import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Environment;
import android.util.Log;

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

/**
* Created by zb.yang on 2017/12/22.
*/

public class ZbCrashHandler implements Thread.UncaughtExceptionHandler {
    private static final String TAG = "ZbCrashHandler";

    private static final String PATH = Environment.getExternalStorageDirectory().getPath()+"/CrashHandler/log";
    private static final String FILE_NAME = "crash";
    private static final String FILE_NAME_SUFFIX = ".trace";

    //系統預設的UncaughtException處理類
    private Thread.UncaughtExceptionHandler mDefaultHandler;
    //CrashHandler例項
    private static ZbCrashHandler INSTANCE;
    //程式的Context物件
    private Context mContext;

    //用來儲存裝置資訊和異常資訊
    private Map<String, String> infos = new HashMap<String, String>();

    private ZbCrashHandler(){

    }

    /**
     * 通過靜態類返回單例
     */
    private static class SingletonHolder {
        private static final ZbCrashHandler INSTANCE = new ZbCrashHandler();
    }

    public static ZbCrashHandler getINSTANCE(){
        return SingletonHolder.INSTANCE;
    }

    /**
     * 初始化
     */
    public void init(Context context){
        mContext = context;
        //獲取系統預設的UncaughtException處理器
        mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();
        //設定該CrashHandler為程式的預設處理器
        Thread.setDefaultUncaughtExceptionHandler(this);
    }


    /**
     * 當UncaughtException發生時會轉入該函式來處理
     */
    @Override
    public void uncaughtException(Thread t, Throwable e) {
        if (!handleException(e) && mDefaultHandler != null) {
            //如果使用者沒有處理則讓系統預設的異常處理器來處理
            mDefaultHandler.uncaughtException(t, e);
        } else {
            try {
                Thread.sleep(3000);
            } catch (InterruptedException ie) {
                LogUtils.e(ie.toString());
            }
            //退出程式
            android.os.Process.killProcess(android.os.Process.myPid());
            System.exit(1);
        }
    }

    /**
     * 自定義錯誤處理,收集錯誤資訊 傳送錯誤報告等操作均在此完成.
     *
     * @param ex
     * @return true:如果處理了該異常資訊;否則返回false.
     */
    private boolean handleException(Throwable ex) {
        if (ex == null) {
            return false;
        }
        //收集裝置引數資訊
        collectDeviceInfo(mContext);
        //儲存日誌檔案
        saveCrashInfo2File(ex);
        return true;
    }

    /**
     * 收集裝置引數資訊
     *
     * @param ctx
     */
    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 (PackageManager.NameNotFoundException e) {
            LogUtils.e(TAG,"CrashHandleran.NameNotFoundException---> error occured when collect package info");
        }
        //收集裝置型號資訊
        Field[] fields = Build.class.getDeclaredFields();
        for (Field field : fields) {
            try {
                field.setAccessible(true);
                infos.put(field.getName(), field.get(null).toString());
            } catch (Exception e) {
                LogUtils.e(TAG,"CrashHandler.NameNotFoundException---> an error occured when collect crash info");
            }
        }
    }

    /**
     * 儲存錯誤資訊到檔案中
     *
     * @param ex
     * @return 返回檔名稱, 便於將檔案傳送到伺服器
     */
    private String saveCrashInfo2File(Throwable ex) {

        if(!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            Log.e(TAG,"sdcard unmounted, skip saveCrashInfo2File");
        }

        //呼叫這個方法之前在6.0之後需要動態許可權請求
        File dir = new File(PATH);
        if(!dir.exists()){
            dir.mkdirs();
        }
        long current = System.currentTimeMillis();
        String time = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date(current));
        String file_name = PATH+FILE_NAME+time+FILE_NAME_SUFFIX;
        File file = new File(file_name);

        try{
            PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(file)));
            pw.println(time);
            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");
            }
            pw.println(sb.toString());
            pw.println();
            ex.printStackTrace(pw);
            Throwable cause = ex.getCause();
            while (cause != null) {
                cause.printStackTrace(pw);
                cause = cause.getCause();
            }
        }catch (Exception e){
            Log.e(TAG,"save crash info into file failed");
        }
       
        return file_name;
    }
   
    public void uploadExceptionToServer(){
        // TODO upload Ecxeption Message to Your Web server;
    }
}