java/w12/repository/InMemoryArticleRepository.java

package com.crawler.repository;

import com.crawler.model.Article;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.stream.Collectors;

public class InMemoryArticleRepository implements ArticleRepository {
    private final Map<String, Article> articles = new ConcurrentHashMap<>();
    private final Map<String, String> urlToIdMap = new ConcurrentHashMap<>();
    private final AtomicInteger idGenerator = new AtomicInteger(1);

    @Override
    public void save(Article article) {
        if (article.getId() == null) {
            article.setId(String.valueOf(idGenerator.getAndIncrement()));
        }
        articles.put(article.getId(), article);
        if (article.getUrl() != null) {
            urlToIdMap.put(article.getUrl(), article.getId());
        }
    }

    @Override
    public void saveAll(List<Article> articleList) {
        for (Article article : articleList) {
            save(article);
        }
    }

    @Override
    public Optional<Article> findById(String id) {
        return Optional.ofNullable(articles.get(id));
    }

    @Override
    public Optional<Article> findByUrl(String url) {
        String id = urlToIdMap.get(url);
        return id != null ? Optional.ofNullable(articles.get(id)) : Optional.empty();
    }

    @Override
    public List<Article> findAll() {
        return new ArrayList<>(articles.values());
    }

    @Override
    public List<Article> findBySource(String source) {
        return articles.values().stream()
                .filter(a -> source.equals(a.getSource()))
                .collect(Collectors.toList());
    }

    @Override
    public void deleteById(String id) {
        Article article = articles.remove(id);
        if (article != null && article.getUrl() != null) {
            urlToIdMap.remove(article.getUrl());
        }
    }

    @Override
    public void deleteAll() {
        articles.clear();
        urlToIdMap.clear();
    }

    @Override
    public int count() {
        return articles.size();
    }

    @Override
    public boolean existsByUrl(String url) {
        return urlToIdMap.containsKey(url);
    }
}