// Copyright (C) 2021 Storj Labs, Inc.
// See LICENSE for copying information.

package uitest

import (
	"context"
	"fmt"
	"net"
	"os"
	"testing"
	"time"

	"github.com/go-rod/rod"
	"github.com/go-rod/rod/lib/defaults"
	"github.com/go-rod/rod/lib/launcher"
	"github.com/go-rod/rod/lib/launcher/flags"
	"github.com/go-rod/rod/lib/utils"
	"github.com/stretchr/testify/require"
	"go.uber.org/zap/zaptest"

	"storj.io/common/testcontext"
)

// Our testing suite heavily uses randomly selected ports, which may collide
// with the launcher lock port. We'll disable the lock port entirely for
// the time being.
func init() { defaults.LockPort = 0 }

// Browser starts a browser for testing using environment variables for configuration.
func Browser(t *testing.T, ctx *testcontext.Context, fn func(*rod.Browser)) {
	showBrowser := os.Getenv("STORJ_TEST_SHOW_BROWSER") != ""
	slowBrowser := os.Getenv("STORJ_TEST_SHOW_BROWSER") == "slow"

	logLauncher := zaptest.NewLogger(t).Named("launcher")

	browserLoaded := browserTimeoutDetector(10 * time.Second)
	defer browserLoaded()

	launch := launcher.New().
		Headless(!showBrowser).
		Leakless(false).
		Devtools(false).
		NoSandbox(true).
		UserDataDir(ctx.Dir("browser")).
		Logger(zapWriter{Logger: logLauncher}).
		Set("enable-logging").
		Set("disable-gpu").
		Set("disable-web-security") // TODO: ensure we have proper CORS for testing

	if browserHost := os.Getenv("STORJ_TEST_BROWER_HOSTPORT"); browserHost != "" {
		host, port, err := net.SplitHostPort(browserHost)
		require.NoError(t, err)
		launch = launch.Set("remote-debugging-address", host).Set(flags.RemoteDebuggingPort, port)
	}

	if browserBin := os.Getenv("STORJ_TEST_BROWSER"); browserBin != "" {
		launch = launch.Bin(browserBin)
	}

	defer func() {
		launch.Kill()
		avoidStall(3*time.Second, launch.Cleanup)
	}()

	url, err := launch.Launch()
	require.NoError(t, err)

	logBrowser := zaptest.NewLogger(t).Named("rod")

	browser := rod.New().
		Timeout(time.Minute).
		Sleeper(func() utils.Sleeper { return timeoutSleeper(5*time.Second, 5) }).
		ControlURL(url).
		Logger(utils.Log(func(msg ...interface{}) {
			logBrowser.Info(fmt.Sprintln(msg...))
		})).
		Context(ctx).
		WithPanic(func(v interface{}) { require.Fail(t, "check failed", v) })

	if slowBrowser {
		browser = browser.SlowMotion(300 * time.Millisecond).Trace(true)
	}

	defer ctx.Check(browser.Close)

	require.NoError(t, browser.Connect())

	browserLoaded()

	fn(browser)
}

func browserTimeoutDetector(duration time.Duration) context.CancelFunc {
	ctx, cancel := context.WithCancel(context.Background())
	go func() {
		t := time.NewTimer(duration)
		defer t.Stop()
		select {
		case <-t.C:
			panic("timeout for starting browser exceeded")
		case <-ctx.Done():
			return
		}
	}()
	return cancel
}

func timeoutSleeper(totalSleep time.Duration, maxTries int) utils.Sleeper {
	singleSleep := totalSleep / time.Duration(maxTries)

	var slept int
	return func(ctx context.Context) error {
		slept++
		if slept > maxTries {
			return &utils.ErrMaxSleepCount{Max: maxTries}
		}

		t := time.NewTimer(singleSleep)
		defer t.Stop()
		select {
		case <-t.C:
		case <-ctx.Done():
		}

		return nil
	}
}

func avoidStall(maxDuration time.Duration, fn func()) {
	done := make(chan struct{})
	go func() {
		fn()
		close(done)
	}()

	timeout := time.NewTicker(maxDuration)
	defer timeout.Stop()
	select {
	case <-done:
	case <-timeout.C:
		fmt.Printf("go-rod did not shutdown within %v\n", maxDuration)
	}
}