feat(payment): add complete payment system with multi-provider support

Add a full payment and subscription system supporting EasyPay (Alipay/WeChat),
Stripe, and direct Alipay/WeChat Pay providers with multi-instance load balancing.

backend/ent/schema/payment_audit_log.go

@@ -0,0 +1,54 @@
+package schema
+
+import (
+	"time"
+
+	"entgo.io/ent"
+	"entgo.io/ent/dialect"
+	"entgo.io/ent/dialect/entsql"
+	"entgo.io/ent/schema"
+	"entgo.io/ent/schema/field"
+	"entgo.io/ent/schema/index"
+)
+
+// PaymentAuditLog holds the schema definition for the PaymentAuditLog entity.
+//
+// 删除策略：硬删除
+// PaymentAuditLog 使用硬删除而非软删除，原因如下：
+//   - 审计日志本身即为不可变记录，通常只追加不修改
+//   - 如需清理历史日志，直接按时间范围批量删除即可
+//   - 保持表结构简洁，提升插入和查询性能
+type PaymentAuditLog struct {
+	ent.Schema
+}
+
+func (PaymentAuditLog) Annotations() []schema.Annotation {
+	return []schema.Annotation{
+		entsql.Annotation{Table: "payment_audit_logs"},
+	}
+}
+
+func (PaymentAuditLog) Fields() []ent.Field {
+	return []ent.Field{
+		field.String("order_id").
+			MaxLen(64),
+		field.String("action").
+			MaxLen(50),
+		field.String("detail").
+			SchemaType(map[string]string{dialect.Postgres: "text"}).
+			Default(""),
+		field.String("operator").
+			MaxLen(100).
+			Default("system"),
+		field.Time("created_at").
+			Immutable().
+			Default(time.Now).
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+	}
+}
+
+func (PaymentAuditLog) Indexes() []ent.Index {
+	return []ent.Index{
+		index.Fields("order_id"),
+	}
+}

