'use client';

import type { AdminErrorDto } from '@impuestos/contracts';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { useState } from 'react';
import { Button } from '@/components/ui/button';
import { EmptyState } from '@/components/ui/empty-state';
import { Input } from '@/components/ui/input';
import { Select } from '@/components/ui/select';
import { Skeleton } from '@/components/ui/skeleton';
import { Table, Td, Th, Tr } from '@/components/ui/table';
import { useT } from '@/i18n/t';
import { api } from '@/lib/api';

const STAGES = ['qr_parse', 'ocr', 'dedupe', 'verify', 'job', 'other'] as const;
const STATUSES = ['open', 'resolved'] as const;

type Stage = (typeof STAGES)[number];
type Status = (typeof STATUSES)[number];

/** Flow H: everything that failed on the way in, with the two things staff can do about it. */
export function ErrorsScreen() {
  const t = useT();
  const [stage, setStage] = useState<Stage | ''>('');
  const [status, setStatus] = useState<Status | ''>('open');
  const [expanded, setExpanded] = useState<string | null>(null);

  const errors = useQuery({
    queryKey: ['admin', 'errors', stage, status],
    queryFn: ({ signal }) =>
      api.listAdminErrors({ ...(stage ? { stage } : {}), ...(status ? { status } : {}) }, signal),
  });

  return (
    <div className="space-y-5">
      <h1 className="text-xl font-semibold tracking-tight">{t('admin.errors.title')}</h1>

      <div className="flex flex-wrap items-end gap-4">
        <label className="space-y-1 text-xs font-medium">
          <span className="block">{t('admin.errors.filterStage')}</span>
          <Select value={stage} onChange={(event) => setStage(event.target.value as Stage | '')}>
            <option value="">{t('admin.errors.all')}</option>
            {STAGES.map((value) => (
              <option key={value} value={value}>
                {t(`admin.errors.stage.${value}` as const)}
              </option>
            ))}
          </Select>
        </label>
        <label className="space-y-1 text-xs font-medium">
          <span className="block">{t('admin.errors.filterStatus')}</span>
          <Select value={status} onChange={(event) => setStatus(event.target.value as Status | '')}>
            <option value="">{t('admin.errors.allStatus')}</option>
            {STATUSES.map((value) => (
              <option key={value} value={value}>
                {t(`admin.errors.status.${value}` as const)}
              </option>
            ))}
          </Select>
        </label>
      </div>

      {errors.isPending ? <Skeleton name="admin-user-row" count={5} /> : null}

      {errors.isError ? (
        <div className="space-y-3">
          <p role="alert" className="text-sm">
            {t('common.error.generic')}
          </p>
          <Button type="button" className="h-9 rounded-lg" onClick={() => void errors.refetch()}>
            {t('common.retry')}
          </Button>
        </div>
      ) : null}

      {errors.data && errors.data.items.length === 0 ? (
        <EmptyState title={t('admin.errors.empty')} />
      ) : null}

      {errors.data && errors.data.items.length > 0 ? (
        <Table>
          <thead>
            <tr>
              <Th>{t('admin.errors.col.when')}</Th>
              <Th>{t('admin.errors.col.stage')}</Th>
              <Th>{t('admin.errors.col.user')}</Th>
              <Th>{t('admin.errors.col.message')}</Th>
              <Th>{t('admin.errors.col.status')}</Th>
            </tr>
          </thead>
          <tbody>
            {errors.data.items.map((row) => (
              <ErrorRow
                key={row.id}
                row={row}
                expanded={expanded === row.id}
                onToggle={() => setExpanded(expanded === row.id ? null : row.id)}
              />
            ))}
          </tbody>
        </Table>
      ) : null}
    </div>
  );
}

function ErrorRow({
  row,
  expanded,
  onToggle,
}: {
  row: AdminErrorDto;
  expanded: boolean;
  onToggle: () => void;
}) {
  const t = useT();

  return (
    <>
      <Tr>
        {/* A timestamp is machine data here, so it stays sortable rather than prose. */}
        <Td className="tnum whitespace-nowrap">{row.createdAt.slice(0, 16).replace('T', ' ')}</Td>
        <Td className="whitespace-nowrap">{t(`admin.errors.stage.${row.stage}` as const)}</Td>
        <Td className="whitespace-nowrap">{row.userEmail ?? t('common.none')}</Td>
        <Td>
          <button
            type="button"
            onClick={onToggle}
            aria-expanded={expanded}
            className="text-left hover:underline"
          >
            {row.message}
          </button>
        </Td>
        <Td className="whitespace-nowrap">{t(`admin.errors.status.${row.status}` as const)}</Td>
      </Tr>
      {expanded ? (
        <tr>
          <Td colSpan={5} className="bg-[var(--surface)]">
            <ExpandedRow row={row} />
          </Td>
        </tr>
      ) : null}
    </>
  );
}

function ExpandedRow({ row }: { row: AdminErrorDto }) {
  const t = useT();
  const queryClient = useQueryClient();
  const [note, setNote] = useState('');

  const invalidate = () => queryClient.invalidateQueries({ queryKey: ['admin', 'errors'] });

  const resolve = useMutation({
    mutationFn: () => api.resolveAdminError(row.id, { note: note.trim() }),
    onSuccess: invalidate,
  });
  const retry = useMutation({
    mutationFn: () => api.retryJob(row.id),
    onSuccess: invalidate,
  });

  return (
    <div className="space-y-3">
      {row.attempts !== null ? (
        <p className="text-xs text-[var(--text-muted)]">
          {t('admin.errors.attempts', { count: row.attempts })}
        </p>
      ) : null}

      <pre className="max-h-64 overflow-auto rounded-lg border bg-[var(--surface-raised)] p-3 text-xs">
        {JSON.stringify(row.payload ?? {}, null, 2)}
      </pre>

      {row.source === 'job' ? (
        <div className="space-y-2">
          <Button
            type="button"
            className="h-9 rounded-lg"
            disabled={retry.isPending}
            onClick={() => retry.mutate()}
          >
            {t('admin.errors.retry')}
          </Button>
          {retry.isError ? (
            <p role="alert" className="text-sm text-overdue">
              {t('common.error.generic')}
            </p>
          ) : null}
        </div>
      ) : null}

      {row.source === 'ingest' && row.status === 'open' ? (
        <form
          className="flex flex-wrap items-end gap-2"
          onSubmit={(event) => {
            event.preventDefault();
            resolve.mutate();
          }}
        >
          <div className="min-w-64 flex-1 space-y-1">
            <label htmlFor={`note-${row.id}`} className="text-xs font-medium">
              {t('admin.errors.note')}
            </label>
            <Input
              id={`note-${row.id}`}
              value={note}
              onChange={(event) => setNote(event.target.value)}
              placeholder={t('admin.errors.notePlaceholder')}
              className="h-9 rounded-lg text-sm"
            />
          </div>
          <Button
            type="submit"
            className="h-9 rounded-lg"
            disabled={note.trim().length === 0 || resolve.isPending}
          >
            {t('admin.errors.resolve')}
          </Button>
          {resolve.isError ? (
            <p role="alert" className="text-sm text-overdue">
              {t('common.error.generic')}
            </p>
          ) : null}
        </form>
      ) : null}
    </div>
  );
}