/*
 * ====================================================================
 * 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/>.
 *
 */
package org.apache.http.client.utils;

import java.net.URI;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.http.Consts;
import org.apache.http.NameValuePair;
import org.apache.http.conn.util.InetAddressUtils;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.TextUtils;

Builder for URI instances. 
Since:
4.2/**
 * Builder for {@link URI} instances.
 *
 * @since 4.2
 */
public class URIBuilder {

    private String scheme;
    private String encodedSchemeSpecificPart;
    private String encodedAuthority;
    private String userInfo;
    private String encodedUserInfo;
    private String host;
    private int port;
    private String path;
    private String encodedPath;
    private String encodedQuery;
    private List<NameValuePair> queryParams;
    private String query;
    private Charset charset;
    private String fragment;
    private String encodedFragment;

    
Constructs an empty instance.
/**
     * Constructs an empty instance.
     */
    public URIBuilder() {
        super();
        this.port = -1;
    }

    
Construct an instance from the string which must be a valid URI.
Params:
string – a valid URI in string form
Throws:
URISyntaxException – if the input is not a valid URI/**
     * Construct an instance from the string which must be a valid URI.
     *
     * @param string a valid URI in string form
     * @throws URISyntaxException if the input is not a valid URI
     */
    public URIBuilder(final String string) throws URISyntaxException {
        super();
        digestURI(new URI(string));
    }

    
Construct an instance from the provided URI.
Params:
uri – /**
     * Construct an instance from the provided URI.
     * @param uri
     */
    public URIBuilder(final URI uri) {
        super();
        digestURI(uri);
    }

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

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

    private List <NameValuePair> parseQuery(final String query, final Charset charset) {
        if (query != null && !query.isEmpty()) {
            return URLEncodedUtils.parse(query, charset);
        }
        return null;
    }

    
Builds a URI instance. /**
     * Builds a {@link URI} instance.
     */
    public URI build() throws URISyntaxException {
        return new URI(buildString());
    }

    private String buildString() {
        final StringBuilder sb = new StringBuilder();
        if (this.scheme != null) {
            sb.append(this.scheme).append(':');
        }
        if (this.encodedSchemeSpecificPart != null) {
            sb.append(this.encodedSchemeSpecificPart);
        } else {
            if (this.encodedAuthority != null) {
                sb.append("//").append(this.encodedAuthority);
            } else if (this.host != null) {
                sb.append("//");
                if (this.encodedUserInfo != null) {
                    sb.append(this.encodedUserInfo).append("@");
                } else if (this.userInfo != null) {
                    sb.append(encodeUserInfo(this.userInfo)).append("@");
                }
                if (InetAddressUtils.isIPv6Address(this.host)) {
                    sb.append("[").append(this.host).append("]");
                } else {
                    sb.append(this.host);
                }
                if (this.port >= 0) {
                    sb.append(":").append(this.port);
                }
            }
            if (this.encodedPath != null) {
                sb.append(normalizePath(this.encodedPath, sb.length() == 0));
            } else if (this.path != null) {
                sb.append(encodePath(normalizePath(this.path, sb.length() == 0)));
            }
            if (this.encodedQuery != null) {
                sb.append("?").append(this.encodedQuery);
            } else if (this.queryParams != null && !this.queryParams.isEmpty()) {
                sb.append("?").append(encodeUrlForm(this.queryParams));
            } else if (this.query != null) {
                sb.append("?").append(encodeUric(this.query));
            }
        }
        if (this.encodedFragment != null) {
            sb.append("#").append(this.encodedFragment);
        } else if (this.fragment != null) {
            sb.append("#").append(encodeUric(this.fragment));
        }
        return sb.toString();
    }

    private static String normalizePath(final String path, final boolean relative) {
        String s = path;
        if (TextUtils.isBlank(s)) {
            return "";
        }
        if (!relative && !s.startsWith("/")) {
            s = "/" + s;
        }
        return s;
    }

    private void digestURI(final URI uri) {
        this.scheme = uri.getScheme();
        this.encodedSchemeSpecificPart = uri.getRawSchemeSpecificPart();
        this.encodedAuthority = uri.getRawAuthority();
        this.host = uri.getHost();
        this.port = uri.getPort();
        this.encodedUserInfo = uri.getRawUserInfo();
        this.userInfo = uri.getUserInfo();
        this.encodedPath = uri.getRawPath();
        this.path = uri.getPath();
        this.encodedQuery = uri.getRawQuery();
        this.queryParams = parseQuery(uri.getRawQuery(), this.charset != null ? this.charset : Consts.UTF_8);
        this.encodedFragment = uri.getRawFragment();
        this.fragment = uri.getFragment();
    }

    private String encodeUserInfo(final String userInfo) {
        return URLEncodedUtils.encUserInfo(userInfo, this.charset != null ? this.charset : Consts.UTF_8);
    }

    private String encodePath(final String path) {
        return URLEncodedUtils.encPath(path, this.charset != null ? this.charset : Consts.UTF_8);
    }

    private String encodeUrlForm(final List<NameValuePair> params) {
        return URLEncodedUtils.format(params, this.charset != null ? this.charset : Consts.UTF_8);
    }

    private String encodeUric(final String fragment) {
        return URLEncodedUtils.encUric(fragment, this.charset != null ? this.charset : Consts.UTF_8);
    }

