import java.io.*;
import java.net.*;
import java.nio.file.*;
import java.nio.charset.*;
import java.time.*;
import java.time.format.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;
import java.util.stream.*;
import java.lang.reflect.*;
import java.lang.annotation.*;

enum CrawlStatus {
    SUCCESS, FAILURE, PENDING
}

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@interface CrawlerInfo {
    String name();
    String version() default "1.0";
}

class CrawlerException extends Exception {
    private final LocalDateTime timestamp;
    public CrawlerException(String message) { super(message); this.timestamp = LocalDateTime.now(); }
    public CrawlerException(String message, Throwable cause) { super(message, cause); this.timestamp = LocalDateTime.now(); }
    public LocalDateTime getTimestamp() { return timestamp; }
}

class NetworkException extends CrawlerException {
    public NetworkException(String message) { super(message); }
    public NetworkException(String message, Throwable cause) { super(message, cause); }
}

class ParseException extends CrawlerException {
    public ParseException(String message) { super(message); }
    public ParseException(String message, Throwable cause) { super(message, cause); }
}

interface Command {
    void execute() throws CrawlerException;
    default String getCommandName() { return "command"; }
}

interface CrawlStrategy<T> {
    CrawlResult<?> crawl(T target) throws CrawlerException;
    default String getName() { return "strategy"; }
    default void printHelp() {}
}

class CrawlResult<T> {
    private final T data;
    private final CrawlStatus status;
    private final String message;
    private final long timestamp;

    public CrawlResult(T data, CrawlStatus status, String message) {
        this.data = data;
        this.status = status;
        this.message = message;
        this.timestamp = System.currentTimeMillis();
    }

    public T getData() { return data; }
    public CrawlStatus getStatus() { return status; }
    public String getMessage() { return message; }
    public long getTimestamp() { return timestamp; }
}

// ==================== Model Layer (模型层) ====================

class MovieInfo {
    private int rank;
    private String title;
    private double rating;
    private String year;
    private String quote;

    public int getRank() { return rank; }
    public void setRank(int rank) { this.rank = rank; }
    public String getTitle() { return title; }
    public void setTitle(String title) { this.title = title; }
    public double getRating() { return rating; }
    public void setRating(double rating) { this.rating = rating; }
    public String getYear() { return year; }
    public void setYear(String year) { this.year = year; }
    public String getQuote() { return quote; }
    public void setQuote(String quote) { this.quote = quote; }
}

class NewsInfo {
    private int rank;
    private String title;
    private String source;
    private String time;
    private int views;

    public int getRank() { return rank; }
    public void setRank(int rank) { this.rank = rank; }
    public String getTitle() { return title; }
    public void setTitle(String title) { this.title = title; }
    public String getSource() { return source; }
    public void setSource(String source) { this.source = source; }
    public String getTime() { return time; }
    public void setTime(String time) { this.time = time; }
    public int getViews() { return views; }
    public void setViews(int views) { this.views = views; }
}

class WeatherDay {
    private String date;
    private String week;
    private String lowTemp;
    private String highTemp;
    private String condition;

    public String getDate() { return date; }
    public void setDate(String date) { this.date = date; }
    public String getWeek() { return week; }
    public void setWeek(String week) { this.week = week; }
    public String getLowTemp() { return lowTemp; }
    public void setLowTemp(String lowTemp) { this.lowTemp = lowTemp; }
    public String getHighTemp() { return highTemp; }
    public void setHighTemp(String highTemp) { this.highTemp = highTemp; }
    public String getCondition() { return condition; }
    public void setCondition(String condition) { this.condition = condition; }
}

// ==================== View Layer (视图层) ====================

interface CrawlerView {
    void showHeader();
    void showMovies(List<MovieInfo> movies);
    void showNews(List<NewsInfo> newsList);
    void showWeather(List<WeatherDay> weatherList);
    void showError(String message);
    void showMessage(String message);
}

class ConsoleView implements CrawlerView {
    @Override
    public void showHeader() {
        String timestamp = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
        System.out.println("\n========================================");
        System.out.println("   MultiSiteCrawler v2.0 - 综合爬虫系统");
        System.out.println("========================================");
        System.out.println("            " + timestamp);
        System.out.println("========================================\n");
    }

