Split internal/web into subpackages before domain-admin growth.

Lay out view, auth, validate, and handlers under internal/web while keeping
the cmd/panel API unchanged; update roadmap and changelog for web-split closure.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/web/handlers/handlers_domains.go

@@ -0,0 +1,186 @@
+package handlers
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"strconv"
+	"sync"
+
+	"github.com/mixeme/selfpost/internal/health"
+	"github.com/mixeme/selfpost/internal/store"
+	"github.com/mixeme/selfpost/internal/web/auth"
+	"github.com/mixeme/selfpost/internal/web/validate"
+)
+
+// domainRow is one line of the domain list: the stored domain plus the rolled-up
+// verdict of its published DNS records, so the operator sees which domains still
+// need a record published without opening each one.
+type domainRow struct {
+	store.Domain
+	DNS health.Status
+}
+
+// HandleDashboard is the authenticated landing page: the list of sending
+// domains with their DKIM/selector and application counts, plus the add-domain
+// form (product.md).
+func (h *Handlers) HandleDashboard(w http.ResponseWriter, r *http.Request) {
+	h.renderDashboard(w, r, http.StatusOK, "", "")
+}
+
+func (h *Handlers) renderDashboard(w http.ResponseWriter, r *http.Request, status int, formErr, formName string) {
+	domains, err := h.domains.List()
+	if err != nil {
+		logf("panel: dashboard: list domains: %v", err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+	h.view.Render(w, status, "dashboard", map[string]any{
+		"Title":    "SelfPost",
+		"User":     auth.CurrentUser(r),
+		"Active":   "domains",
+		"Domains":  h.domainRows(domains),
+		"Error":    formErr,
+		"FormName": formName,
+		"Flash":    dashboardFlash(r),
+	})
+}
+
+func (h *Handlers) domainRows(domains []store.Domain) []domainRow {
+	profileEmail := ""
+	if admin, err := h.store.GetAdmin(); err == nil {
+		profileEmail = admin.DMARCReportEmail
+	}
+	rows := make([]domainRow, len(domains))
+	var wg sync.WaitGroup
+	for i, d := range domains {
+		rows[i] = domainRow{Domain: d, DNS: health.StatusUnknown}
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			record, err := h.domains.DKIMRecord(d)
+			if err != nil {
+				logf("panel: dashboard: domain %d: dkim record: %v", d.ID, err)
+				return
+			}
+			dns, _ := h.domainDNS(d, record, profileEmail, false)
+			rows[i].DNS = dns.Overall
+		}()
+	}
+	wg.Wait()
+	return rows
+}
+
+func dashboardFlash(r *http.Request) string {
+	if r.URL.Query().Get("deleted") != "" {
+		return "Domain deleted."
+	}
+	return ""
+}
+
+// HandleAddDomain validates the submitted name, creates the domain (DKIM key +
+// OpenDKIM reload), and redirects to the domain's page so the DNS record to
+// publish is shown (product.md).
+func (h *Handlers) HandleAddDomain(w http.ResponseWriter, r *http.Request) {
+	if err := r.ParseForm(); err != nil {
+		h.renderDashboard(w, r, http.StatusBadRequest, "Invalid form submission.", "")
+		return
+	}
+	raw := r.PostFormValue("name")
+	name := validate.NormalizeDomain(raw)
+	if err := validate.Domain(name); err != nil {
+		h.renderDashboard(w, r, http.StatusBadRequest, err.Error(), raw)
+		return
+	}
+
+	d, err := h.domains.Add(name)
+	if err != nil {
+		if errors.Is(err, store.ErrDomainExists) {
+			h.renderDashboard(w, r, http.StatusConflict, "That domain is already configured.", raw)
+			return
+		}
+		logf("panel: add domain %q: %v", name, err)
+		h.renderDashboard(w, r, http.StatusInternalServerError,
+			"Could not add the domain. Please check the logs and try again.", raw)
+		return
+	}
+	http.Redirect(w, r, fmt.Sprintf("/domains/%d", d.ID), http.StatusSeeOther)
+}
+
+// HandleDeleteConfirm shows the cascade warning before a domain is removed.
+func (h *Handlers) HandleDeleteConfirm(w http.ResponseWriter, r *http.Request) {
+	d, ok := h.lookupDomain(w, r)
+	if !ok {
+		return
+	}
+	h.view.Render(w, http.StatusOK, "domain_delete", map[string]any{
+		"Title":  "SelfPost — delete " + d.Name,
+		"User":   auth.CurrentUser(r),
+		"Active": "domains",
+		"Domain": d,
+	})
+}
+
+// HandleDeleteDomain performs the deletion and returns to the domain list.
+func (h *Handlers) HandleDeleteDomain(w http.ResponseWriter, r *http.Request) {
+	id, ok := parseDomainID(w, r)
+	if !ok {
+		return
+	}
+	if d, err := h.domains.Get(id); err == nil {
+		defer h.dns.Forget(d.Name)
+	}
+	if err := h.domains.Delete(id); err != nil {
+		if errors.Is(err, store.ErrDomainNotFound) {
+			http.NotFound(w, r)
+			return
+		}
+		logf("panel: delete domain %d: %v", id, err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(w, r, "/domains?deleted=1", http.StatusSeeOther)
+}
+
+// HandleReload re-applies both the OpenDKIM configuration and the Postfix
+// sender map on demand (architecture.md § Panel HTTP surface).
+func (h *Handlers) HandleReload(w http.ResponseWriter, r *http.Request) {
+	if err := h.domains.Resync(); err != nil {
+		logf("panel: manual reload (opendkim): %v", err)
+		http.Error(w, "reload failed", http.StatusInternalServerError)
+		return
+	}
+	if err := h.apps.Resync(); err != nil {
+		logf("panel: manual reload (postfix): %v", err)
+		http.Error(w, "reload failed", http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(w, r, "/status?reloaded=1", http.StatusSeeOther)
+}
+
+func (h *Handlers) lookupDomain(w http.ResponseWriter, r *http.Request) (store.Domain, bool) {
+	id, ok := parseDomainID(w, r)
+	if !ok {
+		return store.Domain{}, false
+	}
+	d, err := h.domains.Get(id)
+	if err != nil {
+		if errors.Is(err, store.ErrDomainNotFound) {
+			http.NotFound(w, r)
+			return store.Domain{}, false
+		}
+		logf("panel: get domain %d: %v", id, err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return store.Domain{}, false
+	}
+	return d, true
+}
+
+func parseDomainID(w http.ResponseWriter, r *http.Request) (int64, bool) {
+	id, err := strconv.ParseInt(r.PathValue("id"), 10, 64)
+	if err != nil || id <= 0 {
+		http.NotFound(w, r)
+		return 0, false
+	}
+	return id, true
+}