新功能(#74): 新增促销系统模型层

Co-authored-by: multica-agent <github@multica.ai>

internal/model/promo_rule/model.go

@@ -0,0 +1,44 @@
+package promo_rule
+
+import (
+	"context"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+	"gorm.io/gorm"
+)
+
+type customPromoRuleLogicModel interface {
+	QueryEnabledByPriority(ctx context.Context) ([]*PromoRule, error)
+	QueryAvailableByPriority(ctx context.Context, now time.Time) ([]*PromoRule, error)
+}
+
+func NewModel(conn *gorm.DB, c *redis.Client) Model {
+	return &customPromoRuleModel{
+		defaultPromoRuleModel: newPromoRuleModel(conn, c),
+	}
+}
+
+func (m *customPromoRuleModel) QueryEnabledByPriority(ctx context.Context) ([]*PromoRule, error) {
+	var list []*PromoRule
+	err := m.QueryNoCacheCtx(ctx, &list, func(conn *gorm.DB, v interface{}) error {
+		return conn.Model(&PromoRule{}).
+			Where("enabled = ?", true).
+			Order("priority DESC, id DESC").
+			Find(v).Error
+	})
+	return list, err
+}
+
+func (m *customPromoRuleModel) QueryAvailableByPriority(ctx context.Context, now time.Time) ([]*PromoRule, error) {
+	var list []*PromoRule
+	err := m.QueryNoCacheCtx(ctx, &list, func(conn *gorm.DB, v interface{}) error {
+		return conn.Model(&PromoRule{}).
+			Where("enabled = ?", true).
+			Where("(start_time IS NULL OR start_time <= ?)", now).
+			Where("(end_time IS NULL OR end_time >= ?)", now).
+			Order("priority DESC, id DESC").
+			Find(v).Error
+	})
+	return list, err
+}