'use client';

import { useQuery } from '@tanstack/react-query';
import Link from 'next/link';
import api from '@/lib/api';
import type { Application } from '@/types';
import { managedServiceTypeLabel } from '@/lib/optional-service-defaults';
import { Database, Plus, AlertTriangle, Clock } from 'lucide-react';
import { useConfirm } from '@/components/confirm-modal';
import { DeleteButtonLabel } from '@/components/delete-button-label';
import { DeletingCardOverlay, deletingResourceMessage } from '@/components/deleting-overlay';
import { filterManagedServices } from '@/lib/product-type';
import { useApplicationDelete } from '@/lib/use-application-delete';

const lifecycleColors: Record<string, string> = {
  active: 'text-green-600 bg-green-50',
  suspended: 'text-amber-700 bg-amber-50',
  pending_deletion: 'text-red-700 bg-red-50',
  deleted: 'text-gray-500 bg-gray-100',
};

const lifecycleLabels: Record<string, string> = {
  active: 'Active',
  suspended: 'Suspended — Unpaid',
  pending_deletion: 'Pending Deletion',
  deleted: 'Deleted',
};

function serviceSubtitle(app: Application): string {
  if (app.productType === 'managed_database') {
    return `${app.databaseType}${app.dbVersion ? ` v${app.dbVersion}` : ''}`;
  }
  if (app.productType === 'managed_redis') {
    return `Redis${app.redisVersion ? ` v${app.redisVersion}` : ''}`;
  }
  if (app.productType === 'managed_rabbitmq') {
    return `RabbitMQ${app.rabbitmqVersion ? ` v${app.rabbitmqVersion}` : ''}`;
  }
  return app.databaseType !== 'none' ? app.databaseType : '—';
}

function formatExpiry(expiresAt?: string): { text: string; urgent: boolean } {
  if (!expiresAt) return { text: '—', urgent: false };
  const diff = new Date(expiresAt).getTime() - Date.now();
  if (diff <= 0) return { text: 'Expired', urgent: true };
  const hours = Math.floor(diff / 3600000);
  const days = Math.floor(hours / 24);
  if (days > 0) return { text: `${days}d ${hours % 24}h remaining`, urgent: days < 3 };
  if (hours > 0) return { text: `${hours}h remaining`, urgent: hours < 6 };
  const mins = Math.floor(diff / 60000);
  return { text: `${mins}m remaining`, urgent: true };
}

export default function ServicesPage() {
  const confirm = useConfirm();

  const { data: servicesRaw = [], isLoading } = useQuery<Application[]>({
    queryKey: ['applications', 'managed'],
    queryFn: () => api.get('/applications', { params: { productType: 'managed' } }).then((r) => r.data),
  });
  const services = filterManagedServices(servicesRaw);

  const { deleteApplication, isDeleting, isAnyDeleting } = useApplicationDelete({
    invalidateKeys: [['applications', 'managed']],
    successMessage: 'Service deleted',
    successWithCreditMessage: 'Service deleted. Prepaid resources are on your dashboard.',
  });

  if (isLoading) {
    return (
      <div className="space-y-6">
        <div className="page-header">
          <div className="skeleton h-8 w-56" />
          <div className="skeleton h-10 w-40 rounded-xl" />
        </div>
        <div className="space-y-3">
          {[1, 2, 3].map((i) => (
            <div key={i} className="card flex items-center gap-4">
              <div className="skeleton w-11 h-11 rounded-xl" />
              <div className="flex-1 space-y-2">
                <div className="skeleton h-4 w-36" />
                <div className="skeleton h-3 w-48" />
              </div>
            </div>
          ))}
        </div>
      </div>
    );
  }

  return (
    <div className="space-y-6">
      <div className="page-header">
        <div>
          <h1 className="page-title">Databases & Services</h1>
          <p className="page-subtitle">
            Standalone databases, Redis, and RabbitMQ — {services.length} service{services.length !== 1 ? 's' : ''}
          </p>
        </div>
        <Link href="/dashboard/services/new" className="btn-primary">
          <Plus className="w-4 h-4 mr-1 inline" /> New Service
        </Link>
      </div>

      {services.length === 0 ? (
        <div className="card text-center py-16">
          <Database className="w-12 h-12 mx-auto mb-4 text-gray-300" />
          <p className="text-gray-600 text-lg font-medium">No managed services yet</p>
          <p className="text-gray-400 mt-1 text-sm">
            Provision a database, Redis, or RabbitMQ without deploying a full application.
          </p>
          <Link href="/dashboard/services/new" className="btn-primary mt-6 inline-flex items-center gap-1">
            <Plus className="w-4 h-4" /> Create your first service
          </Link>
        </div>
      ) : (
        <div className="space-y-3">
          {services.map((svc) => {
            const lifecycle = svc.lifecycleStatus || 'active';
            const expiry = formatExpiry(svc.planExpiresAt);
            const latestStatus = svc.deployments?.[0]?.status || 'pending';
            const cardDeleting = isDeleting(svc.id);
            return (
              <div
                key={svc.id}
                className={`relative card-hover flex flex-col sm:flex-row sm:items-center gap-4 ${
                  lifecycle === 'suspended' ? 'border-l-4 border-l-amber-400' : ''
                } ${lifecycle === 'pending_deletion' ? 'border-l-4 border-l-red-400' : ''} ${cardDeleting ? 'bg-gray-50' : ''}`}
              >
                {cardDeleting && (
                  <DeletingCardOverlay message={deletingResourceMessage('service', svc.name)} />
                )}
                <Link href={`/dashboard/services/${svc.id}`} className="flex items-center gap-3 flex-1 min-w-0 group">
                  <div className="w-10 h-10 rounded-lg bg-indigo-50 flex items-center justify-center shrink-0">
                    <Database className="w-5 h-5 text-indigo-600" />
                  </div>
                  <div className="min-w-0">
                    <p className="font-semibold text-gray-900 group-hover:text-primary-600 truncate">{svc.name}</p>
                    <p className="text-sm text-gray-500">
                      {managedServiceTypeLabel(svc.productType)} · {serviceSubtitle(svc)}
                    </p>
                  </div>
                </Link>
                <div className="flex flex-wrap items-center gap-2 sm:gap-3">
                  <span className={`badge ${latestStatus === 'running' ? 'badge-green' : 'badge-yellow'}`}>
                    {latestStatus}
                  </span>
                  <span
                    className={`inline-flex items-center gap-1 px-2 py-0.5 rounded-full text-xs font-semibold ${
                      lifecycleColors[lifecycle] || 'text-gray-500 bg-gray-100'
                    }`}
                  >
                    {lifecycle === 'suspended' && <AlertTriangle className="w-3 h-3" />}
                    {lifecycleLabels[lifecycle] || lifecycle}
                  </span>
                  <span className={`text-xs ${expiry.urgent ? 'text-red-600 font-semibold' : 'text-gray-500'}`}>
                    {expiry.text}
                  </span>
                  <button
                    type="button"
                    className="btn-ghost text-sm text-red-600 disabled:opacity-50 disabled:pointer-events-none"
                    disabled={isAnyDeleting}
                    onClick={async () => {
                      const ok = await confirm({
                        title: 'Delete service?',
                        message: `Permanently delete "${svc.name}"? This cannot be undone.`,
                        confirmText: 'Delete',
                        variant: 'danger',
                      });
                      if (ok) deleteApplication(svc.id);
                    }}
                  >
                    <DeleteButtonLabel loading={isDeleting(svc.id)} />
                  </button>
                </div>
              </div>
            );
          })}
        </div>
      )}
    </div>
  );
}