package io.vertx.ext.dropwizard.impl;

import io.vertx.ext.dropwizard.Match;
import io.vertx.ext.dropwizard.MatchType;

import java.util.*;
import java.util.AbstractMap.SimpleEntry;
import java.util.Map.Entry;
import java.util.regex.Pattern;
import java.util.stream.Collector;
import java.util.stream.Collectors;

Author:
Julien Viet/**
 * @author <a href="mailto:julien@julienviet.com">Julien Viet</a>
 */
class Matcher {
  private final Map<String, String> exactMatches;
  private final Entry<Pattern, String>[] regexMatches;
  private final Map<String, String> aliases;

  Matcher(List<Match> matches) {
    aliases = new HashMap<>();

    for (Match match : matches) {
      if (match.getAlias() != null) {
        aliases.put(match.getValue(), match.getAlias());
      }
    }

    exactMatches = matches.stream()
      .filter(match -> match.getType() == MatchType.EQUALS && match.getValue() != null)
      .collect(Collectors.toMap(Match::getValue, match -> match.getAlias() != null ? match.getAlias() : match.getValue()));

    @SuppressWarnings("unchecked")
    Entry<Pattern, String>[] entries = matches.stream()
      .filter(match -> match.getType() == MatchType.REGEX && match.getValue() != null)
      .map(match -> new SimpleEntry<>(Pattern.compile(match.getValue()), match.getAlias()))
      .toArray(Entry[]::new);
    regexMatches = entries;
  }

  
Return a non null identifier string when the value matches otherwise returns null. 

The returned identifier can be used to identify the match, it is either the original
value or an alias.
Params:
value – the value to match
Returns:
the identifier or null/**
   * Return a non {@code null} identifier string when the {@code value} matches otherwise returns {@code null}.
   * <p>
   * The returned identifier can be used to identify the match, it is either the original
   * value or an alias.
   *
   * @param value the value to match
   * @return the identifier or null
   */
  String matches(String value) {
    if (exactMatches.size() > 0 && exactMatches.containsKey(value)) {
      String valueOrAlias = exactMatches.get(value);
      if (valueOrAlias != null) {
        return valueOrAlias;
      }
    }
    if (regexMatches.length > 0) {
      for (Entry<Pattern, String> entry : regexMatches) {
        if (entry.getKey().matcher(value).matches()) {
          String alias = entry.getValue();
          if (alias != null) {
            return alias;
          } else {
            return value;
          }
        }
      }
    }
    return null;
  }
}