package com.idormy.sms.forwarder;

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

import androidx.annotation.NonNull;

import com.hjq.toast.ToastUtils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.Thread.UncaughtExceptionHandler;
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;
import java.util.Objects;

/**
 * UncaughtException处理类,当程序发生Uncaught异常的时候,有该类来接管程序,并记录发送错误报告
 */
public class CrashHandler implements UncaughtExceptionHandler {
    private static final String TAG = "CrashHandler";
    //系统默认的UncaughtException处理类
    private Thread.UncaughtExceptionHandler mDefaultHandler;
    //CrashHandler实例
    @SuppressLint("StaticFieldLeak")
    private static final CrashHandler INSTANCE = new CrashHandler();
    //程序的Context对象
    private Context mContext;
    //用来存储设备信息和异常信息
    private final 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 final 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;
    }

    /**
     * 初始化
     */
    public void init(Context context) {
        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(@NonNull Thread thread, @NonNull 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) {
                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(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();
                ToastUtils.delayedShow(R.string.crash_tip, 3000);
                Looper.loop();
            }
        }.start();
        //收集设备参数信息
        collectDeviceInfo(mContext);
        //保存日志文件
        saveCrashInfo2File(ex);
        return true;
    }

    /**
     * 收集设备参数信息
     */
    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(), Objects.requireNonNull(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
     */
    @SuppressWarnings({"ResultOfMethodCallIgnored", "UnusedReturnValue"})
    private String saveCrashInfo2File(Throwable ex) {
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, String> entry : infos.entrySet()) {
            String key = entry.getKey();
            String value = entry.getValue();
            sb.append(key).append("=").append(value).append("\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";

            String path = mContext.getCacheDir().getPath() + File.separator + "crash" + File.separator;
            Log.e(TAG, path);
            File dir = new File(path);
            if (!dir.exists()) {
                dir.mkdirs();
            }
            FileOutputStream fos = new FileOutputStream(path + fileName);
            fos.write(sb.toString().getBytes());
            fos.close();

            return fileName;
        } catch (Exception e) {
            Log.e(TAG, "an error occured while writing file...", e);
        }
        return null;
    }
}