cmd/goupkeep/main.go

@@ -112,6 +112,7 @@ func main() {
 		fmt.Printf("Imported %d monitors and %d alerts from Uptime Kuma v%s\n", len(backup.Sites), len(backup.Alerts), kb.Version)
 	}
 
+	monitor.InitHistoryFromStore()
 	monitor.StartEngine()
 
 	server.Start(server.ServerConfig{

internal/models/models.go

@@ -50,7 +50,13 @@ type User struct {
 	Role      string
 }
 
-// Phase 5: Backup Structure
+type CheckRecord struct {
+	SiteID    int
+	LatencyNs int64
+	IsUp      bool
+	CheckedAt time.Time
+}
+
 type Backup struct {
 	Sites  []Site        `json:"sites"`
 	Alerts []AlertConfig `json:"alerts"`

internal/monitor/history.go

@@ -1,6 +1,7 @@
 package monitor
 
 import (
+	"go-upkeep/internal/store"
 	"sync"
 	"time"
 )
@@ -19,6 +20,31 @@ var (
 	historyMu sync.RWMutex
 )
 
+func InitHistoryFromStore() {
+	s := store.Get()
+	if s == nil {
+		return
+	}
+	all := s.LoadAllHistory(maxHistoryLen)
+	historyMu.Lock()
+	defer historyMu.Unlock()
+	for siteID, records := range all {
+		h := &SiteHistory{}
+		for _, r := range records {
+			h.TotalChecks++
+			if r.IsUp {
+				h.UpChecks++
+			}
+			h.Latencies = append(h.Latencies, time.Duration(r.LatencyNs))
+			h.Statuses = append(h.Statuses, r.IsUp)
+		}
+		histories[siteID] = h
+	}
+	if len(all) > 0 {
+		AddLog("Loaded check history from database")
+	}
+}
+
 func RecordCheck(siteID int, latency time.Duration, isUp bool) {
 	historyMu.Lock()
 	defer historyMu.Unlock()
@@ -43,6 +69,10 @@ func RecordCheck(siteID int, latency time.Duration, isUp bool) {
 	if len(h.Statuses) > maxHistoryLen {
 		h.Statuses = h.Statuses[len(h.Statuses)-maxHistoryLen:]
 	}
+
+	if s := store.Get(); s != nil {
+		go s.SaveCheck(siteID, latency.Nanoseconds(), isUp)
+	}
 }
 
 func GetHistory(siteID int) (SiteHistory, bool) {

internal/server/server.go

@@ -185,6 +185,12 @@ func renderStatusPage(w http.ResponseWriter, title string) {
 		<script>
 			var lastUpdate = null;
 
+			function esc(s) {
+				var d = document.createElement('div');
+				d.appendChild(document.createTextNode(s));
+				return d.innerHTML;
+			}
+
 			function cssClass(status) {
 				return status.replace(/\s+/g, '-');
 			}
@@ -234,13 +240,13 @@ func renderStatusPage(w http.ResponseWriter, title string) {
 					var s = sites[i];
 					var st = s.Paused ? 'PAUSED' : s.Status;
 					var cls = cssClass(st);
-					var meta = s.Type + ' | ' + (s.Type === 'http' ? s.URL : 'Heartbeat Monitor');
+					var meta = esc(s.Type) + ' | ' + (s.Type === 'http' ? esc(s.URL) : 'Heartbeat Monitor');
 					var lc = s.LastCheck ? new Date(s.LastCheck).toLocaleTimeString('en-GB', {hour12: false}) : '—';
 					html += '<div class="card"><div class="info">' +
-						'<div class="name">' + s.Name + '</div>' +
+						'<div class="name">' + esc(s.Name) + '</div>' +
 						'<div class="meta">' + meta + '</div>' +
 						'<div class="meta" style="margin-top:4px;">Last Check: ' + lc + '</div>' +
-						'</div><div class="status ' + cls + '">' + st + '</div></div>';
+						'</div><div class="status ' + cls + '">' + esc(st) + '</div></div>';
 				}
 				c.innerHTML = html;
 			}

internal/store/postgres.go

@@ -56,6 +56,13 @@ func (p *PostgresStore) Init() error {
 			public_key TEXT NOT NULL,
 			role TEXT DEFAULT 'user'
 		);`,
+		`CREATE TABLE IF NOT EXISTS check_history (
+			id SERIAL PRIMARY KEY,
+			site_id INTEGER NOT NULL,
+			latency_ns BIGINT,
+			is_up BOOLEAN,
+			checked_at TIMESTAMP DEFAULT NOW()
+		);`,
 	}
 	for _, q := range queries {
 		if _, err := p.db.Exec(q); err != nil {
@@ -63,6 +70,8 @@ func (p *PostgresStore) Init() error {
 		}
 	}
 
