//go:build e2e

package e2e

import (
	"fmt"
	"os"
	"slices"
	"strings"
	"testing"

	"github.com/mxschmitt/playwright-go"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// Everything else in this suite speaks http, which hides an entire class of defect: the browser
// gates Secure cookies, SameSite=None, Partitioned and anything reading location.protocol on the
// page protocol, so code taking those paths is never executed. setAuthCookie decorating its
// cookies with __Host- on https pages survived for exactly that reason.
//
// These run against the TLS pair in compose-e2e-test.yml, which carries a self-signed certificate
// every context here accepts. That instance also runs with AUTH_SEND_JWT_HEADER, so the widget
// writes its own cookies through setAuthCookie: without it the client-side writer never runs on
// any https page in the stack and every assertion about the attributes it chooses is vacuous.

// An unpartitioned third-party cookie is refused only when storage partitioning is enforced, and
// playwright's own default arguments disable it. Dropping that default and re-supplying it without
// the one feature is the only lever; see "What this suite cannot reach" in the README.
//
// The list is playwright's own and therefore version-specific. It is not trusted on its own: the
// case using it asserts a control first, so a list that stops matching fails as itself.
const (
	playwrightDisabledFeatures = "--disable-features=AvoidUnnecessaryBeforeUnloadCheckSync," +
		"BoundaryEventDispatchTracksNodeRemoval,DestroyProfileOnBrowserClose,DialMediaRouteProvider," +
		"GlobalMediaControls,HttpsUpgrades,LensOverlay,MediaRouter,PaintHolding," +
		"ThirdPartyStoragePartitioning,BlockOriginHeaderModificationOnRedirect,Translate,AutoDeElevate," +
		"OptimizationHints,msForceBrowserSignIn,msEdgeUpdateLaunchServicesPreferredVersion"

	// the one entry that has to go, named once
	partitioningFeature = "ThirdPartyStoragePartitioning,"
)

// withPartitioningEnabled is playwright's own list with the one feature removed, derived rather
// than written out again: the two differ by a single entry in three hundred characters, and a
// second copy is a thing to forget on the next playwright bump
func withPartitioningEnabled(t *testing.T) string {
	t.Helper()

	out := strings.Replace(playwrightDisabledFeatures, partitioningFeature, "", 1)
	require.NotEqual(t, playwrightDisabledFeatures, out,
		"%q is no longer in playwright's default argument list, so removing it enables nothing and "+
			"this browser would block no cookie at all", partitioningFeature)
	return out
}

// The flows worth measuring in a third-party frame. OAuth is absent on purpose: the provider
// callback lands in a popup, which is a top-level context of its own, so the cookie set there is
// keyed to the auth host and never reaches the frame. Telegram is absent because the stack cannot
// answer as Telegram, see #2208.
//
// Email as well as anonymous because the widget's writer keys off the X-JWT header rather than off
// the provider, so the two are expected to behave alike. Expected is not measured, and email is the
// flow an operator running off-domain actually reaches for
var httpsFlows = []struct {
	name   string
	signIn func(t *testing.T, page playwright.Page, frame playwright.FrameLocator)
}{
	{"anonymous", func(t *testing.T, page playwright.Page, frame playwright.FrameLocator) {
		signInAnon(t, page, frame, anonName("httpsreader"))
	}},
	{"email", func(t *testing.T, page playwright.Page, frame playwright.FrameLocator) {
		// the address decides the user id and the mailbox this reads back, so it carries the run
		// id and the case: mailpit keeps everything, and a shared address would let one case read
		// the token another asked for
		signInEmail(t, page, frame, "httpsemail",
			fmt.Sprintf("https-email-%s-%s@example.com", strings.ReplaceAll(t.Name(), "/", "-"), runID))
	}},
}

// httpsThread is a thread on the TLS host page, which is a different site from the widget's own
// origin, so the widget's cookies there are genuinely third-party
func httpsThread(t *testing.T, label string) string {
	t.Helper()
	return fmt.Sprintf("%s/post-https.html?e2e=%s-%s", httpsHostSiteURL, label, runID)
}

// TestHTTPS_CrossOriginSignInSurvivesAReload is what the http cross-origin case cannot assert.
// The widget keeps its token in memory for the life of a page, so signing in and posting proves
// nothing about persistence: only a reload asks whether the cookie was delivered, stored under a
// name the backend reads, and sent back from a third-party frame. On http that cookie cannot even
// be written, since the third-party form requires Secure.
//
// This runs under the browser's default policy, where third-party cookies are allowed.
// TestHTTPS_SessionSurvivesThirdPartyCookieBlocking is the same question with them blocked.
func TestHTTPS_CrossOriginSignInSurvivesAReload(t *testing.T) {
	for _, flow := range httpsFlows {
		t.Run(flow.name, func(t *testing.T) {
			page := newPage(t)

			pauseForAuthLimit()
			_, err := page.Goto(httpsThread(t, "https-signin-"+flow.name))
			require.NoError(t, err)

			frame := widget(t, page)
			flow.signIn(t, page, frame)

			text := "posted over tls by " + flow.name + " " + runID
			postComment(t, frame, text)

