import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

/**
 *
 * @author Pedro
 */
public class Indexer {

    private Map<String, BufferedWriter> buffers = new HashMap<>();

    public Indexer() throws IOException {
        buffers.put("a", new BufferedWriter(new FileWriter("a.txt")));
        buffers.put("bc", new BufferedWriter(new FileWriter("bc.txt")));
        buffers.put("def", new BufferedWriter(new FileWriter("def.txt")));
        buffers.put("ghijk", new BufferedWriter(new FileWriter("ghijk.txt")));
        buffers.put("lmnp", new BufferedWriter(new FileWriter("lmnp.txt")));
        buffers.put("pqrs", new BufferedWriter(new FileWriter("pqrs.txt")));
        buffers.put("tuv", new BufferedWriter(new FileWriter("tuv.txt")));
        buffers.put("wxyz", new BufferedWriter(new FileWriter("wxyz.txt")));
    }

    public void index() throws FileNotFoundException, IOException {
        Map<String, Map<Integer, Integer>> invertedIndex = new TreeMap<>();
        BufferedReader sc = new BufferedReader(new FileReader("tokens.txt"));
        BufferedWriter writer;
        String line;

        for (String key : buffers.keySet()) {
            writer = buffers.get(key);
            invertedIndex.clear();
            while ((line = sc.readLine()) != null) {
                String[] splitedLine = line.split(":");
                int docID = Integer.parseInt(splitedLine[0]);
                String second = splitedLine[1].replaceAll("[^a-zA-Z0-9 ]", "");
                List<String> tokens = new ArrayList<>(Arrays.asList(second.split(" ")));

                for (String cnsmr : tokens) {

                    if (invertedIndex.containsKey(cnsmr)) {
                        Map<Integer, Integer> temp = invertedIndex.get(cnsmr);
                        if (temp.containsKey(docID)) {
                            int cont = temp.get(docID);
                            invertedIndex.get(cnsmr).put(docID, ++cont);
                        } else {
                            invertedIndex.get(cnsmr).put(docID, 1);
                        }
                    } else {
                        Map<Integer, Integer> temp = new HashMap<>();
                        temp.put(docID, 1);
                        invertedIndex.put(cnsmr, temp);
                    }

                }




            }

        }

    }
}