import React, { useEffect, useState } from "react";

import { Alert, Box, Button, CircularProgress, Typography } from "@mui/material";
import { visuallyHidden } from "@mui/utils";

import type { ViewResourceError } from "../hooks/useViewResource";
import { useI18n } from "../i18n/I18nProvider";

type Props = {
  loading?: boolean;
  error?: ViewResourceError | null;
  title: string;
  description?: string;
  retryLabel?: string;
  onRetry?: () => void | Promise<void>;
  compact?: boolean;
};

export default function ViewStateNotice({ loading = false, error = null, title, description, retryLabel, onRetry, compact = false }: Props) {
  const { t } = useI18n();
  const resolvedRetryLabel = retryLabel ?? t("retry");
  const [observedLoading, setObservedLoading] = useState(loading);
  useEffect(() => { if (loading) setObservedLoading(true); }, [loading]);

  // Keep one live region mounted through the read. An idle/error-only consumer
  // has not completed a load; unrelated form edits must not announce anything.
  const status = <Box component="span" role="status" aria-live="polite" aria-atomic="true" sx={visuallyHidden}>
    {loading ? t("loading") : !error && observedLoading ? t("contentLoaded") : ""}
  </Box>;

  if (loading) {
    return (
      <>{status}<Box sx={{ py: compact ? 3 : 6, display: "flex", justifyContent: "center" }}>
        <CircularProgress size={compact ? 24 : 28} aria-label={t("loading")} />
      </Box></>
    );
  }

  if (!error) return <>{status}</>;

  const severity = error.kind === "unauthorized" ? "warning" : error.kind === "unavailable" ? "error" : "error";
  const detail = error.message !== title && error.message !== description ? error.message : null;

  return (
    <>{status}<Alert
      severity={severity}
      sx={{
        mb: compact ? 1.5 : 2,
        alignItems: "flex-start",
        borderRadius: 3,
      }}
      action={error.retryable && onRetry ? <Button color="inherit" size="small" onClick={() => void onRetry()}>{resolvedRetryLabel}</Button> : undefined}
    >
      <Typography sx={{ fontWeight: 800, mb: 0.35 }}>{title}</Typography>
      {description ? <Typography variant="body2">{description}</Typography> : null}
      {detail ? <Typography variant="body2" sx={{ mt: 0.5 }}>{detail}</Typography> : null}
    </Alert></>
  );
}