Massive refactor!

internal/licensecheck/checker.go

@@ -0,0 +1,25 @@
+package internal
+
+import (
+	"sync"
+	"time"
+)
+
+type LicenseChecker struct {
+	LicenseAPIURL string
+	APIKey        string
+	PollInterval  time.Duration
+
+	mu       sync.RWMutex
+	lastGood time.Time
+	valid    bool
+}
+
+func (lc *LicenseChecker) setValid(ok bool) {
+	lc.mu.Lock()
+	defer lc.mu.Unlock()
+	lc.valid = ok
+	if ok {
+		lc.lastGood = time.Now()
+	}
+}