import { useEffect, useState } from 'react';
import { Table, Drawer, Descriptions, Tag, Typography, Spin, Empty, Modal, Button, message } from 'antd';
import type { ColumnsType } from 'antd/es/table';
import {
  fetchCustomers, fetchCustomerDetail, fetchReservedItems, releaseReservedItem,
  CustomerSummary, CustomerDetail, ReservedItem
} from './adminCustomersApi';

const { Title, Text } = Typography;

export default function Customers() {
  const [customers, setCustomers] = useState<CustomerSummary[]>([]);
  const [loading, setLoading] = useState(true);
  const [detail, setDetail] = useState<CustomerDetail | null>(null);
  const [detailLoading, setDetailLoading] = useState(false);
  const [drawerOpen, setDrawerOpen] = useState(false);
  const [reservedFor, setReservedFor] = useState<CustomerSummary | null>(null);
  const [reserved, setReserved] = useState<ReservedItem[]>([]);
  const [reservedLoading, setReservedLoading] = useState(false);
  const [releasing, setReleasing] = useState<number | null>(null);

  function load() {
    return fetchCustomers().then(rows => { setCustomers(rows); setLoading(false); });
  }

  useEffect(() => { load(); }, []);

  async function openDetail(id: number) {
    setDrawerOpen(true);
    setDetailLoading(true);
    const data = await fetchCustomerDetail(id);
    setDetail(data);
    setDetailLoading(false);
  }

  async function openReserved(customer: CustomerSummary) {
    setReservedFor(customer);
    setReservedLoading(true);
    try {
      setReserved(await fetchReservedItems(customer.id));
    } catch (err) {
      message.error((err as Error).message);
      setReserved([]);
    } finally {
      setReservedLoading(false);
    }
  }

  async function handleRelease(item: ReservedItem) {
    if (!reservedFor) return;
    setReleasing(item.item_id);
    try {
      await releaseReservedItem(reservedFor.id, item.item_id);
    } catch (err) {
      message.error(`Couldn't release "${item.name}" — ${(err as Error).message}`);
      return;
    } finally {
      setReleasing(null);
    }
    message.success(`Released "${item.name}"`);
    // Refresh both the popup and the row count behind it, so the count can't
    // disagree with the list it opened from.
    setReserved(await fetchReservedItems(reservedFor.id));
    load();
  }

  const columns: ColumnsType<CustomerSummary> = [
    {
      title: 'Customer',
      dataIndex: 'email',
      sorter: (a, b) => a.email.localeCompare(b.email),
      render: (email: string, row: CustomerSummary) => (
        <div>
          <div>{row.name || <span style={{ opacity: 0.5 }}>No name</span>}</div>
          <div style={{ fontSize: 12, opacity: 0.65 }}>{email}</div>
        </div>
      )
    },
    {
      title: 'Verified',
      dataIndex: 'email_verified',
      filters: [{ text: 'Verified', value: true }, { text: 'Unverified', value: false }],
      onFilter: (value, row) => row.email_verified === value,
      render: (v: boolean) => <Tag color={v ? 'green' : 'default'}>{v ? 'Verified' : 'Unverified'}</Tag>
    },
    {
      title: 'Subscribed',
      dataIndex: 'marketing_consent',
      filters: [{ text: 'Subscribed', value: true }, { text: 'Not subscribed', value: false }],
      onFilter: (value, row) => row.marketing_consent === value,
      render: (v: boolean) => <Tag color={v ? 'blue' : 'default'}>{v ? 'Yes' : 'No'}</Tag>
    },
    {
      title: 'Reserved',
      dataIndex: 'reserved_count',
      render: (count: number, customer: CustomerSummary) =>
        Number(count) > 0 ? (
          <Button
            type="link"
            style={{ padding: 0 }}
            // The whole row opens the customer drawer, so without this the
            // click reaches both handlers and the drawer opens behind the
            // reserved-items dialog.
            onClick={(event) => { event.stopPropagation(); openReserved(customer); }}
          >
            {count} item{Number(count) === 1 ? '' : 's'}
          </Button>
        ) : (
          <Text type="secondary">0</Text>
        )
    },
    {
      title: 'Orders',
      dataIndex: 'order_count',
      sorter: (a, b) => a.order_count - b.order_count,
      defaultSortOrder: 'descend'
    },
    {
      title: 'Total Spent',
      dataIndex: 'total_spent_cents',
      sorter: (a, b) => a.total_spent_cents - b.total_spent_cents,
      render: (v: number) => `$${(v / 100).toFixed(2)}`
    },
    {
      title: 'Last Order',
      dataIndex: 'last_order_at',
      sorter: (a, b) => new Date(a.last_order_at || 0).getTime() - new Date(b.last_order_at || 0).getTime(),
      render: (v: string | null) => (v ? new Date(v).toLocaleDateString() : '—')
    },
    {
      title: 'Joined',
      dataIndex: 'created_at',
      sorter: (a, b) => new Date(a.created_at).getTime() - new Date(b.created_at).getTime(),
      render: (v: string) => new Date(v).toLocaleDateString()
    }
  ];

