import { useState, useEffect, useCallback } from 'react';
import { adminAPI } from '@/api';

interface Tenant {
  id: string; name: string; slug: string; logo: string; description: string;
  status: string; max_members: number; max_storage_mb: number;
  max_api_calls_per_day: number; member_count?: number; created_at: string; expire_at?: string;
}
interface Member { id: string; user_id: string; username: string; email: string; role: string; status: string; joined_at: string; avatar?: string; }
interface Stats { total_tenants: number; active_tenants: number; suspended_tenants: number; total_members: number; pending_invitations: number; }

const Tenant: React.FC = () => {
  const [tab, setTab] = useState<'list' | 'members' | 'stats'>('list');
  const [tenants, setTenants] = useState<Tenant[]>([]);
  const [total, setTotal] = useState(0);
  const [page, setPage] = useState(1);
  const [loading, setLoading] = useState(false);
  const [stats, setStats] = useState<Stats | null>(null);
  const [members, setMembers] = useState<Member[]>([]);
  const [selectedTenant, setSelectedTenant] = useState<string>('');
  const [showCreate, setShowCreate] = useState(false);
  const [form, setForm] = useState({ name: '', slug: '', description: '', max_members: 10, max_storage_mb: 10240, max_api_calls_per_day: 10000 });

  const fetchTenants = useCallback(async () => {
    setLoading(true);
    try {
      const res = await adminAPI.getTenants(page);
      const d = (res as any)?.data || res;
      setTenants(d?.items || []);
      setTotal(d?.total || 0);
    } catch (e) { console.error('fetchTenants:', e); }
    setLoading(false);
  }, [page]);

  const fetchStats = useCallback(async () => {
    try {
      const res = await adminAPI.getTenantStats();
      setStats((res as any)?.data || res);
    } catch (e) { console.error('fetchStats:', e); }
  }, []);

  const fetchMembers = useCallback(async () => {
    if (!selectedTenant) return;
    try {
      const res = await adminAPI.getTenantMembers(selectedTenant);
      const d = (res as any)?.data || res;
      setMembers(d?.items || []);
    } catch (e) { console.error('fetchMembers:', e); }
  }, [selectedTenant]);

  useEffect(() => { fetchTenants(); fetchStats(); }, [fetchTenants, fetchStats]);
  useEffect(() => { if (tab === 'members' && selectedTenant) fetchMembers(); }, [tab, selectedTenant, fetchMembers]);

  const handleCreate = async () => {
    try {
      const params = `?name=${encodeURIComponent(form.name)}&slug=${encodeURIComponent(form.slug)}&description=${encodeURIComponent(form.description)}&max_members=${form.max_members}&max_storage_mb=${form.max_storage_mb}&max_api_calls_per_day=${form.max_api_calls_per_day}`;
      await adminAPI.createTenant(params);
      setShowCreate(false);
      setForm({ name: '', slug: '', description: '', max_members: 10, max_storage_mb: 10240, max_api_calls_per_day: 10000 });
      fetchTenants();
    } catch (e) { console.error('create:', e); }
  };

  const statusColors: Record<string, string> = { active: '#10b981', suspended: '#f59e0b', terminated: '#ef4444' };
  const roleColors: Record<string, string> = { owner: '#a78bfa', admin: '#60a5fa', member: '#94a3b8', viewer: '#64748b' };

  return (
    <div style={{ padding: '24px', color: '#e2e8f0' }}>
      <h1 style={{ fontSize: '24px', fontWeight: 700, marginBottom: '24px' }}>多租户管理</h1>

      {/* Stats cards */}
      {stats && (
        <div style={{ display: 'grid', gridTemplateColumns: 'repeat(5, 1fr)', gap: '16px', marginBottom: '24px' }}>
          {[
            { label: '总租户数', value: stats.total_tenants, color: '#6366f1' },
            { label: '活跃租户', value: stats.active_tenants, color: '#10b981' },
            { label: '已暂停', value: stats.suspended_tenants, color: '#f59e0b' },
            { label: '总成员数', value: stats.total_members, color: '#3b82f6' },
            { label: '待处理邀请', value: stats.pending_invitations, color: '#ec4899' },
          ].map((s, i) => (
            <div key={i} style={{ background: '#1e293b', borderRadius: '12px', padding: '20px', border: `1px solid ${s.color}33` }}>
              <div style={{ fontSize: '32px', fontWeight: 800, color: s.color }}>{s.value}</div>
              <div style={{ fontSize: '13px', color: '#94a3b8', marginTop: '4px' }}>{s.label}</div>
            </div>
          ))}
        </div>
      )}

