Add API for resolver

internal/dis/component/auth/scopes/instances.go

@@ -32,7 +32,6 @@ func (*ListInstancesScope) Scope() component.ScopeInfo {
 }
 
 func (lis *ListInstancesScope) HasScope(param string, r *http.Request) (bool, error) {
-	// TODO: at the moment everyone has this permission
-	// this should change in the future!
-	return true, nil
+	_, user, err := lis.Dependencies.Auth.SessionOf(r)
+	return user != nil, err
 }

internal/dis/component/auth/scopes/news.go

@@ -32,6 +32,6 @@ func (*ListNewsScope) Scope() component.ScopeInfo {
 }
 
 func (lns *ListNewsScope) HasScope(param string, r *http.Request) (bool, error) {
-	// TODO: at the moment everyone has this permission
-	return true, nil
+	_, user, err := lns.Dependencies.Auth.SessionOf(r)
+	return user != nil, err
 }

internal/dis/component/auth/scopes/resolver.go

@@ -0,0 +1,37 @@
+package scopes
+
+import (
+	"net/http"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth"
+)
+
+type ResolverScope struct {
+	component.Base
+	Dependencies struct {
+		Auth *auth.Auth
+	}
+}
+
+var (
+	_ component.ScopeProvider = (*ResolverScope)(nil)
+)
+
+const (
+	ScopeResolver Scope = "url.resolve"
+)
+
+func (*ResolverScope) Scope() component.ScopeInfo {
+	return component.ScopeInfo{
+		Scope:         ScopeResolver,
+		Description:   "resolve a URI to a URL to display it in",
+		DeniedMessage: "",
+		TakesParam:    false,
+	}
+}
+
+func (rs *ResolverScope) HasScope(param string, r *http.Request) (bool, error) {
+	_, user, err := rs.Dependencies.Auth.SessionOf(r)
+	return user != nil, err
+}

internal/dis/component/resolver/api.go

@@ -0,0 +1,53 @@
+package resolver
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth/api"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/auth/scopes"
+	"github.com/tkw1536/pkglib/httpx"
+)
+
+type API struct {
+	component.Base
+	Dependencies struct {
+		Auth     *auth.Auth
+		Resolver *Resolver
+	}
+}
+
+var (
+	_ component.Routeable = (*API)(nil)
+)
+
+func (api *API) Routes() component.Routes {
+	return component.Routes{
+		Prefix: "/api/v1/resolve/",
+		Exact:  true,
+	}
+}
+
+func (a *API) HandleRoute(ctx context.Context, path string) (http.Handler, error) {
+	return &api.Handler[string]{
+		Config: a.Config,
+		Auth:   a.Dependencies.Auth,
+
+		Methods: []string{"GET"},
+
+		Scope: scopes.ScopeResolver,
+		Handler: func(s string, r *http.Request) (string, error) {
+			uri := r.URL.Query().Get("uri")
+			if uri == "" {
+				return "", httpx.ErrBadRequest
+			}
+			target := a.Dependencies.Resolver.Target(uri)
+			if target == "" {
+				return "", httpx.ErrNotFound
+			}
+			return target, nil
+		},
+	}, nil
+}

internal/dis/component/scope.go

@@ -63,7 +63,6 @@ type ScopeProvider interface {
 
 	// Check checks if the given session has access to the given scope.
 	HasScope(param string, r *http.Request) (bool, error)
-	// TODO: move this to a session
 }
 
 // SessionInfo provides information about the current session.