/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/*
 * DO NOT EDIT THIS DOCUMENT MANUALLY !!!
 * THIS FILE IS AUTOMATICALLY GENERATED BY THE TOOLS UNDER
 *    AutoDetect/tools/
 */

package com.cherry.lib.doc.office.thirdpart.mozilla.intl.chardet;

import android.content.ContentResolver;

import com.cherry.lib.doc.office.fc.util.StreamUtils;

import org.mozilla.universalchardet.UniversalDetector;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;

public class CharsetDetector {

    public static boolean found = false;
    public static String charsetStr;

    private CharsetDetector() {
    }

    /**
     * @param imp
     * @return
     * @throws Exception
     */
    public static String detect(BufferedInputStream imp) throws Exception {
        found = false;
        charsetStr = "ASCII";

        nsDetector det = new nsDetector(nsPSMDetector.ALL);

        // Set an observer...
        // The Notify() will be called when a matching charset is found.

        det.Init(new nsICharsetDetectionObserver() {
            public void Notify(String charset) {
                found = true;
                charsetStr = charset;
            }
        });

        byte[] buf = new byte[1024];
        int len;
        boolean done = false;
        boolean isAscii = true;
        int count = 0;
        while ((len = imp.read(buf, 0, buf.length)) != -1 && count <= 50) {
            //
            if (count == 0) {
                // unicode
                if ((buf[0] == -1 && buf[1] == -2)
                        || (buf[1] == -2 && buf[0] == -1)) {
                    charsetStr = "Unicode";
                    return charsetStr;
                }
                // utf-8
                // else if (buf[0] == 0xEF && buf[1] ==0xBB && buf[2] == 0xBF)
                else if (buf[0] == -17 && buf[1] == -69 && buf[2] == -65) {
                    charsetStr = "UTF-8";
                    return charsetStr;
                }
            }
            // Check if the stream is only ascii.

            if (isAscii) {
                isAscii = det.isAscii(buf, len);
            }
            // DoIt if non-ascii and not done yet.
            if (!isAscii && !done) {
                done = det.DoIt(buf, len, false);
            }
            count++;
        }
        det.DataEnd();

        if (isAscii) {
            return "ASCII";
        }

        if (!found) {
            /*String prob[] = det.getProbableCharsets() ;
            if(prob != null && prob.length > 0)
            {
                return prob[0];
            }*/
            return null;
        }

        return charsetStr;
    }

    /**
     * @param fileName
     * @return
     * @throws Exception
     */
    public static String detect(ContentResolver resolver, String fileName) throws Exception {
        InputStream file = StreamUtils.getInputStream(resolver, fileName);
        BufferedInputStream imp = new BufferedInputStream(file);
        // String charset = detect(imp);
        byte[] b = new byte[1024]; // 定义字节数组
        int len = imp.read(b); // 由于信息的传输是以二进制的形式，所以要以二进制的形式进行数据的读取
        // 内容为空，则默认UTF-8
        if (len == -1) {
            return "UTF_8";
        }
        String charset = detectEncoding(b);
        imp.close();

        return charset;
    }

    // 判断字符串的编码格式
    public static String detectEncoding(byte[] bytes) {
        String encoding = "UTF_8";
        try {
            UniversalDetector detector = new UniversalDetector(null);
            detector.handleData(bytes, 0, bytes.length);
            detector.dataEnd();
            encoding = detector.getDetectedCharset();
            detector.reset(); // 清理资源
        } catch (Exception e) {
            e.printStackTrace();
        }
        return encoding;
    }
}
