perf: simplify brewcheck cache - ditch JSON format, store empty file and use

modification timestamp - if no brew, then no cache. if brew, then cache. -
simply check if file exists and is fresh to read cache

1 files changed, 14 insertions, 53 deletions

diff --git a/brewcheck.go b/brewcheck.go
index b811fa6..8223aff 100644
--- a/brewcheck.go
+++ b/brewcheck.go
@@ -1,76 +1,37 @@
 package main
 
 import (
-	"encoding/json"
-	"errors"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"time"
 	"fmt"
 
+	"github.com/adrg/xdg"
 	"github.com/fatih/color"
 )
 
-type BrewCache struct {
-	Found     bool      `json:"found"`
-	Timestamp time.Time `json:"timestamp"`
-}
-
-// Don't check Homebrew installation for a week
 const cacheTTL = 7 * 24 * time.Hour
 
 func EnsureBrewAvailable() {
-	ok, err := isBrewAvailable()
-	if err != nil {
-		color.Red("⚠️  Error checking Homebrew: %v", err)
-		os.Exit(1)
+	cacheFile := filepath.Join(xdg.CacheHome, "wthis", "brew-checked")
+
+	// 1. check if cache file exists and is fresh
+	if info, err := os.Stat(cacheFile); err == nil {
+		if time.Since(info.ModTime()) < cacheTTL {
+			return	// recently verified that brew exists
+		}
 	}
 
-	if !ok {
+	// 2. otherwise, actually check
+	if _, err := exec.LookPath("brew"); err != nil {
+		// brew not found — no cache write
 		color.Red("🍺 Homebrew not installed.")
 		fmt.Println("This tool works only with Homebrew formulae and casks.")
 		os.Exit(1)
 	}
-}
-
-func isBrewAvailable() (bool, error) {
-	cachePath, err := getCacheFile()
-	if err != nil {
-		return false, err
-	}
 
-	// Try to read cache
-	if data, err := os.ReadFile(cachePath); err == nil {
-		var cache BrewCache
-		if json.Unmarshal(data, &cache) == nil {
-			if time.Since(cache.Timestamp) < cacheTTL {
-				return cache.Found, nil
-			}
-		}
-	}
-
-	// Perform actual check
-	_, err = exec.LookPath("brew")
-	found := err == nil
-
-	// Save to cache
-	_ = os.MkdirAll(filepath.Dir(cachePath), 0o755)
-	cache := BrewCache{Found: found, Timestamp: time.Now()}
-	data, _ := json.Marshal(cache)
-	_ = os.WriteFile(cachePath, data, 0o644)
-
-	return found, nil
-}
-
-func getCacheFile() (string, error) {
-	base := os.Getenv("XDG_CACHE_HOME")
-	if base == "" {
-		home, err := os.UserHomeDir()
-		if err != nil {
-			return "", errors.New("cannot determine user home")
-		}
-		base = filepath.Join(home, ".cache")
-	}
-	return filepath.Join(base, "wthis", "brew-check.json"), nil
+	// 3. write cache
+	_ = os.MkdirAll(filepath.Dir(cacheFile), 0o755)
+	_ = os.WriteFile(cacheFile, []byte{}, 0o644)
 }