/*
 * ====================================================================
 * 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.conn.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.annotation.Contract;
import org.apache.http.annotation.ThreadingBehavior;

Parses the list from publicsuffix.org
and configures a PublicSuffixFilter.
Since:
4.4/**
 * Parses the list from <a href="http://publicsuffix.org/">publicsuffix.org</a>
 * and configures a PublicSuffixFilter.
 *
 * @since 4.4
 */
@Contract(threading = ThreadingBehavior.IMMUTABLE)
public final class PublicSuffixListParser {

    public PublicSuffixListParser() {
    }

    
Parses the public suffix list format.

When creating the reader from the file, make sure to use the correct encoding
(the original list is in UTF-8).
Params:
reader – the data reader. The caller is responsible for closing the reader.
Throws:
IOException – on error while reading from list/**
     * Parses the public suffix list format.
     * <p>
     * When creating the reader from the file, make sure to use the correct encoding
     * (the original list is in UTF-8).
     *
     * @param reader the data reader. The caller is responsible for closing the reader.
     * @throws java.io.IOException on error while reading from list
     */
    public PublicSuffixList parse(final Reader reader) throws IOException {
        final List<String> rules = new ArrayList<String>();
        final List<String> exceptions = new ArrayList<String>();
        final BufferedReader r = new BufferedReader(reader);

        String line;
        while ((line = r.readLine()) != null) {
            if (line.isEmpty()) {
                continue;
            }
            if (line.startsWith("//")) {
                continue; //entire lines can also be commented using //
            }
            if (line.startsWith(".")) {
                line = line.substring(1); // A leading dot is optional
            }
            // An exclamation mark (!) at the start of a rule marks an exception to a previous wildcard rule
            final boolean isException = line.startsWith("!");
            if (isException) {
                line = line.substring(1);
            }

            if (isException) {
                exceptions.add(line);
            } else {
                rules.add(line);
            }
        }
        return new PublicSuffixList(DomainType.UNKNOWN, rules, exceptions);
    }

    
Parses the public suffix list format by domain type (currently supported ICANN and PRIVATE).

When creating the reader from the file, make sure to use the correct encoding
(the original list is in UTF-8).
Params:
reader – the data reader. The caller is responsible for closing the reader.
Throws:
IOException – on error while reading from list
Since:
4.5/**
     * Parses the public suffix list format by domain type (currently supported ICANN and PRIVATE).
     * <p>
     * When creating the reader from the file, make sure to use the correct encoding
     * (the original list is in UTF-8).
     *
     * @param reader the data reader. The caller is responsible for closing the reader.
     * @throws java.io.IOException on error while reading from list
     *
     * @since 4.5
     */
    public List<PublicSuffixList> parseByType(final Reader reader) throws IOException {
        final List<PublicSuffixList> result = new ArrayList<PublicSuffixList>(2);

        final BufferedReader r = new BufferedReader(reader);
        final StringBuilder sb = new StringBuilder(256);

        DomainType domainType = null;
        List<String> rules = null;
        List<String> exceptions = null;
        String line;
        while ((line = r.readLine()) != null) {
            if (line.isEmpty()) {
                continue;
            }
            if (line.startsWith("//")) {

                if (domainType == null) {
                    if (line.contains("===BEGIN ICANN DOMAINS===")) {
                        domainType = DomainType.ICANN;
                    } else if (line.contains("===BEGIN PRIVATE DOMAINS===")) {
                        domainType = DomainType.PRIVATE;
                    }
                } else {
                    if (line.contains("===END ICANN DOMAINS===") || line.contains("===END PRIVATE DOMAINS===")) {
                        if (rules != null) {
                            result.add(new PublicSuffixList(domainType, rules, exceptions));
                        }
                        domainType = null;
                        rules = null;
                        exceptions = null;
                    }
                }

                continue; //entire lines can also be commented using //
            }
            if (domainType == null) {
                continue;
            }

            if (line.startsWith(".")) {
                line = line.substring(1); // A leading dot is optional
            }
            // An exclamation mark (!) at the start of a rule marks an exception to a previous wildcard rule
            final boolean isException = line.startsWith("!");
            if (isException) {
                line = line.substring(1);
            }

            if (isException) {
                if (exceptions == null) {
                    exceptions = new ArrayList<String>();
                }
                exceptions.add(line);
            } else {
                if (rules == null) {
                    rules = new ArrayList<String>();
                }
                rules.add(line);
            }
        }
        return result;
    }

}