Add hostname editing feature to agent detail page

- Create enhanced agent detail template with all stats and hostname edit form
- Add UpdateHostname method to store for agent hostname updates
- Add UpdateAgentHostname handler in UI for web form submissions
- Add UpdateHostname endpoint in API handler for JSON requests
- Register new POST /agents/{id}/hostname route for hostname updates
- Improve agent detail page layout with Settings and Danger Zone sections
- Add error handling for missing agents and empty hostname values

cmd/server/main.go

@@ -45,6 +45,7 @@ func main() {
 		protectedRoutes.Use(authMgr.Middleware)
 		protectedRoutes.Get("/", uiHandler.Dashboard)
 		protectedRoutes.Get("/agents/{id}", uiHandler.AgentDetail)
+		protectedRoutes.Post("/agents/{id}/hostname", uiHandler.UpdateAgentHostname)
 		protectedRoutes.Post("/logout", uiHandler.Logout)
 		protectedRoutes.Post("/api/agents/remove-stale", uiHandler.RemoveStaleAgents)
 		protectedRoutes.Post("/api/agents/{id}/delete", uiHandler.DeleteAgent)

internal/api/api.go

@@ -73,3 +73,32 @@ func (h *Handler) DeleteAgent(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(map[string]string{"status": "deleted"})
 }
+
+// UpdateHostname updates the hostname for an agent.
+func (h *Handler) UpdateHostname(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	agentID := r.PathValue("id")
+	if agentID == "" {
+		http.Error(w, "missing agent id", http.StatusBadRequest)
+		return
+	}
+
+	hostname := r.FormValue("hostname")
+	if hostname == "" {
+		http.Error(w, "missing hostname", http.StatusBadRequest)
+		return
+	}
+
+	err := h.store.UpdateHostname(agentID, hostname)
+	if err != nil {
+		http.Error(w, "agent not found", http.StatusNotFound)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]string{"status": "updated"})
+}

internal/store/store.go

@@ -1,12 +1,18 @@
 package store
 
 import (
+	"errors"
 	"sync"
 	"time"
 
 	"nerd-monitor/internal/stats"
 )
 
+var (
+	// ErrAgentNotFound is returned when an agent is not found.
+	ErrAgentNotFound = errors.New("agent not found")
+)
+
 // AgentStats represents the latest stats for an agent.
 type AgentStats struct {
 	ID        string
@@ -76,3 +82,17 @@ func (s *Store) DeleteAgent(id string) {
 
 	delete(s.agents, id)
 }
+
+// UpdateHostname updates the hostname for an agent.
+func (s *Store) UpdateHostname(id string, hostname string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	agent, exists := s.agents[id]
+	if !exists {
+		return ErrAgentNotFound
+	}
+
+	agent.Hostname = hostname
+	return nil
+}

internal/ui/handlers.go

@@ -133,6 +133,30 @@ func (h *Handler) DeleteAgent(w http.ResponseWriter, r *http.Request) {
 	http.Redirect(w, r, "/", http.StatusSeeOther)
 }
 
+// UpdateAgentHostname handles hostname updates for agents.
+func (h *Handler) UpdateAgentHostname(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	agentID := r.PathValue("id")
+	hostname := r.FormValue("hostname")
+
+	if hostname == "" {
+		http.Error(w, "Hostname cannot be empty", http.StatusBadRequest)
+		return
+	}
+
+	err := h.store.UpdateHostname(agentID, hostname)
+	if err != nil {
+		http.NotFound(w, r)
+		return
+	}
+
+	http.Redirect(w, r, "/agents/"+agentID, http.StatusSeeOther)
+}
+
 // getStaleAgents returns agents that haven't reported in 6 months.
 func (h *Handler) getStaleAgents() []*store.AgentStats {
 	const staleThreshold = 6 * 30 * 24 * time.Hour

views/agent_detail.templ

@@ -17,6 +17,7 @@ templ agentDetailContent(agent *store.AgentStats) {
 		@AgentStatusBadge(agent.LastSeen)
 	</div>
 	
+	<!-- CPU Usage Card -->
 	<div class="grid" style="grid-template-columns: 1fr;">
 		<div class="card">
 			<div class="card-title">CPU Usage</div>
@@ -32,6 +33,7 @@ templ agentDetailContent(agent *store.AgentStats) {
 		</div>
 	</div>
 	
+	<!-- Memory and Disk Usage Cards -->
 	<div class="grid" style="margin-top: 1.5rem;">
 		<div class="card">
 			<div class="card-title">Memory Usage</div>
@@ -43,24 +45,49 @@ templ agentDetailContent(agent *store.AgentStats) {
 		</div>
 	</div>
 	
+	<!-- Agent Information and Settings -->
 	<div class="card" style="margin-top: 1.5rem;">
 		<div class="card-title">Agent Information</div>
 		<div class="metric-row">
 			<span class="metric-label">Agent ID</span>
 			<span class="metric-value" style="font-family: monospace; font-size: 0.875rem;">{ agent.ID }</span>
 		</div>
-		<div class="metric-row">
-			<span class="metric-label">Hostname</span>
-			<span class="metric-value">{ agent.Hostname }</span>
-		</div>
 		<div class="metric-row">
 			<span class="metric-label">Last Seen</span>
 			<span class="metric-value">{ agent.LastSeen.Format("2006-01-02 15:04:05") }</span>
 		</div>
 	</div>
 	
-	<div class="btn-group" style="margin-top: 1.5rem;">
+	<!-- Hostname Settings -->
-		<form method="POST" action={ templ.SafeURL(fmt.Sprintf("/api/agents/%s/delete", agent.ID)) } style="margin: 0;" onsubmit="return confirm('Are you sure you want to remove this agent?');">
+	<div class="card" style="margin-top: 1.5rem;">
+		<div class="card-title">Settings</div>
+		<form method="POST" action={ templ.SafeURL(fmt.Sprintf("/agents/%s/hostname", agent.ID)) } style="display: flex; flex-direction: column; gap: 1rem;">
+			<div style="display: flex; flex-direction: column; gap: 0.5rem;">
+				<label for="hostname" style="font-size: 0.875rem; font-weight: 500; color: #cbd5e1;">
+					Hostname
+				</label>
+				<input 
+					type="text" 
+					id="hostname" 
+					name="hostname" 
+					value={ agent.Hostname }
+					required
+					style="padding: 0.5rem 0.75rem; background-color: #1e293b; border: 1px solid #475569; border-radius: 0.375rem; color: #e2e8f0; font-size: 0.875rem;"
+				/>
+			</div>
+			<button type="submit" class="btn btn-primary" style="align-self: flex-start;">
+				Update Hostname
+			</button>
+		</form>
+	</div>
+	
+	<!-- Danger Zone -->
+	<div class="card" style="margin-top: 1.5rem; border-left: 3px solid #ef4444;">
+		<div class="card-title" style="color: #ef4444;">Danger Zone</div>
+		<p style="margin: 0 0 1rem 0; color: #94a3b8; font-size: 0.875rem;">
+			Deleting this agent will remove all its data and history.
+		</p>
+		<form method="POST" action={ templ.SafeURL(fmt.Sprintf("/api/agents/%s/delete", agent.ID)) } style="margin: 0;" onsubmit="return confirm('Are you sure you want to remove this agent? This action cannot be undone.');">
 			<button type="submit" class="btn btn-danger">Delete Agent</button>
 		</form>
 	</div>