import React, { useCallback, useEffect, useMemo, useState } from 'react';
import { Button, Card, Col, Empty, Form, Input, Progress, Row, Select, Space, Tag } from 'antd';
import { CalendarOutlined, PlusOutlined, SearchOutlined, TeamOutlined } from '@ant-design/icons';
import dayjs from 'dayjs';
import { useNavigate } from 'react-router-dom';
import api from '../../api';
import { message } from '../../ui/app-message';
import ExamFormModal from './ExamFormModal';
import type { ClassOption, ExamFormValues, ExamItem } from './types';
import { EXAM_TYPE_OPTIONS } from './types';
import './style.css';

const ExamsPage: React.FC = () => {
  const navigate = useNavigate();
  const [form] = Form.useForm<ExamFormValues>();
  const [data, setData] = useState<ExamItem[]>([]);
  const [classes, setClasses] = useState<ClassOption[]>([]);
  const [loading, setLoading] = useState(false);
  const [saving, setSaving] = useState(false);
  const [modalOpen, setModalOpen] = useState(false);
  const [keyword, setKeyword] = useState('');
  const [examType, setExamType] = useState<string>();
  const [classId, setClassId] = useState<number>();

  const loadClasses = useCallback(async () => {
    const result = await api.get<ClassOption[]>('/classes');
    setClasses(result ?? []);
  }, []);

  const loadExams = useCallback(async () => {
    setLoading(true);
    try {
      const params = new URLSearchParams();
      if (keyword.trim()) params.set('keyword', keyword.trim());
      if (examType) params.set('examType', examType);
      if (classId) params.set('classId', String(classId));
      const result = await api.get<ExamItem[]>(`/exams?${params.toString()}`);
      setData(result ?? []);
    } catch (error) {
      message.error((error as { message?: string })?.message || '加载考试失败');
    } finally {
      setLoading(false);
    }
  }, [classId, examType, keyword]);

  useEffect(() => {
    void loadClasses().catch((error: { message?: string }) => message.error(error?.message || '加载班级失败'));
  }, [loadClasses]);

  useEffect(() => {
    const timer = window.setTimeout(() => void loadExams(), 200);
    return () => window.clearTimeout(timer);
  }, [loadExams]);

  const classOptions = useMemo(
    () => classes.map((item) => ({ value: item.id, label: item.name })),
    [classes],
  );

  const openCreate = () => {
    form.resetFields();
    form.setFieldValue('examDate', dayjs());
    setModalOpen(true);
  };

  const submit = async () => {
    try {
      const values = await form.validateFields();
      setSaving(true);
      const payload = { ...values, examDate: values.examDate.format('YYYY-MM-DD') };
      await api.post('/exams', payload);
      message.success('考试已创建');
      setModalOpen(false);
      await loadExams();
    } catch (error) {
      if ((error as { errorFields?: unknown[] }).errorFields) return;
      message.error((error as { message?: string })?.message || '保存失败');
    } finally {
      setSaving(false);
    }
  };

  return (
    <div className="exam-page">
      <div className="exam-toolbar">
        <Space wrap>
          <Input value={keyword} onChange={(event) => setKeyword(event.target.value)} prefix={<SearchOutlined />} placeholder="搜索考试名称" allowClear />
          <Select value={examType} onChange={setExamType} options={EXAM_TYPE_OPTIONS} placeholder="考试类型" allowClear style={{ width: 140 }} />
          <Select value={classId} onChange={setClassId} options={classOptions} placeholder="考试班级" allowClear showSearch optionFilterProp="label" style={{ width: 180 }} />
        </Space>
        <Space wrap>
          <Button type="primary" icon={<PlusOutlined />} onClick={openCreate}>创建考试</Button>
        </Space>
      </div>

      {data.length === 0 && !loading ? (
        <div className="exam-empty"><Empty description="暂无考试" /></div>
      ) : (
        <Row gutter={[16, 16]}>
          {data.map((exam) => {
            const percent = exam.totalStudents === 0 ? 0 : Math.round((exam.enteredScores / exam.totalStudents) * 100);
            return (
              <Col key={exam.id} xs={24} sm={12} xl={8} xxl={6}>
                <Card
                  className="exam-card"
                  loading={loading}
                  title={<Space><Tag color="blue">{exam.examType}</Tag><span>{exam.examName}</span></Space>}
                  extra={<Tag color="green">成绩录入</Tag>}
                  actions={[
                    <span key="detail" onClick={() => navigate(`/exams/${exam.id}`)}>查看成绩</span>,
                  ]}
                >
                  <div className="exam-meta"><span>科目</span><strong>{exam.subject}</strong></div>
                  <div className="exam-meta"><span><TeamOutlined /> 班级</span><strong>{exam.className}</strong></div>
                  <div className="exam-meta"><span><CalendarOutlined /> 日期</span><strong>{exam.examDate}</strong></div>
                  <div className="exam-progress"><div><span>成绩录入</span><strong>{exam.enteredScores}/{exam.totalStudents}</strong></div><Progress percent={percent} size="small" /></div>
                </Card>
              </Col>
            );
          })}
        </Row>
      )}

      <ExamFormModal open={modalOpen} editing={false} saving={saving} form={form} classes={classes} onCancel={() => setModalOpen(false)} onSubmit={() => void submit()} />
    </div>
  );
};

export default ExamsPage;