feat: Add uptime tooltip showing last failure time and reason

3 files changed, 111 insertions, 45 deletions

diff --git a/internal/server/server.go b/internal/server/server.go
index 4217dd2..499ca31 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -162,12 +162,15 @@ type MonitorData struct {
 	ResponseTime        int64
 	HidePing            bool // Hide response time from display
 	UptimePercent       float64
+	UptimeTooltip       string              // JSON data for uptime tooltip with last failure info
 	Ticks               []*storage.TickData // Aggregated tick data for history bar
 	SSLDaysLeft         int
 	SSLExpiryDate       time.Time
 	SSLTooltip          string // JSON data for SSL expiration tooltip
 	LastCheck           time.Time
 	LastError           string
+	LastFailure         *time.Time // Time of last failure
+	LastFailureError    string     // Error from last failure
 	DisablePingTooltips bool
 }
 
@@ -269,6 +272,11 @@ func (s *Server) handleIndex(w http.ResponseWriter, r *http.Request) {
 					md.SSLTooltip = formatSSLTooltip(*stat.SSLExpiry, stat.SSLDaysLeft, s.config.Display.Timezone)
 				}
 
+				// Set last failure info and uptime tooltip
+				md.LastFailure = stat.LastFailure
+				md.LastFailureError = stat.LastFailureError
+				md.UptimeTooltip = formatUptimeTooltip(stat.UptimePercent, stat.TotalChecks, stat.LastFailure, stat.LastFailureError, s.config.Display.Timezone)
+
 				// Track most recent check time for footer
 				if stat.LastCheck.After(mostRecentCheck) {
 					mostRecentCheck = stat.LastCheck
@@ -559,50 +567,7 @@ func templateFuncs() template.FuncMap {
 			}
 			return "bg-neutral-200 dark:bg-neutral-800"
 		},
-		"simplifyError": func(err string) string {
-			if err == "" {
-				return ""
-			}
-			// Common error patterns to simplify
-			switch {
-			case strings.Contains(err, "no such host"):
-				return "DNS lookup failed"
-			case strings.Contains(err, "connection refused"):
-				return "Connection refused"
-			case strings.Contains(err, "connection reset"):
-				return "Connection reset"
-			case strings.Contains(err, "timeout"):
-				return "Timeout"
-			case strings.Contains(err, "certificate"):
-				return "SSL/TLS error"
-			case strings.Contains(err, "EOF"):
-				return "Connection closed"
-			case strings.Contains(err, "status code"):
-				// Extract status code if present
-				if idx := strings.Index(err, "status code"); idx != -1 {
-					rest := err[idx:]
-					// Try to find the number
-					for i, c := range rest {
-						if c >= '0' && c <= '9' {
-							end := i
-							for end < len(rest) && rest[end] >= '0' && rest[end] <= '9' {
-								end++
-							}
-							return "HTTP " + rest[i:end]
-						}
-					}
-				}
-				return "Unexpected status"
-			case strings.Contains(err, "expected content"):
-				return "Content mismatch"
-			case strings.Contains(err, "i/o timeout"):
-				return "I/O timeout"
-			case strings.Contains(err, "network is unreachable"):
-				return "Network unreachable"
-			default:
-				return "Error"
-			}
-		},
+		"simplifyError": simplifyErrorMessage,
 		"tickTooltipData": func(tick *storage.TickData, mode, timezone string, hidePing bool) string {
 			if tick == nil {
 				data := map[string]interface{}{"header": "No data"}
@@ -912,6 +877,75 @@ func formatLastUpdatedTooltip(t time.Time, timezone string) string {
 	return string(b)
 }
 
