加入优惠码机制，预置3个优惠码

app.py

@@ -776,6 +776,10 @@ class PaymentOrder(db.Model):
             'plan_name': self.plan_name,
             'billing_cycle': self.billing_cycle,
             'amount': float(self.amount) if self.amount else 0,
+            'original_amount': float(self.original_amount) if hasattr(self, 'original_amount') and self.original_amount else None,
+            'discount_amount': float(self.discount_amount) if hasattr(self, 'discount_amount') and self.discount_amount else 0,
+            'promo_code': self.promo_code.code if hasattr(self, 'promo_code') and self.promo_code else None,
+            'is_upgrade': self.is_upgrade if hasattr(self, 'is_upgrade') else False,
             'qr_code_url': self.qr_code_url,
             'status': self.status,
             'is_expired': self.is_expired(),
@@ -786,6 +790,107 @@ class PaymentOrder(db.Model):
         }
 
 
+class PromoCode(db.Model):
+    """优惠码表"""
+    __tablename__ = 'promo_codes'
+
+    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
+    code = db.Column(db.String(50), unique=True, nullable=False, index=True)
+    description = db.Column(db.String(200), nullable=True)
+
+    # 折扣类型和值
+    discount_type = db.Column(db.String(20), nullable=False)  # 'percentage' 或 'fixed_amount'
+    discount_value = db.Column(db.Numeric(10, 2), nullable=False)
+
+    # 适用范围
+    applicable_plans = db.Column(db.String(200), nullable=True)  # JSON格式
+    applicable_cycles = db.Column(db.String(50), nullable=True)  # JSON格式
+    min_amount = db.Column(db.Numeric(10, 2), nullable=True)
+
+    # 使用限制
+    max_uses = db.Column(db.Integer, nullable=True)
+    max_uses_per_user = db.Column(db.Integer, default=1)
+    current_uses = db.Column(db.Integer, default=0)
+
+    # 有效期
+    valid_from = db.Column(db.DateTime, nullable=False)
+    valid_until = db.Column(db.DateTime, nullable=False)
+
+    # 状态
+    is_active = db.Column(db.Boolean, default=True)
+    created_by = db.Column(db.Integer, nullable=True)
+    created_at = db.Column(db.DateTime, default=beijing_now)
+    updated_at = db.Column(db.DateTime, default=beijing_now, onupdate=beijing_now)
+
+    def to_dict(self):
+        return {
+            'id': self.id,
+            'code': self.code,
+            'description': self.description,
+            'discount_type': self.discount_type,
+            'discount_value': float(self.discount_value) if self.discount_value else 0,
+            'applicable_plans': json.loads(self.applicable_plans) if self.applicable_plans else None,
+            'applicable_cycles': json.loads(self.applicable_cycles) if self.applicable_cycles else None,
+            'min_amount': float(self.min_amount) if self.min_amount else None,
+            'max_uses': self.max_uses,
+            'max_uses_per_user': self.max_uses_per_user,
+            'current_uses': self.current_uses,
+            'valid_from': self.valid_from.isoformat() if self.valid_from else None,
+            'valid_until': self.valid_until.isoformat() if self.valid_until else None,
+            'is_active': self.is_active
+        }
+
+
+class PromoCodeUsage(db.Model):
+    """优惠码使用记录表"""
+    __tablename__ = 'promo_code_usage'
+
+    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
+    promo_code_id = db.Column(db.Integer, db.ForeignKey('promo_codes.id'), nullable=False)
+    user_id = db.Column(db.Integer, nullable=False, index=True)
+    order_id = db.Column(db.Integer, db.ForeignKey('payment_orders.id'), nullable=False)
+
+    original_amount = db.Column(db.Numeric(10, 2), nullable=False)
+    discount_amount = db.Column(db.Numeric(10, 2), nullable=False)
+    final_amount = db.Column(db.Numeric(10, 2), nullable=False)
+
+    used_at = db.Column(db.DateTime, default=beijing_now)
+
+    # 关系
+    promo_code = db.relationship('PromoCode', backref='usages')
+    order = db.relationship('PaymentOrder', backref='promo_usage')
+
+
+class SubscriptionUpgrade(db.Model):
+    """订阅升级/降级记录表"""
+    __tablename__ = 'subscription_upgrades'
+
+    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
+    user_id = db.Column(db.Integer, nullable=False, index=True)
+    order_id = db.Column(db.Integer, db.ForeignKey('payment_orders.id'), nullable=False)
+
+    # 原订阅信息
+    from_plan = db.Column(db.String(20), nullable=False)
+    from_cycle = db.Column(db.String(10), nullable=False)
+    from_end_date = db.Column(db.DateTime, nullable=True)
+
+    # 新订阅信息
+    to_plan = db.Column(db.String(20), nullable=False)
+    to_cycle = db.Column(db.String(10), nullable=False)
+    to_end_date = db.Column(db.DateTime, nullable=False)
+
+    # 价格计算
+    remaining_value = db.Column(db.Numeric(10, 2), nullable=False)
+    upgrade_amount = db.Column(db.Numeric(10, 2), nullable=False)
+    actual_amount = db.Column(db.Numeric(10, 2), nullable=False)
+
+    upgrade_type = db.Column(db.String(20), nullable=False)  # 'plan_upgrade', 'cycle_change', 'both'
+    created_at = db.Column(db.DateTime, default=beijing_now)
+
+    # 关系
+    order = db.relationship('PaymentOrder', backref='upgrade_record')
+
+
 # ============================================
 # 模拟盘相关模型
 # ============================================
@@ -982,8 +1087,15 @@ def get_user_subscription_safe(user_id):
         return DefaultSub()
 
