grokking simplicity and refactoring

packages/lab-tool/utils/ssh/context.scm

@@ -0,0 +1,33 @@
+;; utils/ssh/context.scm - SSH context management
+
+(define-module (utils ssh context)
+  #:use-module (ice-9 format)
+  #:use-module (utils logging)
+  #:use-module (utils ssh connection-test)
+  #:export (with-connection-context
+            with-ssh-connection))
+
+;; Pure function: Execute operation with connection validation
+;; Input: connection-validator (thunk -> boolean), operation (thunk)
+;; Output: result of operation or #f if connection invalid
+(define (with-connection-context connection-validator operation)
+  "Pure function to execute operation with connection context"
+  (if (connection-validator)
+      (catch #t
+        operation
+        (lambda (key . args)
+          (values #f (format #f "Operation failed: ~a ~a" key args))))
+      (values #f "Connection validation failed")))
+
+;; Impure wrapper: Execute with SSH connection context and logging
+(define (with-ssh-connection machine-name thunk)
+  "Execute operation with SSH connection context (with side effects: logging)"
+  (let ((connection-validator (lambda () (test-ssh-connection machine-name))))
+    (call-with-values 
+        (lambda () (with-connection-context connection-validator thunk))
+      (lambda (success result)
+        (if success
+            result
+            (begin
+              (log-error "SSH operation failed for ~a: ~a" machine-name result)
+              #f))))))