import React, { useState, useEffect } from 'react';
import { Key, Loader2, Plus, Trash2, Copy, CheckCircle2, Building2 } from 'lucide-react';
import { getApiKeys, createApiKey, deleteApiKey, getTenants } from '../services/dataService';
import { Tenant } from '../types';

export const ApiKeys: React.FC = () => {
  const [tenants, setTenants] = useState<Tenant[]>([]);
  const [selectedTenantId, setSelectedTenantId] = useState<string>('');
  const [apiKeys, setApiKeys] = useState<any[]>([]);
  const [loading, setLoading] = useState(true);
  
  const [newKeyName, setNewKeyName] = useState('');
  const [isGeneratingKey, setIsGeneratingKey] = useState(false);
  const [generatedKey, setGeneratedKey] = useState<string | null>(null);

  useEffect(() => {
    const fetchInitialData = async () => {
      try {
        const fetchedTenants = await getTenants();
        setTenants(fetchedTenants);
        if (fetchedTenants.length > 0) {
          const defaultTenant = fetchedTenants.find(t => t.id !== 'system') || fetchedTenants[0];
          setSelectedTenantId(defaultTenant.id);
        }
      } catch (err) {
        console.error("Failed to load tenants", err);
      } finally {
        setLoading(false);
      }
    };
    fetchInitialData();
  }, []);

  useEffect(() => {
    if (selectedTenantId) {
      loadApiKeys(selectedTenantId);
      setGeneratedKey(null);
    }
  }, [selectedTenantId]);

  const loadApiKeys = async (tenantId: string) => {
    setLoading(true);
    try {
      const keys = await getApiKeys(tenantId);
      setApiKeys(keys);
    } catch (e) {
      console.error("Failed to load API keys", e);
    } finally {
      setLoading(false);
    }
  };

  const handleGenerateApiKey = async () => {
    if (!newKeyName.trim() || !selectedTenantId) return;
    setIsGeneratingKey(true);
    try {
      const res = await createApiKey({ name: newKeyName, tenantId: selectedTenantId });
      setGeneratedKey(res.secret_key);
      setNewKeyName('');
      loadApiKeys(selectedTenantId);
    } catch (err: any) {
      alert(err.message || 'Erro ao gerar chave.');
    } finally {
      setIsGeneratingKey(false);
    }
  };

  const handleRevokeApiKey = async (id: string) => {
    if (!selectedTenantId) return;
    if (confirm('Tem certeza? Todas as integrações usando esta chave pararão de funcionar imediatamente.')) {
      const success = await deleteApiKey(id);
      if (success) {
        loadApiKeys(selectedTenantId);
      }
    }
  };

  const copyToClipboard = (text: string) => {
    navigator.clipboard.writeText(text);
    alert('Chave copiada para a área de transferência!');
  };

  return (
    <div className="max-w-4xl mx-auto space-y-6 pb-12 transition-colors duration-300">
      <div className="flex flex-col sm:flex-row justify-between items-start sm:items-center gap-4">
        <div>
          <h1 className="text-2xl font-bold text-zinc-900 dark:text-zinc-50 tracking-tight">Integrações via API</h1>
          <p className="text-zinc-500 dark:text-zinc-400 text-sm">Gerencie chaves de API para permitir que sistemas externos como o n8n se conectem a organizações específicas.</p>
        </div>
      </div>

      <div className="bg-white dark:bg-dark-card rounded-2xl border border-zinc-200 dark:border-dark-border shadow-sm overflow-hidden p-6 md:p-8">
        <div className="flex flex-col md:flex-row gap-6 mb-8">
          <div className="flex-1">
            <label className="text-xs font-bold text-zinc-500 dark:text-dark-muted uppercase tracking-wider mb-2 block">Selecione a Organização</label>
            <div className="relative">
              <select
                value={selectedTenantId}
                onChange={(e) => setSelectedTenantId(e.target.value)}
                className="w-full appearance-none bg-zinc-50 dark:bg-dark-input border border-zinc-200 dark:border-dark-border px-4 py-3 pr-10 rounded-xl text-sm text-zinc-900 dark:text-zinc-100 focus:ring-2 focus:ring-brand-yellow/20 outline-none transition-all cursor-pointer font-medium"
              >
                {tenants.filter(t => t.id !== 'system').map(t => (
                  <option key={t.id} value={t.id}>{t.name}</option>
                ))}
              </select>
              <div className="pointer-events-none absolute inset-y-0 right-0 flex items-center px-4 text-zinc-500">
                <Building2 size={16} />
              </div>
            </div>
          </div>
        </div>