 
-def activate_user_subscription(user_id, plan_type, billing_cycle):
-    """激活用户订阅"""
+def activate_user_subscription(user_id, plan_type, billing_cycle, extend_from_now=False):
+    """激活用户订阅
+
+    Args:
+        user_id: 用户ID
+        plan_type: 套餐类型
+        billing_cycle: 计费周期
+        extend_from_now: 是否从当前时间开始延长（用于升级场景）
+    """
     try:
         subscription = UserSubscription.query.filter_by(user_id=user_id).first()
         if not subscription:
@@ -993,7 +1105,9 @@ def activate_user_subscription(user_id, plan_type, billing_cycle):
         subscription.subscription_type = plan_type
         subscription.subscription_status = 'active'
         subscription.billing_cycle = billing_cycle
-        subscription.start_date = beijing_now()
+
+        if not extend_from_now or not subscription.start_date:
+            subscription.start_date = beijing_now()
 
         if billing_cycle == 'monthly':
             subscription.end_date = beijing_now() + timedelta(days=30)
@@ -1007,6 +1121,195 @@ def activate_user_subscription(user_id, plan_type, billing_cycle):
         return None
 
 
+def validate_promo_code(code, plan_name, billing_cycle, amount, user_id):
+    """验证优惠码
+
+    Returns:
+        tuple: (promo_code_obj, error_message)
+    """
+    try:
+        promo = PromoCode.query.filter_by(code=code.upper(), is_active=True).first()
+
+        if not promo:
+            return None, "优惠码不存在或已失效"
+
+        # 检查有效期
+        now = beijing_now()
+        if now < promo.valid_from:
+            return None, "优惠码尚未生效"
+        if now > promo.valid_until:
+            return None, "优惠码已过期"
+
+        # 检查使用次数
+        if promo.max_uses and promo.current_uses >= promo.max_uses:
+            return None, "优惠码已被使用完"
+
+        # 检查每用户使用次数
+        if promo.max_uses_per_user:
+            user_usage_count = PromoCodeUsage.query.filter_by(
+                promo_code_id=promo.id,
+                user_id=user_id
+            ).count()
+            if user_usage_count >= promo.max_uses_per_user:
+                return None, f"您已使用过此优惠码（限用{promo.max_uses_per_user}次）"
+
+        # 检查适用套餐
+        if promo.applicable_plans:
+            try:
+                applicable = json.loads(promo.applicable_plans)
+                if plan_name not in applicable:
+                    return None, "该优惠码不适用于此套餐"
+            except:
+                pass
+
+        # 检查适用周期
+        if promo.applicable_cycles:
+            try:
+                applicable = json.loads(promo.applicable_cycles)
+                if billing_cycle not in applicable:
+                    return None, "该优惠码不适用于此计费周期"
+            except:
+                pass
+
+        # 检查最低消费
+        if promo.min_amount and amount < float(promo.min_amount):
+            return None, f"需满{float(promo.min_amount):.2f}元才可使用此优惠码"
+
+        return promo, None
+    except Exception as e:
+        return None, f"验证优惠码时出错: {str(e)}"
+
+
+def calculate_discount(promo_code, amount):
+    """计算优惠金额"""
+    try:
+        if promo_code.discount_type == 'percentage':
+            discount = amount * (float(promo_code.discount_value) / 100)
+        else:  # fixed_amount
+            discount = float(promo_code.discount_value)
+
+        # 确保折扣不超过总金额
+        return min(discount, amount)
+    except:
+        return 0
+
+
+def calculate_remaining_value(subscription, current_plan):
+    """计算当前订阅的剩余价值"""
+    try:
+        if not subscription or not subscription.end_date:
+            return 0
+
+        now = beijing_now()
+        if subscription.end_date <= now:
+            return 0
+
+        days_left = (subscription.end_date - now).days
+
+        if subscription.billing_cycle == 'monthly':
+            daily_value = float(current_plan.monthly_price) / 30
+        else:  # yearly
+            daily_value = float(current_plan.yearly_price) / 365
+
+        return daily_value * days_left
+    except:
+        return 0
+
+
+def calculate_upgrade_price(user_id, to_plan_name, to_cycle, promo_code=None):
+    """计算升级所需价格
+
+    Returns:
+        dict: 包含价格计算结果的字典
+    """
+    try:
+        # 1. 获取当前订阅
+        current_sub = UserSubscription.query.filter_by(user_id=user_id).first()
+
+        # 2. 获取目标套餐
+        to_plan = SubscriptionPlan.query.filter_by(name=to_plan_name, is_active=True).first()
+        if not to_plan:
+            return {'error': '目标套餐不存在'}
+
+        # 3. 计算目标套餐价格
+        new_price = float(to_plan.yearly_price if to_cycle == 'yearly' else to_plan.monthly_price)
+
+        # 4. 如果是新订阅（非升级）
+        if not current_sub or current_sub.subscription_type == 'free':
+            result = {
+                'is_upgrade': False,
+                'new_plan_price': new_price,
+                'remaining_value': 0,
+                'upgrade_amount': new_price,
+                'original_amount': new_price,
+                'discount_amount': 0,
+                'final_amount': new_price,
+                'promo_code': None
+            }
+
+            # 应用优惠码
+            if promo_code:
+                promo, error = validate_promo_code(promo_code, to_plan_name, to_cycle, new_price, user_id)
+                if promo:
+                    discount = calculate_discount(promo, new_price)
+                    result['discount_amount'] = discount
+                    result['final_amount'] = new_price - discount
+                    result['promo_code'] = promo.code
+                elif error:
+                    result['promo_error'] = error
+
+            return result
+
+        # 5. 升级场景：计算剩余价值
+        current_plan = SubscriptionPlan.query.filter_by(name=current_sub.subscription_type, is_active=True).first()
+        if not current_plan:
+            return {'error': '当前套餐信息不存在'}
+
+        remaining_value = calculate_remaining_value(current_sub, current_plan)
+
+        # 6. 计算升级差价
+        upgrade_amount = max(0, new_price - remaining_value)
+
+        # 7. 判断升级类型
+        upgrade_type = 'new'
+        if current_sub.subscription_type != to_plan_name and current_sub.billing_cycle != to_cycle:
+            upgrade_type = 'both'
+        elif current_sub.subscription_type != to_plan_name:
+            upgrade_type = 'plan_upgrade'
+        elif current_sub.billing_cycle != to_cycle:
+            upgrade_type = 'cycle_change'
+
+        result = {
+            'is_upgrade': True,
+            'upgrade_type': upgrade_type,
+            'current_plan': current_sub.subscription_type,
+            'current_cycle': current_sub.billing_cycle,
+            'current_end_date': current_sub.end_date.isoformat() if current_sub.end_date else None,
+            'new_plan_price': new_price,
+            'remaining_value': remaining_value,
+            'upgrade_amount': upgrade_amount,
+            'original_amount': upgrade_amount,
+            'discount_amount': 0,
+            'final_amount': upgrade_amount,
+            'promo_code': None
+        }
+
+        # 8. 应用优惠码
+        if promo_code and upgrade_amount > 0:
+            promo, error = validate_promo_code(promo_code, to_plan_name, to_cycle, upgrade_amount, user_id)
+            if promo:
+                discount = calculate_discount(promo, upgrade_amount)
+                result['discount_amount'] = discount
+                result['final_amount'] = upgrade_amount - discount
+                result['promo_code'] = promo.code
+            elif error:
+                result['promo_error'] = error
+
+        return result
+    except Exception as e:
+        return {'error': str(e)}
+
+
 def initialize_subscription_plans_safe():
     """安全地初始化订阅套餐"""
     try:
@@ -1189,9 +1492,90 @@ def get_subscription_info():
         })
 
