'use client';

import { useCallback, useEffect, useMemo, useState } from 'react';
import { useRouter } from 'next/navigation';
import { ChevronRight, Plus } from 'lucide-react';
import { DocumentFormDialog } from '@/components/documents/document-form-dialog';
import { DocumentPhotosInline } from '@/components/documents/document-photo-gallery';
import { useAuth } from '@/components/id/auth-provider';
import { IdShell } from '@/components/id/shell';
import { useToast } from '@/components/id/toast-provider';
import {
  DOCUMENT_CATEGORIES,
  DOCUMENT_TYPES,
  getDocumentType,
  parseDocumentPhotos,
  parseMetadata,
  QUICK_DOCUMENT_TYPES,
  indexDocumentsByType,
  type DocumentTypeCode
} from '@/lib/document-catalog';
import { apiFetch, getApiErrorMessage, UserDocument } from '@/lib/api';
import { cn } from '@/lib/utils';

import { useRequireAuth } from '@/hooks/use-require-auth';

export default function DocumentsPage() {
  const router = useRouter();
  const { user, token } = useAuth();
  const { isReady, isPinLocked } = useRequireAuth();
  const { showToast } = useToast();
  const [documents, setDocuments] = useState<UserDocument[]>([]);
  const [activeType, setActiveType] = useState<DocumentTypeCode | null>(null);

  const loadDocuments = useCallback(async () => {
    if (!user || !token || isPinLocked) return;
    try {
      const response = await apiFetch<{ documents?: UserDocument[] }>(`/documents/users/${user.id}`, {}, token);
      setDocuments(response.documents ?? []);
    } catch (error) {
      const message = getApiErrorMessage(error, 'Не удалось загрузить документы');
      if (message) showToast(message);
    }
  }, [isPinLocked, showToast, token, user]);

  useEffect(() => {
    if (!isReady || !user || isPinLocked) return;
    void loadDocuments();
  }, [isPinLocked, isReady, loadDocuments, user]);

  const documentsByType = useMemo(() => indexDocumentsByType(documents), [documents]);

  function openCreate(type: DocumentTypeCode) {
    setActiveType(type);
  }

  return (
    <IdShell active="/documents" wide>
      <h1 className="text-2xl font-medium tracking-tight sm:text-3xl">Документы</h1>
      <p className="mt-1 text-sm text-[#667085]">Храните документы и заполняйте формы — ID подставит данные там, где вы разрешите.</p>

      <div className="mt-6 overflow-hidden rounded-[28px] bg-[linear-gradient(135deg,#fff4f4,#fff8ef)] p-5">
        <div className="flex items-center justify-between gap-4">
          <div>
            <p className="text-lg font-medium">Здесь будут ваши документы</p>
            <p className="mt-1 text-sm text-[#667085]">Добавьте паспорт, права или полис — данные сохранятся в зашифрованном виде.</p>
          </div>
          <div className="flex h-16 w-16 items-center justify-center rounded-3xl bg-white text-3xl shadow-sm">🛂</div>
        </div>
      </div>

      <div className="mt-5 grid grid-cols-3 gap-3">
        {QUICK_DOCUMENT_TYPES.map((typeCode) => {
          const config = getDocumentType(typeCode);
          if (!config) return null;
          const Icon = config.icon;
          return (
            <button
              key={typeCode}
              type="button"
              onClick={() => openCreate(typeCode)}
              className="flex min-h-[110px] flex-col items-center justify-center gap-2 rounded-[22px] bg-[#f4f5f8] p-3 text-center transition hover:bg-[#eceef4]"
            >
              <div className={cn('flex h-12 w-12 items-center justify-center rounded-2xl', config.accent)}>
                <Icon className="h-5 w-5" />
              </div>
              <span className="text-[12px] font-medium leading-tight">Добавить {config.shortLabel.toLowerCase()}</span>
            </button>
          );
        })}
      </div>

      {DOCUMENT_CATEGORIES.map((category) => (
        <section key={category.id} className="mt-8">
          <h2 className="mb-3 text-xl font-medium">{category.title}</h2>
          <div className="overflow-hidden rounded-[24px] bg-[#f4f5f8]">
            {DOCUMENT_TYPES.filter((item) => item.category === category.id).map((item) => {
              const Icon = item.icon;
              const existing = documentsByType.get(item.type);
              const photoKeys = existing ? parseDocumentPhotos(parseMetadata(existing.metadataJson)) : [];
              return (
                <div key={item.type} className="border-b border-white/70 last:border-b-0">
                  <button
                    type="button"
                    onClick={() => openCreate(item.type)}
                    className="flex w-full items-center gap-4 px-4 py-4 text-left hover:bg-white/60"
                  >
                    <div className={cn('flex h-11 w-11 items-center justify-center rounded-2xl', item.accent)}>
                      <Icon className="h-5 w-5" />
                    </div>
                    <div className="min-w-0 flex-1">
                      <div className="font-medium">{item.label}</div>
                      {existing ? <div className="truncate text-sm text-[#667085]">{existing.number}</div> : null}
                    </div>
                    {existing ? <ChevronRight className="h-5 w-5 text-[#a8adbc]" /> : <Plus className="h-5 w-5 text-[#a8adbc]" />}
                  </button>
                  {existing && photoKeys.length > 0 && user && token ? (
                    <div className="px-4 pb-4">
                      <DocumentPhotosInline userId={user.id} token={token} storageKeys={photoKeys} />
                    </div>
                  ) : null}
                </div>
              );
            })}
          </div>
        </section>
      ))}

      {activeType ? (
        <DocumentFormDialog
          open={Boolean(activeType)}
          onOpenChange={(open) => {
            if (!open) setActiveType(null);
          }}
          documentType={activeType}
          userId={user?.id ?? ''}
          token={token}
          existing={documentsByType.get(activeType) ?? null}
          onSaved={loadDocuments}
        />
      ) : null}
    </IdShell>
  );
}