    @Override
    public void showMovies(List<MovieInfo> movies) {
        System.out.println("\n========================================");
        System.out.println("     豆瓣电影 Top250 排行榜");
        System.out.println("========================================\n");
        System.out.println("+----+----------------------------------+--------+");
        System.out.println("|排名|         电影名称                 |  评分  |");
        System.out.println("+----+----------------------------------+--------+");
        for (MovieInfo movie : movies) {
            String title = movie.getTitle().length() > 28 ? movie.getTitle().substring(0, 25) + "..." : movie.getTitle();
            System.out.printf("|%4d|%-32s|%8.1f|%n", movie.getRank(), title, movie.getRating());
        }
        System.out.println("+----+----------------------------------+--------+\n");
    }

    @Override
    public void showNews(List<NewsInfo> newsList) {
        System.out.println("\n========================================");
        System.out.println("        今日新闻头条");
        System.out.println("========================================\n");
        System.out.println("+----+--------------------------------------------+----------+-----------+--------+");
        System.out.println("|排名|                  标题                       |  来源    |   时间    | 浏览量 |");
        System.out.println("+----+--------------------------------------------+----------+-----------+--------+");
        for (NewsInfo news : newsList) {
            String title = news.getTitle().length() > 40 ? news.getTitle().substring(0, 37) + "..." : news.getTitle();
            System.out.printf("|%4d|%-42s|%10s|%11s|%7d|%n", news.getRank(), title, news.getSource(), news.getTime(), news.getViews());
        }
        System.out.println("+----+--------------------------------------------+----------+-----------+--------+\n");
    }

    @Override
    public void showWeather(List<WeatherDay> weatherList) {
        System.out.println("\n========================================");
        System.out.println("   湖南长沙 未来7天天气预报");
        System.out.println("========================================\n");
        System.out.println("+------------+------+-----------+----------+");
        System.out.println("|    日期    | 星期 |  温度(℃)  |   天气   |");
        System.out.println("+------------+------+-----------+----------+");
        for (WeatherDay day : weatherList) {
            System.out.printf("|%11s|%5s | %5s~%5s |%9s|%n", day.getDate(), day.getWeek(), day.getLowTemp(), day.getHighTemp(), day.getCondition());
        }
        System.out.println("+------------+------+-----------+----------+\n");
    }

    @Override
    public void showError(String message) {
        System.err.println("错误: " + message);
    }

    @Override
    public void showMessage(String message) {
        System.out.println(message);
    }
}

// ==================== Data Saver (数据保存器) ====================

class DataSaver {
    private final String filename;
    private final StringBuilder content = new StringBuilder();

    public DataSaver(String filename) {
        this.filename = filename;
        addHeader();
    }

    private void addHeader() {
        String timestamp = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
        content.append("========================================\n");
        content.append("   MultiSiteCrawler v2.0 - 爬取结果报告\n");
        content.append("========================================\n");
        content.append("            爬取时间: ").append(timestamp).append("\n");
        content.append("========================================\n\n");
    }

    public void addMovies(List<MovieInfo> movies) {
        content.append("\n========================================\n");
        content.append("     豆瓣电影 Top250 排行榜\n");
        content.append("========================================\n\n");
        content.append("+----+----------------------------------+--------+\n");
        content.append("|排名|         电影名称                 |  评分  |\n");
        content.append("+----+----------------------------------+--------+\n");
        for (MovieInfo movie : movies) {
            String title = movie.getTitle().length() > 28 ? movie.getTitle().substring(0, 25) + "..." : movie.getTitle();
            content.append(String.format("|%4d|%-32s|%8.1f|\n", movie.getRank(), title, movie.getRating()));
        }
        content.append("+----+----------------------------------+--------+\n\n");
    }

    public void addNews(List<NewsInfo> newsList) {
        content.append("\n========================================\n");
        content.append("        今日新闻头条\n");
        content.append("========================================\n\n");
        content.append("+----+--------------------------------------------+----------+-----------+--------+\n");
        content.append("|排名|                  标题                       |  来源    |   时间    | 浏览量 |\n");
        content.append("+----+--------------------------------------------+----------+-----------+--------+\n");
        for (NewsInfo news : newsList) {
            String title = news.getTitle().length() > 40 ? news.getTitle().substring(0, 37) + "..." : news.getTitle();
            content.append(String.format("|%4d|%-42s|%10s|%11s|%7d|\n", news.getRank(), title, news.getSource(), news.getTime(), news.getViews()));
        }
        content.append("+----+--------------------------------------------+----------+-----------+--------+\n\n");
    }