+	p.db.Exec("CREATE INDEX IF NOT EXISTS idx_check_history_site ON check_history(site_id, checked_at DESC)")
+
 	migrations := []string{
 		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS hostname TEXT DEFAULT ''",
 		"ALTER TABLE sites ADD COLUMN IF NOT EXISTS port INTEGER DEFAULT 0",
@@ -184,7 +193,38 @@ func (p *PostgresStore) DeleteUser(id int) error {
 	return err
 }
 
-// --- PHASE 5 ---
+func (p *PostgresStore) SaveCheck(siteID int, latencyNs int64, isUp bool) {
+	p.db.Exec("INSERT INTO check_history (site_id, latency_ns, is_up) VALUES ($1, $2, $3)", siteID, latencyNs, isUp)
+	p.db.Exec(`DELETE FROM check_history WHERE site_id = $1 AND id NOT IN (
+		SELECT id FROM check_history WHERE site_id = $1 ORDER BY checked_at DESC LIMIT 1000
+	)`, siteID)
+}
+
+func (p *PostgresStore) LoadAllHistory(limit int) map[int][]models.CheckRecord {
+	result := make(map[int][]models.CheckRecord)
+	rows, err := p.db.Query(`
+		SELECT site_id, latency_ns, is_up FROM (
+			SELECT site_id, latency_ns, is_up,
+				ROW_NUMBER() OVER (PARTITION BY site_id ORDER BY checked_at DESC) AS rn
+			FROM check_history
+		) sub WHERE rn <= $1`, limit)
+	if err != nil {
+		return result
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var r models.CheckRecord
+		rows.Scan(&r.SiteID, &r.LatencyNs, &r.IsUp)
+		result[r.SiteID] = append(result[r.SiteID], r)
+	}
+	for id, records := range result {
+		for i, j := 0, len(records)-1; i < j; i, j = i+1, j-1 {
+			records[i], records[j] = records[j], records[i]
+		}
+		result[id] = records
+	}
+	return result
+}
 
 func (p *PostgresStore) ExportData() models.Backup {
 	return models.Backup{

internal/store/sqlite.go

@@ -57,7 +57,15 @@ func (s *SQLiteStore) Init() error {
 		username TEXT NOT NULL,
 		public_key TEXT NOT NULL,
 		role TEXT DEFAULT 'user'
-	);`
+	);
+	CREATE TABLE IF NOT EXISTS check_history (
+		id INTEGER PRIMARY KEY AUTOINCREMENT,
+		site_id INTEGER NOT NULL,
+		latency_ns INTEGER,
+		is_up BOOLEAN,
+		checked_at DATETIME DEFAULT CURRENT_TIMESTAMP
+	);
+	CREATE INDEX IF NOT EXISTS idx_check_history_site ON check_history(site_id, checked_at DESC);`
 	_, err = s.db.Exec(createTables)
 	if err != nil {
 		return err
@@ -204,7 +212,38 @@ func (s *SQLiteStore) DeleteUser(id int) error {
 	return err
 }
 
-// --- PHASE 5 ---
+func (s *SQLiteStore) SaveCheck(siteID int, latencyNs int64, isUp bool) {
+	s.db.Exec("INSERT INTO check_history (site_id, latency_ns, is_up) VALUES (?, ?, ?)", siteID, latencyNs, isUp)
+	s.db.Exec(`DELETE FROM check_history WHERE site_id = ? AND id NOT IN (
+		SELECT id FROM check_history WHERE site_id = ? ORDER BY checked_at DESC LIMIT 1000
+	)`, siteID, siteID)
+}
+
+func (s *SQLiteStore) LoadAllHistory(limit int) map[int][]models.CheckRecord {
+	result := make(map[int][]models.CheckRecord)
+	rows, err := s.db.Query(`
+		SELECT site_id, latency_ns, is_up FROM (
+			SELECT site_id, latency_ns, is_up,
+				ROW_NUMBER() OVER (PARTITION BY site_id ORDER BY checked_at DESC) AS rn
+			FROM check_history
+		) WHERE rn <= ?`, limit)
+	if err != nil {
+		return result
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var r models.CheckRecord
+		rows.Scan(&r.SiteID, &r.LatencyNs, &r.IsUp)
+		result[r.SiteID] = append(result[r.SiteID], r)
+	}
+	for id, records := range result {
+		for i, j := 0, len(records)-1; i < j; i, j = i+1, j-1 {
+			records[i], records[j] = records[j], records[i]
+		}
+		result[id] = records
+	}
+	return result
+}
 
