Big refactor

handler/context.go

@@ -0,0 +1,21 @@
+package handler
+
+type ContextKey[T any] string
+
+type Context map[string]any
+
+func GetContextValue[T any](ctx Context, key ContextKey[T]) T {
+	value, present := ctx[string(key)]
+	if !present {
+		var zero T
+		return zero
+	}
+
+	typedValue, _ := value.(T)
+
+	return typedValue
+}
+
+func SetContextValue[T any](ctx Context, key ContextKey[T], value T) {
+	ctx[string(key)] = value
+}

handler/handler.go

@@ -0,0 +1,147 @@
+package handler
+
+import (
+	"fmt"
+	"html/template"
+	"io"
+
+	"git.phc.dm.unipi.it/phc/website"
+	"git.phc.dm.unipi.it/phc/website/articles"
+	"git.phc.dm.unipi.it/phc/website/auth"
+	"git.phc.dm.unipi.it/phc/website/model"
+	"git.phc.dm.unipi.it/phc/website/templates"
+	"git.phc.dm.unipi.it/phc/website/util"
+)
+
+type Service interface {
+	HandleStaticPage(w io.Writer, view string, ctx Context) error
+	HandleUtenti() ([]*model.User, error)
+	HandleStoriaPage(w io.Writer, ctx Context) error
+	HandleQueryAppunti(w io.Writer, query string, ctx Context) error
+	HandleNewsPage(w io.Writer, ctx Context) error
+	HandleLogin(username, password string) (*model.Session, error)
+	HandleUser(token string) *model.User
+	HandleRequiredUser(ctx Context) (*model.User, error)
+	HandleProfilePage(w io.Writer, ctx Context) error
+	HandleArticlePage(w io.Writer, articleID string, ctx Context) error
+}
+
+//
+// Typed context
+//
+
+// UserKey is a typed type for *model.User used to extract a user form a [handler.Context]
+const UserKey ContextKey[*model.User] = "user"
+
+func (ctx Context) getUser() *model.User {
+	return GetContextValue(ctx, UserKey)
+}
+
+// Handler holds references to abstract services for easy testing provided by every module (TODO: Make every field an interface of -Service)
+type DefaultHandler struct {
+	AuthService          auth.Service
+	Renderer             *templates.TemplateRenderer
+	NewsArticlesRegistry *articles.Registry
+	ListaUtenti          website.ListaUtentiService
+	Storia               website.StoriaService
+}
+
+func (h *DefaultHandler) HandleStaticPage(w io.Writer, view string, ctx Context) error {
+	return h.Renderer.Render(w, view, util.Map{
+		"User": ctx.getUser(),
+	})
+}
+
+func (h *DefaultHandler) HandleUtenti() ([]*model.User, error) {
+	utenti, err := h.AuthService.GetUsers()
+	if err != nil {
+		return nil, err
+	}
+
+	return utenti, nil
+}
+
+func (h *DefaultHandler) HandleStoriaPage(w io.Writer, ctx Context) error {
+	storia, err := h.Storia.GetStoria()
+	if err != nil {
+		return err
+	}
+
+	return h.Renderer.Render(w, "storia.html", util.Map{
+		"User":   ctx.getUser(),
+		"Storia": storia,
+	})
+}
+
+func (h *DefaultHandler) HandleQueryAppunti(w io.Writer, query string, ctx Context) error {
+	return h.Renderer.Render(w, "appunti.html", util.Map{
+		"User":  ctx.getUser(),
+		"Query": query,
+	})
+}
+
+func (h *DefaultHandler) HandleNewsPage(w io.Writer, ctx Context) error {
+	articles, err := h.NewsArticlesRegistry.GetArticles()
+	if err != nil {
+		return err
+	}
+
+	return h.Renderer.Render(w, "news.html", util.Map{
+		"User":     ctx.getUser(),
+		"Articles": articles,
+	})
+}
+
+func (h *DefaultHandler) HandleLogin(username, password string) (*model.Session, error) {
+	session, err := h.AuthService.Login(username, password)
+	if err != nil {
+		return nil, err
+	}
+
+	return session, nil
+}
+
+func (h *DefaultHandler) HandleUser(token string) *model.User {
+	user, _ := auth.UserForSession(h.AuthService, token)
+	return user
+}
+
+var ErrNoUser = fmt.Errorf(`user not logged in`)
+
+func (h *DefaultHandler) HandleRequiredUser(ctx Context) (*model.User, error) {
+	user := ctx.getUser()
+	if user == nil {
+		return nil, ErrNoUser
+	}
+
+	return user, nil
+}
+
+func (h *DefaultHandler) HandleProfilePage(w io.Writer, ctx Context) error {
+	user := ctx.getUser()
+	if user == nil {
+		return ErrNoUser
+	}
+
+	return h.Renderer.Render(w, "profilo.html", util.Map{
+		"User": user,
+	})
+}
+
+func (h *DefaultHandler) HandleArticlePage(w io.Writer, articleID string, ctx Context) error {
+	article, err := h.NewsArticlesRegistry.GetArticle(articleID)
+	if err != nil {
+		return err
+	}
+
+	html, err := article.Render()
+	if err != nil {
+		return err
+	}
+
+	return h.Renderer.Render(w, "news-base.html", util.Map{
+		"User":        ctx.getUser(),
+		"Article":     article,
+		"ContentHTML": template.HTML(html),
+	})
+}