        {generatedKey && (
          <div className="mb-8 p-4 bg-green-50 dark:bg-green-900/20 border border-green-200 dark:border-green-800 rounded-xl animate-in fade-in zoom-in duration-200">
            <h4 className="font-bold text-green-800 dark:text-green-300 flex items-center gap-2 mb-2">
              <CheckCircle2 size={18} /> Chave Gerada com Sucesso!
            </h4>
            <p className="text-sm text-green-700 dark:text-green-400 mb-3">
              Copie esta chave agora. Por motivos de segurança, ela <strong>não</strong> será exibida novamente.
            </p>
            <div className="flex items-center gap-2">
              <code className="flex-1 bg-white dark:bg-zinc-950 p-3 rounded-lg text-sm font-mono text-zinc-800 dark:text-zinc-200 border border-green-200 dark:border-green-800 break-all shadow-inner">
                {generatedKey}
              </code>
              <button onClick={() => copyToClipboard(generatedKey)} className="p-3 bg-white dark:bg-zinc-950 border border-green-200 dark:border-green-800 rounded-lg hover:bg-green-100 dark:hover:bg-zinc-800 text-green-700 dark:text-green-400 transition-colors shadow-sm" title="Copiar">
                <Copy size={18} />
              </button>
            </div>
          </div>
        )}

        <div className="flex flex-col sm:flex-row gap-3 mb-8">
          <input
            type="text"
            placeholder="Nome da integração (ex: Webhook n8n - WhatsApp)"
            value={newKeyName}
            onChange={(e) => setNewKeyName(e.target.value)}
            className="flex-1 p-3 border border-zinc-200 dark:border-dark-border rounded-xl bg-zinc-50 dark:bg-dark-input text-zinc-900 dark:text-zinc-100 placeholder-zinc-400 dark:placeholder-zinc-600 focus:outline-none focus:ring-2 focus:ring-brand-yellow/20 focus:border-brand-yellow sm:text-sm transition-all"
          />
          <button
            onClick={handleGenerateApiKey}
            disabled={isGeneratingKey || !newKeyName.trim() || !selectedTenantId}
            className="px-6 py-3 bg-zinc-900 dark:bg-brand-yellow text-white dark:text-zinc-950 rounded-xl font-bold flex items-center justify-center gap-2 hover:opacity-90 transition-opacity disabled:opacity-50 shrink-0 shadow-sm"
          >
            {isGeneratingKey ? <Loader2 className="animate-spin" size={18} /> : <Plus size={18} />}
            Gerar Nova Chave
          </button>
        </div>

        {loading ? (
          <div className="flex justify-center p-8"><Loader2 className="animate-spin text-zinc-400" size={32} /></div>
        ) : apiKeys.length > 0 ? (
          <div className="overflow-x-auto rounded-xl border border-zinc-200 dark:border-dark-border">
            <table className="w-full text-left border-collapse">
              <thead>
                <tr className="bg-zinc-50/80 dark:bg-dark-bg/80 border-b border-zinc-200 dark:border-dark-border">
                  <th className="py-3 px-4 text-xs font-bold text-zinc-500 dark:text-zinc-400 uppercase tracking-wider">Nome da Integração</th>
                  <th className="py-3 px-4 text-xs font-bold text-zinc-500 dark:text-zinc-400 uppercase tracking-wider">Chave (Mascarada)</th>
                  <th className="py-3 px-4 text-xs font-bold text-zinc-500 dark:text-zinc-400 uppercase tracking-wider">Último Uso</th>
                  <th className="py-3 px-4 text-xs font-bold text-zinc-500 dark:text-zinc-400 uppercase tracking-wider text-right">Ações</th>
                </tr>
              </thead>
              <tbody className="divide-y divide-zinc-100 dark:divide-dark-border/50 bg-white dark:bg-dark-card">
                {apiKeys.map(key => (
                  <tr key={key.id} className="hover:bg-zinc-50 dark:hover:bg-dark-input/50 transition-colors">
                    <td className="py-3 px-4 text-sm font-medium text-zinc-900 dark:text-zinc-100 flex items-center gap-2">
                      <Key size={14} className="text-brand-yellow" />
                      {key.name}
                    </td>
                    <td className="py-3 px-4 text-sm font-mono text-zinc-500 dark:text-zinc-400">{key.masked_key}</td>
                    <td className="py-3 px-4 text-xs text-zinc-500 dark:text-zinc-400">
                      {key.last_used_at ? new Date(key.last_used_at).toLocaleString('pt-BR') : 'Nunca'}
                    </td>
                    <td className="py-3 px-4 text-right">
                      <button 
                        onClick={() => handleRevokeApiKey(key.id)}
                        className="p-2 text-zinc-400 hover:text-red-500 hover:bg-red-50 dark:hover:bg-red-900/20 rounded-lg transition-colors inline-flex"
                        title="Revogar Chave"
                      >
                        <Trash2 size={16} />
                      </button>
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        ) : (
          <div className="text-center p-12 border-2 border-dashed border-zinc-200 dark:border-dark-border rounded-xl text-zinc-500 dark:text-zinc-400 bg-zinc-50/30 dark:bg-dark-bg/30">
            <Key size={32} className="mx-auto mb-3 opacity-20" />
            <p className="font-medium text-zinc-600 dark:text-zinc-300">Nenhuma chave de API gerada</p>
            <p className="text-xs mt-1">Crie uma nova chave para conectar sistemas externos a esta organização.</p>
          </div>
        )}
      </div>
    </div>
  );
};