import React, { useEffect, useState, useMemo } from 'react';
import {
  Table,
  Modal,
  Form,
  Select,
  DatePicker,
  InputNumber,
  Input,
  Space,
  message,
  Tag,
  Popconfirm,
  Tabs,
  List,
  Card,
} from 'antd';
import { PlusOutlined, DeleteOutlined, DollarOutlined, CheckOutlined } from '@ant-design/icons';
import dayjs from 'dayjs';
import api from '../../api';
import PermissionButton from '../../components/PermissionButton';

const statusMap: Record<string, { text: string; color: string }> = {
  paid: { text: '已缴', color: 'green' },
  refunded: { text: '已全退', color: 'blue' },
  partial_refund: { text: '部分退还', color: 'orange' },
  deducted: { text: '已全扣', color: 'red' },
};

const refundStatusMap: Record<string, { text: string; color: string }> = {
  pending: { text: '待班主任审批', color: 'orange' },
  head_teacher_approved: { text: '待财务审批', color: 'blue' },
  finance_approved: { text: '已退款', color: 'green' },
  refunded: { text: '已退款', color: 'green' },
};

const installmentStatusMap: Record<string, { text: string; color: string }> = {
  pending: { text: '待缴', color: 'orange' },
  paid: { text: '已缴', color: 'green' },
};

interface PendingRefund {
  id: number;
  student?: { name?: string };
  amount?: number;
  paidDate?: string;
  refundStatus?: string;
  refundRequestedAt?: string;
}

const DepositsPage: React.FC = () => {
  const [data, setData] = useState<any[]>([]);
  const [students, setStudents] = useState<any[]>([]);
  const [loading, setLoading] = useState(false);
  const [createModal, setCreateModal] = useState(false);
  const [refundModal, setRefundModal] = useState<any>(null);
  const [detailModal, setDetailModal] = useState<any>(null);
  const [installmentModal, setInstallmentModal] = useState<number | null>(null);
  const [pendingRefunds, setPendingRefunds] = useState<PendingRefund[]>([]);
  const [pendingLoading, setPendingLoading] = useState(false);
  const [rejectModal, setRejectModal] = useState<any>(null);
  const [rejectReason, setRejectReason] = useState('');
  const [createForm] = Form.useForm();
  const [refundForm] = Form.useForm();
  const [installmentForm] = Form.useForm();
  const [searchText, setSearchText] = useState('');
  const [filterStatus, setFilterStatus] = useState<string | undefined>(undefined);
  const [activeTab, setActiveTab] = useState<string>('all');

  const fetchData = async () => {
    setLoading(true);
    try {
      const [d, s]: any[] = await Promise.all([api.get('/deposits'), api.get('/students')]);
      setData(d);
      setStudents(s);
    } catch (e) {
      console.error(e);
    }
    setLoading(false);
  };

  const fetchPendingRefunds = async () => {
    setPendingLoading(true);
    try {
      const res = await api.get<PendingRefund[]>('/deposits/pending-refunds');
      setPendingRefunds(res || []);
    } catch (e) {
      console.error(e);
    }
    setPendingLoading(false);
  };

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

  const filteredData = useMemo(() => {
    return data.filter((d: any) => {
      if (searchText) {
        const s = searchText.toLowerCase();
        if (!d.student?.name?.toLowerCase().includes(s)) return false;
      }
      if (filterStatus && d.status !== filterStatus) return false;
      return true;
    });
  }, [data, searchText, filterStatus]);

  const handleCreate = async () => {
    const values = await createForm.validateFields();
    try {
      await api.post('/deposits', {
        studentId: values.studentId,
        amount: values.amount,
        paidDate: values.paidDate.format('YYYY-MM-DD'),
        notes: values.notes,
      });
      message.success('押金记录已创建');
      setCreateModal(false);
      createForm.resetFields();
      fetchData();
    } catch (e: any) {
      message.error(e?.message || '操作失败');
    }
  };

