package algs42;
import stdlib.*;
import algs35.ST;
/* ***********************************************************************
 *  Compilation:  javac SymbolDigraph.java
 *  Execution:    java SymbolDigraph
 *  Dependencies: ST.java Digraph.java In.java
 *
 *  %  java SymbolDigraph routes.txt " "
 *  JFK
 *     MCO
 *     ATL
 *     ORD
 *  ATL
 *     HOU
 *     MCO
 *  LAX
 *
 *************************************************************************/

public class SymbolDigraph {
  private final ST<String, Integer> st;  // string -> index
  private final String[] keys;           // index  -> string
  private final Digraph G;
  private final String delimiter;

  public SymbolDigraph(String filename, String delimiter) {
    this.delimiter = delimiter;
    this.st = new ST<>();

    // First pass builds the index by reading strings to associate
    // distinct strings with an index
    In in = new In(filename);
    while (in.hasNextLine()) {
      String[] a = in.readLine().split(delimiter);
      for (int i = 0; i < a.length; i++) {
        if (!st.contains(a[i]))
          st.put(a[i], st.size());
      }
    }

    // inverted index to get string keys in an aray
    this.keys = new String[st.size()];
    for (String name : st.keys()) {
      keys[st.get(name)] = name;
    }

    // second pass builds the digraph by connecting first vertex on each
    // line to all others
    this.G = new Digraph(st.size());
    in = new In(filename);
    while (in.hasNextLine()) {
      String[] a = in.readLine().split(delimiter);
      int v = st.get(a[0]);
      for (int i = 1; i < a.length; i++) {
        int w = st.get(a[i]);
        G.addEdge(v, w);
      }
    }
  }

  public boolean contains(String s) {
    return st.contains(s);
  }

  public int index(String s) {
    return st.get(s);
  }

  public String name(int v) {
    return keys[v];
  }

  public Digraph G() {
    return G;
  }

  public String toString() {
    StringBuilder s = new StringBuilder();
    String NEWLINE = System.getProperty("line.separator");
    s.append(G.V() + " vertices, " + G.E() + " edges " + NEWLINE);
    for (int v = 0; v < G.V(); v++) {
      s.append(name(v));
      for (int w : G.adj (v)) {
        s.append(delimiter);
        s.append(name(w));
      }
      s.append(NEWLINE);
    }
    return s.toString();
  }

  public static void main(String[] args) {
    args = new String[] { "data/jobs.txt", "/" };

    String filename  = args[0];
    String delimiter = args[1];
    SymbolDigraph sg = new SymbolDigraph(filename, delimiter);
    StdOut.println (sg);

    Digraph G = sg.G();
    while (!StdIn.isEmpty()) {
      String t = StdIn.readLine();
      for (int v : G.adj(sg.index(t))) {
        StdOut.println("   " + sg.name(v));
      }
    }
  }
}