 func (s *SQLiteStore) ExportData() models.Backup {
 	return models.Backup{

internal/store/store.go

@@ -27,7 +27,11 @@ type Store interface {
 	UpdateUser(id int, username, publicKey, role string) error
 	DeleteUser(id int) error
 
-	// Phase 5: Backup & Restore
+	// History
+	SaveCheck(siteID int, latencyNs int64, isUp bool)
+	LoadAllHistory(limit int) map[int][]models.CheckRecord
+
+	// Backup & Restore
 	ExportData() models.Backup
 	ImportData(data models.Backup) error
 }

internal/tui/tab_sites.go

@@ -356,7 +356,17 @@ func (m *Model) initSiteHuhForm() tea.Cmd {
 				}),
 			huh.NewInput().Title("Check Interval (seconds)").
 				Placeholder("60").
-				Value(&m.siteFormData.Interval),
+				Value(&m.siteFormData.Interval).
+				Validate(func(s string) error {
+					v, err := strconv.Atoi(s)
+					if err != nil {
+						return fmt.Errorf("must be a number")
+					}
+					if v < 5 {
+						return fmt.Errorf("minimum interval is 5 seconds")
+					}
+					return nil
+				}),
 			huh.NewSelect[string]().Title("Alert Channel").
 				Options(alertOpts...).
 				Value(&m.siteFormData.AlertID),
@@ -369,10 +379,30 @@ func (m *Model) initSiteHuhForm() tea.Cmd {
 			huh.NewInput().Title("Port").
 				Placeholder("0").
 				Description("Target port for TCP port monitors").
-				Value(&m.siteFormData.Port),
+				Value(&m.siteFormData.Port).
+				Validate(func(s string) error {
+					v, err := strconv.Atoi(s)
+					if err != nil {
+						return fmt.Errorf("must be a number")
+					}
+					if v < 0 || v > 65535 {
+						return fmt.Errorf("port must be 0-65535")
+					}
+					return nil
+				}),
 			huh.NewInput().Title("Timeout (seconds)").
 				Placeholder("5").
-				Value(&m.siteFormData.Timeout),
+				Value(&m.siteFormData.Timeout).
+				Validate(func(s string) error {
+					v, err := strconv.Atoi(s)
+					if err != nil {
+						return fmt.Errorf("must be a number")
+					}
+					if v < 1 || v > 300 {
+						return fmt.Errorf("timeout must be 1-300 seconds")
+					}
+					return nil
+				}),
 			huh.NewInput().Title("Description").
 				Placeholder("Optional description").
 				Value(&m.siteFormData.Description),
@@ -382,10 +412,30 @@ func (m *Model) initSiteHuhForm() tea.Cmd {
 				Value(&m.siteFormData.CheckSSL),
 			huh.NewInput().Title("SSL Warning Threshold (days)").
 				Placeholder("7").
-				Value(&m.siteFormData.Threshold),
+				Value(&m.siteFormData.Threshold).
+				Validate(func(s string) error {
+					v, err := strconv.Atoi(s)
+					if err != nil {
+						return fmt.Errorf("must be a number")
+					}
+					if v < 1 {
+						return fmt.Errorf("threshold must be at least 1 day")
+					}
+					return nil
+				}),
 			huh.NewInput().Title("Max Retries Before Alert").
 				Placeholder("0").
-				Value(&m.siteFormData.Retries),
+				Value(&m.siteFormData.Retries).
+				Validate(func(s string) error {
+					v, err := strconv.Atoi(s)
+					if err != nil {
+						return fmt.Errorf("must be a number")
+					}
+					if v < 0 {
+						return fmt.Errorf("retries cannot be negative")
+					}
+					return nil
+				}),
 			huh.NewConfirm().Title("Ignore TLS Errors?").
 				Value(&m.siteFormData.IgnoreTLS),
 		).Title("Advanced"),

internal/tui/tui.go

@@ -40,6 +40,7 @@ const (
 	stateFormSite
 	stateFormAlert
 	stateFormUser
+	stateConfirmDelete
 )
 
 type Model struct {
@@ -62,6 +63,10 @@ type Model struct {
 	isAdmin     bool
 	zones       *zone.Manager
 