backend/ent/schema/payment_order.go

@@ -0,0 +1,190 @@
+package schema
+
+import (
+	"time"
+
+	"entgo.io/ent"
+	"entgo.io/ent/dialect"
+	"entgo.io/ent/dialect/entsql"
+	"entgo.io/ent/schema"
+	"entgo.io/ent/schema/edge"
+	"entgo.io/ent/schema/field"
+	"entgo.io/ent/schema/index"
+)
+
+// PaymentOrder holds the schema definition for the PaymentOrder entity.
+//
+// 删除策略：硬删除
+// PaymentOrder 使用硬删除而非软删除，原因如下：
+//   - 订单通过 status 字段追踪完整生命周期，无需依赖软删除
+//   - 订单审计通过 PaymentAuditLog 表记录，删除前可归档
+//   - 减少查询复杂度，避免软删除过滤开销
+type PaymentOrder struct {
+	ent.Schema
+}
+
+func (PaymentOrder) Annotations() []schema.Annotation {
+	return []schema.Annotation{
+		entsql.Annotation{Table: "payment_orders"},
+	}
+}
+
+func (PaymentOrder) Fields() []ent.Field {
+	return []ent.Field{
+		// 用户信息（冗余存储，避免关联查询）
+		field.Int64("user_id"),
+		field.String("user_email").
+			MaxLen(255),
+		field.String("user_name").
+			MaxLen(100),
+		field.String("user_notes").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "text"}),
+
+		// 金额信息
+		field.Float("amount").
+			SchemaType(map[string]string{dialect.Postgres: "decimal(20,2)"}),
+		field.Float("pay_amount").
+			SchemaType(map[string]string{dialect.Postgres: "decimal(20,2)"}),
+		field.Float("fee_rate").
+			SchemaType(map[string]string{dialect.Postgres: "decimal(10,4)"}).
+			Default(0),
+		field.String("recharge_code").
+			MaxLen(64),
+
+		// 支付信息
+		field.String("out_trade_no").
+			MaxLen(64).
+			Default(""),
+		field.String("payment_type").
+			MaxLen(30),
+		field.String("payment_trade_no").
+			MaxLen(128),
+		field.String("pay_url").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "text"}),
+		field.String("qr_code").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "text"}),
+		field.String("qr_code_img").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "text"}),
+
+		// 订单类型 & 订阅关联
+		field.String("order_type").
+			MaxLen(20).
+			Default("balance"),
+		field.Int64("plan_id").
+			Optional().
+			Nillable(),
+		field.Int64("subscription_group_id").
+			Optional().
+			Nillable(),
+		field.Int("subscription_days").
+			Optional().
+			Nillable(),
+		field.String("provider_instance_id").
+			Optional().
+			Nillable().
+			MaxLen(64),
+
+		// 状态
+		field.String("status").
+			MaxLen(30).
+			Default("PENDING"),
+
+		// 退款信息
+		field.Float("refund_amount").
+			SchemaType(map[string]string{dialect.Postgres: "decimal(20,2)"}).
+			Default(0),
+		field.String("refund_reason").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "text"}),
+		field.Time("refund_at").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+		field.Bool("force_refund").
+			Default(false),
+		field.Time("refund_requested_at").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+		field.String("refund_request_reason").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "text"}),
+		field.String("refund_requested_by").
+			Optional().
+			Nillable().
+			MaxLen(20),
+
+		// 时间节点
+		field.Time("expires_at").
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+		field.Time("paid_at").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+		field.Time("completed_at").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+		field.Time("failed_at").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+		field.String("failed_reason").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "text"}),
+
+		// 来源信息
+		field.String("client_ip").
+			MaxLen(50),
+		field.String("src_host").
+			MaxLen(255),
+		field.String("src_url").
+			Optional().
+			Nillable().
+			SchemaType(map[string]string{dialect.Postgres: "text"}),
+
+		// 时间戳
+		field.Time("created_at").
+			Immutable().
+			Default(time.Now).
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+		field.Time("updated_at").
+			Default(time.Now).
+			UpdateDefault(time.Now).
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+	}
+}
+
+func (PaymentOrder) Edges() []ent.Edge {
+	return []ent.Edge{
+		edge.From("user", User.Type).
+			Ref("payment_orders").
+			Field("user_id").
+			Unique().
+			Required(),
+	}
+}
+
+func (PaymentOrder) Indexes() []ent.Index {
+	return []ent.Index{
+		index.Fields("out_trade_no"),
+		index.Fields("user_id"),
+		index.Fields("status"),
+		index.Fields("expires_at"),
+		index.Fields("created_at"),
+		index.Fields("paid_at"),
+		index.Fields("payment_type", "paid_at"),
+		index.Fields("order_type"),
+	}
+}

backend/ent/schema/payment_provider_instance.go

@@ -0,0 +1,72 @@
+package schema
+
+import (
+	"time"
+
+	"entgo.io/ent"
+	"entgo.io/ent/dialect"
+	"entgo.io/ent/dialect/entsql"
+	"entgo.io/ent/schema"
+	"entgo.io/ent/schema/field"
+	"entgo.io/ent/schema/index"
+)
+
+// PaymentProviderInstance holds the schema definition for the PaymentProviderInstance entity.
+//
+// 删除策略：硬删除
+// PaymentProviderInstance 使用硬删除而非软删除，原因如下：
+//   - 服务商实例为管理员配置的支付通道，删除即表示废弃
+//   - 通过 enabled 字段控制是否启用，删除仅用于彻底移除
+//   - config 字段存储加密后的密钥信息，删除时应彻底清除
+type PaymentProviderInstance struct {
+	ent.Schema
+}
+
+func (PaymentProviderInstance) Annotations() []schema.Annotation {
+	return []schema.Annotation{
+		entsql.Annotation{Table: "payment_provider_instances"},
+	}
+}
+
+func (PaymentProviderInstance) Fields() []ent.Field {
+	return []ent.Field{
+		field.String("provider_key").
+			MaxLen(30).
+			NotEmpty(),
+		field.String("name").
+			MaxLen(100).
+			Default(""),
+		field.String("config").
+			SchemaType(map[string]string{dialect.Postgres: "text"}),
+		field.String("supported_types").
+			MaxLen(200).
+			Default(""),
+		field.Bool("enabled").
+			Default(true),
+		field.String("payment_mode").
+			MaxLen(20).
+			Default(""),
+		field.Int("sort_order").
+			Default(0),
+		field.String("limits").
+			SchemaType(map[string]string{dialect.Postgres: "text"}).
+			Default(""),
+		field.Bool("refund_enabled").
+			Default(false),
+		field.Time("created_at").
+			Immutable().
+			Default(time.Now).
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+		field.Time("updated_at").
+			Default(time.Now).
+			UpdateDefault(time.Now).
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+	}
+}
+
+func (PaymentProviderInstance) Indexes() []ent.Index {
+	return []ent.Index{
+		index.Fields("provider_key"),
+		index.Fields("enabled"),
+	}
+}

