import React, { useEffect, useState, useRef } from 'react';
import './Promotion.css';
import { useUser } from '../../../context/UserContext';

const Promotion = () => {
  const { user } = useUser();
  const [promotions, setPromotions] = useState([]);
  const [torrents, setTorrents] = useState([]);
  const [loading, setLoading] = useState(true);
  const [promoIndex, setPromoIndex] = useState(0);
  const promoTimerRef = useRef(null);

  // 新增：控制创建对话框显示
  const [showCreateDialog, setShowCreateDialog] = useState(false);

  // 创建促销活动表单状态
  const [formData, setFormData] = useState({
    name: '',
    startTime: '',
    endTime: '',
    discountPercentage: '',
    uploadCoeff: '',
    downloadCoeff: '',
    description: ''
  });

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

  useEffect(() => {
    if (promotions.length === 0) return;
    clearInterval(promoTimerRef.current);
    promoTimerRef.current = setInterval(() => {
      setPromoIndex(prev => (prev + 1) % promotions.length);
    }, 5000);
    return () => clearInterval(promoTimerRef.current);
  }, [promotions]);

  const fetchData = async () => {
    try {
      const response = await fetch('/seeds/promotions');
      const json = await response.json();
      const promoData = Array.isArray(json?.data) ? json.data : [];
      setPromotions(promoData);
    } catch (error) {
      console.error('获取促销活动失败:', error);
    } finally {
      setLoading(false);
    }
  };

  const fetchTorrentList = async () => {
    try {
      const response = await fetch('/seeds/list');
      const json = await response.json();
      const torrentList = Array.isArray(json?.data) ? json.data : [];
      setTorrents(torrentList);
    } catch (error) {
      console.error('获取种子列表失败:', error);
    }
  };

  // 打开创建促销活动弹窗
  const openCreateDialog = () => {
    // 重置表单数据
    setFormData({
      name: '',
      startTime: '',
      endTime: '',
      discountPercentage: '',
      uploadCoeff: '',
      downloadCoeff: '',
      description: ''
    });
    setShowCreateDialog(true);
  };

  // 关闭弹窗
  const closeCreateDialog = () => {
    setShowCreateDialog(false);
  };

  // 处理表单输入变化
  const handleInputChange = (e) => {
    const { name, value } = e.target;
    setFormData(prev => ({
      ...prev,
      [name]: value
    }));
  };

  // 提交创建促销活动
  const handleCreatePromotion = async () => {
    if (torrents.length === 0) {
      alert('没有可用的种子，请先上传种子');
      return;
    }
    if (!formData.name.trim()) {
      alert('促销名称不能为空');
      return;
    }
    if (!formData.startTime || !formData.endTime) {
      alert('促销开始时间和结束时间不能为空');
      return;
    }
    if (new Date(formData.startTime) >= new Date(formData.endTime)) {
      alert('促销结束时间必须晚于开始时间');
      return;
    }
    if (!formData.discountPercentage || isNaN(formData.discountPercentage)) {
      alert('折扣百分比必须是数字');
      return;
    }

    const applicableTorrentIds = torrents.map(t => t.id);

    const newPromo = {
      name: formData.name,
      startTime: new Date(formData.startTime).toISOString(),
      endTime: new Date(formData.endTime).toISOString(),
      discountPercentage: Number(formData.discountPercentage),
      uploadCoeff: formData.uploadCoeff ? Number(formData.uploadCoeff) : undefined,
      downloadCoeff: formData.downloadCoeff ? Number(formData.downloadCoeff) : undefined,
      applicableTorrentIds: JSON.stringify(applicableTorrentIds), // ✅ 关键修改
      description: formData.description
    };


    try {
      const res = await fetch('/seeds/promotions', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(newPromo)
      });
      const json = await res.json();
      if (json.code === 200) {
        alert('促销活动创建成功');
        fetchData();
        setShowCreateDialog(false);
      } else {
        alert('创建失败: ' + (json.msg || '未知错误'));
      }
    } catch (err) {
      console.error('创建促销失败:', err);
      alert('创建促销失败');
    }
  };