      {/* Tabs */}
      <div style={{ display: 'flex', gap: '8px', marginBottom: '20px' }}>
        {([['list', '租户列表'], ['members', '成员管理'], ['stats', '统计详情']] as const).map(([k, label]) => (
          <button key={k} onClick={() => setTab(k)}
            style={{ padding: '8px 20px', borderRadius: '8px', border: 'none', cursor: 'pointer',
              background: tab === k ? '#6366f1' : '#1e293b', color: tab === k ? '#fff' : '#94a3b8',
              fontWeight: 600, fontSize: '14px' }}>{label}</button>
        ))}
        {tab === 'list' && (
          <button onClick={() => setShowCreate(true)} style={{ marginLeft: 'auto', padding: '8px 20px', borderRadius: '8px',
            border: 'none', cursor: 'pointer', background: '#6366f1', color: '#fff', fontWeight: 600, fontSize: '14px' }}>
            + 创建租户
          </button>
        )}
      </div>

      {/* Tab content */}
      {tab === 'list' && (
        <div>
          {loading ? <div style={{ textAlign: 'center', padding: '40px', color: '#64748b' }}>加载中...</div> : (
            <table style={{ width: '100%', borderCollapse: 'collapse', background: '#1e293b', borderRadius: '12px', overflow: 'hidden' }}>
              <thead>
                <tr style={{ background: '#0f172a' }}>
                  {['租户名称', '标识', '状态', '成员数', '存储上限', 'API/天', '创建时间', '操作'].map(h => (
                    <th key={h} style={{ padding: '12px 16px', textAlign: 'left', fontSize: '13px', color: '#94a3b8', fontWeight: 600 }}>{h}</th>
                  ))}
                </tr>
              </thead>
              <tbody>
                {tenants.map(t => (
                  <tr key={t.id} style={{ borderBottom: '1px solid #334155' }}>
                    <td style={{ padding: '12px 16px', fontSize: '14px', fontWeight: 600 }}>{t.name}</td>
                    <td style={{ padding: '12px 16px', fontSize: '13px', color: '#94a3b8' }}>{t.slug}</td>
                    <td style={{ padding: '12px 16px' }}>
                      <span style={{ padding: '2px 10px', borderRadius: '12px', fontSize: '12px', fontWeight: 600,
                        background: `${statusColors[t.status]}22`, color: statusColors[t.status] }}>{t.status}</span>
                    </td>
                    <td style={{ padding: '12px 16px', fontSize: '14px' }}>{t.member_count ?? '-'}</td>
                    <td style={{ padding: '12px 16px', fontSize: '13px', color: '#94a3b8' }}>{(t.max_storage_mb / 1024).toFixed(1)} GB</td>
                    <td style={{ padding: '12px 16px', fontSize: '13px', color: '#94a3b8' }}>{t.max_api_calls_per_day.toLocaleString()}</td>
                    <td style={{ padding: '12px 16px', fontSize: '13px', color: '#64748b' }}>{t.created_at?.substring(0, 10)}</td>
                    <td style={{ padding: '12px 16px' }}>
                      <button onClick={() => { setSelectedTenant(t.id); setTab('members'); }}
                        style={{ padding: '4px 12px', borderRadius: '6px', border: '1px solid #475569',
                          background: 'transparent', color: '#94a3b8', cursor: 'pointer', fontSize: '12px' }}>管理</button>
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          )}
          {total > 20 && (
            <div style={{ display: 'flex', justifyContent: 'center', gap: '8px', marginTop: '20px' }}>
              <button onClick={() => setPage(p => Math.max(1, p - 1))} disabled={page <= 1}
                style={{ padding: '6px 16px', borderRadius: '6px', border: '1px solid #475569', background: '#1e293b', color: '#94a3b8', cursor: page <= 1 ? 'not-allowed' : 'pointer' }}>上一页</button>
              <span style={{ padding: '6px 16px', color: '#94a3b8' }}>第 {page} 页</span>
              <button onClick={() => setPage(p => p + 1)} disabled={page * 20 >= total}
                style={{ padding: '6px 16px', borderRadius: '6px', border: '1px solid #475569', background: '#1e293b', color: '#94a3b8', cursor: page * 20 >= total ? 'not-allowed' : 'pointer' }}>下一页</button>
            </div>
          )}
        </div>
      )}

