func organizeJSONPatchIntoFleetPatchDetails()

in pkg/controllers/workapplier/drift_detection_takeover.go [165:270]
80 lines of code
15 McCabe index (conditional complexity)

func organizeJSONPatchIntoFleetPatchDetails(patch jsondiff.Patch, manifestObjMap map[string]interface{}) ([]fleetv1beta1.PatchDetail, error) {
	// Pre-allocate the slice for the patch details. The organization procedure typically will yield
	// the same number of PatchDetail items as the JSON patch operations.
	details := make([]fleetv1beta1.PatchDetail, 0, len(patch))

	// A side note: here Fleet takes an expedient approach processing null JSON paths, by treating
	// null paths as empty strings.

	// Process only the first 100 ops.
	// TO-DO (chenyu1): Impose additional size limits.
	for idx := 0; idx < len(patch) && idx < patchDetailPerObjLimit; idx++ {
		op := patch[idx]
		pathPtr, err := jsonpointer.Parse(op.Path)
		if err != nil {
			// An invalid path is found; normally this should not happen.
			wrappedErr := fmt.Errorf("failed to parse the JSON path %s: %w", op.Path, err)
			_ = controller.NewUnexpectedBehaviorError(wrappedErr)
			return nil, wrappedErr
		}
		fromPtr, err := jsonpointer.Parse(op.From)
		if err != nil {
			// An invalid path is found; normally this should not happen.
			wrappedErr := fmt.Errorf("failed to parse the JSON path %s: %w", op.From, err)
			_ = controller.NewUnexpectedBehaviorError(wrappedErr)
			return nil, wrappedErr
		}

		switch op.Type {
		case jsondiff.OperationAdd:
			details = append(details, fleetv1beta1.PatchDetail{
				Path:          op.Path,
				ValueInMember: fmt.Sprint(op.Value),
			})
		case jsondiff.OperationRemove:
			// Fleet here skips validation as the JSON data is just marshalled.
			hubValue, err := pathPtr.Eval(manifestObjMap)
			if err != nil {
				wrappedErr := fmt.Errorf("failed to evaluate the JSON path %s in the manifest object: %w", op.Path, err)
				_ = controller.NewUnexpectedBehaviorError(wrappedErr)
				return nil, wrappedErr
			}
			details = append(details, fleetv1beta1.PatchDetail{
				Path:       op.Path,
				ValueInHub: fmt.Sprintf("%v", hubValue),
			})
		case jsondiff.OperationReplace:
			// Fleet here skips validation as the JSON data is just marshalled.
			hubValue, err := pathPtr.Eval(manifestObjMap)
			if err != nil {
				wrappedErr := fmt.Errorf("failed to evaluate the JSON path %s in the manifest object: %w", op.Path, err)
				_ = controller.NewUnexpectedBehaviorError(wrappedErr)
				return nil, wrappedErr
			}
			details = append(details, fleetv1beta1.PatchDetail{
				Path:          op.Path,
				ValueInMember: fmt.Sprint(op.Value),
				ValueInHub:    fmt.Sprintf("%v", hubValue),
			})
		case jsondiff.OperationMove:
			// Normally the Move operation will not be returned as factorization is disabled
			// for the JSON patch calculation process; however, Fleet here still processes them
			// just in case.
			//
			// Each Move operation will be parsed into two separate operations.
			hubValue, err := fromPtr.Eval(manifestObjMap)
			if err != nil {
				wrappedErr := fmt.Errorf("failed to evaluate the JSON path %s in the manifest object: %w", op.Path, err)
				_ = controller.NewUnexpectedBehaviorError(wrappedErr)
				return nil, wrappedErr
			}
			details = append(details, fleetv1beta1.PatchDetail{
				Path:       op.From,
				ValueInHub: fmt.Sprintf("%v", hubValue),
			})
			details = append(details, fleetv1beta1.PatchDetail{
				Path:          op.Path,
				ValueInMember: fmt.Sprintf("%v", hubValue),
			})
		case jsondiff.OperationCopy:
			// Normally the Copy operation will not be returned as factorization is disabled
			// for the JSON patch calculation process; however, Fleet here still processes them
			// just in case.
			//
			// Each Copy operation will be parsed into an Add operation.
			hubValue, err := fromPtr.Eval(manifestObjMap)
			if err != nil {
				wrappedErr := fmt.Errorf("failed to evaluate the JSON path %s in the manifest object: %w", op.Path, err)
				_ = controller.NewUnexpectedBehaviorError(wrappedErr)
				return nil, wrappedErr
			}
			details = append(details, fleetv1beta1.PatchDetail{
				Path:          op.Path,
				ValueInMember: fmt.Sprintf("%v", hubValue),
			})
		case jsondiff.OperationTest:
			// The Test op is a no-op in Fleet's use case. Normally it will not be returned, either.
		default:
			// An unexpected op is returned.
			wrappedErr := fmt.Errorf("an unexpected JSON patch operation is returned (%s)", op)
			_ = controller.NewUnexpectedBehaviorError(wrappedErr)
			return nil, wrappedErr
		}
	}

	return details, nil
}