package edu.rice.hj.example.comp322;

import edu.rice.hj.api.HjRunnable;
import edu.rice.hj.api.HjSuspendable;
import edu.rice.hj.api.SuspendableException;

import static edu.rice.hj.Module1.asyncNb;
import static edu.rice.hj.Module1.launchHabaneroApp;

/**
 * <p>Lecture2 class.</p>
 *
 * @author <a href="http://shams.web.rice.edu/">Shams Imam</a> (shams@rice.edu)
 */
public class Lecture2 {

    /**
     * <p>returnInAsync.</p>
     *
     * @param condition a boolean.
     */
    public static void returnInAsync(final boolean condition) {
        if (!condition) {
            // this return is not inside the async
            return; // returns from returnInAsync()
        }

        asyncNb(new HjRunnable() {
            @Override
            public void run() {
                System.out.println("Inside async");
                if (condition) {
                    // this return only returns from the async,
                    // it doesn't return from the returnInAsync() method
                    return;
                }
                // do something else
            }
        });

        System.out.println("I will be printed if the async is created!");
    }

    /**
     * <p>breakAndContinue.</p>
     *
     * @param condition a boolean.
     */
    public static void breakAndContinue(final boolean condition) {
        WHILE_1:
        // label to identify the while loop
        while (condition) {
            asyncNb(new HjRunnable() {
                @Override
                public void run() {
                    while (condition) {
                        break; // Okay
                    }
                    // break; // ERROR --- does not relate to the WHILE-1 loop
                }
            });
        }
    }

    public static class StaticFieldCommunication {
        static int sum1 = 0, sum2 = 0;

        public static void main(final String[] argv) { // caller
            // effectively final variable
            final int[] X = new int[20];
            // Initialize X

            // Async’s have same access rules as lambdas
            // effectively final variable are accessible inside lambdas
            // static fields are accessible inside lambdas

            launchHabaneroApp(new HjSuspendable() {
                @Override
                public void run() throws SuspendableException {
                    asyncNb(new HjRunnable() {
                        @Override
                        public void run() {
                            for (int i = X.length / 2; i < X.length; i++) {
                                sum2 += X[i];
                            }
                        }
                    });
                    asyncNb(new HjRunnable() {
                        @Override
                        public void run() {
                            for (int i = 0; i < X.length / 2; i++) {
                                sum1 += X[i];
                            }
                        }
                    });
                }
            });
            final int sum = sum1 + sum2;
        }
    }

    public static class ObjectBasedCommunication {
        public static void main(final String[] argv) { // caller
            // effectively final variable
            final int[] X = new int[20];
            // Initialize X

            // effectively final variable
            final TwoIntegers r = new TwoIntegers();

            // Async’s have same access rules as lambdas
            // effectively final variable are accessible inside lambdas

            launchHabaneroApp(new HjSuspendable() {
                @Override
                public void run() throws SuspendableException {
                    asyncNb(new HjRunnable() {
                        @Override
                        public void run() {
                            for (int i = X.length / 2; i < X.length; i++) {
                                // accessing field 'sum2' of an effectively final variable and modifying it
                                r.sum2 += X[i];
                            }
                        }
                    });
                    asyncNb(new HjRunnable() {
                        @Override
                        public void run() {
                            for (int i = 0; i < X.length / 2; i++) {
                                // accessing field 'sum1' of an effectively final variable and modifying it
                                r.sum1 += X[i];
                            }
                        }
                    });
                }
            });
            final int sum = r.sum1 + r.sum2;
        }

        public static class TwoIntegers {
            int sum1;
            int sum2;
        }
    }

}