      {tab === 'members' && (
        <div>
          <div style={{ marginBottom: '16px' }}>
            <select value={selectedTenant} onChange={e => setSelectedTenant(e.target.value)}
              style={{ padding: '8px 12px', borderRadius: '8px', background: '#1e293b', color: '#e2e8f0', border: '1px solid #475569', fontSize: '14px' }}>
              <option value="">选择租户...</option>
              {tenants.map(t => <option key={t.id} value={t.id}>{t.name}</option>)}
            </select>
          </div>
          {selectedTenant && (
            <table style={{ width: '100%', borderCollapse: 'collapse', background: '#1e293b', borderRadius: '12px', overflow: 'hidden' }}>
              <thead>
                <tr style={{ background: '#0f172a' }}>
                  {['用户名', '邮箱', '角色', '状态', '加入时间'].map(h => (
                    <th key={h} style={{ padding: '12px 16px', textAlign: 'left', fontSize: '13px', color: '#94a3b8', fontWeight: 600 }}>{h}</th>
                  ))}
                </tr>
              </thead>
              <tbody>
                {members.map(m => (
                  <tr key={m.id} style={{ borderBottom: '1px solid #334155' }}>
                    <td style={{ padding: '12px 16px', fontSize: '14px', fontWeight: 600 }}>{m.username || m.user_id.substring(0, 8)}</td>
                    <td style={{ padding: '12px 16px', fontSize: '13px', color: '#94a3b8' }}>{m.email || '-'}</td>
                    <td style={{ padding: '12px 16px' }}>
                      <span style={{ padding: '2px 10px', borderRadius: '12px', fontSize: '12px', fontWeight: 600,
                        background: `${roleColors[m.role]}22`, color: roleColors[m.role] }}>{m.role}</span>
                    </td>
                    <td style={{ padding: '12px 16px' }}>
                      <span style={{ color: m.status === 'active' ? '#10b981' : '#ef4444', fontSize: '13px' }}>{m.status}</span>
                    </td>
                    <td style={{ padding: '12px 16px', fontSize: '13px', color: '#64748b' }}>{m.joined_at?.substring(0, 16)}</td>
                  </tr>
                ))}
              </tbody>
            </table>
          )}
        </div>
      )}

      {tab === 'stats' && stats && (
        <div style={{ background: '#1e293b', borderRadius: '12px', padding: '32px' }}>
          <div style={{ display: 'grid', gridTemplateColumns: 'repeat(2, 1fr)', gap: '24px' }}>
            {Object.entries(stats).map(([k, v]) => (
              <div key={k} style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', padding: '16px', background: '#0f172a', borderRadius: '8px' }}>
                <span style={{ fontSize: '14px', color: '#94a3b8' }}>{k.replace(/_/g, ' ').toUpperCase()}</span>
                <span style={{ fontSize: '24px', fontWeight: 800, color: '#6366f1' }}>{String(v)}</span>
              </div>
            ))}
          </div>
        </div>
      )}

      {/* Create modal */}
      {showCreate && (
        <div style={{ position: 'fixed', inset: 0, background: 'rgba(0,0,0,0.6)', display: 'flex', alignItems: 'center', justifyContent: 'center', zIndex: 1000 }}
          onClick={() => setShowCreate(false)}>
          <div onClick={e => e.stopPropagation()} style={{ background: '#1e293b', borderRadius: '16px', padding: '32px', width: '480px', maxWidth: '90vw' }}>
            <h2 style={{ fontSize: '20px', fontWeight: 700, marginBottom: '24px' }}>创建租户</h2>
            {[
              { k: 'name', label: '租户名称', type: 'text' },
              { k: 'slug', label: '标识(英文)', type: 'text' },
              { k: 'description', label: '描述', type: 'text' },
              { k: 'max_members', label: '最大成员数', type: 'number' },
              { k: 'max_storage_mb', label: '存储上限(MB)', type: 'number' },
              { k: 'max_api_calls_per_day', label: 'API调用/天', type: 'number' },
            ].map(f => (
              <div key={f.k} style={{ marginBottom: '16px' }}>
                <label style={{ display: 'block', fontSize: '13px', color: '#94a3b8', marginBottom: '6px' }}>{f.label}</label>
                <input type={f.type} value={(form as any)[f.k]} onChange={e => setForm({ ...form, [f.k]: f.type === 'number' ? Number(e.target.value) : e.target.value })}
                  style={{ width: '100%', padding: '10px 12px', borderRadius: '8px', background: '#0f172a', color: '#e2e8f0', border: '1px solid #475569', fontSize: '14px', boxSizing: 'border-box' }} />
              </div>
            ))}
            <div style={{ display: 'flex', gap: '12px', marginTop: '24px' }}>
              <button onClick={() => setShowCreate(false)} style={{ flex: 1, padding: '10px', borderRadius: '8px', border: '1px solid #475569', background: 'transparent', color: '#94a3b8', cursor: 'pointer', fontSize: '14px' }}>取消</button>
              <button onClick={handleCreate} style={{ flex: 1, padding: '10px', borderRadius: '8px', border: 'none', background: '#6366f1', color: '#fff', cursor: 'pointer', fontSize: '14px', fontWeight: 600 }}>创建</button>
            </div>
          </div>
        </div>
      )}
    </div>
  );
};

export default Tenant;