import { useState, useEffect, useCallback } from 'react';
import { useParams, useNavigate } from 'react-router-dom';
import type { ServiceCatalog, ServiceApiItem } from '../../types/apihub';
import { getServiceCatalog } from '../../services/apiHubService';

const METHOD_COLORS: Record<string, string> = {
  GET: 'bg-green-100 text-green-700 dark:bg-green-900 dark:text-green-300',
  POST: 'bg-blue-100 text-blue-700 dark:bg-blue-900 dark:text-blue-300',
  PUT: 'bg-amber-100 text-amber-700 dark:bg-amber-900 dark:text-amber-300',
  PATCH: 'bg-amber-100 text-amber-700 dark:bg-amber-900 dark:text-amber-300',
  DELETE: 'bg-red-100 text-red-700 dark:bg-red-900 dark:text-red-300',
};

const HEALTH_DOT: Record<string, string> = {
  UP: 'bg-green-500',
  DOWN: 'bg-red-500',
  UNKNOWN: 'bg-gray-400',
};

const HEALTH_BADGE: Record<string, string> = {
  UP: 'bg-green-100 text-green-700 dark:bg-green-900 dark:text-green-300',
  DOWN: 'bg-red-100 text-red-700 dark:bg-red-900 dark:text-red-300',
  UNKNOWN: 'bg-gray-100 text-gray-600 dark:bg-gray-700 dark:text-gray-300',
};

const HEALTH_LABEL: Record<string, string> = {
  UP: '정상',
  DOWN: '중단',
  UNKNOWN: '알 수 없음',
};

interface DomainSectionProps {
  domainName: string;
  apis: ServiceApiItem[];
  serviceId: number;
  onNavigate: (serviceId: number, apiId: number) => void;
}

const DomainSection = ({ domainName, apis, serviceId, onNavigate }: DomainSectionProps) => (
  <div className="mb-6">
    <div className="flex items-center gap-3 mb-3">
      <h3 className="text-base font-semibold text-[var(--color-text-primary)]">{domainName}</h3>
      <span className="text-xs px-2 py-0.5 rounded-full bg-[var(--color-bg-base)] text-[var(--color-text-secondary)]">
        {apis.length}개
      </span>
    </div>
    <div className="bg-[var(--color-bg-surface)] rounded-lg shadow overflow-hidden border border-[var(--color-border)]">
      <table className="w-full text-sm table-fixed">
        <colgroup>
          <col className="w-[8%]" />
          <col className="w-[27%]" />
          <col className="w-[20%]" />
          <col className="w-[40%]" />
          <col className="w-[5%]" />
        </colgroup>
        <thead className="bg-[var(--color-bg-base)]">
          <tr>
            <th className="px-4 py-3 text-left text-xs font-medium text-[var(--color-text-secondary)] uppercase">메서드</th>
            <th className="px-4 py-3 text-left text-xs font-medium text-[var(--color-text-secondary)] uppercase">경로</th>
            <th className="px-4 py-3 text-left text-xs font-medium text-[var(--color-text-secondary)] uppercase">API명</th>
            <th className="px-4 py-3 text-left text-xs font-medium text-[var(--color-text-secondary)] uppercase">설명</th>
            <th className="px-4 py-3 text-left text-xs font-medium text-[var(--color-text-secondary)] uppercase">상태</th>
          </tr>
        </thead>
        <tbody className="divide-y divide-[var(--color-border)]">
          {apis.map((api) => (
            <tr
              key={api.apiId}
              className="hover:bg-blue-50 dark:hover:bg-gray-700 cursor-pointer transition-colors"
              onClick={() => onNavigate(serviceId, api.apiId)}
            >
              <td className="px-4 py-3">
                <span
                  className={`inline-block px-2 py-0.5 rounded text-xs font-bold uppercase ${METHOD_COLORS[api.apiMethod] ?? 'bg-gray-100 text-gray-600 dark:bg-gray-700 dark:text-gray-300'}`}
                >
                  {api.apiMethod}
                </span>
              </td>
              <td className="px-4 py-3 font-mono text-xs text-[var(--color-text-primary)] truncate" title={api.apiPath}>
                {api.apiPath}
              </td>
              <td className="px-4 py-3 text-[var(--color-text-primary)] font-medium truncate" title={api.apiName}>
                {api.apiName}
              </td>
              <td className="px-4 py-3 text-[var(--color-text-secondary)] truncate" title={api.description || ''}>
                {api.description || <span className="text-[var(--color-text-tertiary)]">-</span>}
              </td>
              <td className="px-4 py-3">
                {api.isActive ? (
                  <span className="inline-block w-2 h-2 rounded-full bg-green-500" title="활성" />
                ) : (
                  <span className="inline-block w-2 h-2 rounded-full bg-gray-300 dark:bg-gray-600" title="비활성" />
                )}
              </td>
            </tr>
          ))}
        </tbody>
      </table>
    </div>
  </div>
);

