MusicDatabase

import java.util.Scanner;
import java.util.ArrayList;
import java.util.stream.Stream;

public class MusicDatabase {


    // TODO: Copy findExact and findContains methods from Ch 9, Part 2: ArrayList Searching here.

    public static void listBandSongs(Scanner sc, ArrayList <String> bands,
            ArrayList <ArrayList <String>> songs) {

        System.out.print("Enter band: ");
        sc.nextLine();
        String bandName = sc.nextLine();

        if (!(bands.contains(bandName))) {
            System.out.println(bandName + " not found in database!\n");
        } else {
            int indexOfBand = bands.indexOf(bandName);
            System.out.printf("%s song list:\n%s\n", bandName, songs.get(indexOfBand).toString());
            System.out.println();
        }
    }

    public static void searchBandSongs(Scanner sc, ArrayList <String> bands,
            ArrayList <ArrayList <String>> songs) {

        System.out.print("Search for: ");
        sc.nextLine();
        String input = sc.nextLine();

        ArrayList <Integer> returnedBands = new ArrayList <>(findContains(input, bands));
        ArrayList <Integer> returnedSongs;
        if (returnedBands.size() > 0) {
            for (Integer b : returnedBands) {
                String bandMatched = bands.get(b);
                System.out.println("Band Matched: " + bandMatched);
                System.out.printf("Songs Matched by %s:\n", bandMatched);


                returnedSongs = new ArrayList <>(findContains(input,
                        Config.SONGS.get(b)));
                for (Integer s : returnedSongs) {
                    System.out.println("\t" + songs.get(b).get(s));
                }
                System.out.println();
            }
        } else {
            System.out.println("Band and/or song is not found.\n");
        }
    }

    public static void modifyBandSong(Scanner sc, boolean toAdd, ArrayList <String> bands,
            ArrayList <ArrayList <String>> songs) {
        System.out.print("Enter band: ");
        sc.nextLine();
        String band = sc.nextLine();
        ArrayList <Integer> bandMatch = findExact(band, bands);
        if (bandMatch.size() > 0) {
            System.out.println(band + " found in the database!");
            if (!toAdd) {
                System.out.print("Delete? (y/n) ");
                if (readChar(sc) == 'y') {
                    bands.remove((int) bandMatch.get(0));
                    songs.remove((int) bandMatch.get(0));
                    System.out.println(band + " deleted.");
                    return;
                }
            }
            System.out.print("Enter song: ");
            String song = sc.nextLine();
            ArrayList <Integer> songMatch = findExact(song, songs.get(bandMatch.get(0)));
            if (songMatch.size() > 0) {
                System.out.println("Modifying band: " + band);
                if (toAdd) {
                    System.out.println("Song, " + song + ", already exists in database!");
                } else {
                    songs.get(bandMatch.get(0)).remove((int) songMatch.get(0));
                    System.out.println("Song, " + song + ", deleted.");
                }
            } else {
                if (toAdd && song.length() > 0) {
                    songs.get(bandMatch.get(0)).add(song);
                    System.out.println("Song, " + song + ", added.");
                } else {
                    System.out.println("Song, " + song + ", does not exist in database!");
                }
            }
        } else {
            System.out.println(band + " does not exist in the database!");
            if (toAdd) {
                System.out.print("Add? (y/n) ");
                if (readChar(sc) == 'y') {
                    bands.add(band);
                    songs.add(new ArrayList <String>());
                    System.out.println(band + " added.");
                }
            }
        }
    }

    public static char readChar(Scanner sc) {
        return sc.next().toLowerCase().charAt(0);
    }

    public static ArrayList <Integer> findExact(String s, ArrayList <String> arr) {

        // returning null if arr is null
        if (arr == null) {
            return null;
        }

        // creating an integer array list
        ArrayList <Integer> indices = new ArrayList <Integer>();

        // looping through each index in arr
        for (int i = 0; i < arr.size(); i++) {
            // if both s and arr.get(i) are null, adding index to list
            if (s == null && arr.get(i) == null) {
                indices.add(i);
            }
            // otherwise if both are not null and are equal, adding to list
            else if (s != null && arr.get(i) != null && s.equals(arr.get(i))) {
                indices.add(i);
            }
        }

        return indices;
    }

    public static ArrayList <Integer> findContains(String s, ArrayList <String> arr) {

        // returning null if arr is null
        if (arr == null) {
            return null;
        }

        // ceating an integer array list
        ArrayList <Integer> indices = new ArrayList <Integer>();

        // looping through each index in arr
        for (int i = 0; i < arr.size(); i++) {
            // if both s and arr.get(i) are null, adding index to list
            if (s == null && arr.get(i) == null) {
                indices.add(i);
            }

            // otherwise if both are not null and arr.get(i) contains s, adding
            // to list
            else if (s != null && arr.get(i) != null && arr.get(i).contains(s)) {
                indices.add(i);
            }
        }
        return indices;
    }

    public static void displayMenu() {
        System.out.print("(A)dd a band and/or a song.\n" +
                "(D)elete a band and/or a song.\n" +
                "(B)ands list.\n" +
                "(L)ist a band's song list.\n" +
                "(S)earch for a band and/or a song.\n" +
                "(?) Display this full menu.\n" +
                "(Q)uit.\n" +
                "Action (? for full menu): ");
    }

    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);

        StringBuilder asterisks = new StringBuilder(80);
        Stream.generate(() -> '*').limit(80).forEach(asterisks::append);

        System.out.println(asterisks);
        System.out.println("Welcome to the music database!");
        System.out.println(asterisks);
        System.out.println();

        char userChoice;

        do {
            displayMenu();
            //userChoice = scan.next().toLowerCase().charAt(0);
            userChoice = readChar(scan);

            if (userChoice == 'a') {
                modifyBandSong(scan, true, Config.BANDS, Config.SONGS);
            } else if (userChoice == 'd') {
                modifyBandSong(scan, false, Config.BANDS, Config.SONGS);
            } else if (userChoice == 'b') {
                System.out.println("Bands: " + Config.BANDS.toString());
            } else if (userChoice == 'l') {
                listBandSongs(scan, Config.BANDS, Config.SONGS);
            } else if (userChoice == 's') {
                searchBandSongs(scan, Config.BANDS, Config.SONGS);
            } else if (userChoice == '?') {
                displayMenu();
            } else {
                System.out.println("Invalid choice made.\n");
            }
        } while (userChoice != 'q');
    } // end main

} // end class