  const handleDeletePromotion = async (promotionId) => {
    if (!window.confirm('确认删除该促销活动吗？')) return;

    try {
      const res = await fetch(`/seeds/promotions/${promotionId}`, { method: 'DELETE' });
      const json = await res.json();
      if (json.success) {
        alert('删除成功');
        fetchData();
      } else {
        alert('删除失败: ' + json.message);
      }
    } catch (err) {
      console.error('删除失败:', err);
    }
  };

  const isAdmin = user?.role === 'admin';
  const prevPromo = () => setPromoIndex((promoIndex - 1 + promotions.length) % promotions.length);
    const nextPromo = () => setPromoIndex((promoIndex + 1) % promotions.length);
  const currentPromo = promotions[promoIndex];

  if (loading) {
    return <div className="promotion-container">加载中...</div>;
  }

  return (
    <div className="promotion-container carousel-container">
      <section className="carousel-section">
        <h2>当前促销活动</h2>

        {isAdmin && (
          <button className="create-btn" onClick={openCreateDialog}>
            创建促销活动
          </button>
        )}

        {promotions.length === 0 || !currentPromo ? (
          <div className="empty-state">暂无促销活动</div>
        ) : (
          <div
            className="carousel"
            onMouseEnter={() => clearInterval(promoTimerRef.current)}
            onMouseLeave={() => {
              promoTimerRef.current = setInterval(() => {
                setPromoIndex(prev => (prev + 1) % promotions.length);
              }, 3000);
            }}
          >
            <button className="arrow left" onClick={prevPromo}>&lt;</button>
            <div className="slide">
              <div><strong>促销名称：</strong>{currentPromo?.name ?? '未知'}</div>
              <div><strong>促销时间：</strong>
                {currentPromo?.pStartTime && currentPromo?.pEndTime
                  ? `${new Date(currentPromo.pStartTime).toLocaleString()} ～ ${new Date(currentPromo.pEndTime).toLocaleString()}`
                  : '未知'}
              </div>
              <div><strong>上传奖励系数：</strong>{currentPromo?.uploadCoeff ?? '无'}</div>
              <div><strong>下载折扣系数：</strong>{currentPromo?.downloadCoeff ?? '无'}</div>
              {currentPromo?.description && (
                <div><strong>描述：</strong>{currentPromo.description}</div>
              )}
              {isAdmin && (
                <button className="delete-btn" onClick={() => handleDeletePromotion(currentPromo.id)}>
                  删除该活动
                </button>
              )}
            </div>
            <button className="arrow right" onClick={nextPromo}>&gt;</button>
          </div>
        )}
      </section>

      {/* 创建促销活动弹窗 */}
      {showCreateDialog && (
        <div className="dialog-overlay">
          <div className="dialog">
            <h3>创建促销活动</h3>
            <div className="form-item">
              <label>促销名称：</label>
              <input
                type="text"
                name="name"
                value={formData.name}
                onChange={handleInputChange}
                placeholder="请输入促销名称"
              />
            </div>
            <div className="form-item">
              <label>开始时间：</label>
              <input
                type="datetime-local"
                name="startTime"
                value={formData.startTime}
                onChange={handleInputChange}
              />
            </div>
            <div className="form-item">
              <label>结束时间：</label>
              <input
                type="datetime-local"
                name="endTime"
                value={formData.endTime}
                onChange={handleInputChange}
              />
            </div>
            <div className="form-item">
              <label>折扣百分比(数字)：</label>
              <input
                type="number"
                name="discountPercentage"
                value={formData.discountPercentage}
                onChange={handleInputChange}
                placeholder="例如：20 表示 20% 折扣"
                min="0"
                max="100"
              />
            </div>
            <div className="form-item">
              <label>上传奖励系数(可选)：</label>
              <input
                type="number"
                name="uploadCoeff"
                value={formData.uploadCoeff}
                onChange={handleInputChange}
                placeholder="例如：1.5"
                step="0.1"
              />
            </div>
            <div className="form-item">
              <label>下载折扣系数(可选)：</label>
              <input
                type="number"
                name="downloadCoeff"
                value={formData.downloadCoeff}
                onChange={handleInputChange}
                placeholder="例如：0.8"
                step="0.1"
              />
            </div>
            <div className="form-item">
              <label>描述(可选)：</label>
              <textarea
                name="description"
                value={formData.description}
                onChange={handleInputChange}
                placeholder="促销活动描述"
                rows={3}
              />
            </div>
            <div className="dialog-buttons">
              <button onClick={handleCreatePromotion}>确定</button>
              <button onClick={closeCreateDialog}>取消</button>
            </div>
          </div>
        </div>
      )}
    </div>
  );
};

export default Promotion;


