/*
 * Copyright 2012 ZXing authors
 *
 * Licensed 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.
 */

package com.google.zxing.client.android.result.supplement;

import android.text.Html;
import android.widget.TextView;

import com.google.zxing.client.android.HttpHelper;
import com.google.zxing.client.result.URIParsedResult;

import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Retrieves the title of a web page as supplemental info.
 *
 * @author Sean Owen
 */
final class TitleRetriever extends SupplementalInfoRetriever {

    private static final Pattern TITLE_PATTERN = Pattern.compile("<title>([^<]+)");
    private static final int MAX_TITLE_LEN = 100;

    private final String httpUrl;

    TitleRetriever(TextView textView, URIParsedResult result) {
        super(textView);
        this.httpUrl = result.getURI();
    }

    @Override
    void retrieveSupplementalInfo() {
        CharSequence contents;
        try {
            contents = HttpHelper.downloadViaHttp(httpUrl, HttpHelper.ContentType.HTML, 4096);
        } catch (IOException ioe) {
            // ignore this
            return;
        }
        if (contents != null && contents.length() > 0) {
            Matcher m = TITLE_PATTERN.matcher(contents);
            if (m.find()) {
                String title = m.group(1);
                if (title != null && !title.isEmpty()) {
                    title = Html.fromHtml(title).toString();
                    if (title.length() > MAX_TITLE_LEN) {
                        title = title.substring(0, MAX_TITLE_LEN) + "...";
                    }
                    append(httpUrl, null, new String[]{title}, httpUrl);
                }
            }
        }
    }

}
