perf: cache homebrew installation check - looking for brew path takes a

significant amount of time - caching (supports XDG) brew check result to improve
performance

2 files changed, 77 insertions, 9 deletions

diff --git a/brewcheck.go b/brewcheck.go
new file mode 100644
index 0000000..b811fa6
--- /dev/null
+++ b/brewcheck.go
@@ -0,0 +1,76 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"time"
+	"fmt"
+
+	"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)
+	}
+
+	if !ok {
+		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
+}
diff --git a/main.go b/main.go
index ca60c40..95c90b5 100644
--- a/main.go
+++ b/main.go
@@ -3,7 +3,6 @@ package main
 import (
     "fmt"
     "os"
-    "os/exec"
     "context"
     "log"
     "github.com/fatih/color"
@@ -11,14 +10,7 @@ import (
 )
 
 func main() {
-	// Check if Homebrew is installed
-    _, brewInstallationErr := exec.LookPath("brew")
-    if brewInstallationErr != nil {
-        color.Red("🍺 Homebrew not installed.")
-        fmt.Println("This tool is for looking up formulae/cask information about packages installed with Homebrew.")
-        fmt.Println("If you don't have Homebrew, it's no use.")
-        os.Exit(0)
-    }
+	EnsureBrewAvailable()
 
     // declare CLI app
     cmd := &cli.Command{