  return (
    <div>
      <Title level={4}>Customers</Title>
      <Table
        rowKey="id"
        loading={loading}
        dataSource={customers}
        columns={columns}
        onRow={row => ({ onClick: () => openDetail(row.id), style: { cursor: 'pointer' } })}
        pagination={{ pageSize: 10 }}
      />

      <Drawer
        title={detail?.customer.name || detail?.customer.email || 'Customer'}
        open={drawerOpen}
        onClose={() => { setDrawerOpen(false); setDetail(null); }}
        width={480}
      >
        {detailLoading || !detail ? (
          <Spin />
        ) : (
          <>
            <Descriptions column={1} size="small" bordered>
              <Descriptions.Item label="Email">{detail.customer.email}</Descriptions.Item>
              <Descriptions.Item label="Verified">
                <Tag color={detail.customer.email_verified ? 'green' : 'default'}>
                  {detail.customer.email_verified ? 'Verified' : 'Unverified'}
                </Tag>
              </Descriptions.Item>
              <Descriptions.Item label="Marketing consent">
                <Tag color={detail.customer.marketing_consent ? 'blue' : 'default'}>
                  {detail.customer.marketing_consent ? 'Subscribed' : 'Not subscribed'}
                </Tag>
                {detail.customer.marketing_consent_at && (
                  <div style={{ fontSize: 12, opacity: 0.65, marginTop: 4 }}>
                    since {new Date(detail.customer.marketing_consent_at).toLocaleDateString()}
                  </div>
                )}
              </Descriptions.Item>
              <Descriptions.Item label="Joined">
                {new Date(detail.customer.created_at).toLocaleDateString()}
              </Descriptions.Item>
            </Descriptions>

            <Title level={5} style={{ marginTop: 24 }}>Order History</Title>
            {detail.orders.length === 0 ? (
              <Empty description="No orders yet" />
            ) : (
              <Table
                rowKey="id"
                size="small"
                dataSource={detail.orders}
                pagination={false}
                columns={[
                  { title: 'Item', dataIndex: 'item_name' },
                  { title: 'Amount', dataIndex: 'amount_cents', render: (v: number) => `$${(v / 100).toFixed(2)}` },
                  {
                    title: 'Processor',
                    dataIndex: 'processor',
                    render: (v: string) => <Tag>{v}</Tag>
                  },
                  { title: 'Status', dataIndex: 'status' },
                  { title: 'Date', dataIndex: 'created_at', render: (v: string) => new Date(v).toLocaleDateString() }
                ]}
              />
            )}
          </>
        )}
      </Drawer>

      <Modal
        title={reservedFor ? `Items reserved by ${reservedFor.email}` : 'Reserved items'}
        open={reservedFor !== null}
        onCancel={() => setReservedFor(null)}
        footer={null}
        destroyOnHidden
        width={640}
      >
        {reservedLoading ? <Spin /> : null}
        {!reservedLoading && !reserved.length ? (
          <Empty description="This customer isn't holding any items" />
        ) : null}
        {!reservedLoading && reserved.length > 0 && (
          <Table
            rowKey="item_id"
            dataSource={reserved}
            pagination={false}
            size="small"
            columns={[
              { title: 'Item', dataIndex: 'name' },
              {
                title: 'Price',
                dataIndex: 'price_cents',
                render: (v: number) => `$${(v / 100).toFixed(2)}`
              },
              {
                title: 'Reservation expires',
                dataIndex: 'expires_at',
                render: (v: string) => new Date(v).toLocaleString()
              },
              {
                title: '',
                render: (_: unknown, item: ReservedItem) => (
                  <Button
                    size="small"
                    danger
                    loading={releasing === item.item_id}
                    onClick={() => handleRelease(item)}
                  >
                    Release
                  </Button>
                )
              }
            ]}
          />
        )}
      </Modal>
    </div>
  );
}