 
+@app.route('/api/promo-code/validate', methods=['POST'])
+def validate_promo_code_api():
+    """验证优惠码"""
+    try:
+        if 'user_id' not in session:
+            return jsonify({'success': False, 'error': '未登录'}), 401
+
+        data = request.get_json()
+        code = data.get('code', '').strip()
+        plan_name = data.get('plan_name')
+        billing_cycle = data.get('billing_cycle')
+        amount = data.get('amount', 0)
+
+        if not code or not plan_name or not billing_cycle:
+            return jsonify({'success': False, 'error': '参数不完整'}), 400
+
+        # 验证优惠码
+        promo, error = validate_promo_code(code, plan_name, billing_cycle, amount, session['user_id'])
+
+        if error:
+            return jsonify({
+                'success': False,
+                'valid': False,
+                'error': error
+            })
+
+        # 计算折扣
+        discount_amount = calculate_discount(promo, amount)
+        final_amount = amount - discount_amount
+
+        return jsonify({
+            'success': True,
+            'valid': True,
+            'promo_code': promo.to_dict(),
+            'discount_amount': discount_amount,
+            'final_amount': final_amount
+        })
+
+    except Exception as e:
+        return jsonify({
+            'success': False,
+            'error': f'验证失败: {str(e)}'
+        }), 500
+
+
+@app.route('/api/subscription/calculate-price', methods=['POST'])
+def calculate_subscription_price():
+    """计算订阅价格（支持升级和优惠码）"""
+    try:
+        if 'user_id' not in session:
+            return jsonify({'success': False, 'error': '未登录'}), 401
+
+        data = request.get_json()
+        to_plan = data.get('to_plan')
+        to_cycle = data.get('to_cycle')
+        promo_code = data.get('promo_code', '').strip() or None
+
+        if not to_plan or not to_cycle:
+            return jsonify({'success': False, 'error': '参数不完整'}), 400
+
+        # 计算价格
+        result = calculate_upgrade_price(session['user_id'], to_plan, to_cycle, promo_code)
+
+        if 'error' in result:
+            return jsonify({
+                'success': False,
+                'error': result['error']
+            }), 400
+
+        return jsonify({
+            'success': True,
+            'data': result
+        })
+
+    except Exception as e:
+        return jsonify({
+            'success': False,
+            'error': f'计算失败: {str(e)}'
+        }), 500
+
+
 @app.route('/api/payment/create-order', methods=['POST'])
 def create_payment_order():
-    """创建支付订单"""
+    """创建支付订单（支持升级和优惠码）"""
     try:
         if 'user_id' not in session:
             return jsonify({'success': False, 'error': '未登录'}), 401
@@ -1199,23 +1583,21 @@ def create_payment_order():
         data = request.get_json()
         plan_name = data.get('plan_name')
         billing_cycle = data.get('billing_cycle')
+        promo_code = data.get('promo_code', '').strip() or None
 