// import React, { useEffect, useState, useRef } from 'react';
// import './Promotion.css';
// import { useUser } from '../../../context/UserContext';

// const Promotion = () => {
//   const { user } = useUser();
//   const [promotions, setPromotions] = useState([]);
//   const [torrents, setTorrents] = useState([]);
//   const [loading, setLoading] = useState(true);
//   const [promoIndex, setPromoIndex] = useState(0);
//   const promoTimerRef = useRef(null);

//   // 新增：控制模态框显示与表单状态
//   const [showCreateModal, setShowCreateModal] = useState(false);
//   const [formData, setFormData] = useState({
//     name: '',
//     description: '',
//     discountPercentage: 0,
//     startTime: '',
//     endTime: '',
//     applicableTorrentIds: [],
//   });

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

//   useEffect(() => {
//     if (promotions.length === 0) return;
//     clearInterval(promoTimerRef.current);
//     promoTimerRef.current = setInterval(() => {
//       setPromoIndex(prev => (prev + 1) % promotions.length);
//     }, 5000);
//     return () => clearInterval(promoTimerRef.current);
//   }, [promotions]);

//   const fetchData = async () => {
//     try {
//       const response = await fetch('/seeds/promotions');
//       const json = await response.json();
//       const promoData = Array.isArray(json?.data) ? json.data : [];
//       setPromotions(promoData);
//     } catch (error) {
//       console.error('获取促销活动失败:', error);
//     } finally {
//       setLoading(false);
//     }
//   };

//   const fetchTorrentList = async () => {
//     try {
//       const response = await fetch('/seeds/list');
//       const json = await response.json();
//       const torrentList = Array.isArray(json?.data) ? json.data : [];
//       setTorrents(torrentList);
//     } catch (error) {
//       console.error('获取种子列表失败:', error);
//     }
//   };

//   // 打开模态框时，重置表单数据，默认设置时间并填入所有种子ID
//   const openCreateModal = () => {
//     if (torrents.length === 0) {
//       alert('没有可用的种子，请先上传种子');
//       return;
//     }
//     setFormData({
//       name: '',
//       description: '',
//       discountPercentage: 20,
//       startTime: new Date().toISOString().slice(0, 16), // 用于datetime-local输入框，格式 YYYY-MM-DDTHH:mm
//       endTime: new Date(Date.now() + 7 * 86400000).toISOString().slice(0, 16),
//       applicableTorrentIds: torrents.map(t => t.id),
//     });
//     setShowCreateModal(true);
//   };

//   // 表单输入处理
//   const handleInputChange = (e) => {
//     const { name, value } = e.target;
//     setFormData(prev => ({
//       ...prev,
//       [name]: name === 'discountPercentage' ? Number(value) : value,
//     }));
//   };

//   // 点击确定提交创建
//   const handleCreateConfirm = async () => {
//     if (!formData.name) {
//       alert('促销名称不能为空');
//       return;
//     }
//     if (!formData.startTime || !formData.endTime) {
//       alert('请选择开始时间和结束时间');
//       return;
//     }
//     if (formData.discountPercentage <= 0 || formData.discountPercentage >= 100) {
//       alert('折扣百分比应在1-99之间');
//       return;
//     }
//     if (!formData.applicableTorrentIds.length) {
//       alert('请选择适用的种子');
//       return;
//     }

//     // 准备发送数据，适配后端字段名
//     const newPromo = {
//       name: formData.name,
//       description: formData.description,
//       discountPercentage: formData.discountPercentage,
//       startTime: new Date(formData.startTime).toISOString(),
//       endTime: new Date(formData.endTime).toISOString(),
//       applicableTorrentIds: formData.applicableTorrentIds,
//     };