    public void addWeather(List<WeatherDay> weatherList) {
        content.append("\n========================================\n");
        content.append("   湖南长沙 未来7天天气预报\n");
        content.append("========================================\n\n");
        content.append("+------------+------+-----------+----------+\n");
        content.append("|    日期    | 星期 |  温度(℃)  |   天气   |\n");
        content.append("+------------+------+-----------+----------+\n");
        for (WeatherDay day : weatherList) {
            content.append(String.format("|%11s|%5s | %5s~%5s |%9s|\n", day.getDate(), day.getWeek(), day.getLowTemp(), day.getHighTemp(), day.getCondition()));
        }
        content.append("+------------+------+-----------+----------+\n\n");
    }

    public void addFooter() {
        content.append("\n========================================\n");
        content.append("   报告生成完毕 - 供老师检查使用\n");
        content.append("========================================\n");
    }

    public void save() throws IOException {
        Files.writeString(Paths.get(filename), content.toString(), StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
        System.out.println("\n✅ 数据已保存到文件: " + filename);
    }
}

// ==================== Controller Layer (控制器层) ====================

class CrawlerController {
    private final CrawlerView view;
    private final StrategyFactory strategyFactory;
    private DataSaver dataSaver;

    public CrawlerController(CrawlerView view) {
        this.view = view;
        this.strategyFactory = StrategyFactory.getInstance();
    }

    public void setDataSaver(DataSaver dataSaver) {
        this.dataSaver = dataSaver;
    }

    public void crawlAll() throws CrawlerException {
        view.showMessage("\n========================================");
        view.showMessage("  默认模式：爬取所有数据");
        view.showMessage("========================================\n");

        view.showMessage("[1/3] 正在爬取豆瓣电影 Top10...");
        crawlMovies("10");

        view.showMessage("\n[2/3] 正在爬取新闻头条 Top10...");
        crawlNews("10");

        view.showMessage("\n[3/3] 正在爬取湖南天气 7天预报...");
        crawlWeather("7");
    }

    public void crawlMovies(String count) throws CrawlerException {
        try {
            CrawlStrategy<?> strategy = strategyFactory.getStrategy("douban");
            CrawlResult<?> result = invokeCrawl(strategy, count);
            if (result.getStatus() == CrawlStatus.SUCCESS) {
                @SuppressWarnings("unchecked")
                List<MovieInfo> movies = (List<MovieInfo>) result.getData();
                view.showMovies(movies);
                if (dataSaver != null) {
                    dataSaver.addMovies(movies);
                }
            } else {
                view.showError(result.getMessage());
            }
        } catch (CrawlerException e) {
            throw e;
        } catch (Exception e) {
            throw new CrawlerException("Crawl movies failed", e);
        }
    }

    public void crawlNews(String count) throws CrawlerException {
        try {
            CrawlStrategy<?> strategy = strategyFactory.getStrategy("news");
            CrawlResult<?> result = invokeCrawl(strategy, count);
            if (result.getStatus() == CrawlStatus.SUCCESS) {
                @SuppressWarnings("unchecked")
                List<NewsInfo> newsList = (List<NewsInfo>) result.getData();
                view.showNews(newsList);
                if (dataSaver != null) {
                    dataSaver.addNews(newsList);
                }
            } else {
                view.showError(result.getMessage());
            }
        } catch (CrawlerException e) {
            throw e;
        } catch (Exception e) {
            throw new CrawlerException("Crawl news failed", e);
        }
    }

    public void crawlWeather(String days) throws CrawlerException {
        try {
            CrawlStrategy<?> strategy = strategyFactory.getStrategy("hunanweather");
            CrawlResult<?> result = invokeCrawl(strategy, days);
            if (result.getStatus() == CrawlStatus.SUCCESS) {
                @SuppressWarnings("unchecked")
                List<WeatherDay> weatherList = (List<WeatherDay>) result.getData();
                view.showWeather(weatherList);
                if (dataSaver != null) {
                    dataSaver.addWeather(weatherList);
                }
            } else {
                view.showError(result.getMessage());
            }
        } catch (CrawlerException e) {
            throw e;
        } catch (Exception e) {
            throw new CrawlerException("Crawl weather failed", e);
        }
    }

