package notify

import (
	"context"
	"errors"
	"sync"
	"sync/atomic"
	"testing"
)

func TestSessionIsAliveHandlesUninitializedValue(t *testing.T) {
	var alive atomic.Value
	if sessionIsAlive(&alive) {
		t.Fatal("uninitialized alive should be false")
	}
}

func TestSessionMarkStartedUpdatesAliveAndStatus(t *testing.T) {
	var alive atomic.Value
	alive.Store(false)
	status := Status{Alive: false, Reason: "old", Err: errors.New("old")}
	var mu sync.Mutex

	sessionMarkStarted(&alive, &mu, &status)

	gotAlive, _ := alive.Load().(bool)
	if !gotAlive {
		t.Fatal("alive not marked true")
	}
	if !status.Alive || status.Reason != "" || status.Err != nil {
		t.Fatalf("unexpected status after start: %+v", status)
	}
}

func TestSessionMarkStoppedRunsCleanupAndStop(t *testing.T) {
	var alive atomic.Value
	alive.Store(true)
	status := Status{Alive: true}
	stopCtx, stopFn := context.WithCancel(context.Background())
	defer stopFn()

	cleanupCalls := 0
	boom := errors.New("boom")

	sessionMarkStopped(&alive, nil, &status, "stopped", boom, stopFn,
		func() { cleanupCalls++ },
		func() { cleanupCalls++ },
	)

	gotAlive, _ := alive.Load().(bool)
	if gotAlive {
		t.Fatal("alive not marked false")
	}
	if status.Alive || status.Reason != "stopped" || !errors.Is(status.Err, boom) {
		t.Fatalf("unexpected status after stop: %+v", status)
	}
	if cleanupCalls != 2 {
		t.Fatalf("cleanupCalls = %d, want 2", cleanupCalls)
	}
	select {
	case <-stopCtx.Done():
	default:
		t.Fatal("stop function was not called")
	}
}

func TestSessionStatusValueReturnsCopy(t *testing.T) {
	status := Status{Alive: true, Reason: "ok"}
	var mu sync.Mutex

	snapshot := sessionStatusValue(&mu, &status)
	status.Reason = "changed"

	if snapshot.Reason != "ok" {
		t.Fatalf("snapshot.Reason = %q, want ok", snapshot.Reason)
	}
}