HackNight.scala

package wlhacknight

import scala.io.Source
import java.io.File
import java.util.Arrays
import scala.collection.mutable.ArrayBuffer
import scala.collection.immutable.HashMap
import scala.util.Random

/**
 * Alice in Markov Chains for West London Hack Night
 *
 * Developed in 1.5 hours by Scala team.
 * Post-night development by Peter L Jones
 */

/**
 * TODO: Add song, verse and line start / end points
 */

object HackNight extends App {

    case class Node(value: String, var meta: Map[String, Int]) {
        def incr(str: String) = meta += (str -> (meta.getOrElse(str, 0) + 1))
        def findNext() = meta.toList(Random.nextInt(meta.size))._1
    }

    def somekindofparsingfunction(list: List[String], nodemap: Map[String, Node]): Map[String, Node] = {
        list match {
            case h :: Nil => nodemap
            case token :: t => {
                nodemap get token match {
                    case None => somekindofparsingfunction(t, nodemap + (token -> Node(token, Map(t.head -> 1))))
                    case Some(x) => {
                        x.incr(t.head)
                        somekindofparsingfunction(t, nodemap)
                    }
                }
            }
        }
    }

    val lines = Source.fromFile(new File("lyrics.txt")).getLines.map(line => line.split(" "))

    val regex = "[^a-z]".r

    val words = lines.foldLeft(new ArrayBuffer[String]())((acc, line) => acc ++ line)
        .map(word => regex.replaceAllIn(word.toLowerCase(), "")).toList

    val whoknows = somekindofparsingfunction(words, HashMap[String, Node]())

    println(whoknows + "\n\n")

    var nextNode = whoknows.toList(Random.nextInt(whoknows.size))._2

    (1 to 4)
        .map(_ => {
            (1 to (3 + Random.nextInt(3)))
                .map(_ => {
                    (1 to (5 + Random.nextInt(5)))
                        .map(_ => {
                            if (nextNode.value != "")
                                print(nextNode.value + " ")
                            nextNode = whoknows(nextNode.findNext)
                        })
                    println()
                })
            println()
        })
}