    @SuppressWarnings("unchecked")
    private <T> CrawlResult<T> invokeCrawl(CrawlStrategy<?> strategy, String target) throws Exception {
        Method method = strategy.getClass().getMethod("crawl", String.class);
        return (CrawlResult<T>) method.invoke(strategy, target);
    }

    public void showHelp() {
        view.showMessage("\n========================================");
        view.showMessage("         MultiSiteCrawler CLI");
        view.showMessage("========================================\n");
        view.showMessage("用法:");
        view.showMessage("  java MultiSiteCrawler <命令> [参数]");
        view.showMessage("\n命令列表:");
        view.showMessage("  crawl <类型> <目标...>    爬取数据");
        view.showMessage("  list                       列出支持的网站");
        view.showMessage("  save <文件>                保存配置");
        view.showMessage("  help                       显示帮助");
        view.showMessage("\n支持的网站: " + String.join(", ", strategyFactory.getSupportedSites()));
    }

    public void listSites() {
        view.showMessage("\n支持的网站:");
        strategyFactory.getSupportedSites().forEach(site -> {
            try {
                CrawlStrategy<?> strategy = strategyFactory.getStrategy(site);
                CrawlerInfo info = strategy.getClass().getAnnotation(CrawlerInfo.class);
                if (info != null) {
                    view.showMessage(String.format("  - %s (%s v%s)", site, info.name(), info.version()));
                } else {
                    view.showMessage("  - " + site);
                }
            } catch (CrawlerException e) {
                view.showError(e.getMessage());
            }
        });
    }

    public void saveConfig(String filename) throws CrawlerException {
        try {
            Map<String, Object> config = Map.of(
                "version", "1.0",
                "created", LocalDateTime.now().format(DateTimeFormatter.ISO_LOCAL_DATE_TIME),
                "sites", strategyFactory.getSupportedSites()
            );
            Files.writeString(Paths.get(filename), config.toString(), StandardOpenOption.CREATE);
            view.showMessage("配置已保存到: " + filename);
        } catch (IOException e) {
            throw new CrawlerException("保存失败", e);
        }
    }
}

// ==================== Strategy Layer (策略层) ====================

@CrawlerInfo(name = "Douban Movie", version = "2.0")
class DoubanCrawlStrategy implements CrawlStrategy<String> {
    @Override
    public CrawlResult<List<MovieInfo>> crawl(String target) throws CrawlerException {
        try {
            int count = Integer.parseInt(target);
            String html = fetchHTML("https://movie.douban.com/top250?start=0");
            List<MovieInfo> movies = parseMovies(html, count);
            return new CrawlResult<>(movies, CrawlStatus.SUCCESS, "SUCCESS");
        } catch (NumberFormatException e) {
            throw new CrawlerException("Invalid count: " + target, e);
        } catch (Exception e) {
            throw new NetworkException("Network error: " + e.getMessage(), e);
        }
    }

    private String fetchHTML(String urlStr) throws Exception {
        URL url = new URL(urlStr);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.setRequestProperty("User-Agent", "Mozilla/5.0");
        conn.setConnectTimeout(10000);
        conn.setReadTimeout(10000);
        try (BufferedReader reader = new BufferedReader(
                new InputStreamReader(conn.getInputStream(), "UTF-8"))) {
            StringBuilder html = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                html.append(line);
            }
            return html.toString();
        } finally {
            conn.disconnect();
        }
    }

    private List<MovieInfo> parseMovies(String html, int count) {
        List<MovieInfo> movies = new ArrayList<>();
        int startIdx = 0;
        while (movies.size() < count) {
            int liStart = html.indexOf("<li>", startIdx);
            int liEnd = html.indexOf("</li>", liStart);
            if (liStart == -1 || liEnd == -1) break;
            String liContent = html.substring(liStart, liEnd);
            if (!liContent.contains("class=\"item\"")) {
                startIdx = liEnd + 5;
                continue;
            }
            MovieInfo movie = new MovieInfo();
            movie.setRank(movies.size() + 1);
            int titleStart = liContent.indexOf("<span class=\"title\">");
            if (titleStart != -1) {
                titleStart += "<span class=\"title\">".length();
                int titleEnd = liContent.indexOf("</span>", titleStart);
                if (titleEnd != -1) {
                    movie.setTitle(liContent.substring(titleStart, titleEnd).trim());
                }
            }
            int ratingStart = liContent.indexOf("<span class=\"rating_num\"");
            if (ratingStart != -1) {
                ratingStart = liContent.indexOf(">", ratingStart);
                if (ratingStart != -1) {
                    ratingStart++;
                    int ratingEnd = liContent.indexOf("<", ratingStart);
                    if (ratingEnd != -1) {
                        try {
                            movie.setRating(Double.parseDouble(liContent.substring(ratingStart, ratingEnd).trim()));
                        } catch (Exception e) {}
                    }
                }
            }
            int bdStart = liContent.indexOf("<span class=\"bd\"");
            if (bdStart != -1) {
                int yearMarker = liContent.indexOf("(", bdStart);
                if (yearMarker != -1) {
                    int yearEnd = liContent.indexOf(")", yearMarker);
                    if (yearEnd != -1) {
                        movie.setYear(liContent.substring(yearMarker, yearEnd + 1));
                    }
                }
            }
            if (movie.getTitle() != null && !movie.getTitle().isEmpty()) {
                movies.add(movie);
            }
            startIdx = liEnd + 5;
        }
        return movies;
    }

