(ns vibe.integration.coverage
  "Entry point that runs the vibe server under Cloverage instrumentation so the
   black-box integration tests produce a line-coverage report.

   Cloverage normally instruments the source and then runs a test suite in-process.
   Here the 'suite' is the outside world: the runner starts the real server and blocks
   until the JVM gets SIGTERM (`docker compose stop`), then Cloverage writes its reports.

   Deliberately does not require any vibe.* source namespace at load time: those must
   be loaded by Cloverage (instrumented), not by us."
  (:require [cloverage.coverage :as cov]))

(defmethod cov/runner-fn :integration [_]
  (fn [_nses]
    (let [stop (promise)
          main (Thread/currentThread)]
      ((requiring-resolve 'vibe.core/start-server))
      ;; The report is written by the main thread after the runner returns, but the JVM
      ;; only stays up while shutdown hooks run, so the hook must wait for the main thread.
      (.addShutdownHook (Runtime/getRuntime)
                        (Thread. (fn []
                                   (deliver stop true)
                                   (.join main))))
      @stop
      {:errors 0})))

(defn -main [& args]
  ;; Cloverage's own System/exit would deadlock inside the shutdown hook above.
  (binding [cov/*exit-after-test* false]
    (apply cov/-main args))
  (shutdown-agents))