    
Sets URI scheme.
/**
     * Sets URI scheme.
     */
    public URIBuilder setScheme(final String scheme) {
        this.scheme = scheme;
        return this;
    }

    
Sets URI user info. The value is expected to be unescaped and may contain non ASCII
characters.
/**
     * Sets URI user info. The value is expected to be unescaped and may contain non ASCII
     * characters.
     */
    public URIBuilder setUserInfo(final String userInfo) {
        this.userInfo = userInfo;
        this.encodedSchemeSpecificPart = null;
        this.encodedAuthority = null;
        this.encodedUserInfo = null;
        return this;
    }

    
Sets URI user info as a combination of username and password. These values are expected to
be unescaped and may contain non ASCII characters.
/**
     * Sets URI user info as a combination of username and password. These values are expected to
     * be unescaped and may contain non ASCII characters.
     */
    public URIBuilder setUserInfo(final String username, final String password) {
        return setUserInfo(username + ':' + password);
    }

    
Sets URI host.
/**
     * Sets URI host.
     */
    public URIBuilder setHost(final String host) {
        this.host = host;
        this.encodedSchemeSpecificPart = null;
        this.encodedAuthority = null;
        return this;
    }

    
Sets URI port.
/**
     * Sets URI port.
     */
    public URIBuilder setPort(final int port) {
        this.port = port < 0 ? -1 : port;
        this.encodedSchemeSpecificPart = null;
        this.encodedAuthority = null;
        return this;
    }

    
Sets URI path. The value is expected to be unescaped and may contain non ASCII characters.
/**
     * Sets URI path. The value is expected to be unescaped and may contain non ASCII characters.
     */
    public URIBuilder setPath(final String path) {
        this.path = path;
        this.encodedSchemeSpecificPart = null;
        this.encodedPath = null;
        return this;
    }

    
Removes URI query.
/**
     * Removes URI query.
     */
    public URIBuilder removeQuery() {
        this.queryParams = null;
        this.query = null;
        this.encodedQuery = null;
        this.encodedSchemeSpecificPart = null;
        return this;
    }

    
Sets URI query.

The value is expected to be encoded form data.
See Also:
URLEncodedUtils.parse
Deprecated:
(4.3) use setParameters(List<NameValuePair>) or setParameters(NameValuePair...)/**
     * Sets URI query.
     * <p>
     * The value is expected to be encoded form data.
     *
     * @deprecated (4.3) use {@link #setParameters(List)} or {@link #setParameters(NameValuePair...)}
     *
     * @see URLEncodedUtils#parse
     */
    @Deprecated
    public URIBuilder setQuery(final String query) {
        this.queryParams = parseQuery(query, this.charset != null ? this.charset : Consts.UTF_8);
        this.query = null;
        this.encodedQuery = null;
        this.encodedSchemeSpecificPart = null;
        return this;
    }

    
Sets URI query parameters. The parameter name / values are expected to be unescaped
and may contain non ASCII characters.

Please note query parameters and custom query component are mutually exclusive. This method
will remove custom query if present.

Since:
4.3/**
     * Sets URI query parameters. The parameter name / values are expected to be unescaped
     * and may contain non ASCII characters.
     * <p>
     * Please note query parameters and custom query component are mutually exclusive. This method
     * will remove custom query if present.
     * </p>
     *
     * @since 4.3
     */
    public URIBuilder setParameters(final List <NameValuePair> nvps) {
        if (this.queryParams == null) {
            this.queryParams = new ArrayList<NameValuePair>();
        } else {
            this.queryParams.clear();
        }
        this.queryParams.addAll(nvps);
        this.encodedQuery = null;
        this.encodedSchemeSpecificPart = null;
        this.query = null;
        return this;
    }

    
Adds URI query parameters. The parameter name / values are expected to be unescaped
and may contain non ASCII characters.

Please note query parameters and custom query component are mutually exclusive. This method
will remove custom query if present.

Since:
4.3/**
     * Adds URI query parameters. The parameter name / values are expected to be unescaped
     * and may contain non ASCII characters.
     * <p>
     * Please note query parameters and custom query component are mutually exclusive. This method
     * will remove custom query if present.
     * </p>
     *
     * @since 4.3
     */
    public URIBuilder addParameters(final List <NameValuePair> nvps) {
        if (this.queryParams == null) {
            this.queryParams = new ArrayList<NameValuePair>();
        }
        this.queryParams.addAll(nvps);
        this.encodedQuery = null;
        this.encodedSchemeSpecificPart = null;
        this.query = null;
        return this;
    }

    
Sets URI query parameters. The parameter name / values are expected to be unescaped
and may contain non ASCII characters.

