import org.apache.fluo.api.config.FluoConfiguration;
import org.apache.fluo.api.data.Bytes;
import org.apache.fluo.recipes.core.data.RowHasher;

public class RowHasherExample {


  private static final RowHasher PAGE_ROW_HASHER = new RowHasher("p");

  // Provide one place to obtain row hasher.
  public static RowHasher getPageRowHasher() {
    return PAGE_ROW_HASHER;
  }

  public static void main(String[] args) {
    RowHasher pageRowHasher = getPageRowHasher();

    String revUrl = "org.wikipedia/accumulo";

    // Add a hash prefix to the row. Use this hashedRow in your transaction
    Bytes hashedRow = pageRowHasher.addHash(revUrl);
    System.out.println("hashedRow      : " + hashedRow);

    // Remove the prefix. This can be used by transactions dealing with the hashed row.
    Bytes orig = pageRowHasher.removeHash(hashedRow);
    System.out.println("orig           : " + orig);


    // Generate table optimizations for the recipe. This can be called when setting up an
    // application that uses a hashed row.
    int numTablets = 20;

    // The following code would normally be called before initializing Fluo. This code
    // registers table optimizations for your prefix+hash.
    FluoConfiguration conf = new FluoConfiguration();
    RowHasher.configure(conf, PAGE_ROW_HASHER.getPrefix(), numTablets);

    // Normally you would not call the following code, it would be called automatically for you by
    // TableOperations.optimizeTable(). Calling this code here to show what table optimization will
    // be generated.
    TableOptimizations tableOptimizations = new RowHasher.Optimizer()
        .getTableOptimizations(PAGE_ROW_HASHER.getPrefix(), conf.getAppConfiguration());
    System.out.println("Balance config : " + tableOptimizations.getTabletGroupingRegex());
    System.out.println("Splits         : ");
    tableOptimizations.getSplits().forEach(System.out::println);
    System.out.println();
  }
}