//     try {
//       const res = await fetch('/seeds/promotions', {
//         method: 'POST',
//         headers: { 'Content-Type': 'application/json' },
//         body: JSON.stringify(newPromo),
//       });
//       const json = await res.json();
//       if (json.code === 200) {
//         alert('促销活动创建成功');
//         setShowCreateModal(false);
//         fetchData();
//       } else {
//         alert('创建失败: ' + (json.msg || '未知错误'));
//       }
//     } catch (err) {
//       console.error('创建促销失败:', err);
//       alert('创建促销失败');
//     }
//   };

//   const handleCancel = () => {
//     setShowCreateModal(false);
//   };

//   const handleDeletePromotion = async (promotionId) => {
//     if (!window.confirm('确认删除该促销活动吗？')) return;

//     try {
//       const res = await fetch(`/seeds/promotions/${promotionId}`, { method: 'DELETE' });
//       const json = await res.json();
//       if (json.success) {
//         alert('删除成功');
//         fetchData();
//       } else {
//         alert('删除失败: ' + json.message);
//       }
//     } catch (err) {
//       console.error('删除失败:', err);
//     }
//   };

//   const isAdmin = user?.role === 'admin';
//   const prevPromo = () => setPromoIndex((promoIndex - 1 + promotions.length) % promotions.length);
//   const nextPromo = () => setPromoIndex((promoIndex + 1) % promotions.length);
//   const currentPromo = promotions[promoIndex];

//   if (loading) {
//     return <div className="promotion-container">加载中...</div>;
//   }

//   return (
//     <div className="promotion-container carousel-container">
//       <section className="carousel-section">
//         <h2>当前促销活动</h2>

//         {isAdmin && (
//           <button className="create-btn" onClick={openCreateModal}>
//             创建促销活动
//           </button>
//         )}

//         {promotions.length === 0 || !currentPromo ? (
//           <div className="empty-state">暂无促销活动</div>
//         ) : (
//           <div
//             className="carousel"
//             onMouseEnter={() => clearInterval(promoTimerRef.current)}
//             onMouseLeave={() => {
//               promoTimerRef.current = setInterval(() => {
//                 setPromoIndex(prev => (prev + 1) % promotions.length);
//               }, 3000);
//             }}
//           >
//             <button className="arrow left" onClick={prevPromo}>&lt;</button>
//             <div className="slide">
//               <div><strong>促销名称：</strong>{currentPromo?.name ?? '未知'}</div>
//               <div><strong>促销时间：</strong>
//                 {currentPromo?.startTime && currentPromo?.endTime
//                   ? `${new Date(currentPromo.startTime).toLocaleString()} ～ ${new Date(currentPromo.endTime).toLocaleString()}`
//                   : '未知'}
//               </div>
//               <div><strong>折扣百分比：</strong>{currentPromo?.discountPercentage ?? '无'}</div>
//               {currentPromo?.description && (
//                 <div><strong>描述：</strong>{currentPromo.description}</div>
//               )}
//               {isAdmin && (
//                 <button className="delete-btn" onClick={() => handleDeletePromotion(currentPromo.id)}>
//                   删除该活动
//                 </button>
//               )}
//             </div>
//             <button className="arrow right" onClick={nextPromo}>&gt;</button>
//           </div>
//         )}
//       </section>