         if not plan_name or not billing_cycle:
             return jsonify({'success': False, 'error': '参数不完整'}), 400
 
-        # 获取套餐信息
-        try:
-            plan = SubscriptionPlan.query.filter_by(name=plan_name, is_active=True).first()
-            if not plan:
-                # 如果表不存在，使用默认价格
-                prices = {'pro': {'monthly': 0.01, 'yearly': 0.08}, 'max': {'monthly': 0.1, 'yearly': 0.8}}
-                amount = prices.get(plan_name, {}).get(billing_cycle, 0.01)
-            else:
-                amount = plan.monthly_price if billing_cycle == 'monthly' else plan.yearly_price
-        except:
-            # 默认价格
-            prices = {'pro': {'monthly': 0.01, 'yearly': 0.08}, 'max': {'monthly': 0.1, 'yearly': 0.8}}
-            amount = prices.get(plan_name, {}).get(billing_cycle, 0.01)
+        # 计算价格（包括升级和优惠码）
+        price_result = calculate_upgrade_price(session['user_id'], plan_name, billing_cycle, promo_code)
+
+        if 'error' in price_result:
+            return jsonify({'success': False, 'error': price_result['error']}), 400
+
+        amount = price_result['final_amount']
+        original_amount = price_result['original_amount']
+        discount_amount = price_result['discount_amount']
+        is_upgrade = price_result.get('is_upgrade', False)
 
         # 创建订单
         try:
@@ -1225,10 +1607,52 @@ def create_payment_order():
                 billing_cycle=billing_cycle,
                 amount=amount
             )
+
+            # 添加扩展字段（使用动态属性）
+            if hasattr(order, 'original_amount') or True:  # 兼容性检查
+                order.original_amount = original_amount
+                order.discount_amount = discount_amount
+                order.is_upgrade = is_upgrade
+
+                # 如果使用了优惠码，关联优惠码
+                if promo_code and price_result.get('promo_code'):
+                    promo_obj = PromoCode.query.filter_by(code=promo_code.upper()).first()
+                    if promo_obj:
+                        order.promo_code_id = promo_obj.id
+
+                # 如果是升级，记录原套餐信息
+                if is_upgrade:
+                    order.upgrade_from_plan = price_result.get('current_plan')
+
             db.session.add(order)
             db.session.commit()
+
+            # 如果是升级订单，创建升级记录
+            if is_upgrade and price_result.get('upgrade_type'):
+                try:
+                    upgrade_record = SubscriptionUpgrade(
+                        user_id=session['user_id'],
+                        order_id=order.id,
+                        from_plan=price_result['current_plan'],
+                        from_cycle=price_result['current_cycle'],
+                        from_end_date=datetime.fromisoformat(price_result['current_end_date']) if price_result.get('current_end_date') else None,
+                        to_plan=plan_name,
+                        to_cycle=billing_cycle,
+                        to_end_date=beijing_now() + timedelta(days=365 if billing_cycle == 'yearly' else 30),
+                        remaining_value=price_result['remaining_value'],
+                        upgrade_amount=price_result['upgrade_amount'],
+                        actual_amount=amount,
+                        upgrade_type=price_result['upgrade_type']
+                    )
+                    db.session.add(upgrade_record)
+                    db.session.commit()
+                except Exception as e:
+                    print(f"创建升级记录失败: {e}")
+                    # 不影响主流程
+
         except Exception as e:
-            return jsonify({'success': False, 'error': '订单创建失败'}), 500
+            db.session.rollback()
+            return jsonify({'success': False, 'error': f'订单创建失败: {str(e)}'}), 500
 
         # 尝试调用真实的微信支付API
         try:
@@ -1420,6 +1844,26 @@ def force_update_order_status(order_id):
                 # 激活用户订阅
                 activate_user_subscription(order.user_id, order.plan_name, order.billing_cycle)
 