			// the assertion the whole file exists for
			pauseForAuthLimit()
			_, err = page.Reload()
			require.NoError(t, err)

			frame = widget(t, page)
			assertSignedIn(t, page, frame)
			waitVisible(t, comment(frame, text))
		})
	}
}

// TestHTTPS_AuthCookiesCarryTheThirdPartyForm reads the cookies the browser actually stored for
// the widget's origin while it is embedded elsewhere. A cookie the browser refused is not in this
// list at all, and one the browser kept but will not send from a frame is worse than useless, so
// the attributes are the assertion and not the sign-in they enable.
//
// Both cookies are checked and not the JWT alone: the fetcher reads XSRF-TOKEN and returns its
// value as a header, and go-pkgz/auth refuses a cookie-borne token whose header does not match, so
// a JWT arriving beside an XSRF cookie the frame cannot receive authenticates nobody.
func TestHTTPS_AuthCookiesCarryTheThirdPartyForm(t *testing.T) {
	page := newPage(t)

	pauseForAuthLimit()
	_, err := page.Goto(httpsThread(t, "https-cookies"))
	require.NoError(t, err)

	frame := widget(t, page)
	signInAnon(t, page, frame, anonName("httpscookies"))

	cookies, err := page.Context().Cookies()
	require.NoError(t, err)

	// both writers are in play here: the backend sets its own pair, and the widget sets a
	// partitioned pair of the same names through setAuthCookie. Every copy has to be usable from
	// a third-party frame, and the partitioned one has to exist, or the assertions below would be
	// reading the server's cookie and saying nothing about the client's
	for _, name := range []string{"JWT", "XSRF-TOKEN"} {
		var partitioned int
		var seen int
		for _, c := range cookies {
			if c.Name != name {
				continue
			}
			seen++
			assert.True(t, c.Secure, "a %s cookie is not Secure, so a third-party frame can never receive it", name)
			require.NotNil(t, c.SameSite, "a %s cookie carries no SameSite at all", name)
			assert.Equal(t, *playwright.SameSiteAttributeNone, *c.SameSite,
				"a %s cookie is not SameSite=None, and SameSite is judged against the top-level site, so "+
					"anything stricter is never sent from an embedded widget", name)
			if c.PartitionKey != nil {
				partitioned++
			}
		}
		require.NotZero(t, seen, "no %s cookie was stored at all, so the browser refused what was sent: %v",
			name, cookieNames(cookies))
		assert.NotZero(t, partitioned,
			"no partitioned %s cookie was stored, so setAuthCookie either did not run or chose attributes "+
				"a blocking browser will drop", name)
	}

	// the XSRF value has to be readable by the widget's own script, which is what puts it in the
	// header the backend matches the token against
	for _, c := range cookies {
		if c.Name == "XSRF-TOKEN" {
			assert.False(t, c.HttpOnly, "the XSRF cookie has to be readable by the widget's own script")
		}
	}

	// no name the server does not read. A __Host- prefixed cookie is a perfectly valid cookie the
	// browser stores happily, which is why writing one is a defect nothing rejects: the backend
	// looks for JWT and the fetcher reads XSRF-TOKEN, and neither finds a decorated name.
	//
	// this can only fail because the instance runs with AUTH_SEND_JWT_HEADER, which is what makes
	// the widget write cookies of its own instead of leaving the server's pair alone.
	for _, c := range cookies {
		assert.NotContains(t, c.Name, "__Host-",
			"a __Host- prefixed cookie was stored, and nothing on either side reads that name")
	}
}

// TestHTTPS_SessionSurvivesThirdPartyCookieBlocking is the reload question under the policy that
// makes it hard. With storage partitioning enforced an ordinary third-party cookie is dropped, so
// the session survives only because the widget's own cookies carry Partitioned; the server's pair
// does not, and vanishes.
//
// The control comes first and is not decoration: playwright's default arguments disable the policy
// outright, so a run configured wrongly keeps every third-party cookie and this case would pass
// while asserting nothing at all.
func TestHTTPS_SessionSurvivesThirdPartyCookieBlocking(t *testing.T) {
	blocking, err := pw.Chromium.Launch(playwright.BrowserTypeLaunchOptions{
		Headless:          playwright.Bool(os.Getenv("E2E_HEADLESS") != "false"),
		IgnoreDefaultArgs: []string{playwrightDisabledFeatures},
		Args: []string{
			withPartitioningEnabled(t),
			"--test-third-party-cookie-phaseout",
			"--host-resolver-rules=MAP remark42-https 127.0.0.1, MAP host-site-https 127.0.0.1",
		},
	})
	require.NoError(t, err)
	t.Cleanup(func() { _ = blocking.Close() })

	for _, flow := range httpsFlows {
		t.Run(flow.name, func(t *testing.T) {
			// a context of its own, so neither case inherits what the other stored
			page := newPageOn(t, blocking)

			pauseForAuthLimit()
			_, err := page.Goto(httpsThread(t, "https-blocked-"+flow.name))
			require.NoError(t, err)
			frame := widget(t, page)

			assertPartitioningEnforced(t, page)

			flow.signIn(t, page, frame)