+	deleteID   int
+	deleteName string
+	deleteTab  int
+
 	// harmonica animation state
 	pulseSpring harmonica.Spring
 	pulsePos    float64
@@ -95,6 +100,41 @@ func (m Model) Init() tea.Cmd {
 func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	var cmd tea.Cmd
 
+	if m.state == stateConfirmDelete {
+		if keyMsg, ok := msg.(tea.KeyMsg); ok {
+			switch keyMsg.String() {
+			case "y", "Y":
+				if store.Get() != nil {
+					switch m.deleteTab {
+					case 0:
+						store.Get().DeleteSite(m.deleteID)
+						monitor.RemoveSite(m.deleteID)
+						m.adjustCursor(len(m.sites) - 1)
+					case 1:
+						store.Get().DeleteAlert(m.deleteID)
+						m.adjustCursor(len(m.alerts) - 1)
+					case 3:
+						store.Get().DeleteUser(m.deleteID)
+						m.adjustCursor(len(m.users) - 1)
+					}
+				}
+				m.refreshData()
+				m.state = stateDashboard
+				if m.deleteTab == 3 {
+					m.state = stateUsers
+				}
+			case "n", "N", "esc":
+				m.state = stateDashboard
+				if m.deleteTab == 3 {
+					m.state = stateUsers
+				}
+			case "ctrl+c":
+				return m, tea.Quit
+			}
+		}
+		return m, nil
+	}
+
 	// Form state: forward ALL messages to huh (keys, timers, resize, etc.)
 	if m.state == stateFormSite || m.state == stateFormAlert || m.state == stateFormUser {
 		if keyMsg, ok := msg.(tea.KeyMsg); ok {
@@ -270,19 +310,22 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 					m.refreshData()
 				}
 			case "d", "backspace":
-				if m.currentTab == 1 && len(m.alerts) > 0 {
-					store.Get().DeleteAlert(m.alerts[m.cursor].ID)
-					m.adjustCursor(len(m.alerts) - 1)
-				} else if m.currentTab == 0 && len(m.sites) > 0 {
-					id := m.sites[m.cursor].ID
-					store.Get().DeleteSite(id)
-					monitor.RemoveSite(id)
-					m.adjustCursor(len(m.sites) - 1)
+				if m.currentTab == 0 && len(m.sites) > 0 {
+					m.deleteID = m.sites[m.cursor].ID
+					m.deleteName = m.sites[m.cursor].Name
+					m.deleteTab = 0
+					m.state = stateConfirmDelete
+				} else if m.currentTab == 1 && len(m.alerts) > 0 {
+					m.deleteID = m.alerts[m.cursor].ID
+					m.deleteName = m.alerts[m.cursor].Name
+					m.deleteTab = 1
+					m.state = stateConfirmDelete
 				} else if m.currentTab == 3 && m.isAdmin && len(m.users) > 0 {
-					store.Get().DeleteUser(m.users[m.cursor].ID)
-					m.adjustCursor(len(m.users) - 1)
+					m.deleteID = m.users[m.cursor].ID
+					m.deleteName = m.users[m.cursor].Username
+					m.deleteTab = 3
+					m.state = stateConfirmDelete
 				}
-				m.refreshData()
 			}
 		}
 	}
@@ -426,6 +469,16 @@ func (m Model) pulseIndicator() string {
 
 func (m Model) View() string {
 	switch m.state {
+	case stateConfirmDelete:
+		kind := "monitor"
+		if m.deleteTab == 1 {
+			kind = "alert"
+		} else if m.deleteTab == 3 {
+			kind = "user"
+		}
+		msg := dangerStyle.Render(fmt.Sprintf("Delete %s \"%s\"?", kind, m.deleteName))
+		hint := subtleStyle.Render("[y] Confirm  [n] Cancel")
+		return lipgloss.NewStyle().Padding(2, 4).Render(msg + "\n\n" + hint)
 	case stateFormSite, stateFormAlert, stateFormUser:
 		if m.huhForm != nil {
 			title := ""