  const handleRefund = async () => {
    const values = await refundForm.validateFields();
    try {
      await api.put(`/deposits/${refundModal.id}/refund`, {
        refundDate: values.refundDate.format('YYYY-MM-DD'),
        deductionAmount: values.deductionAmount || 0,
        deductionReason: values.deductionReason,
        notes: values.notes,
      });
      message.success('退还操作完成');
      setRefundModal(null);
      refundForm.resetFields();
      fetchData();
    } catch (e: any) {
      message.error(e?.message || '操作失败');
    }
  };

  const handleRequestRefund = async (record: any) => {
    try {
      await api.post(`/deposits/${record.id}/request-refund`);
      message.success('退款申请已提交');
      fetchData();
    } catch (e: any) {
      message.error(e?.message || '操作失败');
    }
  };

  const handleApproveRefund = async (record: any) => {
    try {
      await api.put(`/deposits/${record.id}/approve-refund`);
      message.success('审批通过');
      fetchPendingRefunds();
      fetchData();
    } catch (e: any) {
      message.error(e?.message || '操作失败');
    }
  };


  const handleRejectRefund = async () => {
    if (!rejectModal) return;
    try {
      await api.put(`/deposits/${rejectModal.id}/reject-refund`, { reason: rejectReason || '未说明原因' });
      message.success('已驳回退款申请');
      setRejectModal(null);
      setRejectReason('');
      fetchPendingRefunds();
      fetchData();
    } catch (e: any) {
      message.error(e?.message || '驳回失败');
    }
  };
  const handleAddInstallment = async () => {
    if (installmentModal == null) return;
    const values = await installmentForm.validateFields();
    try {
      await api.post(`/deposits/${installmentModal}/installments`, {
        amount: values.amount,
        dueDate: values.dueDate.format('YYYY-MM-DD'),
      });
      message.success('分期已添加');
      setInstallmentModal(null);
      installmentForm.resetFields();
      fetchData();
    } catch (e: any) {
      message.error(e?.message || '操作失败');
    }
  };

  const handlePayInstallment = async (installmentId: number) => {
    try {
      await api.put(`/deposits/installments/${installmentId}`, {
        paidDate: dayjs().format('YYYY-MM-DD'),
        status: 'paid',
      });
      message.success('分期已标记为已缴');
      fetchData();
    } catch (e: any) {
      message.error(e?.message || '操作失败');
    }
  };

  const handleDeleteInstallment = async (installmentId: number) => {
    try {
      await api.delete(`/deposits/installments/${installmentId}`);
      message.success('分期已删除');
      fetchData();
    } catch (e: any) {
      message.error(e?.message || '操作失败');
    }
  };

