/**
 * UncaughtException處理類,當程式發生Uncaught異常的時候,由該類來接管程式,並記錄傳送錯誤報告.
 * 
 *  需要在Application中註冊，為了要在程式啟動器就監控整個程式。
 *  CrashHandler.getInstanc().init(this);
 */
public class CrashHandler implements Thread.UncaughtExceptionHandler {

    public static final String TAG = "CrashHandler";

    //系統預設的UncaughtException處理類
    private Thread.UncaughtExceptionHandler mDefaultHandler;
    //CrashHandler例項
    private static CrashHandler 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>();

    //用於格式化日期,作為日誌檔名的一部分
    private DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");

    /** 保證只有一個CrashHandler例項 */
    private CrashHandler() {}

    /** 獲取CrashHandler例項 ,單例模式 */
    public static CrashHandler getInstance() {
        if (instance == null) {
            synchronized (CrashHandler.class) {
                if (instance == null) {
                    synchronized (CrashHandler.class) {
                        instance = new CrashHandler();
                    }
                }
            }
        }
        return 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 thread, Throwable ex) {
        if (!handleException(ex) && 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(thread, ex);
        } else {
            // 已經人為處理,系統自己退出
            try {
                Thread.sleep(3000);
            } catch (InterruptedException e1) {
                e1.printStackTrace();
            }
            Locator_Application.getInstance().finishAll();
        }
    }

    /*private CountDownTimer countDownTimer = new CountDownTimer(3000, 1000) {
        @Override
        public void onTick(long millisUntilFinished) {
        }

        @Override
        public void onFinish() {
            //退出程式
            Locator_Application.getInstance().finishAll();
        }
    };*/


    /**
     * 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);

        //使用Toast來顯示異常資訊
        new Thread() {
            @Override
            public void run() {
                Looper.prepare();
                Toast.makeText(mContext, "很抱歉,程式出現異常,即將退出.", Toast.LENGTH_SHORT).show();
                Looper.loop();
            }
        }.start();
        //儲存日誌檔案
        saveCatchInfo2File(ex);
        return true;
    }

    /**
     * 收集裝置引數資訊
     * @param ctx
     */
    public 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) {
            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);
            }
        }
    }

    /**
     * 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 saveCatchInfo2File(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 {
            long timestamp = System.currentTimeMillis();
            String time = formatter.format(new Date());
            String fileName = "crash-" + time + "-" + timestamp + ".log";
            if (SDCardUtils.isSDCardEnable()) {
                String path = SDCardUtils.getSDCardPaths(false).get(0) + "/miwa/crash/";
                File dir = new File(path);
                if (!FileUtils.createOrExistsDir(dir)) {  // 判斷目錄是否存在，不存在則判斷是否建立成功
                    Logger.e(dir + "目錄建立失敗");
                    return "";
                }
                FileOutputStream fos = new FileOutputStream(path + fileName);
                fos.write(sb.toString().getBytes());
                //傳送給開發人員
                sendCrashLog2PM(path+fileName);
                fos.close();
            }
            return fileName;
        } catch (Exception e) {
            Log.e(TAG, "an error occured while writing file...", e);
        }
        return null;
    }

    /**
     * 將捕獲的導致崩潰的錯誤資訊傳送給開發人員
     *
     * 目前只將log日誌儲存在sdcard 和輸出到LogCat中，並未傳送給後臺。
     */
    private void sendCrashLog2PM(String fileName){
        if(!new File(fileName).exists()){
            Toast.makeText(mContext, "日誌檔案不存在！", Toast.LENGTH_SHORT).show();
            return;
        }
        FileInputStream fis = null;
        BufferedReader reader = null;
        String s = null;
        try {
            fis = new FileInputStream(fileName);
            reader = new BufferedReader(new InputStreamReader(fis, "GBK"));
            while(true){
                s = reader.readLine();
                if(s == null) break;
                //由於目前尚未確定以何種方式傳送，所以先打出log日誌。
                Log.i("info", s.toString());

            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally{   // 關閉流
            try {
                reader.close();
                fis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}