package jcascalog.example;

import com.twitter.maple.tap.StdoutTap;
import jcascalog.Api;
import jcascalog.Option;
import jcascalog.Playground;
import jcascalog.Subquery;
import jcascalog.op.Count;
import jcascalog.op.GT;
import jcascalog.op.LT;
import jcascalog.op.Multiply;


public class Examples {
    public static void twentyFiveYearOlds() {
        Api.execute(
          new StdoutTap(),
          new Subquery("?person")
            .predicate(Playground.AGE, "?person", 25));
    }

    public static void lessThanThirtyYearsOld() {
        Api.execute(
          new StdoutTap(),
          new Subquery("?person")
            .predicate(Playground.AGE, "?person", "?age")
            .predicate(new LT(), "?age", 30));
    }

    public static void lessThanThirtyYearsOldWithAge() {
        Api.execute(
          new StdoutTap(),
          new Subquery("?person", "?age")
            .predicate(Playground.AGE, "?person", "?age")
            .predicate(new LT(), "?age", 30));
    }

    public static void doubleAges() {
        Api.execute(
          new StdoutTap(),
          new Subquery("?person", "?double-age")
            .predicate(Playground.AGE, "?person", "?age")
            .predicate(new Multiply(), "?age", 2).out("?double-age"));
    }

    public static void distinctPeopleFromFollows() {
        Api.execute(
          new StdoutTap(),
          new Subquery("?person")
            .predicate(Playground.FOLLOWS, "?person", "_")
            .predicate(Option.DISTINCT, true));
    }

    public static void nonDistinctPeopleFromFollows() {
        Api.execute(
          new StdoutTap(),
          new Subquery("?person")
            .predicate(Playground.FOLLOWS, "?person", "_"));
    }
    
    public static void malePeopleEmilyFollows() {
        Api.execute(
          new StdoutTap(),
          new Subquery("?person")
            .predicate(Playground.FOLLOWS, "emily", "?person")
            .predicate(Playground.GENDER, "?person", "m"));
    }
    
    public static void followsManyFollows() {
        Subquery manyFollows =
                new Subquery("?person")                    
                    .predicate(Playground.FOLLOWS, "?person", "_")
                    .predicate(new Count(), "?count")
                    .predicate(new GT(), "?count", 2);
        Api.execute(
          new StdoutTap(),
          new Subquery("?person1", "?person2")
            .predicate(manyFollows, "?person1")
            .predicate(manyFollows, "?person2")
            .predicate(Playground.FOLLOWS, "?person1", "?person2"));
    }

    public static void followsManyFollowsConcise() {
        // this implementation uses Api.each to shorten the implementation
        Subquery manyFollows =
                new Subquery("?person")
                    .predicate(Playground.FOLLOWS, "?person", "_")
                    .predicate(new Count(), "?count")
                    .predicate(new GT(), "?count", 2);
        Api.execute(
          new StdoutTap(),
          new Subquery("?person1", "?person2")
            .predicate(Api.each(manyFollows), "?person1", "?person2")
            .predicate(Playground.FOLLOWS, "?person1", "?person2"));
    }    
    
    public static void sentenceUniqueWords() {
        Api.execute(
          new StdoutTap(),
          new Subquery("?word")
            .predicate(Playground.SENTENCE, "?sentence")
            .predicate(new Split(), "?sentence").out("?word")
            .predicate(Option.DISTINCT, true));
    }

    public static void wordCount() {
        Api.execute(
          new StdoutTap(),
          new Subquery("?word", "?count")
            .predicate(Playground.SENTENCE, "?sentence")
            .predicate(new Split(), "?sentence").out("?word")
            .predicate(new Count(), "?count"));
    }

    public static void lineCountWithFiles() {
        Api.execute(
          Api.hfsTextline("/tmp/myresults"),
          new Subquery("?count")
            .predicate(Api.hfsTextline("src/jvm/jcascalog/example"), "_")
            .predicate(new Count(), "?count"));
    }
}