Move internal packages to an internal folder

For reference: https://go.dev/doc/go1.4#internalpackages

internal/http/response/html/html.go

@@ -0,0 +1,88 @@
+// SPDX-FileCopyrightText: Copyright The Miniflux Authors. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package html // import "miniflux.app/v2/internal/http/response/html"
+
+import (
+	"net/http"
+
+	"miniflux.app/v2/internal/http/response"
+	"miniflux.app/v2/internal/logger"
+)
+
+// OK creates a new HTML response with a 200 status code.
+func OK(w http.ResponseWriter, r *http.Request, body interface{}) {
+	builder := response.New(w, r)
+	builder.WithHeader("Content-Type", "text/html; charset=utf-8")
+	builder.WithHeader("Cache-Control", "no-cache, max-age=0, must-revalidate, no-store")
+	builder.WithBody(body)
+	builder.Write()
+}
+
+// ServerError sends an internal error to the client.
+func ServerError(w http.ResponseWriter, r *http.Request, err error) {
+	logger.Error("[HTTP:Internal Server Error] %s => %v", r.URL, err)
+
+	builder := response.New(w, r)
+	builder.WithStatus(http.StatusInternalServerError)
+	builder.WithHeader("Content-Security-Policy", `default-src 'self'`)
+	builder.WithHeader("Content-Type", "text/html; charset=utf-8")
+	builder.WithHeader("Cache-Control", "no-cache, max-age=0, must-revalidate, no-store")
+	builder.WithBody(err)
+	builder.Write()
+}
+
+// BadRequest sends a bad request error to the client.
+func BadRequest(w http.ResponseWriter, r *http.Request, err error) {
+	logger.Error("[HTTP:Bad Request] %s => %v", r.URL, err)
+
+	builder := response.New(w, r)
+	builder.WithStatus(http.StatusBadRequest)
+	builder.WithHeader("Content-Security-Policy", `default-src 'self'`)
+	builder.WithHeader("Content-Type", "text/html; charset=utf-8")
+	builder.WithHeader("Cache-Control", "no-cache, max-age=0, must-revalidate, no-store")
+	builder.WithBody(err)
+	builder.Write()
+}
+
+// Forbidden sends a forbidden error to the client.
+func Forbidden(w http.ResponseWriter, r *http.Request) {
+	logger.Error("[HTTP:Forbidden] %s", r.URL)
+
+	builder := response.New(w, r)
+	builder.WithStatus(http.StatusForbidden)
+	builder.WithHeader("Content-Type", "text/html; charset=utf-8")
+	builder.WithHeader("Cache-Control", "no-cache, max-age=0, must-revalidate, no-store")
+	builder.WithBody("Access Forbidden")
+	builder.Write()
+}
+
+// NotFound sends a page not found error to the client.
+func NotFound(w http.ResponseWriter, r *http.Request) {
+	logger.Error("[HTTP:Not Found] %s", r.URL)
+
+	builder := response.New(w, r)
+	builder.WithStatus(http.StatusNotFound)
+	builder.WithHeader("Content-Type", "text/html; charset=utf-8")
+	builder.WithHeader("Cache-Control", "no-cache, max-age=0, must-revalidate, no-store")
+	builder.WithBody("Page Not Found")
+	builder.Write()
+}
+
+// Redirect redirects the user to another location.
+func Redirect(w http.ResponseWriter, r *http.Request, uri string) {
+	http.Redirect(w, r, uri, http.StatusFound)
+}
+
+// RequestedRangeNotSatisfiable sends a range not satisfiable error to the client.
+func RequestedRangeNotSatisfiable(w http.ResponseWriter, r *http.Request, contentRange string) {
+	logger.Error("[HTTP:Range Not Satisfiable] %s", r.URL)
+
+	builder := response.New(w, r)
+	builder.WithStatus(http.StatusRequestedRangeNotSatisfiable)
+	builder.WithHeader("Content-Type", "text/html; charset=utf-8")
+	builder.WithHeader("Cache-Control", "no-cache, max-age=0, must-revalidate, no-store")
+	builder.WithHeader("Content-Range", contentRange)
+	builder.WithBody("Range Not Satisfiable")
+	builder.Write()
+}