import java.time.LocalDate;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.regex.Pattern;

// ─────────────────────────────────────────────
// 策略接口
// ─────────────────────────────────────────────
interface ParseStrategy {
    boolean supports(String url);
    Article parse(String url);
    String  getName();
    default int getPriority() { return 100; }
}

// ─────────────────────────────────────────────
// 策略实现1：GitHub 专属（priority=10）
// ─────────────────────────────────────────────
class GithubParseStrategy implements ParseStrategy {
    @Override
    public boolean supports(String url) {
        return url != null && url.matches("^https?://(www\\.)?github\\.com/.*");
    }

    @Override
    public Article parse(String url) {
        String path  = url.replaceFirst("https?://(www\\.)?github\\.com/", "");
        String[] parts = path.split("/");
        String owner = parts.length > 0 ? parts[0] : "unknown";
        String repo  = parts.length > 1 ? parts[1] : "repo";
        return new Article("[GitHub] " + owner + "/" + repo, url,
                           "(GitHub stub)", owner, LocalDate.now());
    }

    @Override public String getName()    { return "GithubParseStrategy"; }
    @Override public int    getPriority(){ return 10; }
}

// ─────────────────────────────────────────────
// 策略实现2：通用默认兜底（priority=999）
// ─────────────────────────────────────────────
class DefaultParseStrategy implements ParseStrategy {
    private static final Pattern URL_PATTERN =
        Pattern.compile("^https?://[^\\s/$.?#].[^\\s]*$");

    @Override
    public boolean supports(String url) {
        return url != null && URL_PATTERN.matcher(url).matches();
    }

    @Override
    public Article parse(String url) {
        String domain = url.replaceFirst("https?://", "").replaceAll("/.*", "");
        return new Article("文章来自 " + domain, url,
                           "(default stub)", "unknown", LocalDate.now());
    }

    @Override public String getName()    { return "DefaultParseStrategy"; }
    @Override public int    getPriority(){ return 999; }
}

// ─────────────────────────────────────────────
// 策略选择器
// ─────────────────────────────────────────────
class StrategySelector {
    private final List<ParseStrategy> strategies = new ArrayList<>();

    public StrategySelector() {
        strategies.add(new GithubParseStrategy());
        strategies.add(new DefaultParseStrategy());
        strategies.sort(Comparator.comparingInt(ParseStrategy::getPriority));
    }

    public ParseStrategy select(String url) {
        return strategies.stream()
                         .filter(s -> s.supports(url))
                         .findFirst().orElse(null);
    }

    public List<ParseStrategy> getAll() { return List.copyOf(strategies); }
}