backend/ent/schema/subscription_plan.go

@@ -0,0 +1,77 @@
+package schema
+
+import (
+	"time"
+
+	"entgo.io/ent"
+	"entgo.io/ent/dialect"
+	"entgo.io/ent/dialect/entsql"
+	"entgo.io/ent/schema"
+	"entgo.io/ent/schema/field"
+	"entgo.io/ent/schema/index"
+)
+
+// SubscriptionPlan holds the schema definition for the SubscriptionPlan entity.
+//
+// 删除策略：硬删除
+// SubscriptionPlan 使用硬删除而非软删除，原因如下：
+//   - 套餐为管理员维护的商品配置，删除即表示下架移除
+//   - 通过 for_sale 字段控制是否在售，删除仅用于彻底移除
+//   - 已购买的订阅记录保存在 UserSubscription 中，不受套餐删除影响
+type SubscriptionPlan struct {
+	ent.Schema
+}
+
+func (SubscriptionPlan) Annotations() []schema.Annotation {
+	return []schema.Annotation{
+		entsql.Annotation{Table: "subscription_plans"},
+	}
+}
+
+func (SubscriptionPlan) Fields() []ent.Field {
+	return []ent.Field{
+		field.Int64("group_id"),
+		field.String("name").
+			MaxLen(100).
+			NotEmpty(),
+		field.String("description").
+			SchemaType(map[string]string{dialect.Postgres: "text"}).
+			Default(""),
+		field.Float("price").
+			SchemaType(map[string]string{dialect.Postgres: "decimal(20,2)"}),
+		field.Float("original_price").
+			SchemaType(map[string]string{dialect.Postgres: "decimal(20,2)"}).
+			Optional().
+			Nillable(),
+		field.Int("validity_days").
+			Default(30),
+		field.String("validity_unit").
+			MaxLen(10).
+			Default("day"),
+		field.String("features").
+			SchemaType(map[string]string{dialect.Postgres: "text"}).
+			Default(""),
+		field.String("product_name").
+			MaxLen(100).
+			Default(""),
+		field.Bool("for_sale").
+			Default(true),
+		field.Int("sort_order").
+			Default(0),
+		field.Time("created_at").
+			Immutable().
+			Default(time.Now).
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+		field.Time("updated_at").
+			Default(time.Now).
+			UpdateDefault(time.Now).
+			SchemaType(map[string]string{dialect.Postgres: "timestamptz"}),
+	}
+}
+
+func (SubscriptionPlan) Indexes() []ent.Index {
+	return []ent.Index{
+		index.Fields("group_id"),
+		index.Fields("for_sale"),
+	}
+}

backend/ent/schema/user.go

@@ -87,6 +87,7 @@ func (User) Edges() []ent.Edge {
 		edge.To("usage_logs", UsageLog.Type),
 		edge.To("attribute_values", UserAttributeValue.Type),
 		edge.To("promo_code_usages", PromoCodeUsage.Type),
+		edge.To("payment_orders", PaymentOrder.Type),
 	}
 }