feat: add Arch update helper and web UI

internal/updater/updater.go

@@ -0,0 +1,149 @@
+package updater
+
+import (
+	"bufio"
+	"context"
+	"os/exec"
+	"strings"
+)
+
+type Package struct {
+	Source    string
+	Name      string
+	Current   string
+	Available string
+}
+
+type Result struct {
+	Packages []Package
+	Warnings []string
+}
+
+type Options struct {
+	CheckAUR bool
+}
+
+func (r Result) Total() int {
+	return len(r.Packages)
+}
+
+func (r Result) Summary() string {
+	total := r.Total()
+	switch total {
+	case 0:
+		return "No updates available."
+	case 1:
+		return "1 update available."
+	default:
+		return strings.TrimSpace(strings.Join([]string{itoa(total), "updates available."}, " "))
+	}
+}
+
+func Check(ctx context.Context) (Result, error) {
+	return CheckWithOptions(ctx, Options{CheckAUR: true})
+}
+
+func CheckWithOptions(ctx context.Context, opts Options) (Result, error) {
+	var result Result
+
+	pacman, err := checkPacman(ctx)
+	if err != nil {
+		result.Warnings = append(result.Warnings, err.Error())
+	}
+	result.Packages = append(result.Packages, pacman...)
+
+	if opts.CheckAUR {
+		aur, err := checkAUR(ctx)
+		if err != nil {
+			result.Warnings = append(result.Warnings, err.Error())
+		}
+		result.Packages = append(result.Packages, aur...)
+	}
+
+	return result, nil
+}
+
+func checkPacman(ctx context.Context) ([]Package, error) {
+	if _, err := exec.LookPath("checkupdates"); err == nil {
+		out, err := exec.CommandContext(ctx, "checkupdates").Output()
+		if err != nil {
+			return nil, nil
+		}
+		return parseUpdates("pacman", string(out)), nil
+	}
+
+	out, err := exec.CommandContext(ctx, "pacman", "-Qu").Output()
+	if err != nil {
+		return nil, nil
+	}
+	return parseUpdates("pacman", string(out)), nil
+}
+
+func checkAUR(ctx context.Context) ([]Package, error) {
+	helper := AURHelper()
+	if helper == "" {
+		return nil, nil
+	}
+
+	out, err := exec.CommandContext(ctx, helper, "-Qua").Output()
+	if err != nil {
+		return nil, nil
+	}
+	return parseUpdates("aur", string(out)), nil
+}
+
+func AURHelper() string {
+	for _, name := range []string{"paru", "yay"} {
+		if _, err := exec.LookPath(name); err == nil {
+			return name
+		}
+	}
+	return ""
+}
+
+func parseUpdates(source, output string) []Package {
+	var packages []Package
+	scanner := bufio.NewScanner(strings.NewReader(output))
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" {
+			continue
+		}
+		packages = append(packages, parseLine(source, line))
+	}
+	return packages
+}
+
+func parseLine(source, line string) Package {
+	fields := strings.Fields(line)
+	pkg := Package{Source: source}
+	if len(fields) == 0 {
+		return pkg
+	}
+
+	pkg.Name = fields[0]
+	if len(fields) >= 4 && fields[2] == "->" {
+		pkg.Current = fields[1]
+		pkg.Available = fields[3]
+		return pkg
+	}
+	if len(fields) >= 3 && fields[1] == "->" {
+		pkg.Available = fields[2]
+		return pkg
+	}
+	return pkg
+}
+
+func itoa(n int) string {
+	if n == 0 {
+		return "0"
+	}
+	var buf [20]byte
+	i := len(buf)
+	for n > 0 {
+		i--
+		buf[i] = byte('0' + n%10)
+		n /= 10
+	}
+	return string(buf[i:])
+}