feat: initial release

internal/web/middleware/middleware.go

@@ -0,0 +1,53 @@
+package middleware
+
+import (
+	"fmt"
+	"net/http"
+	"slices"
+)
+
+type Middleware interface {
+	Client(r *http.Request) error
+	Handler(http.Handler) http.Handler
+}
+
+type BaseMiddleware struct{}
+
+func (BaseMiddleware) Client(*http.Request) error { return nil }
+
+func (BaseMiddleware) Handler(h http.Handler) http.Handler { return h }
+
+type MiddlewareBuilder struct {
+	middlewares []Middleware
+}
+
+func (b *MiddlewareBuilder) Use(middleware Middleware) *MiddlewareBuilder {
+	b.middlewares = append(b.middlewares, middleware)
+	return b
+}
+
+type middlewareProxy struct {
+	middlewares []Middleware
+}
+
+func (p *middlewareProxy) Client(r *http.Request) error {
+	for _, m := range p.middlewares {
+		if err := m.Client(r); err != nil {
+			return fmt.Errorf("%T: %w", m, err)
+		}
+	}
+	return nil
+}
+
+func (p *middlewareProxy) Handler(h http.Handler) http.Handler {
+	for _, f := range slices.Backward(p.middlewares) {
+		h = f.Handler(h)
+	}
+	return h
+}
+
+func (b *MiddlewareBuilder) Prepare() Middleware {
+	return &middlewareProxy{
+		middlewares: append([]Middleware(nil), b.middlewares...),
+	}
+}