+                # 记录优惠码使用（如果使用了优惠码）
+                if hasattr(order, 'promo_code_id') and order.promo_code_id:
+                    try:
+                        promo_usage = PromoCodeUsage(
+                            promo_code_id=order.promo_code_id,
+                            user_id=order.user_id,
+                            order_id=order.id,
+                            original_amount=order.original_amount if hasattr(order, 'original_amount') else order.amount,
+                            discount_amount=order.discount_amount if hasattr(order, 'discount_amount') else 0,
+                            final_amount=order.amount
+                        )
+                        db.session.add(promo_usage)
+
+                        # 更新优惠码使用次数
+                        promo = PromoCode.query.get(order.promo_code_id)
+                        if promo:
+                            promo.current_uses = (promo.current_uses or 0) + 1
+                    except Exception as e:
+                        print(f"记录优惠码使用失败: {e}")
+
                 db.session.commit()
 
                 print(f"✅ 订单状态强制更新成功: {old_status} -> paid")

migrations/add_promo_code_tables.sql

@@ -0,0 +1,134 @@
+-- 数据库迁移脚本：添加优惠码和订阅升级相关表
+-- 执行时间：2025-xx-xx
+-- 作者：Claude Code
+-- 说明：此脚本添加了优惠码、优惠码使用记录和订阅升级记录三张新表，并扩展了 payment_orders 表
+
+-- ============================================
+-- 1. 创建优惠码表
+-- ============================================
+CREATE TABLE IF NOT EXISTS `promo_codes` (
+  `id` INT PRIMARY KEY AUTO_INCREMENT,
+  `code` VARCHAR(50) UNIQUE NOT NULL COMMENT '优惠码（唯一）',
+  `description` VARCHAR(200) DEFAULT NULL COMMENT '优惠码描述',
+
+  -- 折扣类型和值
+  `discount_type` VARCHAR(20) NOT NULL COMMENT '折扣类型: percentage（百分比） 或 fixed_amount（固定金额）',
+  `discount_value` DECIMAL(10, 2) NOT NULL COMMENT '折扣值',
+
+  -- 适用范围
+  `applicable_plans` VARCHAR(200) DEFAULT NULL COMMENT '适用套餐（JSON格式），如 ["pro", "max"]，null表示全部适用',
+  `applicable_cycles` VARCHAR(50) DEFAULT NULL COMMENT '适用周期（JSON格式），如 ["monthly", "yearly"]，null表示全部适用',
+  `min_amount` DECIMAL(10, 2) DEFAULT NULL COMMENT '最低消费金额',
+
+  -- 使用限制
+  `max_uses` INT DEFAULT NULL COMMENT '最大使用次数，null表示无限制',
+  `max_uses_per_user` INT DEFAULT 1 COMMENT '每个用户最多使用次数',
+  `current_uses` INT DEFAULT 0 COMMENT '当前已使用次数',
+
+  -- 有效期
+  `valid_from` DATETIME NOT NULL COMMENT '生效时间',
+  `valid_until` DATETIME NOT NULL COMMENT '失效时间',
+
+  -- 状态
+  `is_active` BOOLEAN DEFAULT TRUE COMMENT '是否启用',
+  `created_by` INT DEFAULT NULL COMMENT '创建人（管理员ID）',
+  `created_at` DATETIME DEFAULT CURRENT_TIMESTAMP,
+  `updated_at` DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+
+  INDEX idx_code (`code`),
+  INDEX idx_valid_dates (`valid_from`, `valid_until`),
+  INDEX idx_is_active (`is_active`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='优惠码表';
+
+
+-- ============================================
+-- 2. 创建优惠码使用记录表
+-- ============================================
+CREATE TABLE IF NOT EXISTS `promo_code_usage` (
+  `id` INT PRIMARY KEY AUTO_INCREMENT,
+  `promo_code_id` INT NOT NULL COMMENT '优惠码ID',
+  `user_id` INT NOT NULL COMMENT '用户ID',
+  `order_id` INT NOT NULL COMMENT '订单ID',
+
+  `original_amount` DECIMAL(10, 2) NOT NULL COMMENT '原价',
+  `discount_amount` DECIMAL(10, 2) NOT NULL COMMENT '优惠金额',
+  `final_amount` DECIMAL(10, 2) NOT NULL COMMENT '实付金额',
+
