Refresh indicator goes red on error.

It will stay flashing red until the next refresh, at which point it goes
back to its normal color. On a successful refresh, it still stops.

Also, add a deadline of 15 seconds to the refresh command.

moonmath.go

@@ -2,21 +2,30 @@ package main
 
 import (
 	"fmt"
+	"io"
+	"log/slog"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"code.humancabbage.net/sam/moonmath/coindesk"
 	"code.humancabbage.net/sam/moonmath/config"
 	"code.humancabbage.net/sam/moonmath/tui"
 	"github.com/alecthomas/kong"
+	tea "github.com/charmbracelet/bubbletea"
 )
 
 var CLI struct {
 	Asset      []string `short:"a" default:"BTC" help:"Asset(s) to project."`
 	ConfigFile string   `short:"c" help:"Path to YAML configuration file."`
+	Perf       bool     `help:"Display internal performance stats."`
 }
 
 func main() {
+	logFile := setupLogging()
+	defer func() {
+		_ = logFile.Close()
+	}()
 	ctx := kong.Parse(&CLI)
 	if ctx.Error != nil {
 		fail(ctx.Error)
@@ -30,12 +39,45 @@ func main() {
 		asset := coindesk.Asset(strings.ToUpper(CLI.Asset[i]))
 		assets = append(assets, asset)
 	}
-	p := tui.New(assets, allCfg)
+	m := tui.New(assets, allCfg, CLI.Perf)
+	p := tea.NewProgram(m,
+		tea.WithAltScreen(),
+		tea.WithFPS(30),
+	)
 	if _, err := p.Run(); err != nil {
 		fail(err)
 	}
 }
 
+func setupLogging() io.Closer {
+	homePath, err := os.UserHomeDir()
+	if err != nil {
+		panic(err)
+	}
+
+	programConfigPath := filepath.Join(homePath, ".moonmath")
+	err = os.MkdirAll(programConfigPath, 0755)
+	if err != nil {
+		panic(err)
+	}
+
+	errLogPath := filepath.Join(programConfigPath, "errors.log")
+	errLogFile, err := os.OpenFile(
+		errLogPath,
+		os.O_CREATE|os.O_APPEND|os.O_WRONLY,
+		0600,
+	)
+	if err != nil {
+		panic(err)
+	}
+
+	slog.SetDefault(slog.New(
+		slog.NewTextHandler(errLogFile, &slog.HandlerOptions{
+			Level: slog.LevelError,
+		})))
+	return errLogFile
+}
+
 func fail(err error) {
 	fmt.Printf("program error: %v\n", err)
 	os.Exit(1)

tui/asset/asset.go

@@ -3,6 +3,7 @@ package asset
 import (
 	"context"
 	"fmt"
+	"log/slog"
 	"time"
 
 	"code.humancabbage.net/sam/moonmath/coindesk"
@@ -83,8 +84,7 @@ func New(cfg config.Data) (m Model) {
 
 	m.indicator = spinner.New()
 	m.indicator.Spinner = spinner.Points
-	m.indicator.Style = lipgloss.NewStyle().
-		Foreground(lipgloss.Color("69"))
+	m.indicator.Style = indicatorNormalStyle
 
 	return
 }
@@ -108,33 +108,30 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 		switch msg := msg.inner.(type) {
 		case refresh:
 			m.refreshing = true
-			return m, func() tea.Msg {
-				// TODO: log errors
-				_ = m.math.Refresh(context.TODO())
-				return Msg{m.math.Asset, m.math}
-			}
-		case moon.Math:
-			m.math = msg
-			refillProperties(&m)
-			refillProjections(&m)
+			m.indicator.Style = indicatorNormalStyle
 			return m, tea.Batch(
-				// schedule the next refresh
-				tea.Tick(time.Second*30,
-					func(t time.Time) tea.Msg {
-						return Msg{m.math.Asset, refresh{}}
-					}),
-				// wait a bit to stop the indicator, so that it's more obvious
-				// even when the refresh completes quickly.
-				tea.Tick(time.Millisecond*500,
-					func(t time.Time) tea.Msg {
-						return Msg{m.math.Asset, stopIndicator{}}
-					}),
+				m.resumeIndicator,
+				m.refresh,
 			)
+		case update:
+			commands := []tea.Cmd{m.scheduleRefresh()}
+			if msg.err == nil {
+				m.math = msg.math
+				refillProperties(&m)
+				refillProjections(&m)
+				commands = append(commands, m.stopIndicator())
+			} else {
+				m.indicator.Style = indicatorErrorStyle
+			}
+			return m, tea.Batch(commands...)
 		case stopIndicator:
 			m.refreshing = false
 			return m, nil
 		}
 	case spinner.TickMsg:
+		if !m.refreshing {
+			return m, nil
+		}
 		var cmd tea.Cmd
 		m.indicator, cmd = m.indicator.Update(msg)
 		return m, cmd
@@ -143,8 +140,47 @@ func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
 }
 
 type refresh struct{}
+type update struct {
+	math moon.Math
+	err  error
+}
 type stopIndicator struct{}
 
