Initial commit on Forgejo

Fresh repository history for elektrine/tarakan-client hosted at
https://git.elektrine.com/elektrine/tarakan-client.

internal/updatecheck/updatecheck.go

@@ -0,0 +1,263 @@
+// Package updatecheck tells users when a newer tarakan release is available.
+package updatecheck
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const (
+	// DefaultRepo is where official release binaries are published.
+	DefaultRepo = "atomine-elektrine/tarakan-client"
+	// InstallHint is the one-liner people already use to install or upgrade.
+	InstallHint = "curl -fsSL https://tarakan.lol/install.sh | bash"
+	cacheTTL    = 24 * time.Hour
+	httpTimeout = 3 * time.Second
+)
+
+// githubAPIBase is overridden in tests.
+var githubAPIBase = "https://api.github.com"
+
+// Result is one comparison of the running binary against the latest release.
+type Result struct {
+	Current         string
+	Latest          string
+	UpdateAvailable bool
+}
+
+// Notice is a short human line for stderr (empty when no update).
+func (r Result) Notice() string {
+	if !r.UpdateAvailable || r.Latest == "" {
+		return ""
+	}
+	return fmt.Sprintf(
+		"tarakan %s is available (you have %s). Update:\n  %s",
+		displayVersion(r.Latest),
+		displayVersion(r.Current),
+		InstallHint,
+	)
+}
+
+// MaybeNotify checks for a newer release and prints a notice to w when one
+// exists. Network and disk errors are ignored so update checks never break
+// normal CLI work. Set TARAKAN_SKIP_UPDATE_CHECK=1 to disable.
+func MaybeNotify(w io.Writer, current string) {
+	if w == nil || skipEnabled() {
+		return
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), httpTimeout)
+	defer cancel()
+	result, err := Check(ctx, current)
+	if err != nil || !result.UpdateAvailable {
+		return
+	}
+	if notice := result.Notice(); notice != "" {
+		fmt.Fprintln(w, notice)
+	}
+}
+
+// Check returns whether current is older than the latest GitHub release.
+// Results are cached under the user config dir for cacheTTL.
+func Check(ctx context.Context, current string) (Result, error) {
+	current = normalizeVersion(current)
+	result := Result{Current: current}
+	if current == "" || current == "dev" {
+		return result, nil
+	}
+	if skipEnabled() {
+		return result, nil
+	}
+
+	latest, fromCache, err := latestVersion(ctx)
+	if err != nil {
+		return result, err
+	}
+	result.Latest = latest
+	result.UpdateAvailable = compareVersions(current, latest) < 0
+	_ = fromCache
+	return result, nil
+}
+
+func skipEnabled() bool {
+	v := strings.TrimSpace(os.Getenv("TARAKAN_SKIP_UPDATE_CHECK"))
+	return v == "1" || strings.EqualFold(v, "true") || strings.EqualFold(v, "yes")
+}
+
+func latestVersion(ctx context.Context) (string, bool, error) {
+	if cached, ok := readCache(); ok {
+		return cached, true, nil
+	}
+	latest, err := fetchLatestGitHub(ctx, DefaultRepo)
+	if err != nil {
+		return "", false, err
+	}
+	_ = writeCache(latest)
+	return latest, false, nil
+}
+
+type cacheFile struct {
+	Latest    string    `json:"latest"`
+	CheckedAt time.Time `json:"checked_at"`
+}
+
+func cachePath() (string, error) {
+	dir, err := os.UserConfigDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(dir, "tarakan", "update-check.json"), nil
+}
+
+func readCache() (string, bool) {
+	path, err := cachePath()
+	if err != nil {
+		return "", false
+	}
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return "", false
+	}
+	var c cacheFile
+	if err := json.Unmarshal(raw, &c); err != nil {
+		return "", false
+	}
+	if c.Latest == "" || time.Since(c.CheckedAt) > cacheTTL {
+		return "", false
+	}
+	return normalizeVersion(c.Latest), true
+}
+
+func writeCache(latest string) error {
+	path, err := cachePath()
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(path), 0o700); err != nil {
+		return err
+	}
+	raw, err := json.MarshalIndent(cacheFile{
+		Latest:    normalizeVersion(latest),
+		CheckedAt: time.Now().UTC(),
+	}, "", "  ")
+	if err != nil {
+		return err
+	}
+	raw = append(raw, '\n')
+	return os.WriteFile(path, raw, 0o600)
+}
+
+func fetchLatestGitHub(ctx context.Context, repo string) (string, error) {
+	repo = strings.TrimSpace(repo)
+	if repo == "" {
+		return "", errors.New("empty repo")
+	}
+	url := strings.TrimRight(githubAPIBase, "/") + "/repos/" + repo + "/releases/latest"
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Accept", "application/vnd.github+json")
+	req.Header.Set("User-Agent", "tarakan-client-updatecheck")
+
+	client := &http.Client{Timeout: httpTimeout}
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("github releases: HTTP %d", resp.StatusCode)
+	}
+	var body struct {
+		TagName string `json:"tag_name"`
+	}
+	if err := json.NewDecoder(io.LimitReader(resp.Body, 1<<20)).Decode(&body); err != nil {
+		return "", err
+	}
+	tag := normalizeVersion(body.TagName)
+	if tag == "" {
+		return "", errors.New("github releases: empty tag_name")
+	}
+	return tag, nil
+}
+
+func displayVersion(v string) string {
+	v = normalizeVersion(v)
+	if v == "" {
+		return "unknown"
+	}
+	return "v" + v
+}
+
+// normalizeVersion strips a leading "v" and whitespace.
+func normalizeVersion(v string) string {
+	v = strings.TrimSpace(v)
+	v = strings.TrimPrefix(v, "v")
+	v = strings.TrimPrefix(v, "V")
+	return strings.TrimSpace(v)
+}
+
+// compareVersions returns -1 if a < b, 0 if equal, 1 if a > b.
+// Handles dotted numeric versions (1.2.3). Missing trailing segments are 0
+// (so "0.2" equals "0.2.0"). Non-numeric tails compare as strings.
+func compareVersions(a, b string) int {
+	a = normalizeVersion(a)
+	b = normalizeVersion(b)
+	if a == b {
+		return 0
+	}
+	as := strings.Split(a, ".")
+	bs := strings.Split(b, ".")
+	n := len(as)
+	if len(bs) > n {
+		n = len(bs)
+	}
+	for i := 0; i < n; i++ {
+		an, aOk := versionPart(as, i)
+		bn, bOk := versionPart(bs, i)
+		if aOk && bOk {
+			if an < bn {
+				return -1
+			}
+			if an > bn {
+				return 1
+			}
+			continue
+		}
+		// Fall back to string compare for pre-release-ish segments.
+		ap, bp := "", ""
+		if i < len(as) {
+			ap = as[i]
+		}
+		if i < len(bs) {
+			bp = bs[i]
+		}
+		if ap < bp {
+			return -1
+		}
+		if ap > bp {
+			return 1
+		}
+	}
+	return 0
+}
+
+func versionPart(parts []string, i int) (int, bool) {
+	if i >= len(parts) || parts[i] == "" {
+		return 0, true
+	}
+	n, err := strconv.Atoi(parts[i])
+	if err != nil {
+		return 0, false
+	}
+	return n, true
+}