  const columns = [
    { title: '学生', render: (_: any, r: any) => r.student?.name || '-' },
    { title: '押金金额', dataIndex: 'amount', render: (v: number) => `¥${Number(v).toFixed(2)}` },
    { title: '缴纳日期', dataIndex: 'paidDate' },
    {
      title: '状态',
      dataIndex: 'status',
      render: (s: string) => <Tag color={statusMap[s]?.color}>{statusMap[s]?.text || s}</Tag>,
    },
    {
      title: '退款审批',
      dataIndex: 'refundStatus',
      render: (s: string) =>
        s ? <Tag color={refundStatusMap[s]?.color}>{refundStatusMap[s]?.text || s}</Tag> : '-',
    },
    {
      title: '退还金额',
      dataIndex: 'refundAmount',
      render: (v: any) => (v != null ? `¥${Number(v).toFixed(2)}` : '-'),
    },
    {
      title: '扣除金额',
      dataIndex: 'deductionAmount',
      render: (v: any) => (v > 0 ? `¥${Number(v).toFixed(2)}` : '-'),
    },
    { title: '扣除原因', dataIndex: 'deductionReason', render: (v: any) => v || '-' },
    { title: '退还日期', dataIndex: 'refundDate', render: (v: any) => v || '-' },
    { title: '备注', dataIndex: 'notes', render: (v: any) => v || '-' },
    {
      title: '操作',
      width: 240,
      render: (_: any, record: any) => (
        <Space>
          <PermissionButton
            permission="deposit:view"
            size="small"
            onClick={() => {
              setDetailModal(record);
            }}
          >
            详情
          </PermissionButton>
          {record.status === 'paid' && !record.refundStatus && (
            <>
              <PermissionButton
                permission="deposit:edit"
                size="small"
                type="primary"
                onClick={() => {
                  setRefundModal(record);
                  refundForm.setFieldsValue({ refundDate: dayjs(), deductionAmount: 0 });
                }}
              >
                退还
              </PermissionButton>
              <PermissionButton
                permission="deposit:edit"
                size="small"
                onClick={() => handleRequestRefund(record)}
              >
                申请退款
              </PermissionButton>
            </>
          )}
          <Popconfirm
            title="确定删除？"
            onConfirm={async () => {
              try {
                await api.delete(`/deposits/${record.id}`);
                message.success('删除成功');
                fetchData();
              } catch (e: any) {
                message.error(e?.message || '删除失败');
              }
            }}
          >
            <PermissionButton
              permission="deposit:delete"
              size="small"
              danger
              icon={<DeleteOutlined />}
            >
              删除
            </PermissionButton>
          </Popconfirm>
        </Space>
      ),
    },
  ];

  const pendingColumns = [
    { title: '学生', render: (_: any, r: any) => r.student?.name || '-' },
    { title: '押金金额', dataIndex: 'amount', render: (v: number) => `¥${Number(v).toFixed(2)}` },
    { title: '缴纳日期', dataIndex: 'paidDate' },
    {
      title: '审批状态',
      dataIndex: 'refundStatus',
      render: (s: string) => <Tag color={refundStatusMap[s]?.color}>{refundStatusMap[s]?.text || s}</Tag>,
    },
    {
      title: '申请时间',
      dataIndex: 'refundRequestedAt',
      render: (v: any) => (v ? dayjs(v).format('YYYY-MM-DD HH:mm') : '-'),
    },
    {
      title: '操作',
      render: (_: unknown, record: PendingRefund) => (
        <Space>
          <PermissionButton
            permission="deposit:approve"
            size="small"
            type="primary"
            icon={<CheckOutlined />}
            onClick={() => handleApproveRefund(record)}
          >
            审批通过
          </PermissionButton>
          <PermissionButton
            permission="deposit:approve"
            size="small"
            danger
            onClick={() => {
              setRejectModal(record);
              setRejectReason('');
            }}
          >
            驳回
          </PermissionButton>
        </Space>
      ),
    },
  ];

  return (
    <div>
      <Tabs
        activeKey={activeTab}
        onChange={(key) => {
          setActiveTab(key);
          if (key === 'pending') fetchPendingRefunds();
        }}
        items={[
          {
            key: 'all',
            label: '押金列表',
            children: (
              <>
                <div
                  style={{
                    marginBottom: 16,
                    display: 'flex',
                    justifyContent: 'space-between',
                    flexWrap: 'wrap',
                    gap: 8,
                  }}
                >
                  <Space wrap>
                    <Input.Search
                      placeholder="搜索学生姓名"
                      allowClear
                      style={{ width: 180 }}
                      onSearch={(v) => setSearchText(v)}
                      onChange={(e) => {
                        if (!e.target.value) setSearchText('');
                      }}
                    />
                    <Select
                      placeholder="状态筛选"
                      allowClear
                      style={{ width: 120 }}
                      value={filterStatus}
                      onChange={(v) => setFilterStatus(v)}
                      options={[
                        { value: 'paid', label: '已缴' },
                        { value: 'refunded', label: '已全退' },
                        { value: 'partial_refund', label: '部分退还' },
                        { value: 'deducted', label: '已全扣' },
                      ]}
                    />
                  </Space>
                  <PermissionButton
                    permission="deposit:create"
                    type="primary"
                    icon={<PlusOutlined />}
                    onClick={() => {
                      createForm.resetFields();
                      createForm.setFieldsValue({ amount: 500, paidDate: dayjs() });
                      setCreateModal(true);
                    }}
                  >
                    收取押金
                  </PermissionButton>
                </div>
                <Table
                  columns={columns}
                  dataSource={filteredData}
                  rowKey="id"
                  loading={loading}
                  scroll={{ x: 'max-content' }}
                  pagination={{ pageSize: 15, showTotal: (total) => `共 ${total} 条` }}
                />
              </>
            ),
          },
          {
            key: 'pending',
            label: '待审批退款',
            children: (
              <Table
                columns={pendingColumns}
                dataSource={pendingRefunds}
                rowKey="id"
                loading={pendingLoading}
                scroll={{ x: 'max-content' }}
                pagination={{ pageSize: 15, showTotal: (total) => `共 ${total} 条` }}
              />
            ),
          },
        ]}
      />