+func (m Model) refresh() tea.Msg {
+	ctx, cancel := context.WithDeadline(
+		context.Background(),
+		time.Now().Add(time.Second*15))
+	defer cancel()
+	err := m.math.Refresh(ctx)
+	if err != nil {
+		slog.Error("refresh",
+			"asset", m.math.Asset,
+			"err", err,
+		)
+	}
+	return Msg{m.math.Asset, update{m.math, err}}
+}
+
+func (m Model) resumeIndicator() tea.Msg {
+	return m.indicator.Tick()
+}
+
+func (m Model) scheduleRefresh() tea.Cmd {
+	return tea.Tick(time.Second*30,
+		func(t time.Time) tea.Msg {
+			return Msg{m.math.Asset, refresh{}}
+		})
+}
+
+func (m Model) stopIndicator() tea.Cmd {
+	// wait a bit to stop the indicator, so that it's more obvious
+	// even when the refresh completes quickly.
+	return tea.Tick(time.Millisecond*500,
+		func(t time.Time) tea.Msg {
+			return Msg{m.math.Asset, stopIndicator{}}
+		})
+}
+
 func refillProperties(m *Model) {
 	rows := []table.Row{
 		{"Asset", string(m.math.Asset)},
@@ -199,3 +235,9 @@ func (m Model) View() string {
 var baseStyle = lipgloss.NewStyle().
 	BorderStyle(lipgloss.RoundedBorder()).
 	BorderForeground(lipgloss.Color("240"))
+
+var indicatorNormalStyle = lipgloss.NewStyle().
+	Foreground(lipgloss.Color("69"))
+
+var indicatorErrorStyle = lipgloss.NewStyle().
+	Foreground(lipgloss.Color("160"))

tui/perf/perf.go

@@ -0,0 +1,42 @@
+package perf
+
+import (
+	"fmt"
+	"sync/atomic"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+type Model struct {
+	updates *atomic.Int64
+	views   *atomic.Int64
+}
+
+func New() (m Model) {
+	m.updates = new(atomic.Int64)
+	m.views = new(atomic.Int64)
+	return
+}
+
+func (m Model) Init() tea.Cmd {
+	return nil
+}
+
+func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
+	return m, nil
+}
+
+func (m Model) View() string {
+	updates := m.updates.Load()
+	views := m.views.Load()
+	s := fmt.Sprintf("updates: %d\tviews: %d", updates, views)
+	return s
+}
+
+func (m Model) AddUpdate() {
+	m.updates.Add(1)
+}
+
+func (m Model) AddView() {
+	m.views.Add(1)
+}

tui/tui.go

@@ -6,25 +6,20 @@ import (
 	"code.humancabbage.net/sam/moonmath/coindesk"
 	"code.humancabbage.net/sam/moonmath/config"
 	"code.humancabbage.net/sam/moonmath/tui/asset"
+	"code.humancabbage.net/sam/moonmath/tui/perf"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
 )
 
 type Model struct {
-	assets []asset.Model
+	assets       []asset.Model
+	stats        perf.Model
+	displayStats bool
 }
 
-func New(assets []coindesk.Asset, cfg config.All) (p *tea.Program) {
-	model := newModel(assets, cfg)
-	p = tea.NewProgram(
-		model,
-		tea.WithAltScreen(),
-		tea.WithFPS(30),
-	)
-	return
-}
-
-func newModel(assets []coindesk.Asset, cfg config.All) (m Model) {
+func New(assets []coindesk.Asset, cfg config.All, displayStats bool) (m Model) {
+	m.stats = perf.New()
+	m.displayStats = displayStats
 	// construct models for each asset, but don't filter out dupes
 	seen := map[coindesk.Asset]struct{}{}
 	for _, a := range assets {
@@ -52,6 +47,7 @@ func (m Model) Init() tea.Cmd {
 }
 
 func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	m.stats.AddUpdate()
 	switch msg := msg.(type) {
 	// handle keys for quitting
 	case tea.KeyMsg:
@@ -78,11 +74,15 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 }
 
 func (m Model) View() string {
+	m.stats.AddView()
 	var ss []string
 	for i := range m.assets {
 		s := m.assets[i].View()
 		ss = append(ss, s)
 	}
+	if m.displayStats {
+		ss = append(ss, m.stats.View())
+	}
 	r := lipgloss.JoinVertical(lipgloss.Center, ss...)
 	return r
 }