Please note query parameters and custom query component are mutually exclusive. This method
will remove custom query if present.

Since:
4.3/**
     * Sets URI query parameters. The parameter name / values are expected to be unescaped
     * and may contain non ASCII characters.
     * <p>
     * Please note query parameters and custom query component are mutually exclusive. This method
     * will remove custom query if present.
     * </p>
     *
     * @since 4.3
     */
    public URIBuilder setParameters(final NameValuePair... nvps) {
        if (this.queryParams == null) {
            this.queryParams = new ArrayList<NameValuePair>();
        } else {
            this.queryParams.clear();
        }
        for (final NameValuePair nvp: nvps) {
            this.queryParams.add(nvp);
        }
        this.encodedQuery = null;
        this.encodedSchemeSpecificPart = null;
        this.query = null;
        return this;
    }

    
Adds parameter to URI query. The parameter name and value are expected to be unescaped
and may contain non ASCII characters.

Please note query parameters and custom query component are mutually exclusive. This method
will remove custom query if present.

/**
     * Adds parameter to URI query. The parameter name and value are expected to be unescaped
     * and may contain non ASCII characters.
     * <p>
     * Please note query parameters and custom query component are mutually exclusive. This method
     * will remove custom query if present.
     * </p>
     */
    public URIBuilder addParameter(final String param, final String value) {
        if (this.queryParams == null) {
            this.queryParams = new ArrayList<NameValuePair>();
        }
        this.queryParams.add(new BasicNameValuePair(param, value));
        this.encodedQuery = null;
        this.encodedSchemeSpecificPart = null;
        this.query = null;
        return this;
    }

    
Sets parameter of URI query overriding existing value if set. The parameter name and value
are expected to be unescaped and may contain non ASCII characters.

Please note query parameters and custom query component are mutually exclusive. This method
will remove custom query if present.

/**
     * Sets parameter of URI query overriding existing value if set. The parameter name and value
     * are expected to be unescaped and may contain non ASCII characters.
     * <p>
     * Please note query parameters and custom query component are mutually exclusive. This method
     * will remove custom query if present.
     * </p>
     */
    public URIBuilder setParameter(final String param, final String value) {
        if (this.queryParams == null) {
            this.queryParams = new ArrayList<NameValuePair>();
        }
        if (!this.queryParams.isEmpty()) {
            for (final Iterator<NameValuePair> it = this.queryParams.iterator(); it.hasNext(); ) {
                final NameValuePair nvp = it.next();
                if (nvp.getName().equals(param)) {
                    it.remove();
                }
            }
        }
        this.queryParams.add(new BasicNameValuePair(param, value));
        this.encodedQuery = null;
        this.encodedSchemeSpecificPart = null;
        this.query = null;
        return this;
    }

    
Clears URI query parameters.
Since:
4.3/**
     * Clears URI query parameters.
     *
     * @since 4.3
     */
    public URIBuilder clearParameters() {
        this.queryParams = null;
        this.encodedQuery = null;
        this.encodedSchemeSpecificPart = null;
        return this;
    }

    
Sets custom URI query. The value is expected to be unescaped and may contain non ASCII
characters.

Please note query parameters and custom query component are mutually exclusive. This method
will remove query parameters if present.

Since:
4.3/**
     * Sets custom URI query. The value is expected to be unescaped and may contain non ASCII
     * characters.
     * <p>
     * Please note query parameters and custom query component are mutually exclusive. This method
     * will remove query parameters if present.
     * </p>
     *
     * @since 4.3
     */
    public URIBuilder setCustomQuery(final String query) {
        this.query = query;
        this.encodedQuery = null;
        this.encodedSchemeSpecificPart = null;
        this.queryParams = null;
        return this;
    }

    
Sets URI fragment. The value is expected to be unescaped and may contain non ASCII
characters.
/**
     * Sets URI fragment. The value is expected to be unescaped and may contain non ASCII
     * characters.
     */
    public URIBuilder setFragment(final String fragment) {
        this.fragment = fragment;
        this.encodedFragment = null;
        return this;
    }

    
Since:
4.3/**
     * @since 4.3
     */
    public boolean isAbsolute() {
        return this.scheme != null;
    }

    
Since:
4.3/**
     * @since 4.3
     */
    public boolean isOpaque() {
        return this.path == null;
    }

    public String getScheme() {
        return this.scheme;
    }

    public String getUserInfo() {
        return this.userInfo;
    }

    public String getHost() {
        return this.host;
    }

    public int getPort() {
        return this.port;
    }

    public String getPath() {
        return this.path;
    }

    public List<NameValuePair> getQueryParams() {
        return this.queryParams != null
                        ? new ArrayList<NameValuePair>(this.queryParams)
                        : new ArrayList<NameValuePair>();
    }

    public String getFragment() {
        return this.fragment;
    }

    @Override
    public String toString() {
        return buildString();
    }

}