+// formatUptimeTooltip creates JSON data for uptime percentage tooltip
+func formatUptimeTooltip(uptimePercent float64, totalChecks int64, lastFailure *time.Time, lastFailureError string, timezone string) string {
+	loc := time.Local
+
+	if timezone != "" && timezone != "Local" && timezone != "Browser" {
+		if l, err := time.LoadLocation(timezone); err == nil {
+			loc = l
+		}
+	}
+
+	rows := []map[string]string{
+		{"label": "Uptime", "value": fmt.Sprintf("%.2f%%", uptimePercent), "class": ""},
+		{"label": "Total Checks", "value": fmt.Sprintf("%d", totalChecks), "class": ""},
+	}
+
+	if lastFailure != nil {
+		t := lastFailure.In(loc)
+		failureTime := t.Format("Jan 2, 2006 15:04:05")
+		rows = append(rows, map[string]string{"label": "Last Failure", "value": failureTime, "class": "error"})
+
+		if lastFailureError != "" {
+			// Simplify the error for display
+			simplifiedError := simplifyErrorMessage(lastFailureError)
+			rows = append(rows, map[string]string{"label": "Failure Reason", "value": simplifiedError, "class": ""})
+		}
+	} else {
+		rows = append(rows, map[string]string{"label": "Last Failure", "value": "Never", "class": "success"})
+	}
+
+	data := map[string]interface{}{
+		"header": "Uptime Statistics",
+		"rows":   rows,
+	}
+
+	b, _ := json.Marshal(data)
+	return string(b)
+}
+
+// simplifyErrorMessage simplifies error messages for display
+func simplifyErrorMessage(err string) string {
+	if err == "" {
+		return ""
+	}
+	switch {
+	case strings.Contains(err, "no such host"):
+		return "DNS lookup failed"
+	case strings.Contains(err, "connection refused"):
+		return "Connection refused"
+	case strings.Contains(err, "connection reset"):
+		return "Connection reset"
+	case strings.Contains(err, "timeout"):
+		return "Timeout"
+	case strings.Contains(err, "certificate"):
+		return "SSL/TLS error"
+	case strings.Contains(err, "EOF"):
+		return "Connection closed"
+	case strings.Contains(err, "status code"):
+		return "Unexpected status"
+	case strings.Contains(err, "expected content"):
+		return "Content mismatch"
+	case strings.Contains(err, "i/o timeout"):
+		return "I/O timeout"
+	case strings.Contains(err, "network is unreachable"):
+		return "Network unreachable"
+	default:
+		return "Error"
+	}
+}
+
 // statusToClass converts a status to a CSS class
 func statusToClass(status string) string {
 	switch status {
diff --git a/internal/server/templates/index.html b/internal/server/templates/index.html
index cd37584..c192a66 100644
--- a/internal/server/templates/index.html
+++ b/internal/server/templates/index.html
@@ -104,7 +104,7 @@
                                 </div>
                             </div>
                             <div class="flex items-center gap-2 flex-shrink-0">
-                                <span class="text-sm font-medium {{if ge .UptimePercent 99.0}}text-emerald-600 dark:text-emerald-400{{else if ge .UptimePercent 95.0}}text-yellow-600 dark:text-yellow-400{{else}}text-red-600 dark:text-red-400{{end}}">{{formatUptime .UptimePercent}}</span>
+                                <span class="text-sm font-medium {{if ge .UptimePercent 99.0}}text-emerald-600 dark:text-emerald-400{{else if ge .UptimePercent 95.0}}text-yellow-600 dark:text-yellow-400{{else}}text-red-600 dark:text-red-400{{end}}"{{if not $monitor.DisablePingTooltips}} data-tooltip='{{.UptimeTooltip}}'{{end}}>{{formatUptime .UptimePercent}}</span>
                             </div>
                         </div>
                         <!-- History Bar -->
diff --git a/internal/storage/sqlite.go b/internal/storage/sqlite.go
index 48cf432..ce62e67 100644
--- a/internal/storage/sqlite.go
+++ b/internal/storage/sqlite.go
@@ -52,6 +52,8 @@ type MonitorStats struct {
 	SSLExpiry        *time.Time
 	SSLDaysLeft      int
 	TotalChecks      int64
+	LastFailure      *time.Time // Time of last failure
+	LastFailureError string     // Error message from last failure
 }
 
 // TickData represents aggregated data for one tick in the history bar
@@ -375,6 +377,36 @@ func (s *Storage) GetAllMonitorStats(ctx context.Context) (map[string]*MonitorSt
 		}
 	}
 
+	// Get last failure for each monitor
+	rows, err = s.db.QueryContext(ctx, `
+		SELECT monitor_name, timestamp, error
+		FROM check_results
+		WHERE status != 'up' AND error != ''
+		AND (monitor_name, timestamp) IN (
+			SELECT monitor_name, MAX(timestamp)
+			FROM check_results
+			WHERE status != 'up' AND error != ''
+			GROUP BY monitor_name
+		)
+	`)
+	if err != nil {
+		return nil, fmt.Errorf("failed to query last failures: %w", err)
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var name string
+		var timestamp time.Time
+		var errorMsg string
+		if err := rows.Scan(&name, &timestamp, &errorMsg); err != nil {
+			return nil, fmt.Errorf("failed to scan last failure: %w", err)
+		}
+		if ms, ok := stats[name]; ok {
+			ms.LastFailure = &timestamp
+			ms.LastFailureError = errorMsg
+		}
+	}
+
 	return stats, nil
 }