package strategy;

import java.util.HashMap;
import java.util.Map;
import java.util.function.Supplier;

public class CrawlStrategyFactory {
    private static final Map<String, Supplier<CrawlStrategy>> strategyMap = new HashMap<>();

    static {
        strategyMap.put("dangdang", DangDangStrategy::new);
        strategyMap.put("weather", WeatherStrategy::new);
        strategyMap.put("maoyan", MovieStrategy::new);
        strategyMap.put("12306", Train12306Strategy::new);
        strategyMap.put("csdn", CsdnBlogStrategy::new);
    }

    public static CrawlStrategy getStrategy(String name) {
        Supplier<CrawlStrategy> supplier = strategyMap.get(name.toLowerCase());
        if (supplier == null) {
            throw new IllegalArgumentException("Unknown strategy: " + name);
        }
        return supplier.get();
    }

    public static <T extends CrawlStrategy> CrawlStrategy getStrategy(Class<T> strategyClass) {
        try {
            return strategyClass.getDeclaredConstructor().newInstance();
        } catch (Exception e) {
            throw new IllegalArgumentException("Cannot instantiate strategy: " + strategyClass.getName(), e);
        }
    }

    public static void registerStrategy(String name, Supplier<CrawlStrategy> supplier) {
        if (name == null || supplier == null) {
            throw new IllegalArgumentException("Name and supplier cannot be null");
        }
        strategyMap.put(name.toLowerCase(), supplier);
    }

    public static boolean hasStrategy(String name) {
        return strategyMap.containsKey(name.toLowerCase());
    }

    public static int getStrategyCount() {
        return strategyMap.size();
    }

    public static String[] getStrategyNames() {
        return strategyMap.keySet().toArray(new String[0]);
    }
}