package agent

import (
	"context"
	"log/slog"
	"path/filepath"
	"testing"
	"time"

	"gitea.mynodes.xyz/ilker/llmgw/internal/agent/supervisor"
)

// TestAgentStopsWhenContextEnds pins down something cancellation does not do by
// itself. A bidirectional stream spends its life blocked reading, and HTTP/2
// stops watching the context once the request headers are away, so an agent
// that only cancels keeps reading until something kills it. Under systemd that
// is the full stop timeout on every restart, followed by SIGKILL.
func TestAgentStopsWhenContextEnds(t *testing.T) {
	serverTLS, clientTLS := pki(t, "llmgw-node01")
	svc, inv, url := startTLS(t, serverTLS)

	cfg := DefaultConfig()
	cfg.NodeID = "llmgw-node01"
	cfg.Server = url
	cfg.TLS = clientTLS
	cfg.HeartbeatInterval = 50 * time.Millisecond
	cfg.Discovery.SkipGPUs = true
	cfg.Discovery.IBRoot = filepath.Join(t.TempDir(), "absent")
	cfg.Superv = supervisor.Config{
		WorkDir: t.TempDir(), LogLines: 8,
		StopTimeout: time.Second, HealthInterval: 20 * time.Millisecond,
	}

	client, err := Client(cfg.TLS, 5*time.Second)
	if err != nil {
		t.Fatal(err)
	}
	ag, err := New(cfg, client, slog.New(slog.DiscardHandler))
	if err != nil {
		t.Fatal(err)
	}

	ctx, cancel := context.WithCancel(context.Background())
	done := make(chan struct{})
	go func() { _ = ag.Run(ctx); close(done) }()

	// Cancelling before the stream is established would prove nothing: the
	// blocked read is the case that matters.
	if !eventually(t, 10*time.Second, registered(svc, inv, "llmgw-node01")) {
		t.Fatal("the agent never registered")
	}

	cancel()
	select {
	case <-done:
	case <-time.After(5 * time.Second):
		t.Fatal("the agent did not stop within 5s of being told to")
	}
}