package adminapi

import (
	"context"
	"net/http"
	"testing"
	"time"

	"galaxy/user/internal/config"

	"github.com/stretchr/testify/require"
)

func TestServerRunDisabledWaitsForContext(t *testing.T) {
	t.Parallel()

	server := NewServer(config.AdminHTTPConfig{}, http.HandlerFunc(func(http.ResponseWriter, *http.Request) {
		t.Fatal("disabled admin server must not serve requests")
	}), nil)

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	errCh := make(chan error, 1)
	go func() {
		errCh <- server.Run(ctx)
	}()

	cancel()

	select {
	case err := <-errCh:
		require.ErrorIs(t, err, context.Canceled)
	case <-time.After(2 * time.Second):
		t.Fatal("disabled admin server did not stop after context cancellation")
	}
}

func TestServerRunServesMetricsOnly(t *testing.T) {
	t.Parallel()

	server := NewServer(config.AdminHTTPConfig{
		Addr:              "127.0.0.1:0",
		ReadHeaderTimeout: 2 * time.Second,
		ReadTimeout:       10 * time.Second,
		IdleTimeout:       time.Minute,
	}, http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		_, _ = w.Write([]byte("sample_metric 1\n"))
	}), nil)

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	errCh := make(chan error, 1)
	go func() {
		errCh <- server.Run(ctx)
	}()

	addr := waitForListener(t, server)

	metricsResponse, err := http.Get("http://" + addr + "/metrics")
	require.NoError(t, err)
	t.Cleanup(func() { _ = metricsResponse.Body.Close() })
	require.Equal(t, http.StatusOK, metricsResponse.StatusCode)

	rootResponse, err := http.Get("http://" + addr + "/")
	require.NoError(t, err)
	t.Cleanup(func() { _ = rootResponse.Body.Close() })
	require.Equal(t, http.StatusNotFound, rootResponse.StatusCode)

	cancel()

	select {
	case err := <-errCh:
		require.NoError(t, err)
	case <-time.After(2 * time.Second):
		t.Fatal("admin server did not stop after context cancellation")
	}
}

func waitForListener(t *testing.T, server *Server) string {
	t.Helper()

	deadline := time.Now().Add(2 * time.Second)
	for time.Now().Before(deadline) {
		server.stateMu.RLock()
		listener := server.listener
		server.stateMu.RUnlock()
		if listener != nil {
			return listener.Addr().String()
		}

		time.Sleep(10 * time.Millisecond)
	}

	t.Fatal("admin server listener did not start")
	return ""
}