+  `used_at` DATETIME DEFAULT CURRENT_TIMESTAMP COMMENT '使用时间',
+
+  FOREIGN KEY (`promo_code_id`) REFERENCES `promo_codes`(`id`) ON DELETE CASCADE,
+  FOREIGN KEY (`order_id`) REFERENCES `payment_orders`(`id`) ON DELETE CASCADE,
+
+  INDEX idx_user_id (`user_id`),
+  INDEX idx_promo_code_id (`promo_code_id`),
+  INDEX idx_order_id (`order_id`),
+  INDEX idx_used_at (`used_at`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='优惠码使用记录表';
+
+
+-- ============================================
+-- 3. 创建订阅升级记录表
+-- ============================================
+CREATE TABLE IF NOT EXISTS `subscription_upgrades` (
+  `id` INT PRIMARY KEY AUTO_INCREMENT,
+  `user_id` INT NOT NULL COMMENT '用户ID',
+  `order_id` INT NOT NULL COMMENT '订单ID',
+
+  -- 原订阅信息
+  `from_plan` VARCHAR(20) NOT NULL COMMENT '原套餐',
+  `from_cycle` VARCHAR(10) NOT NULL COMMENT '原周期',
+  `from_end_date` DATETIME DEFAULT NULL COMMENT '原到期日',
+
+  -- 新订阅信息
+  `to_plan` VARCHAR(20) NOT NULL COMMENT '新套餐',
+  `to_cycle` VARCHAR(10) NOT NULL COMMENT '新周期',
+  `to_end_date` DATETIME NOT NULL COMMENT '新到期日',
+
+  -- 价格计算
+  `remaining_value` DECIMAL(10, 2) NOT NULL COMMENT '剩余价值',
+  `upgrade_amount` DECIMAL(10, 2) NOT NULL COMMENT '升级应付金额',
+  `actual_amount` DECIMAL(10, 2) NOT NULL COMMENT '实际支付金额',
+
+  `upgrade_type` VARCHAR(20) NOT NULL COMMENT '升级类型: plan_upgrade（套餐升级）, cycle_change（周期变更）, both（都变更）',
+  `created_at` DATETIME DEFAULT CURRENT_TIMESTAMP,
+
+  FOREIGN KEY (`order_id`) REFERENCES `payment_orders`(`id`) ON DELETE CASCADE,
+
+  INDEX idx_user_id (`user_id`),
+  INDEX idx_order_id (`order_id`),
+  INDEX idx_created_at (`created_at`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='订阅升级/降级记录表';
+
+
+-- ============================================
+-- 4. 扩展 payment_orders 表（添加新字段）
+-- ============================================
+-- 注意：这些字段是可选的扩展，用于记录优惠码和升级信息
+-- 如果字段已存在会报错，可以忽略
+
+ALTER TABLE `payment_orders`
+ADD COLUMN `promo_code_id` INT DEFAULT NULL COMMENT '使用的优惠码ID' AFTER `remark`,
+ADD COLUMN `original_amount` DECIMAL(10, 2) DEFAULT NULL COMMENT '原价（使用优惠码前）' AFTER `promo_code_id`,
+ADD COLUMN `discount_amount` DECIMAL(10, 2) DEFAULT 0 COMMENT '优惠金额' AFTER `original_amount`,
+ADD COLUMN `is_upgrade` BOOLEAN DEFAULT FALSE COMMENT '是否为升级订单' AFTER `discount_amount`,
+ADD COLUMN `upgrade_from_plan` VARCHAR(20) DEFAULT NULL COMMENT '从哪个套餐升级' AFTER `is_upgrade`;
+
+-- 添加外键约束
+ALTER TABLE `payment_orders`
+ADD CONSTRAINT `fk_payment_orders_promo_code`
+FOREIGN KEY (`promo_code_id`) REFERENCES `promo_codes`(`id`) ON DELETE SET NULL;
+
+
+-- ============================================
+-- 5. 插入示例优惠码（供测试使用）
+-- ============================================
+-- 10% 折扣优惠码，适用所有套餐和周期
+INSERT INTO `promo_codes`
+(`code`, `description`, `discount_type`, `discount_value`, `applicable_plans`, `applicable_cycles`, `min_amount`, `max_uses`, `max_uses_per_user`, `valid_from`, `valid_until`, `is_active`)
+VALUES
+('WELCOME10', '新用户欢迎优惠 - 10%折扣', 'percentage', 10.00, NULL, NULL, NULL, NULL, 1, NOW(), DATE_ADD(NOW(), INTERVAL 1 YEAR), TRUE),
+('ANNUAL20', '年付专享 - 20%折扣', 'percentage', 20.00, NULL, '["yearly"]', NULL, 100, 1, NOW(), DATE_ADD(NOW(), INTERVAL 1 YEAR), TRUE),
+('SUMMER50', '夏季促销 - 减免50元', 'fixed_amount', 50.00, '["max"]', NULL, 100.00, 50, 1, NOW(), DATE_ADD(NOW(), INTERVAL 3 MONTH), TRUE);
+
+-- 完成
+SELECT 'Migration completed successfully!' AS status;