//       {/* 创建促销模态框 */}
//       {showCreateModal && (
//         <div className="modal-overlay">
//           <div className="modal-content">
//             <h3>创建促销活动</h3>
//             <label>
//               促销名称:
//               <input
//                 type="text"
//                 name="name"
//                 value={formData.name}
//                 onChange={handleInputChange}
//               />
//             </label>
//             <label>
//               描述:
//               <textarea
//                 name="description"
//                 value={formData.description}
//                 onChange={handleInputChange}
//                 rows={3}
//               />
//             </label>
//             <label>
//               折扣百分比:
//               <input
//                 type="number"
//                 name="discountPercentage"
//                 value={formData.discountPercentage}
//                 min={1}
//                 max={99}
//                 onChange={handleInputChange}
//               />
//             </label>
//             <label>
//               开始时间:
//               <input
//                 type="datetime-local"
//                 name="startTime"
//                 value={formData.startTime}
//                 onChange={handleInputChange}
//               />
//             </label>
//             <label>
//               结束时间:
//               <input
//                 type="datetime-local"
//                 name="endTime"
//                 value={formData.endTime}
//                 onChange={handleInputChange}
//               />
//             </label>
//             <label>
//               适用种子ID（逗号分隔，可留空默认所有）:
//               <input
//                 type="text"
//                 name="applicableTorrentIds"
//                 value={formData.applicableTorrentIds.join(',')}
//                 onChange={(e) => {
//                   const ids = e.target.value
//                     .split(',')
//                     .map(id => id.trim())
//                     .filter(id => id !== '')
//                     .map(id => Number(id))
//                     .filter(id => !isNaN(id));
//                   setFormData(prev => ({ ...prev, applicableTorrentIds: ids }));
//                 }}
//               />
//             </label>

//             <div className="modal-buttons">
//               <button onClick={handleCreateConfirm}>确定</button>
//               <button onClick={handleCancel}>取消</button>
//             </div>
//           </div>
//         </div>
//       )}

//       {/* 模态框简单样式 */}
//       <style>{`
//         .modal-overlay {
//           position: fixed;
//           top: 0; left: 0; right: 0; bottom: 0;
//           background: rgba(0,0,0,0.4);
//           display: flex;
//           justify-content: center;
//           align-items: center;
//           z-index: 999;
//         }
//         .modal-content {
//           background: white;
//           padding: 20px;
//           border-radius: 6px;
//           width: 320px;
//           max-width: 90%;
//         }
//         .modal-content label {
//           display: block;
//           margin-bottom: 10px;
//           font-size: 14px;
//         }
//         .modal-content input[type="text"],
//         .modal-content input[type="number"],
//         .modal-content input[type="datetime-local"],
//         .modal-content textarea {
//           width: 100%;
//           box-sizing: border-box;
//           padding: 5px;
//           font-size: 14px;
//           margin-top: 4px;
//         }
//         .modal-buttons {
//           margin-top: 15px;
//           text-align: right;
//         }
//         .modal-buttons button {
//           margin-left: 10px;
//           padding: 6px 12px;
//           font-size: 14px;
//         }
//       `}</style>
//     </div>
//   );
// };

// export default Promotion;


// import React, { useEffect, useState, useRef } from 'react';
// import './Promotion.css';
// import { useUser } from '../../../context/UserContext';

// const Promotion = () => {
//   const { user } = useUser();
//   const [promotions, setPromotions] = useState([]);
//   const [torrents, setTorrents] = useState([]); // 新增，存放种子列表
//   const [loading, setLoading] = useState(true);
//   const [promoIndex, setPromoIndex] = useState(0);
//   const promoTimerRef = useRef(null);

//   useEffect(() => {
//     fetchData();
//     fetchTorrentList();  // 新增，获取种子列表
//   }, []);

//   useEffect(() => {
//     if (promotions.length === 0) return;
//     clearInterval(promoTimerRef.current);
//     promoTimerRef.current = setInterval(() => {
//       setPromoIndex(prev => (prev + 1) % promotions.length);
//     }, 5000);
//     return () => clearInterval(promoTimerRef.current);
//   }, [promotions]);

//   // 获取促销数据
//   const fetchData = async () => {
//     try {
//       const response = await fetch('/seeds/promotions');
//       const json = await response.json();
//       const promoData = Array.isArray(json?.data) ? json.data : [];
//       setPromotions(promoData);
//     } catch (error) {
//       console.error('获取促销活动失败:', error);
//     } finally {
//       setLoading(false);
//     }
//   };

//   // 获取种子列表，赋值给torrents
//   const fetchTorrentList = async () => {
//     try {
//       const response = await fetch('/seeds/list');
//       const json = await response.json();
//       const torrentList = Array.isArray(json?.data) ? json.data : [];
//       setTorrents(torrentList);
//     } catch (error) {
//       console.error('获取种子列表失败:', error);
//     }
//   };

