refactor: update package paths and improve client context handling

client/client.go

@@ -1,14 +1,15 @@
 package client
 
+import "context"
+
 type Client struct {
 	config *Configuration
 	token  *Token
 }
 
-var c = struct {
-	client      *Client
-	initialized bool
-}{}
+type contextKeyType string
+
+var contextKey contextKeyType = "client"
 
 type accessTokenRequest struct {
 	GrantType    string `json:"grant_type"`
@@ -18,10 +19,6 @@ type accessTokenRequest struct {
 
 func NewClient(config *Configuration) *Client {
 
-	if c.initialized {
-		return c.client
-	}
-
 	client := &Client{
 		config: config,
 	}
@@ -33,7 +30,31 @@ func NewClient(config *Configuration) *Client {
 
 	client.token = token
 
-	c.client = client
-
-	return c.client
+	return client
+}
+
+func FromContext(ctx context.Context) *Client {
+	client := ctx.Value(contextKey)
+	if client == nil {
+		return nil
+	}
+
+	if c, ok := client.(*Client); ok {
+		return c
+	}
+
+	return nil
+}
+
+func NewWithContext(ctx context.Context) context.Context {
+	client := ctx.Value(contextKey)
+	if client == nil {
+		return ctx
+	}
+
+	if c, ok := client.(*Client); ok {
+		return context.WithValue(ctx, contextKey, c)
+	}
+
+	return ctx
 }