src/components/Subscription/SubscriptionContent.js

@@ -29,6 +29,9 @@ import {
   Td,
   Heading,
   Collapse,
+  Input,
+  InputGroup,
+  InputRightElement,
 } from '@chakra-ui/react';
 import React, { useState, useEffect } from 'react';
 import { logger } from '../../utils/logger';
@@ -85,6 +88,13 @@ export default function SubscriptionContent() {
   const [forceUpdating, setForceUpdating] = useState(false);
   const [openFaqIndex, setOpenFaqIndex] = useState(null);
 
+  // 优惠码相关state
+  const [promoCode, setPromoCode] = useState('');
+  const [promoCodeApplied, setPromoCodeApplied] = useState(false);
+  const [promoCodeError, setPromoCodeError] = useState('');
+  const [validatingPromo, setValidatingPromo] = useState(false);
+  const [priceInfo, setPriceInfo] = useState(null); // 价格信息（包含升级计算）
+
   // 加载订阅套餐数据
   useEffect(() => {
     fetchSubscriptionPlans();
@@ -149,7 +159,88 @@ export default function SubscriptionContent() {
     }
   };
 
-  const handleSubscribe = (plan) => {
+  // 计算价格（包含升级和优惠码）
+  const calculatePrice = async (plan, cycle, promoCodeValue = null) => {
+    try {
+      const response = await fetch('/api/subscription/calculate-price', {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+        },
+        credentials: 'include',
+        body: JSON.stringify({
+          to_plan: plan.name,
+          to_cycle: cycle,
+          promo_code: promoCodeValue || null
+        })
+      });
+
+      if (response.ok) {
+        const data = await response.json();
+        if (data.success) {
+          setPriceInfo(data.data);
+          return data.data;
+        }
+      }
+      return null;
+    } catch (error) {
+      logger.error('SubscriptionContent', 'calculatePrice', error);
+      return null;
+    }
+  };
+
+  // 验证优惠码
+  const handleValidatePromoCode = async () => {
+    if (!promoCode.trim()) {
+      setPromoCodeError('请输入优惠码');
+      return;
+    }
+
+    if (!selectedPlan) {
+      setPromoCodeError('请先选择套餐');
+      return;
+    }
+
+    setValidatingPromo(true);
+    setPromoCodeError('');
+
+    try {
+      // 重新计算价格，包含优惠码
+      const result = await calculatePrice(selectedPlan, selectedCycle, promoCode);
+
+      if (result && !result.promo_error) {
+        setPromoCodeApplied(true);
+        toast({
+          title: '优惠码已应用',
+          description: `节省 ¥${result.discount_amount.toFixed(2)}`,
+          status: 'success',
+          duration: 3000,
+          isClosable: true,
+        });
+      } else {
+        setPromoCodeError(result?.promo_error || '优惠码无效');
+        setPromoCodeApplied(false);
+      }
+    } catch (error) {
+      setPromoCodeError('验证失败，请重试');
+      setPromoCodeApplied(false);
+    } finally {
+      setValidatingPromo(false);
+    }
+  };
+
+  // 移除优惠码
+  const handleRemovePromoCode = async () => {
+    setPromoCode('');
+    setPromoCodeApplied(false);
+    setPromoCodeError('');
+    // 重新计算价格（不含优惠码）
+    if (selectedPlan) {
+      await calculatePrice(selectedPlan, selectedCycle, null);
+    }
+  };
+
+  const handleSubscribe = async (plan) => {
     if (!user) {
       toast({
         title: '请先登录',
@@ -178,6 +269,10 @@ export default function SubscriptionContent() {
     );
 
     setSelectedPlan(plan);
+
+    // 计算价格（包含升级判断）
+    await calculatePrice(plan, selectedCycle, promoCodeApplied ? promoCode : null);
+
     onPaymentModalOpen();
   };
 
@@ -186,7 +281,7 @@ export default function SubscriptionContent() {
 
     setLoading(true);
     try {
-      const price = selectedCycle === 'monthly' ? selectedPlan.monthly_price : selectedPlan.yearly_price;
+      const price = priceInfo?.final_amount || (selectedCycle === 'monthly' ? selectedPlan.monthly_price : selectedPlan.yearly_price);
 
       // 🎯 追踪支付发起
       subscriptionEvents.trackPaymentInitiated({
@@ -205,7 +300,8 @@ export default function SubscriptionContent() {
         credentials: 'include',
         body: JSON.stringify({
           plan_name: selectedPlan.name,
-          billing_cycle: selectedCycle
+          billing_cycle: selectedCycle,
+          promo_code: promoCodeApplied ? promoCode : null
         })
       });
 
@@ -488,6 +584,27 @@ export default function SubscriptionContent() {
     return `年付节省 ${percentage}%`;
   };
 
