package cloud.tianai.captcha.site;

import java.security.SecureRandom;
import java.util.Base64;
import java.util.Collection;
import java.util.Collections;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

public class SiteManager {

    private final ConcurrentHashMap<String, SiteConfig> sitesBySiteKey = new ConcurrentHashMap<>();
    private final ConcurrentHashMap<String, SiteConfig> sitesBySiteId = new ConcurrentHashMap<>();
    private final SecureRandom random = new SecureRandom();

    public SiteConfig registerSite(String name, Set<String> domains, Set<String> allowedTypes) {
        SiteConfig config = new SiteConfig();
        config.setSiteId(generateId());
        config.setSiteKey(generateKey());
        config.setSecretKey(generateKey());
        config.setName(name);
        config.setDomains(domains);
        config.setAllowedTypes(allowedTypes);

        sitesBySiteKey.put(config.getSiteKey(), config);
        sitesBySiteId.put(config.getSiteId(), config);
        return config;
    }

    public SiteConfig getSiteBySiteKey(String siteKey) {
        return sitesBySiteKey.get(siteKey);
    }

    public SiteConfig getSiteBySiteId(String siteId) {
        return sitesBySiteId.get(siteId);
    }

    public boolean validateSiteKey(String siteKey, String domain) {
        SiteConfig config = sitesBySiteKey.get(siteKey);
        if (config == null || !config.isEnabled()) {
            return false;
        }
        if (domain != null && config.getDomains() != null && !config.getDomains().isEmpty()) {
            return config.getDomains().contains(domain) || config.getDomains().contains("*");
        }
        return true;
    }

    public boolean validateSecretKey(String siteKey, String secretKey) {
        SiteConfig config = sitesBySiteKey.get(siteKey);
        return config != null && config.getSecretKey().equals(secretKey);
    }

    public boolean isTypeAllowed(String siteKey, String type) {
        SiteConfig config = sitesBySiteKey.get(siteKey);
        if (config == null) return false;
        if (config.getAllowedTypes() == null || config.getAllowedTypes().isEmpty()) return true;
        return config.getAllowedTypes().contains(type);
    }

    public void removeSite(String siteKey) {
        SiteConfig config = sitesBySiteKey.remove(siteKey);
        if (config != null) {
            sitesBySiteId.remove(config.getSiteId());
        }
    }

    public Collection<SiteConfig> getAllSites() {
        return Collections.unmodifiableCollection(sitesBySiteKey.values());
    }

    private String generateId() {
        byte[] bytes = new byte[16];
        random.nextBytes(bytes);
        return Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
    }

    private String generateKey() {
        byte[] bytes = new byte[32];
        random.nextBytes(bytes);
        return Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
    }
}