      {/* Create Modal */}
      <Modal
        title="收取押金"
        open={createModal}
        onOk={handleCreate}
        onCancel={() => setCreateModal(false)}
        okText="确认"
      >
        <Form form={createForm} layout="vertical">
          <Form.Item
            name="studentId"
            label="学生"
            rules={[{ required: true, message: '请选择学生' }]}
          >
            <Select
              showSearch
              optionFilterProp="label"
              placeholder="搜索并选择学生"
              options={students
                .filter((s: any) => s.status === 'active')
                .map((s: any) => ({
                  value: s.id,
                  label: `${s.name} (${s.idNumber || s.phone || ''})`,
                }))}
            />
          </Form.Item>
          <Form.Item name="amount" label="押金金额（元）" rules={[{ required: true }]}>
            <InputNumber min={0} precision={2} style={{ width: '100%' }} />
          </Form.Item>
          <Form.Item name="paidDate" label="缴纳日期" rules={[{ required: true }]}>
            <DatePicker style={{ width: '100%' }} placeholder="选择缴纳日期" format="YYYY-MM-DD" />
          </Form.Item>
          <Form.Item name="notes" label="备注">
            <Input.TextArea rows={2} />
          </Form.Item>
        </Form>
      </Modal>

      {/* Refund Modal */}
      <Modal
        title={`退还押金 - ${refundModal?.student?.name}`}
        open={!!refundModal}
        onOk={handleRefund}
        onCancel={() => setRefundModal(null)}
        okText="确认退还"
      >
        <Form form={refundForm} layout="vertical">
          <div style={{ marginBottom: 16, padding: 12, background: '#f5f5f5', borderRadius: 8 }}>
            押金金额: <strong>¥{Number(refundModal?.amount || 0).toFixed(2)}</strong>
          </div>
          <Form.Item name="refundDate" label="退还日期" rules={[{ required: true }]}>
            <DatePicker style={{ width: '100%' }} placeholder="选择退还日期" format="YYYY-MM-DD" />
          </Form.Item>
          <Form.Item name="deductionAmount" label="扣除金额（元）" extra="如无扣除填0">
            <InputNumber
              min={0}
              max={Number(refundModal?.amount || 500)}
              precision={2}
              style={{ width: '100%' }}
            />
          </Form.Item>
          <Form.Item name="deductionReason" label="扣除原因">
            <Input placeholder="如：房间损坏赔偿" />
          </Form.Item>
          <Form.Item name="notes" label="备注">
            <Input.TextArea rows={2} />
          </Form.Item>
        </Form>
      </Modal>

