public IOpenApiReferenceable ResolveReference()

in src/Microsoft.OpenApi/Models/OpenApiDocument.cs [344:425]
65 lines of code
19 McCabe index (conditional complexity)

            public IOpenApiReferenceable ResolveReference(OpenApiReference reference, bool useExternal)
        {
            if (reference == null)
            {
                return null;
            }

            // Todo: Verify if we need to check to see if this external reference is actually targeted at this document.
            if (useExternal)
            {
                if (this.Workspace == null)
                {
                    throw new ArgumentException(Properties.SRResource.WorkspaceRequredForExternalReferenceResolution);
                }
                return this.Workspace.ResolveReference(reference);
            } 

            if (!reference.Type.HasValue)
            {
                throw new ArgumentException(Properties.SRResource.LocalReferenceRequiresType);
            }

            // Special case for Tag
            if (reference.Type == ReferenceType.Tag)
            {
                foreach (var tag in this.Tags)
                {
                    if (tag.Name == reference.Id)
                    {
                        tag.Reference = reference;
                        return tag;
                    }
                }

                return null;
            }

            if (this.Components == null)
            {
                throw new OpenApiException(string.Format(Properties.SRResource.InvalidReferenceId, reference.Id));
            }

            try
            {
                switch (reference.Type)
                {
                    case ReferenceType.Schema:
                        return this.Components.Schemas[reference.Id];

                    case ReferenceType.Response:
                        return this.Components.Responses[reference.Id];

                    case ReferenceType.Parameter:
                        return this.Components.Parameters[reference.Id];

                    case ReferenceType.Example:
                        return this.Components.Examples[reference.Id];

                    case ReferenceType.RequestBody:
                        return this.Components.RequestBodies[reference.Id];

                    case ReferenceType.Header:
                        return this.Components.Headers[reference.Id];

                    case ReferenceType.SecurityScheme:
                        return this.Components.SecuritySchemes[reference.Id];

                    case ReferenceType.Link:
                        return this.Components.Links[reference.Id];

                    case ReferenceType.Callback:
                        return this.Components.Callbacks[reference.Id];

                    default:
                        throw new OpenApiException(Properties.SRResource.InvalidReferenceType);
                }
            }
            catch (KeyNotFoundException)
            {
                throw new OpenApiException(string.Format(Properties.SRResource.InvalidReferenceId, reference.Id));
            }
        }