import { useQuery } from "@tanstack/react-query";
import {
  Alert,
  Box,
  Button,
  Chip,
  CircularProgress,
  Paper,
  Stack,
  Typography,
} from "@mui/material";
import { Link } from "react-router";
import { vendorOperationsApi } from "@/domain/vendor-operations/api/vendor-operations-api";

export default function NotificationsPage() {
  const {
    data = [],
    isLoading,
    error,
  } = useQuery({
    queryKey: ["vendor-operations", "notifications"],
    queryFn: vendorOperationsApi.notifications,
    refetchInterval: 30_000,
  });

  const groups = data.reduce((result, item) => {
    const items = result.get(item.group) ?? [];
    items.push(item);
    result.set(item.group, items);
    return result;
  }, new Map<string, typeof data>());

  return (
    <Box className="flex flex-col gap-4 p-4">
      <Box>
        <Typography variant="h5" component="h1">
          Items requiring attention
        </Typography>
        <Typography color="text.secondary">
          Medium-severity vendor reminders refresh automatically. They do not create banners or
          toasts.
        </Typography>
      </Box>
      {isLoading && <CircularProgress aria-label="Loading notifications" />}
      {Boolean(error) && <Alert severity="error">{error?.message}</Alert>}
      {!isLoading && !error && data.length === 0 && (
        <Paper variant="outlined" className="p-6">
          <Typography>No vendor alerts require attention.</Typography>
        </Paper>
      )}
      {[...groups.entries()].map(([group, items]) => (
        <Paper key={group} variant="outlined" className="p-4">
          <Stack direction="row" spacing={1} className="mb-3" sx={{ alignItems: "center" }}>
            <Typography variant="h6">{group}</Typography>
            <Chip label={items.length} size="small" />
          </Stack>
          <Stack spacing={2}>
            {items.map((item) => (
              <Paper key={item.id} variant="outlined" className="p-3">
                <Stack
                  direction={{ xs: "column", md: "row" }}
                  sx={{ gap: 2, justifyContent: "space-between" }}
                >
                  <Box>
                    <Stack direction="row" spacing={1} sx={{ alignItems: "center" }}>
                      <Chip label={item.severity} color="warning" size="small" />
                      <Typography sx={{ fontWeight: 600 }}>{item.title}</Typography>
                    </Stack>
                    <Typography color="text.secondary" className="mt-1">
                      {item.workOrderNumber ??
                        item.workOrders?.map((workOrder) => workOrder.workOrderNumber).join(" ↔ ")}
                    </Typography>
                    {item.scheduledAt != null && (
                      <Typography variant="caption">
                        Scheduled {new Date(item.scheduledAt).toLocaleString()}
                      </Typography>
                    )}
                  </Box>
                  <Stack direction="row" spacing={1} sx={{ alignItems: "center" }}>
                    {item.action != null && (
                      <Button component={Link} to={item.action.href} variant="contained">
                        {item.action.label}
                      </Button>
                    )}
                    {item.actions?.map((action) => (
                      <Button
                        key={action.href}
                        component={Link}
                        to={action.href}
                        variant="outlined"
                      >
                        {action.label}
                      </Button>
                    ))}
                  </Stack>
                </Stack>
              </Paper>
            ))}
          </Stack>
        </Paper>
      ))}
    </Box>
  );
}