package webapp

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/runbear-io/beardrive/internal/remote"
)

// authHub builds an auth-enabled hub server with one project.
func authHub(t *testing.T, allowSignup bool) (*Server, *BuiltinAuth, Project) {
	t.Helper()
	auth, err := OpenBuiltinAuth(filepath.Join(t.TempDir(), "auth.json"), allowSignup, nil)
	if err != nil {
		t.Fatal(err)
	}
	srv, p, _ := newHub(t, true, nil)
	srv.Auth = auth
	return srv, auth, p
}

// signupAndSession creates an account through the real signup page and
// returns its session cookie.
func signupAndSession(t *testing.T, h http.Handler, email, name, pass string) *http.Cookie {
	t.Helper()
	form := url.Values{"email": {email}, "name": {name}, "password": {pass}}
	req := httptest.NewRequest("POST", "/auth/signup", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != http.StatusSeeOther {
		t.Fatalf("signup: %d %s", rec.Code, rec.Body)
	}
	for _, c := range rec.Result().Cookies() {
		if c.Name == sessionCookie {
			return c
		}
	}
	t.Fatal("signup set no session cookie")
	return nil
}

func TestAuthGatesAPI(t *testing.T) {
	srv, auth, p := authHub(t, true)
	h := srv.Handler()

	// open surface: config, auth pages, static frontend
	if rec := do(t, h, "GET", "/api/config", nil); rec.Code != 200 ||
		!strings.Contains(rec.Body.String(), `"enabled":true`) ||
		!strings.Contains(rec.Body.String(), "/auth/cli") {
		t.Fatalf("config must stay open and advertise auth: %d %s", rec.Code, rec.Body)
	}
	if rec := do(t, h, "GET", "/auth/login", nil); rec.Code != 200 {
		t.Fatalf("login page: %d", rec.Code)
	}
	if rec := do(t, h, "GET", "/", nil); rec.Code != 200 {
		t.Fatalf("frontend: %d", rec.Code)
	}

	// gated surface
	for _, u := range []string{"/api/projects", "/api/p/" + p.ID + "/tree", "/api/p/" + p.ID + "/store/list?prefix=journal/"} {
		if rec := do(t, h, "GET", u, nil); rec.Code != http.StatusUnauthorized {
			t.Errorf("GET %s without auth: %d, want 401", u, rec.Code)
		}
	}

	// a valid Bearer token opens it
	cookie := signupAndSession(t, h, "a@x.io", "Alice", "password1")
	_ = cookie
	u := auth.users // reach in for the user id
	var uid string
	for id := range u {
		uid = id
	}
	tok, err := auth.issueToken(uid, "test-device")
	if err != nil {
		t.Fatal(err)
	}
	req := httptest.NewRequest("GET", "/api/projects", nil)
	req.Header.Set("Authorization", "Bearer "+tok)
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != 200 {
		t.Fatalf("with token: %d %s", rec.Code, rec.Body)
	}
	// a session cookie works too (browser)
	req = httptest.NewRequest("GET", "/api/projects", nil)
	req.AddCookie(cookie)
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != 200 {
		t.Fatalf("with cookie: %d %s", rec.Code, rec.Body)
	}
	// garbage token stays out
	req = httptest.NewRequest("GET", "/api/projects", nil)
	req.Header.Set("Authorization", "Bearer bdt_nope")
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != http.StatusUnauthorized {
		t.Fatalf("bad token: %d, want 401", rec.Code)
	}
}

func TestLoginWrongPassword(t *testing.T) {
	srv, _, _ := authHub(t, true)
	h := srv.Handler()
	signupAndSession(t, h, "a@x.io", "Alice", "password1")

	form := url.Values{"email": {"a@x.io"}, "password": {"wrong-pass"}}
	req := httptest.NewRequest("POST", "/auth/login", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "Wrong email or password") {
		t.Fatalf("wrong password: %d", rec.Code)
	}
	if len(rec.Result().Cookies()) != 0 {
		t.Fatal("wrong password must not create a session")
	}
}

func TestSignupDisabled(t *testing.T) {
	srv, auth, _ := authHub(t, false)
	h := srv.Handler()
	form := url.Values{"email": {"a@x.io"}, "name": {"A"}, "password": {"password1"}}
	req := httptest.NewRequest("POST", "/auth/signup", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "invite-only") {
		t.Fatalf("signup while disabled: %d %s", rec.Code, rec.Body)
	}
	if len(auth.users) != 0 {
		t.Fatal("account created despite allow_signup=false")
	}
}