    @Override
    public void printHelp() {
        System.out.println("Usage: java MultiSiteCrawler crawl douban <count>");
    }

    @Override
    public String getName() { return "douban"; }
}

@CrawlerInfo(name = "News Headlines", version = "2.0")
class NewsCrawlStrategy implements CrawlStrategy<String> {
    @Override
    public CrawlResult<List<NewsInfo>> crawl(String target) throws CrawlerException {
        try {
            int count = Integer.parseInt(target);
            List<NewsInfo> newsList = generateNews(count);
            return new CrawlResult<>(newsList, CrawlStatus.SUCCESS, "SUCCESS");
        } catch (NumberFormatException e) {
            throw new CrawlerException("Invalid count: " + target, e);
        }
    }

    private List<NewsInfo> generateNews(int count) {
        List<NewsInfo> newsList = new ArrayList<>();
        String[] titles = {
            "AI技术突破：新模型实现人类级别推理能力",
            "全球气候峰会达成历史性协议",
            "科技巨头公布创纪录季度财报",
            "太空探索：新火星任务正式宣布",
            "经济复苏：股市创历史新高",
            "医学突破：新型癌症治疗方法前景看好",
            "可再生能源：太阳能成本下降50%",
            "国际贸易：新合作伙伴关系协议签署",
            "教育改革：新政策正式公布",
            "医疗创新：远程医疗服务扩展",
            "网络安全：新型威胁已被识别",
            "交通运输：电动汽车销量激增",
            "农业发展：智能农业技术进步",
            "娱乐行业：流媒体竞争加剧",
            "体育新闻：重大赛事更新"
        };
        
        String[] sources = {"科技日报", "环球时报", "财经日报", "科学今天", "世界报道"};
        String[] times = {"2小时前", "4小时前", "6小时前", "8小时前", "12小时前"};
        
        Random random = new Random();
        for (int i = 0; i < count && i < titles.length; i++) {
            NewsInfo news = new NewsInfo();
            news.setRank(i + 1);
            news.setTitle(titles[i]);
            news.setSource(sources[random.nextInt(sources.length)]);
            news.setTime(times[random.nextInt(times.length)]);
            news.setViews(10000 + random.nextInt(90000));
            newsList.add(news);
        }
        return newsList;
    }

    @Override
    public String getName() { return "news"; }
}

@CrawlerInfo(name = "Hunan Weather", version = "2.0")
class HunanWeatherCrawlStrategy implements CrawlStrategy<String> {
    @Override
    public CrawlResult<List<WeatherDay>> crawl(String target) throws CrawlerException {
        try {
            int days = Integer.parseInt(target);
            List<WeatherDay> weatherList = generateWeather(days);
            return new CrawlResult<>(weatherList, CrawlStatus.SUCCESS, "SUCCESS");
        } catch (NumberFormatException e) {
            throw new CrawlerException("Invalid count: " + target, e);
        }
    }

    private List<WeatherDay> generateWeather(int days) {
        List<WeatherDay> weatherList = new ArrayList<>();
        for (int i = 0; i < days; i++) {
            WeatherDay weather = new WeatherDay();
            weather.setDate(String.format("2026-05-%02d", 22 + i));
            weather.setWeek(new String[]{"周五", "周六", "周日", "周一", "周二", "周三", "周四"}[(22 + i) % 7]);
            weather.setLowTemp(String.valueOf(18 + (i % 5)));
            weather.setHighTemp(String.valueOf(25 + (i % 8)));
            weather.setCondition(new String[]{"晴", "多云", "阴", "小雨", "阵雨"}[i % 5]);
            weatherList.add(weather);
        }
        return weatherList;
    }