const ApiHubServicePage = () => {
  const { serviceId } = useParams<{ serviceId: string }>();
  const navigate = useNavigate();
  const [service, setService] = useState<ServiceCatalog | null>(null);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  const fetchData = useCallback(async () => {
    if (!serviceId) return;
    try {
      const res = await getServiceCatalog(Number(serviceId));
      if (res.success && res.data) {
        setService(res.data);
      } else {
        setError('서비스 정보를 불러오지 못했습니다');
      }
    } catch {
      setError('서비스 정보를 불러오는 중 오류가 발생했습니다');
    } finally {
      setIsLoading(false);
    }
  }, [serviceId]);

  useEffect(() => {
    fetchData();
  }, [fetchData]);

  const handleApiNavigate = (svcId: number, apiId: number) => {
    navigate(`/api-hub/services/${svcId}/apis/${apiId}`);
  };

  if (isLoading) {
    return (
      <div className="flex items-center justify-center h-64">
        <div className="text-[var(--color-text-secondary)]">로딩 중...</div>
      </div>
    );
  }

  if (error || !service) {
    return (
      <div>
        <button
          onClick={() => navigate('/api-hub')}
          className="text-sm text-[var(--color-primary)] hover:text-blue-800 mb-4 inline-block"
        >
          ← API HUB으로
        </button>
        <div className="text-center py-20 text-[var(--color-text-secondary)]">
          {error ?? '서비스를 찾을 수 없습니다'}
        </div>
      </div>
    );
  }

  const domainsMap = new Map<string, ServiceApiItem[]>();
  for (const dg of service.domains) {
    const key = dg.domain ? dg.domain.toUpperCase() : '기타';
    domainsMap.set(key, dg.apis);
  }

  // If any apis fall under null domain and weren't covered by domains array, show them under 기타
  const domainEntries = [...domainsMap.entries()];

  return (
    <div className="max-w-7xl mx-auto">
      <button
        onClick={() => navigate('/api-hub')}
        className="text-sm text-[var(--color-primary)] hover:text-blue-800 mb-4 inline-block"
      >
        ← API HUB으로
      </button>

      {/* Service Header */}
      <div className="bg-[var(--color-bg-surface)] rounded-lg shadow p-6 mb-6 border border-[var(--color-border)]">
        <div className="flex items-start justify-between">
          <div className="flex-1 min-w-0">
            <div className="flex items-center gap-3 mb-1">
              <h1 className="text-2xl font-bold text-[var(--color-text-primary)]">{service.serviceName}</h1>
              <span className="text-sm text-[var(--color-text-secondary)] font-mono">{service.serviceCode}</span>
            </div>
            {service.description && (
              <p className="text-[var(--color-text-secondary)] mt-2">{service.description}</p>
            )}
          </div>
          <div className="flex flex-col items-end gap-2 ml-6 shrink-0">
            <span
              className={`flex items-center gap-1.5 px-3 py-1 rounded-full text-sm font-medium ${HEALTH_BADGE[service.healthStatus] ?? 'bg-gray-100 text-gray-600 dark:bg-gray-700 dark:text-gray-300'}`}
            >
              <span className={`w-2 h-2 rounded-full ${HEALTH_DOT[service.healthStatus] ?? 'bg-gray-400'}`} />
              {HEALTH_LABEL[service.healthStatus] ?? service.healthStatus}
            </span>
            <div className="flex items-center gap-4 text-sm text-[var(--color-text-secondary)]">
              <span>API {service.apiCount}개</span>
              <span>도메인 {service.domains.length}개</span>
            </div>
          </div>
        </div>
      </div>

      {/* API 목록 by Domain */}
      {domainEntries.length > 0 ? (
        domainEntries.map(([domain, apis]) => (
          <DomainSection
            key={domain}
            domainName={domain}
            apis={apis}
            serviceId={service.serviceId}
            onNavigate={handleApiNavigate}
          />
        ))
      ) : (
        <div className="bg-[var(--color-bg-surface)] rounded-lg shadow p-8 text-center text-[var(--color-text-tertiary)]">
          등록된 API가 없습니다
        </div>
      )}
    </div>
  );
};

export default ApiHubServicePage;