			// the chain this case rests on, asserted before the reload can fail on the end of it:
			// the server sends X-JWT only under AUTH_SEND_JWT_HEADER, setAuthCookie writes its own
			// pair only when the fetcher sees that header, and only that pair carries Partitioned,
			// since the server's own cookies carry none. drop the flag from the service and the
			// reload below signs nobody in, which reads as a defect in cookie handling instead of a
			// stack that cannot test it
			written, err := page.Context().Cookies()
			require.NoError(t, err)
			require.True(t, slices.ContainsFunc(written, func(c playwright.Cookie) bool {
				return c.Name == "JWT" && c.PartitionKey != nil
			}), "no partitioned JWT cookie was written before the reload, so the widget's own writer never ran: "+
				"remark42-https is most likely no longer configured with AUTH_SEND_JWT_HEADER. stored: %v",
				cookieNames(written))

			pauseForAuthLimit()
			_, err = page.Reload()
			require.NoError(t, err)

			frame = widget(t, page)
			assertSignedIn(t, page, frame)

			// and it survived because the widget's own cookies are partitioned, which is the only
			// form a blocking browser keeps
			cookies, err := page.Context().Cookies()
			require.NoError(t, err)
			for _, name := range []string{"JWT", "XSRF-TOKEN"} {
				var stored *playwright.Cookie
				for i, c := range cookies {
					if c.Name == name {
						stored = &cookies[i]
						break
					}
				}
				require.NotNil(t, stored, "no %s cookie survived the blocking browser: %v", name, cookieNames(cookies))
				assert.NotNil(t, stored.PartitionKey,
					"the %s cookie is not partitioned, so it only survived because the browser was not blocking", name)
			}
		})
	}
}

// assertPartitioningEnforced proves the browser refuses an ordinary third-party cookie before any
// case leans on it. Both cookies are written and read back inside a single frame evaluate, and the
// read is `document.cookie` rather than the context's cookie list, because the two are different
// channels with no ordering between them.
//
// Pinned to a build rather than stated as a rule: playwright 1.62.1 ships chromium 151.0.7922.34,
// where Blink's CookieJar::SetCookie queues the write and returns without a completion callback,
// and the renderer's own document.cookie getter is the barrier that forces the pending write to
// settle. Playwright's Context().Cookies() is a browser-session Storage.getCookies that never
// touches that frame's jar, so reading the control through it can find the name absent because the
// write has not landed yet, which is precisely the outcome the control exists to rule out. An
// implementation is free to serialize both calls in the browser process, so this is what to
// re-check on a playwright bump.
//
// The sentinel is the positive half and it has to come first: a valid third-party cookie proves the
// write path and the partitioned path are both live, and only then does the control's absence mean
// the browser turned it down rather than that nothing was written at all
func assertPartitioningEnforced(t *testing.T, page playwright.Page) {
	t.Helper()

	const (
		sentinel = "e2esentinel"
		control  = "e2econtrol"
	)

	// one evaluate: both writes, then the getter that settles them, returned as separate answers so
	// a missing sentinel and a surviving control stay distinguishable
	raw, err := page.FrameLocator("#remark42 iframe").Locator("body").Evaluate(`() => {
		document.cookie = 'e2econtrol=1; Path=/; Secure; SameSite=None';
		document.cookie = 'e2esentinel=1; Path=/; Secure; SameSite=None; Partitioned';
		const names = document.cookie.split(';').map((c) => c.trim().split('=')[0]);
		return { sentinel: names.includes('e2esentinel'), control: names.includes('e2econtrol'), all: names };
	}`, nil)
	require.NoError(t, err)

	got, ok := raw.(map[string]any)
	require.True(t, ok, "expected an object from the frame, got %T (%v)", raw, raw)

	require.Equal(t, true, got["sentinel"],
		"a %s cookie in the third-party form the browser still accepts was not stored, so nothing was "+
			"written at all and the absence of %s below would mean nothing. cookies in the frame: %v",
		sentinel, control, got["all"])

	require.Equal(t, false, got["control"],
		"an ordinary third-party %s cookie survived alongside the partitioned %s, so this browser is "+
			"not partitioning storage and nothing here is being tested. playwright's default argument "+
			"list has most likely changed: see playwrightDisabledFeatures. cookies in the frame: %v",
		control, sentinel, got["all"])
}

func cookieNames(cookies []playwright.Cookie) []string {
	out := make([]string, 0, len(cookies))
	for _, c := range cookies {
		out = append(out, c.Name)
	}
	return out
}