import {
  Alert,
  Badge,
  Group,
  Paper,
  Progress,
  SimpleGrid,
  Stack,
  Table,
  Text,
} from "@mantine/core";
import { AlertTriangle, Train } from "lucide-react";

import type { DeferredBookingRow, FleetAvailabilityRow } from "@/types/trainScheduling";

export function FleetAvailabilitySummary({
  fleetAvailability = [],
  deferredBookings = [],
}: {
  fleetAvailability?: FleetAvailabilityRow[];
  deferredBookings?: DeferredBookingRow[];
}) {
  if (!fleetAvailability.length && !deferredBookings.length) return null;

  const totalNeeded = fleetAvailability.reduce((sum, row) => sum + row.needed, 0);
  const totalAvailable = fleetAvailability.reduce((sum, row) => sum + row.available, 0);
  const totalShortfall = fleetAvailability.reduce((sum, row) => sum + row.shortfall, 0);
  const fillRate =
    totalNeeded > 0 ? Math.round((Math.min(totalAvailable, totalNeeded) / totalNeeded) * 100) : 100;

  return (
    <Paper p="md" radius="xl" withBorder>
      <Stack gap="md">
        <Group justify="space-between" align="flex-start" wrap="wrap">
          <Group gap="xs">
            <Train size={18} />
            <Stack gap={2}>
              <Text fw={600} size="sm">
                Fleet wagon availability
              </Text>
              <Text size="xs" c="dimmed">
                Plan is capped to available physical wagons by type
              </Text>
            </Stack>
          </Group>
          <Badge variant="light" color={totalShortfall > 0 ? "yellow" : "green"}>
            {fillRate}% fleet coverage
          </Badge>
        </Group>

        {totalNeeded > 0 ? (
          <Stack gap={6}>
            <Group justify="space-between">
              <Text size="xs" c="dimmed">
                {Math.min(totalAvailable, totalNeeded)} of {totalNeeded} wagon slots can be filled
              </Text>
            </Group>
            <Progress
              value={fillRate}
              size="sm"
              radius="xl"
              color={totalShortfall > 0 ? "yellow" : "green"}
            />
          </Stack>
        ) : null}

        {fleetAvailability.length > 0 ? (
          <Table striped highlightOnHover withTableBorder>
            <Table.Thead>
              <Table.Tr>
                <Table.Th>Wagon type</Table.Th>
                <Table.Th>Needed</Table.Th>
                <Table.Th>Available</Table.Th>
                <Table.Th>Shortfall</Table.Th>
              </Table.Tr>
            </Table.Thead>
            <Table.Tbody>
              {fleetAvailability.map((row) => (
                <Table.Tr key={row.wagonTypeId}>
                  <Table.Td>{row.wagonTypeCode}</Table.Td>
                  <Table.Td>{row.needed}</Table.Td>
                  <Table.Td>{row.available}</Table.Td>
                  <Table.Td>
                    {row.shortfall > 0 ? (
                      <Badge color="red" variant="light" size="sm">
                        {row.shortfall}
                      </Badge>
                    ) : (
                      <Text size="sm" c="green">
                        0
                      </Text>
                    )}
                  </Table.Td>
                </Table.Tr>
              ))}
            </Table.Tbody>
          </Table>
        ) : null}

        {totalShortfall > 0 || deferredBookings.length > 0 ? (
          <Alert color="yellow" variant="light" radius="lg" icon={<AlertTriangle size={16} />}>
            <Text size="sm">
              Train will depart with available wagons only.
              {deferredBookings.length
                ? ` ${deferredBookings.length} booking(s) will wait for the next train.`
                : ""}
            </Text>
          </Alert>
        ) : null}

        {deferredBookings.length > 0 ? (
          <SimpleGrid cols={{ base: 1, md: 2 }} spacing="sm">
            {deferredBookings.map((booking) => (
              <Paper key={booking.id} p="sm" radius="lg" withBorder bg="gray.0">
                <Group justify="space-between" align="flex-start" wrap="nowrap">
                  <Stack gap={2}>
                    <Text size="sm" fw={600}>
                      {booking.reference}
                    </Text>
                    <Text size="xs" c="dimmed">
                      {booking.reason}
                    </Text>
                  </Stack>
                  <Badge variant="light" color="orange" size="sm">
                    Next train
                  </Badge>
                </Group>
              </Paper>
            ))}
          </SimpleGrid>
        ) : null}
      </Stack>
    </Paper>
  );
}