feat: add Order model, status constants, and AppError

model/order.go

@@ -0,0 +1,58 @@
+package model
+
+import "time"
+
+type OrderStatus string
+
+const (
+	StatusPending  OrderStatus = "pending"
+	StatusAccepted OrderStatus = "accepted"
+	StatusCanceled OrderStatus = "canceled"
+)
+
+type Order struct {
+	ID          string      `json:"id"`
+	Status      OrderStatus `json:"status"`
+	ServiceTime time.Time   `json:"service_time"`
+	Duration    int         `json:"duration"`
+	Address     string      `json:"address"`
+	ProviderID  *string    `json:"provider_id"`
+	CreatedAt   time.Time  `json:"created_at"`
+	UpdatedAt   time.Time  `json:"updated_at"`
+}
+
+type CreateOrderRequest struct {
+	ServiceTime time.Time `json:"service_time" binding:"required"`
+	Duration    int       `json:"duration" binding:"required,gt=0"`
+	Address     string    `json:"address" binding:"required"`
+}
+
+type AcceptOrderRequest struct {
+	ProviderID string `json:"provider_id" binding:"required"`
+}
+
+type CancelOrderRequest struct{}
+
+type AppError struct {
+	Code       string `json:"error"`
+	Message    string `json:"message"`
+	HTTPStatus int    `json:"-"`
+}
+
+func NewAppError(code, message string, httpStatus int) *AppError {
+	return &AppError{Code: code, Message: message, HTTPStatus: httpStatus}
+}
+
+func (e *AppError) Error() string {
+	return e.Message
+}
+
+// 预定义错误
+var (
+	ErrNotFound       = NewAppError("not_found", "订单不存在", 404)
+	ErrConflict       = NewAppError("conflict", "订单已被其他服务者接单", 409)
+	ErrInvalidState   = func(op string) *AppError {
+		return NewAppError("invalid_state", "订单已取消，无法" + op, 400)
+	}
+	ErrStatusConflict = NewAppError("conflict", "订单状态已变更，请重试", 409)
+)