package ai.d.ai07;

import drjava.util.F;
import drjava.util.ListUtil;
import drjava.util.StringUtil;
import structcom.sc03.PStringLit;

public class GroupingTest {
  public static void main(String[] args) {
    String poem =
      "for each line in file:\n" +
      "  compare file \"/bla1/$file\" to file \"/bla2/$file\"";

    String groupedPoem =
      "[[for] [each] [line] [in] [file]:]\n" +
      "[[  ][[compare] [file] [\"/bla1/$file\"] [to] [file] [\"/bla2/$file\"]]]";
    group(poem, "lines");
    group(poem, "linesWithIndent");
    group(poem, "words");
    group(poem, "stringLits");
    group(poem, "words_skipGrouped");
    String grouped = group(poem, "stringLits+words_skipGrouped+linesWithIndent");
    System.out.println("Expected =>");
    System.out.println(StringUtil.indent(2, groupedPoem));
  }

  private static String group(String poem, String operator) {
    try {
      System.out.println(operator + " =>");
      String grouped = doGroup(poem, operator);
      System.out.println(StringUtil.indent(2, grouped));
      return grouped;
    } catch (Throwable e) {
      System.out.println(operator + "  ERROR: " + e);
      return "";
    }
  }

  private static String doGroup(String poem, String operator) {
    String[] split = operator.split("\\+");
    if (split.length > 1) {
      for (String op : split) poem = doGroup(poem, op);
      return poem;
    }

    if (operator.equals("lines"))
      return groupLines(poem);
    if (operator.equals("linesWithIndent"))
      return groupLinesWithIndent(poem);
    if (operator.equals("words"))
      return groupWords(poem);
    if (operator.equals("stringLits"))
      return groupStringLits(poem);
    if (operator.equals("words_skipGrouped"))
      return groupWords_skipGrouped(poem);
    throw new RuntimeException("Unknown operator '" + operator + "'");
  }

  private static String groupLines(String poem) {
    return StringUtil.join("\n", ListUtil.map(StringUtil.toLines(poem), new F<String, String>() {
      public String _(String s) {
        return "[" + s + "]";
      }
    }));
  }

  private static String groupLinesWithIndent(String poem) {
    return StringUtil.join("\n", ListUtil.map(StringUtil.toLines(poem), new F<String, String>() {
      public String _(String s) {
        if (s.startsWith("  "))
          return "[[  ][" + s.substring(2) + "]]";
        else
          return "[" + s + "]";
      }
    }));
  }

  private static String groupWords(String poem) {
    return groupByPredicate(poem, new F<Character, Boolean>() {
      public Boolean _(Character c) {
        return Character.isLetterOrDigit(c);
      }
    });
  }

  private static String groupWords_skipGrouped(String poem) {
    return groupByPredicate_skipGrouped(poem, new F<Character, Boolean>() {
      public Boolean _(Character c) {
        return Character.isLetterOrDigit(c);
      }
    });
  }

  private static String groupByPredicate(String poem, F<Character, Boolean> pred) {
    StringBuilder buf = new StringBuilder();
    for (int i = 0; i < poem.length(); i++) {
      char c = poem.charAt(i);
      if (!pred._(c))
        buf.append(c);
      else {
        int j = i+1;
        while (j < poem.length() && pred._(poem.charAt(j)))
          ++j;
        buf.append("[" + poem.substring(i, j) + "]");
        i = j-1;
      }
    }
    return buf.toString();
  }

  private static String groupByPredicate_skipGrouped(String poem, F<Character, Boolean> pred) {
    StringBuilder buf = new StringBuilder();
    for (int i = 0; i < poem.length(); i++) {
      char c = poem.charAt(i);
      if (c == '[') {
        int j = findEndOfGroup(poem, i); // TODO: This is unreliable
        buf.append(poem.substring(i, j));
        i = j-1;
      } else if (!pred._(c))
        buf.append(c);
      else {
        int j = i+1;
        while (j < poem.length() && pred._(poem.charAt(j)))
          ++j;
        buf.append("[" + poem.substring(i, j) + "]");
        i = j-1;
      }
    }
    return buf.toString();
  }

  private static int findEndOfGroup(String poem, int i) {
    while (i < poem.length() && poem.charAt(i) != ']')
      ++i;
    return i;
  }

  private static String groupStringLits(String poem) {
    StringBuilder buf = new StringBuilder();
    for (int i = 0; i < poem.length(); i++) {
      char c = poem.charAt(i);
      if (c == '"') {
        PStringLit parser = new PStringLit();
        parser.setText(poem, i);
        parser.parse();
        int j = parser.getIdx();
        buf.append("[" + poem.substring(i, j) + "]");
        i = j-1;
      } else
        buf.append(c);
    }
    return buf.toString();
  }
}