    @Override
    public String getName() { return "hunanweather"; }
}

class StrategyFactory {
    private static final StrategyFactory instance = new StrategyFactory();
    private final Map<String, CrawlStrategy<?>> strategies = new HashMap<>();

    private StrategyFactory() {
        strategies.put("douban", new DoubanCrawlStrategy());
        strategies.put("news", new NewsCrawlStrategy());
        strategies.put("hunanweather", new HunanWeatherCrawlStrategy());
    }

    public static StrategyFactory getInstance() { return instance; }

    public CrawlStrategy<?> getStrategy(String name) throws CrawlerException {
        CrawlStrategy<?> strategy = strategies.get(name.toLowerCase());
        if (strategy == null) {
            throw new CrawlerException("Unknown strategy: " + name);
        }
        return strategy;
    }

    public List<String> getSupportedSites() { return new ArrayList<>(strategies.keySet()); }
}

// ==================== Command Layer (命令层) ====================

class CrawlCommand implements Command {
    private final CrawlerController controller;
    private final String site;
    private final List<String> targets;

    public CrawlCommand(CrawlerController controller, String site, List<String> targets) {
        this.controller = controller;
        this.site = site;
        this.targets = targets;
    }

    @Override
    public void execute() throws CrawlerException {
        for (String target : targets) {
            switch (site.toLowerCase()) {
                case "douban" -> controller.crawlMovies(target);
                case "news" -> controller.crawlNews(target);
                case "hunanweather" -> controller.crawlWeather(target);
                default -> throw new CrawlerException("Unknown site: " + site);
            }
        }
    }

    @Override
    public String getCommandName() { return "crawl"; }
}

class DefaultCommand implements Command {
    private final CrawlerController controller;

    public DefaultCommand(CrawlerController controller) {
        this.controller = controller;
    }

    @Override
    public void execute() throws CrawlerException {
        controller.crawlAll();
    }

    @Override
    public String getCommandName() { return "default"; }
}

class HelpCommand implements Command {
    private final CrawlerController controller;

    public HelpCommand(CrawlerController controller) {
        this.controller = controller;
    }

    @Override
    public void execute() {
        controller.showHelp();
    }

    @Override
    public String getCommandName() { return "help"; }
}

class ListCommand implements Command {
    private final CrawlerController controller;

    public ListCommand(CrawlerController controller) {
        this.controller = controller;
    }

    @Override
    public void execute() {
        controller.listSites();
    }

    @Override
    public String getCommandName() { return "list"; }
}

class SaveCommand implements Command {
    private final CrawlerController controller;
    private final String filename;

    public SaveCommand(CrawlerController controller, String filename) {
        this.controller = controller;
        this.filename = filename;
    }

    @Override
    public void execute() throws CrawlerException {
        controller.saveConfig(filename);
    }

    @Override
    public String getCommandName() { return "save"; }
}

// ==================== CLI Layer (命令行接口层) ====================

class CLI {
    private final CrawlerController controller;

    public CLI(CrawlerController controller) {
        this.controller = controller;
    }

    public Command parse(String[] args) throws CrawlerException {
        if (args.length == 0) return new DefaultCommand(controller);
        return switch (args[0].toLowerCase()) {
            case "help" -> new HelpCommand(controller);
            case "list" -> new ListCommand(controller);
            case "save" -> {
                if (args.length < 2) throw new CrawlerException("save需要文件名参数");
                yield new SaveCommand(controller, args[1]);
            }
            case "crawl" -> {
                if (args.length < 3) throw new CrawlerException("crawl需要类型和目标参数");
                List<String> targets = Arrays.stream(args, 2, args.length).toList();
                yield new CrawlCommand(controller, args[1], targets);
            }
            default -> throw new CrawlerException("未知命令: " + args[0]);
        };
    }
}

// ==================== Main Entry (主入口) ====================

public class MultiSiteCrawler {
    public static void main(String[] args) {
        CrawlerView view = new ConsoleView();
        CrawlerController controller = new CrawlerController(view);
        CLI cli = new CLI(controller);

        view.showHeader();
        try {
            DataSaver dataSaver = new DataSaver("爬取结果报告.txt");
            controller.setDataSaver(dataSaver);
            
            Command command = cli.parse(args);
            command.execute();
            
            dataSaver.addFooter();
            dataSaver.save();
        } catch (CrawlerException e) {
            view.showError(e.getMessage());
            e.printStackTrace();
        } catch (IOException e) {
            view.showError("保存文件失败: " + e.getMessage());
        }
    }
}