      {/* Detail Modal */}
      <Modal
        title={`押金详情 - ${detailModal?.student?.name}`}
        open={!!detailModal}
        onCancel={() => setDetailModal(null)}
        footer={null}
        width={640}
      >
        {detailModal && (
          <div>
            <Card size="small" style={{ marginBottom: 16 }}>
              <p><strong>押金金额:</strong> ¥{Number(detailModal.amount).toFixed(2)}</p>
              <p><strong>缴纳日期:</strong> {detailModal.paidDate}</p>
              <p>
                <strong>状态:</strong>{' '}
                <Tag color={statusMap[detailModal.status]?.color}>
                  {statusMap[detailModal.status]?.text || detailModal.status}
                </Tag>
              </p>
              {detailModal.refundStatus && (
                <p>
                  <strong>退款审批:</strong>{' '}
                  <Tag color={refundStatusMap[detailModal.refundStatus]?.color}>
                    {refundStatusMap[detailModal.refundStatus]?.text || detailModal.refundStatus}
                  </Tag>
                </p>
              )}
              {detailModal.notes && <p><strong>备注:</strong> {detailModal.notes}</p>}
            </Card>

            {/* Installments Section */}
            <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: 8 }}>
              <h4 style={{ margin: 0 }}>分期记录</h4>
              <PermissionButton
                permission="deposit:edit"
                size="small"
                type="primary"
                icon={<PlusOutlined />}
                onClick={() => {
                  setInstallmentModal(detailModal.id);
                  installmentForm.resetFields();
                }}
              >
                添加分期
              </PermissionButton>
            </div>
            {detailModal.installments?.length > 0 ? (
              <List
                dataSource={detailModal.installments}
                renderItem={(item: any) => (
                  <List.Item
                    actions={[
                      item.status === 'pending' && (
                        <PermissionButton
                          key="pay"
                          permission="deposit:edit"
                          size="small"
                          type="primary"
                          icon={<DollarOutlined />}
                          onClick={() => handlePayInstallment(item.id)}
                        >
                          标记已缴
                        </PermissionButton>
                      ),
                      <Popconfirm
                        title="确定删除？"
                        onConfirm={() => handleDeleteInstallment(item.id)}
                      >
                        <PermissionButton key="del" permission="deposit:delete" size="small" danger icon={<DeleteOutlined />}>
                        删除
                      </PermissionButton>
                      </Popconfirm>
                    ].filter(Boolean)}
                  >
                    <List.Item.Meta
                      title={`¥${Number(item.amount).toFixed(2)}`}
                      description={`到期: ${item.dueDate}${item.paidDate ? ` | 缴纳: ${item.paidDate}` : ''}`}
                    />
                    <Tag color={installmentStatusMap[item.status]?.color}>
                      {installmentStatusMap[item.status]?.text || item.status}
                    </Tag>
                  </List.Item>
                )}
              />
            ) : (
              <p style={{ color: '#999' }}>暂无分期记录</p>
            )}
          </div>
        )}
      </Modal>

      {/* Add Installment Modal */}
      <Modal
        title="添加分期"
        open={installmentModal != null}
        onOk={handleAddInstallment}
        onCancel={() => setInstallmentModal(null)}
        okText="确认"
      >
        <Form form={installmentForm} layout="vertical">
          <Form.Item name="amount" label="分期金额（元）" rules={[{ required: true }]}>
            <InputNumber min={0} precision={2} style={{ width: '100%' }} />
          </Form.Item>
          <Form.Item name="dueDate" label="到期日期" rules={[{ required: true }]}>
            <DatePicker style={{ width: '100%' }} placeholder="选择到期日期" format="YYYY-MM-DD" />
          </Form.Item>
        </Form>
      </Modal>

      {/* Reject Refund Modal */}
      <Modal
        title={`驳回退款申请 - ${rejectModal?.student?.name || ''}`}
        open={!!rejectModal}
        onOk={handleRejectRefund}
        onCancel={() => { setRejectModal(null); setRejectReason(''); }}
        okText="确认驳回"
        okButtonProps={{ danger: true }}
      >
        <Input.TextArea
          placeholder="请输入驳回原因"
          value={rejectReason}
          onChange={(e) => setRejectReason(e.target.value)}
          rows={3}
        />
      </Modal>
    </div>
  );
};

export default DepositsPage;