package ru.webanimal.academy_lesson04_threads;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    //==============================================================================================
    // Static
    //==============================================================================================

    private static final int FPS_LIMIT = 240;


    //==============================================================================================
    // Fields
    //==============================================================================================

    private Thread tOne;
    private Thread tTwo;
    private final ThreadSwitch ts = new ThreadSwitch();
    private boolean isRunning = true;


    //==============================================================================================
    // Activity callbacks
    //==============================================================================================

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        createThreads();
    }

    @Override
    protected void onStart() {
        super.onStart();
        startThreads();
    }

    @Override
    protected void onStop() {
        stopThreads();
        super.onStop();
    }

    //==============================================================================================
    // Private methods
    //==============================================================================================

    private class LeftLeg implements Runnable {
        @Override
        public void run() {
            int fps = 0;
            while (isRunning) {
                if (fps > FPS_LIMIT) {
                    synchronized (ts) {
                        if (ts.get() % 2 == 0) {
                            System.out.println("Left step");
                            ts.raise(); // 0 ---> 1
                        }
                        fps = 0;
                    }
                }
                fps++;
            }
        }
    }

    private class RightLeg implements Runnable {
        @Override
        public void run() {
            int fps = 0;
            while (isRunning) {
                if (fps > FPS_LIMIT) {
                    synchronized (ts) {
                        if (ts.get() % 2 != 0) {
                            System.out.println("Right step");
                            ts.clear(); // 1 ---> 0
                        }
                        fps = 0;
                    }
                }
                fps++;
            }
        }
    }

    private void createThreads() {
        if (tOne == null) {
            tOne = new Thread(new LeftLeg());
        }

        if (tTwo == null) {
            tTwo = new Thread(new RightLeg());
        }
    }

    private void startThreads() {
        synchronized (ts) {
            ts.clear(); // Always LeftLeg is first on start
        }
        isRunning = true;

        if (tOne != null && (!tOne.isAlive() || tOne.isInterrupted())) {
            tOne.start();
        }

        if (tTwo != null && (!tTwo.isAlive() || tTwo.isInterrupted())) {
            tTwo.start();
        }
    }

    private void stopThreads() {
        isRunning = false;

        if (tOne != null && (tOne.isAlive() || !tOne.isInterrupted())) {
            tOne.interrupt();
        }

        if (tTwo != null && (tTwo.isAlive() || !tTwo.isInterrupted())) {
            tTwo.interrupt();
        }
    }
}