refactor: removed unused functions from the model package and gave ap…

…propriate names to the structures

cli/cli.go

@@ -164,7 +164,7 @@ func (c *CLI) Run(ctx context.Context, command string, params []string) {
 			return
 		}
 		c.Shipment.ResetSystemInfo()
-		c.Shipment.SystemInfo.Status = model.StatusEnumReadyToShip
+		c.Shipment.SystemInfo.Status = model.StatusReadyToShip
 		err := c.Client.Put(ctx, c.Shipment)
 		if err != nil {
 			printError(err)
@@ -180,7 +180,7 @@ func (c *CLI) Run(ctx context.Context, command string, params []string) {
 			printError("'done' command can be only used in the CLI's App mode. Call first `id <record-id>`")
 			return
 		}
-		rr, err := c.Client.UpdateStatus(ctx, c.Shipment.ID, model.StatusEnumCompleted)
+		rr, err := c.Client.UpdateStatus(ctx, c.Shipment.ID, model.StatusCompleted)
 		if err != nil {
 			printError(err)
 			return
@@ -312,9 +312,9 @@ func (c *CLI) Run(ctx context.Context, command string, params []string) {
 			return
 		}
 		// convert under_construction to ready to ship
-		if shipment.SystemInfo.Status == model.StatusEnumUnderConstruction {
+		if shipment.SystemInfo.Status == model.StatusUnderConstruction {
 			shipment.ResetSystemInfo()
-			shipment.SystemInfo.Status = model.StatusEnumReadyToShip
+			shipment.SystemInfo.Status = model.StatusReadyToShip
 			err = c.Client.Put(ctx, shipment)
 			if err != nil {
 				printError(err)
@@ -380,9 +380,9 @@ func (c *CLI) Run(ctx context.Context, command string, params []string) {
 			return
 		}
 		statusStr := strings.TrimSpace(strings.ToUpper(params[0]))
-		if statusStr == string(model.StatusEnumReadyToShip) {
+		if statusStr == string(model.StatusReadyToShip) {
 			c.Shipment.MarkAsReadyForShipment()
-			rr, err := c.Client.UpdateStatus(ctx, c.Shipment.ID, model.StatusEnumReadyToShip)
+			rr, err := c.Client.UpdateStatus(ctx, c.Shipment.ID, model.StatusReadyToShip)
 			if err != nil {
 				printError(err)
 				return

model/result.go

@@ -0,0 +1,130 @@
+package model
+
+type Result struct {
+	ID                   string       `json:"id"`
+	ReturnValue          ReturnStatus `json:"return_value"`
+	Status               Status       `json:"status"`
+	LastUpdatedTimestamp string       `json:"last_updated_timestamp"`
+	Version              int          `json:"version"`
+}
+
+func NewReturnResultWithID(id string) *Result {
+	return &Result{
+		ID:          id,
+		ReturnValue: ReturnStatusNone,
+		Status:      StatusNone,
+	}
+}
+
+func (rr *Result) IsSuccessful() bool {
+	return rr.ReturnValue == ReturnStatusSUCCESS
+}
+
+func (rr *Result) GetErrorMessage() string {
+	return rr.ReturnValue.GetErrorMessage()
+}
+
+// ReturnStatus defines the statuses for queue operations.
+type ReturnStatus int
+
+const (
+	ReturnStatusNone ReturnStatus = iota
+	ReturnStatusSUCCESS
+	ReturnStatusFailedIDNotProvided
+	ReturnStatusFailedIDNotFound
+	ReturnStatusFailedRecordNotConstructed
+	ReturnStatusFailedOnCondition
+	ReturnStatusFailedEmptyQueue
+	ReturnStatusFailedIllegalState
+	ReturnStatusFailedDynamoError
+)
+
+// String maps ReturnStatus values to their string representations.
+func (e ReturnStatus) String() string {
+	switch e {
+	case ReturnStatusNone:
+		return "NONE"
+	case ReturnStatusSUCCESS:
+		return "SUCCESS"
+	case ReturnStatusFailedIDNotProvided:
+		return "FAILED_ID_NOT_PROVIDED"
+	case ReturnStatusFailedIDNotFound:
+		return "FAILED_ID_NOT_FOUND"
+	case ReturnStatusFailedRecordNotConstructed:
+		return "FAILED_RECORD_NOT_CONSTRUCTED"
+	case ReturnStatusFailedOnCondition:
+		return "FAILED_ON_CONDITION"
+	case ReturnStatusFailedEmptyQueue:
+		return "FAILED_EMPTY_QUEUE"
+	case ReturnStatusFailedIllegalState:
+		return "FAILED_ILLEGAL_STATE"
+	case ReturnStatusFailedDynamoError:
+		return "FAILED_DYNAMO_ERROR"
+	default:
+		return "UNKNOWN"
+	}
+}
+
+// GetErrorMessage returns the associated error message for the ReturnStatus value.
+func (e ReturnStatus) GetErrorMessage() string {
+	switch e {
+	case ReturnStatusNone:
+		return "No error"
+	case ReturnStatusFailedIDNotProvided:
+		return "ID was not provided!"
+	case ReturnStatusFailedIDNotFound:
+		return "Provided Shipment ID was not found in the Dynamo DB!"
+	case ReturnStatusFailedRecordNotConstructed:
+		return "Shipment record not yet fully constructed .. cannot execute API!"
+	case ReturnStatusFailedOnCondition:
+		return "Condition on the 'version' attribute has failed!"
+	case ReturnStatusFailedEmptyQueue:
+		return "Cannot proceed, queue is empty!"
+	case ReturnStatusFailedIllegalState:
+		return "Illegal state, cannot proceed!"
+	case ReturnStatusFailedDynamoError:
+		return "Unspecified DynamoDB error is encountered!"
+	default:
+		return "API was not called!"
+	}
+}
+
+type DequeueResult struct {
+	*Result
+	DequeuedShipmentObject *Shipment `json:"-"`
+}
+
+func NewDequeueResultFromReturnResult(result *Result) *DequeueResult {
+	return &DequeueResult{
+		Result: result,
+	}
+}
+
+// EnqueueResult represents the result for the enqueue() API call.
+type EnqueueResult struct {
+	*Result            // Embedded type for inheritance-like behavior in Go
+	Shipment *Shipment `json:"-"`
+}
+
+// NewEnqueueResultWithID constructs a new EnqueueResult with the provided ID.
+func NewEnqueueResultWithID(id string) *EnqueueResult {
+	return &EnqueueResult{
+		Result: &Result{
+			ID: id,
+		},
+	}
+}
+
+// PeekResult represents the result for the peek() API call.
+type PeekResult struct {
+	*Result                        // Embedded type for inheritance-like behavior in Go
+	TimestampMillisUTC   int64     `json:"timestamp_milliseconds_utc"`
+	PeekedShipmentObject *Shipment `json:"-"`
+}
+
+// NewPeekResult constructs a new PeekResult with the default values.
+func NewPeekResult() *PeekResult {
+	return &PeekResult{
+		Result: &Result{},
+	}
+}