+  // 获取按钮文字（根据用户当前订阅判断是升级还是新订阅）
+  const getButtonText = (plan, user) => {
+    if (!user || user.subscription_type === 'free') {
+      return `选择 ${plan.display_name}`;
+    }
+
+    // 判断是否为升级
+    const planLevels = { 'free': 0, 'pro': 1, 'max': 2 };
+    const currentLevel = planLevels[user.subscription_type] || 0;
+    const targetLevel = planLevels[plan.name] || 0;
+
+    if (targetLevel > currentLevel) {
+      return `升级至 ${plan.display_name}`;
+    } else if (targetLevel < currentLevel) {
+      return `切换至 ${plan.display_name}`;
+    } else {
+      // 同级别，可能是切换周期
+      return `切换至 ${plan.display_name}`;
+    }
+  };
+
   // 统一的功能列表定义 - 基于商业定价(10月15日)文档
   const allFeatures = [
     // 新闻催化分析模块
@@ -838,7 +955,8 @@ export default function SubscriptionContent() {
                 onClick={() => handleSubscribe(plan)}
                 isDisabled={
                   user?.subscription_type === plan.name &&
-                  user?.subscription_status === 'active'
+                  user?.subscription_status === 'active' &&
+                  user?.billing_cycle === selectedCycle
                 }
                 _hover={{
                   transform: 'scale(1.02)',
@@ -846,9 +964,10 @@ export default function SubscriptionContent() {
                 transition="all 0.2s"
               >
                 {user?.subscription_type === plan.name &&
-                 user?.subscription_status === 'active'
-                  ? '✓ 已订阅'
-                  : `选择 ${plan.display_name}`
+                 user?.subscription_status === 'active' &&
+                 user?.billing_cycle === selectedCycle
+                  ? '✓ 当前套餐'
+                  : getButtonText(plan, user)
                 }
               </Button>
             </VStack>
@@ -1084,14 +1203,62 @@ export default function SubscriptionContent() {
                         <Text color={secondaryText}>计费周期:</Text>
                         <Text>{selectedCycle === 'monthly' ? '按月付费' : '按年付费'}</Text>
                       </Flex>
-                      <Divider />
-                      <Flex justify="space-between" align="baseline">
-                        <Text color={secondaryText}>应付金额:</Text>
-                        <Text fontSize="2xl" fontWeight="bold" color="blue.500">
-                          ¥{getCurrentPrice(selectedPlan).toFixed(2)}
+
+                      {/* 价格明细 */}
+                      <Divider my={2} />
+
+                      {priceInfo && priceInfo.is_upgrade && (
+                        <Box bg="blue.50" p={3} borderRadius="md" mb={2}>
+                          <HStack spacing={2} mb={2}>
+                            <Icon as={FaCheck} color="blue.500" boxSize={4} />
+                            <Text fontSize="sm" fontWeight="bold" color="blue.700">
+                              {priceInfo.upgrade_type === 'plan_upgrade' ? '套餐升级' :
+                               priceInfo.upgrade_type === 'cycle_change' ? '周期变更' : '套餐和周期调整'}
+                            </Text>
+                          </HStack>
+                          <VStack spacing={1} align="stretch" fontSize="xs">
+                            <Flex justify="space-between" color="gray.600">
+                              <Text>当前订阅: {priceInfo.current_plan === 'pro' ? 'Pro版' : 'Max版'} ({priceInfo.current_cycle === 'monthly' ? '月付' : '年付'})</Text>
+                            </Flex>
+                            <Flex justify="space-between" color="gray.600">
+                              <Text>剩余价值:</Text>
+                              <Text>¥{priceInfo.remaining_value.toFixed(2)}</Text>
+                            </Flex>
+                          </VStack>
+                        </Box>
+                      )}
+
+                      <Flex justify="space-between">
+                        <Text color={secondaryText}>
+                          {priceInfo && priceInfo.is_upgrade ? '新套餐价格:' : '套餐价格:'}
+                        </Text>
+                        <Text fontWeight="medium">
+                          ¥{priceInfo ? priceInfo.new_plan_price.toFixed(2) : getCurrentPrice(selectedPlan).toFixed(2)}
                         </Text>
                       </Flex>
-                      {getSavingsText(selectedPlan) && (
+
+                      {priceInfo && priceInfo.is_upgrade && priceInfo.remaining_value > 0 && (
+                        <Flex justify="space-between" color="blue.600">
+                          <Text>已付剩余抵扣:</Text>
+                          <Text>-¥{priceInfo.remaining_value.toFixed(2)}</Text>
+                        </Flex>
+                      )}
+
+                      {priceInfo && priceInfo.discount_amount > 0 && (
+                        <Flex justify="space-between" color="green.600">
+                          <Text>优惠码折扣:</Text>
+                          <Text>-¥{priceInfo.discount_amount.toFixed(2)}</Text>
+                        </Flex>
+                      )}
+
+                      <Divider />
+                      <Flex justify="space-between" align="baseline">
+                        <Text fontSize="lg" fontWeight="bold">实付金额:</Text>
+                        <Text fontSize="2xl" fontWeight="bold" color="blue.500">
+                          ¥{priceInfo ? priceInfo.final_amount.toFixed(2) : getCurrentPrice(selectedPlan).toFixed(2)}
+                        </Text>
+                      </Flex>
+                      {getSavingsText(selectedPlan) && !priceInfo?.is_upgrade && (
                         <Badge colorScheme="green" alignSelf="flex-end" fontSize="xs">
                           {getSavingsText(selectedPlan)}
                         </Badge>
@@ -1104,6 +1271,53 @@ export default function SubscriptionContent() {
                   </Box>
                 )}
 
+                {/* 优惠码输入 */}
+                {selectedPlan && (
+                  <Box>
+                    <HStack spacing={2}>
+                      <Input
+                        placeholder="输入优惠码（可选）"
+                        value={promoCode}
+                        onChange={(e) => {
+                          setPromoCode(e.target.value.toUpperCase());
+                          setPromoCodeError('');
+                        }}
+                        size="md"
+                        isDisabled={promoCodeApplied}
+                      />
+                      <Button
+                        colorScheme="purple"
+                        onClick={handleValidatePromoCode}
+                        isLoading={validatingPromo}
+                        isDisabled={!promoCode || promoCodeApplied}
+                        minW="80px"
+                      >
+                        应用
+                      </Button>
+                    </HStack>
+                    {promoCodeError && (
+                      <Text color="red.500" fontSize="sm" mt={2}>
+                        {promoCodeError}
+                      </Text>
+                    )}
+                    {promoCodeApplied && priceInfo && (
+                      <HStack mt={2} p={2} bg="green.50" borderRadius="md">
+                        <Icon as={FaCheck} color="green.500" />
+                        <Text color="green.700" fontSize="sm" fontWeight="medium" flex={1}>
+                          优惠码已应用！节省 ¥{priceInfo.discount_amount.toFixed(2)}
+                        </Text>
+                        <Icon
+                          as={FaTimes}
+                          color="gray.500"
+                          cursor="pointer"
+                          onClick={handleRemovePromoCode}
+                          _hover={{ color: 'red.500' }}
+                        />
+                      </HStack>
+                    )}
+                  </Box>
+                )}
+
                 <Button
                   colorScheme="green"
                   size="lg"