Add middleware to interface

Author: Vilsol

middleware/processor.go

@@ -0,0 +1,15 @@
+package middleware
+
+var processorInstance Processor
+
+func SetProcessor(processor Processor) {
+	processorInstance = processor
+}
+
+func GetProcessor() Processor {
+	if processorInstance == nil {
+		panic("middleware processor is nil")
+	}
+
+	return processorInstance
+}

middleware/types.go

@@ -0,0 +1,21 @@
+package middleware
+
+type Processor interface {
+	// Validate request
+	// If returns nil, it will pass the request onwards
+	// If returns a pointer, request will get replied to with provided response
+	Request(resource string, headers map[string][]string) *RequestResponse
+
+	// Validate and filter response
+	// If returns nil, it will pass the request onwards with the returned data
+	// If returns a pointer, request will get replied to with provided response without data
+	Response(resource string, headers map[string][]string, data []map[string]interface{}) ([]map[string]interface{}, *RequestResponse)
+}
+
+type RequestResponse struct {
+	// Return status code (http or otherwise)
+	Code int
+
+	// Return message
+	Message string
+}

plugins/types.go

@@ -2,6 +2,7 @@ package plugins
 
 import (
 	"github.com/StratoAPI/Interface/filter"
+	"github.com/StratoAPI/Interface/middleware"
 )
 
 type Plugin interface {
@@ -63,6 +64,27 @@ type Filter interface {
 	CreateFilter(filter string) (interface{}, error)
 }
 
+type Middleware interface {
+	// Initialize the middleware.
+	Initialize() error
+
+	// Start the middleware. Does not have to be blocking.
+	Start() error
+
+	// Graceful stopping of the middleware with a 30s timeout.
+	Stop() error
+
+	// Validate request
+	// If returns nil, it will pass the request onwards
+	// If returns a pointer, request will get replied to with provided response
+	Request(resource string, headers map[string][]string) *middleware.RequestResponse
+
+	// Validate and filter response
+	// If returns nil, it will pass the request onwards with the returned data
+	// If returns a pointer, request will get replied to with provided response without data
+	Response(resource string, headers map[string][]string, data []map[string]interface{}) ([]map[string]interface{}, *middleware.RequestResponse)
+}
+
 type Registry interface {
 	// Register a facade
 	RegisterFacade(name string, facade Facade) error