null &&
                    contentType.getMimeType().equals(ContentType.APPLICATION_FORM_URLENCODED.getMimeType())) {
                try {
                    final List<NameValuePair> formParams = URLEncodedUtils.parse(originalEntity);
                    if (!formParams.isEmpty()) {
                        parameters = formParams;
                    }
                } catch (final IOException ignore) {
                }
            } else {
                entity = originalEntity;
            }
        }

        final URI originalUri;
        if (request instanceof HttpUriRequest) {
            uri = ((HttpUriRequest) request).getURI();
        } else {
            uri = URI.create(request.getRequestLine().getUri());
        }

        if (request instanceof Configurable) {
            config = ((Configurable) request).getConfig();
        } else {
            config = null;
        }
        return this;
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public RequestBuilder setCharset(final Charset charset) {
        this.charset = charset;
        return this;
    }

    
Since:
4.4/**
     * @since 4.4
     */
    public Charset getCharset() {
        return charset;
    }

    public String getMethod() {
        return method;
    }

    public ProtocolVersion getVersion() {
        return version;
    }

    public RequestBuilder setVersion(final ProtocolVersion version) {
        this.version = version;
        return this;
    }

    public URI getUri() {
        return uri;
    }

    public RequestBuilder setUri(final URI uri) {
        this.uri = uri;
        return this;
    }

    public RequestBuilder setUri(final String uri) {
        this.uri = uri != null ? URI.create(uri) : null;
        return this;
    }

    public Header getFirstHeader(final String name) {
        return headerGroup != null ? headerGroup.getFirstHeader(name) : null;
    }

    public Header getLastHeader(final String name) {
        return headerGroup != null ? headerGroup.getLastHeader(name) : null;
    }

    public Header[] getHeaders(final String name) {
        return headerGroup != null ? headerGroup.getHeaders(name) : null;
    }

    public RequestBuilder addHeader(final Header header) {
        if (headerGroup == null) {
            headerGroup = new HeaderGroup();
        }
        headerGroup.addHeader(header);
        return this;
    }

    public RequestBuilder addHeader(final String name, final String value) {
        if (headerGroup == null) {
            headerGroup = new HeaderGroup();
        }
        this.headerGroup.addHeader(new BasicHeader(name, value));
        return this;
    }

    public RequestBuilder removeHeader(final Header header) {
        if (headerGroup == null) {
            headerGroup = new HeaderGroup();
        }
        headerGroup.removeHeader(header);
        return this;
    }

    public RequestBuilder removeHeaders(final String name) {
        if (name == null || headerGroup == null) {
            return this;
        }
        for (final HeaderIterator i = headerGroup.iterator(); i.hasNext(); ) {
            final Header header = i.nextHeader();
            if (name.equalsIgnoreCase(header.getName())) {
                i.remove();
            }
        }
        return this;
    }

    public RequestBuilder setHeader(final Header header) {
        if (headerGroup == null) {
            headerGroup = new HeaderGroup();
        }
        this.headerGroup.updateHeader(header);
        return this;
    }

    public RequestBuilder setHeader(final String name, final String value) {
        if (headerGroup == null) {
            headerGroup = new HeaderGroup();
        }
        this.headerGroup.updateHeader(new BasicHeader(name, value));
        return this;
    }

    public HttpEntity getEntity() {
        return entity;
    }

    public RequestBuilder setEntity(final HttpEntity entity) {
        this.entity = entity;
        return this;
    }

    public List<NameValuePair> getParameters() {
        return parameters != null ? new ArrayList<NameValuePair>(parameters) :
            new ArrayList<NameValuePair>();
    }

    public RequestBuilder addParameter(final NameValuePair nvp) {
        Args.notNull(nvp, "Name value pair");
        if (parameters == null) {
            parameters = new LinkedList<NameValuePair>();
        }
        parameters.add(nvp);
        return this;
    }

    public RequestBuilder addParameter(final String name, final String value) {
        return addParameter(new BasicNameValuePair(name, value));
    }

    public RequestBuilder addParameters(final NameValuePair... nvps) {
        for (final NameValuePair nvp: nvps) {
            addParameter(nvp);
        }
        return this;
    }

    public RequestConfig getConfig() {
        return config;
    }

    public RequestBuilder setConfig(final RequestConfig config) {
        this.config = config;
        return this;
    }

    public HttpUriRequest build() {
        final HttpRequestBase result;
        URI uriNotNull = this.uri != null ? this.uri : URI.create("/");
        HttpEntity entityCopy = this.entity;
        if (parameters != null && !parameters.isEmpty()) {
            if (entityCopy == null && (HttpPost.METHOD_NAME.equalsIgnoreCase(method)
                    || HttpPut.METHOD_NAME.equalsIgnoreCase(method))) {
                entityCopy = new UrlEncodedFormEntity(parameters, charset != null ? charset : HTTP.DEF_CONTENT_CHARSET);
            } else {
                try {
                    uriNotNull = new URIBuilder(uriNotNull)
                      .setCharset(this.charset)
                      .addParameters(parameters)
                      .build();
                } catch (final URISyntaxException ex) {
                    // should never happen
                }
            }
        }
        if (entityCopy == null) {
            result = new InternalRequest(method);
        } else {
            final InternalEntityEclosingRequest request = new InternalEntityEclosingRequest(method);
            request.setEntity(entityCopy);
            result = request;
        }
        result.setProtocolVersion(this.version);
        result.setURI(uriNotNull);
        if (this.headerGroup != null) {
            result.setHeaders(this.headerGroup.getAllHeaders());
        }
        result.setConfig(this.config);
        return result;
    }

    static class InternalRequest extends HttpRequestBase {

        private final String method;

        InternalRequest(final String method) {
            super();
            this.method = method;
        }

        @Override
        public String getMethod() {
            return this.method;
        }

    }

    static class InternalEntityEclosingRequest extends HttpEntityEnclosingRequestBase {

        private final String method;

        InternalEntityEclosingRequest(final String method) {
            super();
            this.method = method;
        }

        @Override
        public String getMethod() {
            return this.method;
        }

    }

    @Override
    public String toString() {
        final StringBuilder builder = new StringBuilder();
        builder.append("RequestBuilder [method=");
        builder.append(method);
        builder.append(", charset=");
        builder.append(charset);
        builder.append(", version=");
        builder.append(version);
        builder.append(", uri=");
        builder.append(uri);
        builder.append(", headerGroup=");
        builder.append(headerGroup);
        builder.append(", entity=");
        builder.append(entity);
        builder.append(", parameters=");
        builder.append(parameters);
        builder.append(", config=");
        builder.append(config);
        builder.append("]");
        return builder.toString();
    }

}