//   // 创建促销时，自动使用当前种子的id列表，而不是写死
//   const handleCreatePromotion = async () => {
//     if (torrents.length === 0) {
//       alert('没有可用的种子，请先上传种子');
//       return;
//     }

//     const applicableTorrentIds = torrents.map(t => t.id); // 获取所有种子id数组

//     const newPromo = {
//       name: '测试促销活动',
//       startTime: new Date().toISOString(),
//       endTime: new Date(Date.now() + 7 * 86400000).toISOString(),
//       discountPercentage: 20,
//       applicableTorrentIds: applicableTorrentIds, // 动态传入种子ID数组
//       description: '这是一个测试促销活动'
//     };

//     try {
//       const res = await fetch('/seeds/promotions', {
//         method: 'POST',
//         headers: {
//           'Content-Type': 'application/json'
//         },
//         body: JSON.stringify(newPromo)
//       });
//       const json = await res.json();
//       if (json.code === 200) {
//         alert('促销活动创建成功');
//         fetchData();
//       } else {
//         alert('创建失败: ' + (json.msg || '未知错误'));
//       }
//     } catch (err) {
//       console.error('创建促销失败:', err);
//       alert('创建促销失败');
//     }
//   };

//   const handleDeletePromotion = async (promotionId) => {
//     if (!window.confirm('确认删除该促销活动吗？')) return;

//     try {
//       const res = await fetch(`/seeds/promotions/${promotionId}`, {
//         method: 'DELETE'
//       });
//       const json = await res.json();
//       if (json.success) {
//         alert('删除成功');
//         fetchData();
//       } else {
//         alert('删除失败: ' + json.message);
//       }
//     } catch (err) {
//       console.error('删除失败:', err);
//     }
//   };

//   const isAdmin = user?.role === 'admin';
//   const prevPromo = () => setPromoIndex((promoIndex - 1 + promotions.length) % promotions.length);
//   const nextPromo = () => setPromoIndex((promoIndex + 1) % promotions.length);
//   const currentPromo = promotions[promoIndex];

//   if (loading) {
//     return <div className="promotion-container">加载中...</div>;
//   }

//   return (
//     <div className="promotion-container carousel-container">
//       <section className="carousel-section">
//         <h2>当前促销活动</h2>

//         {isAdmin && (
//           <button className="create-btn" onClick={handleCreatePromotion}>
//             创建促销活动
//           </button>
//         )}

//         {promotions.length === 0 || !currentPromo ? (
//           <div className="empty-state">暂无促销活动</div>
//         ) : (
//           <div
//             className="carousel"
//             onMouseEnter={() => clearInterval(promoTimerRef.current)}
//             onMouseLeave={() => {
//               promoTimerRef.current = setInterval(() => {
//                 setPromoIndex(prev => (prev + 1) % promotions.length);
//               }, 3000);
//             }}
//           >
//             <button className="arrow left" onClick={prevPromo}>&lt;</button>
//             <div className="slide">
//               <div><strong>促销名称：</strong>{currentPromo?.name ?? '未知'}</div>
//               <div><strong>促销时间：</strong>
//                 {currentPromo?.pStartTime && currentPromo?.pEndTime
//                   ? `${new Date(currentPromo.pStartTime).toLocaleString()} ～ ${new Date(currentPromo.pEndTime).toLocaleString()}`
//                   : '未知'}
//               </div>
//               <div><strong>上传奖励系数：</strong>{currentPromo?.uploadCoeff ?? '无'}</div>
//               <div><strong>下载折扣系数：</strong>{currentPromo?.downloadCoeff ?? '无'}</div>
//               {currentPromo?.description && (
//                 <div><strong>描述：</strong>{currentPromo.description}</div>
//               )}
//               {isAdmin && (
//                 <button className="delete-btn" onClick={() => handleDeletePromotion(currentPromo.id)}>
//                   删除该活动
//                 </button>
//               )}
//             </div>
//             <button className="arrow right" onClick={nextPromo}>&gt;</button>
//           </div>
//         )}
//       </section>
//     </div>
//   );
// };

// export default Promotion;