feat(01-03): add deterministic rich CLI output

- Inject bonfire.Output from stdin/stdout/stderr with stdlib widgets and x/term
- Degrade spinner, progress, table and prompts without a TTY or color
- Reject plugin command names that are not namespace:verb

bonfire/widgets.go

@@ -0,0 +1,210 @@
+package bonfire
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+	"time"
+	"unicode/utf8"
+)
+
+var spinnerFrames = []rune{'⠋', '⠙', '⠹', '⠸', '⠼', '⠴', '⠦', '⠧', '⠇', '⠏'}
+
+const (
+	boxTopLeft     = "┌"
+	boxTopRight    = "┐"
+	boxBottomLeft  = "└"
+	boxBottomRight = "┘"
+	boxHorizontal  = "─"
+	boxVertical    = "│"
+	boxTeeRight    = "├"
+	boxTeeLeft     = "┤"
+	boxTeeDown     = "┬"
+	boxTeeUp       = "┴"
+	boxCross       = "┼"
+)
+
+func (c *console) Spinner(message string, fn func() error) error {
+	if fn == nil {
+		fn = func() error { return nil }
+	}
+	if !c.tty {
+		c.Printf("[...] %s\n", message)
+		return fn()
+	}
+
+	done := make(chan struct{})
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		i := 0
+		ticker := time.NewTicker(80 * time.Millisecond)
+		defer ticker.Stop()
+		c.Printf("\r%s %s", c.style(ansiCyan, string(spinnerFrames[0])), message)
+		for {
+			select {
+			case <-done:
+				return
+			case <-ticker.C:
+				i++
+				frame := spinnerFrames[i%len(spinnerFrames)]
+				c.Printf("\r%s %s", c.style(ansiCyan, string(frame)), message)
+			}
+		}
+	}()
+
+	err := fn()
+	close(done)
+	wg.Wait()
+	if err != nil {
+		c.Printf("\r%s %s\n", c.style(ansiRed, symCross), message)
+		return err
+	}
+	c.Printf("\r%s %s\n", c.style(ansiGreen, symCheck), message)
+	return nil
+}
+
+func (c *console) Progress(total int, fn func(Progress) error) error {
+	if total < 1 {
+		total = 1
+	}
+	bar := &progressBar{c: c, total: total, lastPct: -1}
+	if fn == nil {
+		return nil
+	}
+	err := fn(bar)
+	if c.tty && bar.current >= bar.total {
+		c.Println()
+	}
+	return err
+}
+
+type progressBar struct {
+	c       *console
+	total   int
+	current int
+	lastPct int
+}
+
+func (p *progressBar) Advance(step int) {
+	if step < 1 {
+		step = 1
+	}
+	p.current += step
+	if p.current > p.total {
+		p.current = p.total
+	}
+	pct := 0
+	if p.total > 0 {
+		pct = p.current * 100 / p.total
+	}
+	if p.c.tty {
+		p.renderTTY(pct)
+		return
+	}
+	if p.lastPct >= 0 && pct/10 == p.lastPct/10 && pct != 100 {
+		return
+	}
+	if pct == 0 && p.lastPct < 0 {
+		p.lastPct = 0
+		return
+	}
+	if pct%10 == 0 || pct == 100 {
+		p.c.Printf("[%d/%d] %d%%\n", p.current, p.total, pct)
+		p.lastPct = pct
+	}
+}
+
+func (p *progressBar) renderTTY(pct int) {
+	width := 40
+	filled := 0
+	if p.total > 0 {
+		filled = p.current * width / p.total
+	}
+	if filled > width {
+		filled = width
+	}
+	bar := strings.Repeat("█", filled) + strings.Repeat(" ", width-filled)
+	color := progressColor(pct)
+	p.c.Printf("\r %s %5.1f%% %d/%d", p.c.style(color, bar), float64(pct), p.current, p.total)
+}
+
+func progressColor(pct int) string {
+	switch {
+	case pct >= 100:
+		return "\x1b[38;5;34m"
+	case pct >= 50:
+		return "\x1b[38;5;36m"
+	default:
+		return "\x1b[38;5;37m"
+	}
+}
+
+func (c *console) Table(headers []string, rows [][]string) {
+	if !c.tty {
+		c.Println(strings.Join(headers, "\t"))
+		for _, row := range rows {
+			c.Println(strings.Join(padRow(row, len(headers)), "\t"))
+		}
+		return
+	}
+	cols := len(headers)
+	all := make([][]string, 0, 1+len(rows))
+	all = append(all, headers)
+	for _, row := range rows {
+		all = append(all, padRow(row, cols))
+	}
+	widths := make([]int, cols)
+	for _, row := range all {
+		for i, cell := range row {
+			if n := utf8.RuneCountInString(cell); n > widths[i] {
+				widths[i] = n
+			}
+		}
+	}
+	c.Println(boxLine(widths, boxTopLeft, boxTeeDown, boxTopRight))
+	c.Println(boxRow(headers, widths, true, c))
+	c.Println(boxLine(widths, boxTeeRight, boxCross, boxTeeLeft))
+	for _, row := range rows {
+		c.Println(boxRow(padRow(row, cols), widths, false, c))
+	}
+	c.Println(boxLine(widths, boxBottomLeft, boxTeeUp, boxBottomRight))
+}
+
+func padRow(row []string, n int) []string {
+	out := make([]string, n)
+	for i := 0; i < n; i++ {
+		if i < len(row) {
+			out[i] = row[i]
+		}
+	}
+	return out
+}
+
+func boxLine(widths []int, left, mid, right string) string {
+	var b strings.Builder
+	b.WriteString(left)
+	for i, w := range widths {
+		if i > 0 {
+			b.WriteString(mid)
+		}
+		b.WriteString(strings.Repeat(boxHorizontal, w+2))
+	}
+	b.WriteString(right)
+	return b.String()
+}
+
+func boxRow(cells []string, widths []int, header bool, c *console) string {
+	var b strings.Builder
+	b.WriteString(boxVertical)
+	for i, cell := range cells {
+		pad := widths[i] - utf8.RuneCountInString(cell)
+		text := cell
+		if header {
+			text = c.style("\x1b[1m", cell)
+		}
+		fmt.Fprintf(&b, " %s%s %s", text, strings.Repeat(" ", pad), boxVertical)
+	}
+	return b.String()
+}