package com.heweather.owp.crash;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Build;
import android.os.Environment;
import android.os.Looper;
import android.util.Log;

import org.apache.log4j.Logger;

import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.reflect.Field;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;


public class CrashHandler implements Thread.UncaughtExceptionHandler {

    private Logger logger;

    private static final String TAG = "CrashHandler";

    // CrashHandler 实例  
    @SuppressLint("StaticFieldLeak")
    private static CrashHandler INSTANCE = new CrashHandler();

    // 程序的 Context 对象  
    private Context mContext;

    // 系统默认的 UncaughtException 处理类  
    private Thread.UncaughtExceptionHandler mDefaultHandler;

    // 用来存储设备信息和异常信息  
    private Map<String, String> infos = new HashMap<>();

    // 用于格式化日期,作为日志文件名的一部分  
    @SuppressLint("SimpleDateFormat")
    private DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH-mm-ss");


    /**
     * 保证只有一个 CrashHandler 实例
     */
    private CrashHandler() {
    }

    /**
     * 获取 CrashHandler 实例 ,单例模式
     */
    public static CrashHandler getInstance() {
        return INSTANCE;
    }

    /**
     * 始化
     */
    public void init( Context context) {

        logger = Logger.getLogger(CrashHandler.class);
        mContext = context;

        // 获取系统默认的 UncaughtException 处理器  
        mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();

        // 设置该 CrashHandler 为程序的默认处理器  
        Thread.setDefaultUncaughtExceptionHandler(this);
    }

    /**
     * 当 UncaughtException 发生时会转入该函数来处理
     */
    @Override
    public void uncaughtException(Thread thread, Throwable ex) {
        if (!handleException(ex) && mDefaultHandler != null) {
            // 如果用户没有处理则让系统默认的异常处理器来处理  
            mDefaultHandler.uncaughtException(thread, ex);
        } else {
            try {
                Thread.sleep(3000);
            } catch (InterruptedException e) {
                e.printStackTrace();
                Log.e(TAG, "error : ", e);
            }

            // 退出程序
            android.os.Process.killProcess(android.os.Process.myPid());
            System.exit(1);
        }
    }

    /**
     * 自定义错误处理,收集错误信息,发送错误报告等操作均在此完成
     *
     * @return true:如果处理了该异常信息;否则返回 false
     */
    private boolean handleException(final Throwable ex) {
        if (ex == null) {
            return false;
        }

        // 使用 Toast 来显示异常信息  
        new Thread() {
            @Override
            public void run() {
                Looper.prepare();
                logger.error("系统异常退出", ex);

//                Toast.makeText(mContext, "很抱歉,程序出现异常,即将退出。!!!!"+path, Toast.LENGTH_LONG).show();
                Looper.loop();
            }
        }.start();

        // 收集设备参数信息  
        collectDeviceInfo(mContext);
        // 保存日志文件  
        String path = saveCrashInfo2File(ex);
        Log.d(TAG, "handleException: " + path);
        return true;
    }

    /**
     * 收集设备参数信息
     *
     */
    private void collectDeviceInfo(Context ctx) {
        try {
            PackageManager pm = ctx.getPackageManager();
            PackageInfo pi = pm.getPackageInfo(ctx.getPackageName(), PackageManager.GET_ACTIVITIES);

            if (pi != null) {
                String versionName = pi.versionName == null ? "null" : pi.versionName;
                String versionCode = pi.versionCode + "";
                infos.put("versionName", versionName);
                infos.put("versionCode", versionCode);
            }
        } catch (NameNotFoundException e) {
            Log.e(TAG, "an error occured when collect package info", e);
        }

        Field[] fields = Build.class.getDeclaredFields();
        for (Field field : fields) {
            try {
                field.setAccessible(true);
                infos.put(field.getName(), field.get(null).toString());
                Log.d(TAG, field.getName() + " : " + field.get(null));
            } catch (Exception e) {
                Log.e(TAG, "an error occured when collect crash info", e);
            }
        }
    }

    /**
     * 保存错误信息到文件中
     * @return 返回文件名称, 便于将文件传送到服务器
     */
    private String saveCrashInfo2File(Throwable ex) {
        StringBuffer sb = new StringBuffer();
        for (Map.Entry<String, String> entry : infos.entrySet()) {
            String key   = entry.getKey();
            String value = entry.getValue();
            sb.append(key + "=" + value + "\n");
        }

        Writer writer      = new StringWriter();
        PrintWriter printWriter = new PrintWriter(writer);
        ex.printStackTrace(printWriter);
        Throwable cause = ex.getCause();
        while (cause != null) {
            cause.printStackTrace(printWriter);
            cause = cause.getCause();
        }
        printWriter.close();

        String result = writer.toString();
        sb.append(result);
        try {
            String time      = formatter.format(new Date());
            String fileName  = time + ".log";

            if ( Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
                String path = Environment.getExternalStorageDirectory().getPath() + "/Heweather/";
                File dir  = new File(path);
                if (!dir.exists()) {
                    dir.mkdirs();
                }
                FileOutputStream fos = new FileOutputStream(path + fileName);
                fos.write(sb.toString().getBytes());
                fos.close();
            }
            Log.d(TAG, "saveCrashInfo2File: " + fileName);
            return fileName;
        } catch (Exception e) {
            Log.e(TAG, "an error occured while writing file...", e);
        }
        return null;
    }

}