package ru.wadman.smalllight;

import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.WindowManager;
import android.widget.RelativeLayout;

import java.io.IOException;

public class MyActivity extends Activity implements SurfaceHolder.Callback, View.OnClickListener {

    private final static String SETTING_NAME = "default";
    private final static String SETTING_FLASH = "isFlash";

    private SurfaceHolder mHolder;
    private Camera mCamera = null;
    private SurfaceView mPreview;
    private boolean isFlashMode = true;
    private boolean isFlashAvail = false;
    private float mBrightness;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);
        RelativeLayout layout = (RelativeLayout)findViewById(R.id.back);
        layout.setOnClickListener(this);
        mBrightness = getScreenBrightness();
        isFlashAvail = getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
        isFlashMode = getSharedPreferences(SETTING_NAME, Context.MODE_PRIVATE).getBoolean(SETTING_FLASH, isFlashMode) & isFlashAvail;
        mPreview = (SurfaceView) findViewById(R.id.surfaceView);
        if (isFlashAvail) {
            mHolder = mPreview.getHolder();
            mHolder.addCallback(this);
            mCamera = Camera.open();
            try {
                mCamera.setPreviewDisplay(mHolder);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        turnFlashOn();
    }

    private float getScreenBrightness() {
        return getWindow().getAttributes().screenBrightness;
    }

    private void setScreenBrightness(float brightness) {
        WindowManager.LayoutParams layout = getWindow().getAttributes();
        layout.screenBrightness = brightness;
        getWindow().setAttributes(layout);
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        if (isFlashAvail) {
            mHolder = holder;
            try {
                mCamera.setPreviewDisplay(mHolder);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        if (isFlashAvail) {
            mCamera.stopPreview();
            mHolder = null;
        }
    }

    private void turnFlashOn() {
        if (isFlashMode) {
            Camera.Parameters params = mCamera.getParameters();
            params.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
            mCamera.setParameters(params);
            mCamera.startPreview();
        } else {
            mPreview.getRootView().setBackgroundColor(Color.WHITE);
            setScreenBrightness(1);
        }
    }

    private void turnFlashOff() {
        if (isFlashMode) {
            Camera.Parameters params = mCamera.getParameters();
            params.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
            mCamera.setParameters(params);
            mCamera.stopPreview();
        } else {
            mPreview.getRootView().setBackgroundColor(Color.BLACK);
            setScreenBrightness(mBrightness);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        turnFlashOff();
    }

    @Override
    protected void onResume() {
        super.onResume();
        turnFlashOn();
    }

    @Override
    protected void onDestroy() {
        turnFlashOff();
        if (mCamera != null) {
            mCamera.release();
        }
        final SharedPreferences.Editor editor = getSharedPreferences(SETTING_NAME, Context.MODE_PRIVATE).edit();
        editor.putBoolean(SETTING_FLASH, isFlashMode);
        editor.apply();
        super.onDestroy();
    }

    @Override
    public void onClick(View v) {
        if (isFlashAvail) {
            turnFlashOff();
            isFlashMode = !isFlashMode;
            turnFlashOn();
        }
    }
}