package publichttp

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

	"galaxy/authsession/internal/service/confirmemailcode"
	"galaxy/authsession/internal/service/sendemailcode"

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

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

	cfg := DefaultConfig()
	cfg.Addr = ""

	_, err := NewServer(cfg, Dependencies{
		SendEmailCode: sendEmailCodeFunc(func(context.Context, sendemailcode.Input) (sendemailcode.Result, error) {
			return sendemailcode.Result{}, nil
		}),
		ConfirmEmailCode: confirmEmailCodeFunc(func(context.Context, confirmemailcode.Input) (confirmemailcode.Result, error) {
			return confirmemailcode.Result{}, nil
		}),
	})

	require.Error(t, err)
	assert.Contains(t, err.Error(), "addr")
}

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

	cfg := DefaultConfig()
	cfg.Addr = mustFreeAddr(t)

	server, err := NewServer(cfg, Dependencies{
		SendEmailCode: sendEmailCodeFunc(func(context.Context, sendemailcode.Input) (sendemailcode.Result, error) {
			return sendemailcode.Result{ChallengeID: "challenge-123"}, nil
		}),
		ConfirmEmailCode: confirmEmailCodeFunc(func(context.Context, confirmemailcode.Input) (confirmemailcode.Result, error) {
			return confirmemailcode.Result{DeviceSessionID: "device-session-123"}, nil
		}),
	})
	require.NoError(t, err)

	runErr := make(chan error, 1)
	go func() {
		runErr <- server.Run(context.Background())
	}()

	client := newTestHTTPClient(t)
	waitForPublicSendEmailCodeReady(t, client, cfg.Addr)

	shutdownCtx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	require.NoError(t, server.Shutdown(shutdownCtx))
	waitForServerRunResult(t, runErr)
}

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

	cfg := DefaultConfig()
	cfg.Addr = mustFreeAddr(t)

	server, err := NewServer(cfg, Dependencies{
		SendEmailCode: sendEmailCodeFunc(func(context.Context, sendemailcode.Input) (sendemailcode.Result, error) {
			return sendemailcode.Result{ChallengeID: "challenge-123"}, nil
		}),
		ConfirmEmailCode: confirmEmailCodeFunc(func(context.Context, confirmemailcode.Input) (confirmemailcode.Result, error) {
			return confirmemailcode.Result{DeviceSessionID: "device-session-123"}, nil
		}),
	})
	require.NoError(t, err)

	runErr := make(chan error, 1)
	go func() {
		runErr <- server.Run(context.Background())
	}()

	client := newTestHTTPClient(t)
	waitForPublicSendEmailCodeReady(t, client, cfg.Addr)

	for _, path := range []string{"/healthz", "/readyz", "/metrics"} {
		request, reqErr := http.NewRequest(http.MethodGet, "http://"+cfg.Addr+path, nil)
		require.NoError(t, reqErr)

		response, err := client.Do(request)
		require.NoError(t, err)
		_, _ = io.ReadAll(response.Body)
		response.Body.Close()

		assert.Equalf(t, http.StatusNotFound, response.StatusCode, "path %s", path)
	}

	shutdownCtx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	require.NoError(t, server.Shutdown(shutdownCtx))
	waitForServerRunResult(t, runErr)
}

func newTestHTTPClient(t *testing.T) *http.Client {
	t.Helper()

	transport := &http.Transport{
		DisableKeepAlives: true,
	}
	t.Cleanup(transport.CloseIdleConnections)

	return &http.Client{
		Timeout:   250 * time.Millisecond,
		Transport: transport,
	}
}

func waitForPublicSendEmailCodeReady(t *testing.T, client *http.Client, addr string) {
	t.Helper()

	require.Eventually(t, func() bool {
		response, err := client.Post(
			"http://"+addr+"/api/v1/public/auth/send-email-code",
			"application/json",
			bytes.NewBufferString(`{"email":"pilot@example.com"}`),
		)
		if err != nil {
			return false
		}
		defer response.Body.Close()
		_, _ = io.ReadAll(response.Body)

		return response.StatusCode == http.StatusOK
	}, 5*time.Second, 25*time.Millisecond, "public HTTP server did not become reachable")
}

func waitForServerRunResult(t *testing.T, runErr <-chan error) {
	t.Helper()

	var err error
	require.Eventually(t, func() bool {
		select {
		case err = <-runErr:
			return true
		default:
			return false
		}
	}, 5*time.Second, 10*time.Millisecond, "public HTTP server did not stop")
	require.NoError(t, err)
}

func mustFreeAddr(t *testing.T) string {
	t.Helper()

	listener, err := net.Listen("tcp", "127.0.0.1:0")
	require.NoError(t, err)
	defer func() {
		assert.NoError(t, listener.Close())
	}()

	return listener.Addr().String()
}