// The browser flow bdrive login drives: session → /auth/cli redirect with a
// one-time code → exchange for a device token.
func TestCLICallbackFlow(t *testing.T) {
	srv, _, p := authHub(t, true)
	h := srv.Handler()
	cookie := signupAndSession(t, h, "cli@x.io", "CLI", "password1")

	// non-loopback redirect is refused
	req := httptest.NewRequest("GET", "/auth/cli?redirect="+url.QueryEscape("http://evil.example/cb")+"&state=s", nil)
	req.AddCookie(cookie)
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != http.StatusBadRequest {
		t.Fatalf("non-loopback redirect: %d, want 400", rec.Code)
	}

	// without a session, /auth/cli sends the browser to the login page
	req = httptest.NewRequest("GET", "/auth/cli?redirect="+url.QueryEscape("http://127.0.0.1:9999/callback")+"&state=s1", nil)
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != http.StatusSeeOther || !strings.Contains(rec.Header().Get("Location"), "/auth/login") {
		t.Fatalf("cli without session: %d %s", rec.Code, rec.Header().Get("Location"))
	}

	// with a session: redirect back to the loopback with code+state
	req = httptest.NewRequest("GET", "/auth/cli?redirect="+url.QueryEscape("http://127.0.0.1:9999/callback")+"&state=s1", nil)
	req.AddCookie(cookie)
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != http.StatusSeeOther {
		t.Fatalf("cli redirect: %d", rec.Code)
	}
	loc, err := url.Parse(rec.Header().Get("Location"))
	if err != nil || loc.Host != "127.0.0.1:9999" || loc.Query().Get("state") != "s1" {
		t.Fatalf("callback location = %v", rec.Header().Get("Location"))
	}
	code := loc.Query().Get("code")

	// exchange the code for a token
	rec = do(t, h, "POST", "/api/auth/exchange", map[string]string{"code": code, "device": "laptop"})
	if rec.Code != 200 {
		t.Fatalf("exchange: %d %s", rec.Code, rec.Body)
	}
	var out struct {
		Token string `json:"token"`
		User  User   `json:"user"`
	}
	if err := json.Unmarshal(rec.Body.Bytes(), &out); err != nil {
		t.Fatal(err)
	}
	if out.Token == "" || out.User.Email != "cli@x.io" {
		t.Fatalf("exchange = %+v", out)
	}
	// the code is single-use
	if rec := do(t, h, "POST", "/api/auth/exchange", map[string]string{"code": code}); rec.Code != http.StatusUnauthorized {
		t.Fatalf("code reuse: %d, want 401", rec.Code)
	}
	// the token opens the API
	req = httptest.NewRequest("GET", "/api/p/"+p.ID+"/tree", nil)
	req.Header.Set("Authorization", "Bearer "+out.Token)
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != 200 {
		t.Fatalf("token on api: %d", rec.Code)
	}
}

func TestDeviceCodeFlow(t *testing.T) {
	srv, _, _ := authHub(t, true)
	h := srv.Handler()
	cookie := signupAndSession(t, h, "dev@x.io", "Dev", "password1")

	rec := do(t, h, "POST", "/api/auth/device/start", map[string]string{"device": "server-1"})
	if rec.Code != 200 {
		t.Fatalf("start: %d %s", rec.Code, rec.Body)
	}
	var start struct {
		Code string `json:"code"`
	}
	if err := json.Unmarshal(rec.Body.Bytes(), &start); err != nil || start.Code == "" {
		t.Fatalf("start = %s (%v)", rec.Body, err)
	}

	// pending until approved
	rec = do(t, h, "POST", "/api/auth/device/poll", map[string]string{"code": start.Code})
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "pending") {
		t.Fatalf("poll before approve: %d %s", rec.Code, rec.Body)
	}

	// approve from a signed-in browser
	form := url.Values{"code": {start.Code}}
	req := httptest.NewRequest("POST", "/auth/device", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(cookie)
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "Device connected") {
		t.Fatalf("approve: %d %s", rec.Code, rec.Body)
	}

	rec = do(t, h, "POST", "/api/auth/device/poll", map[string]string{"code": start.Code, "device": "server-1"})
	var out struct {
		Token string `json:"token"`
		User  User   `json:"user"`
	}
	if err := json.Unmarshal(rec.Body.Bytes(), &out); err != nil || out.Token == "" {
		t.Fatalf("poll after approve: %d %s", rec.Code, rec.Body)
	}
	if out.User.Email != "dev@x.io" {
		t.Fatalf("user = %+v", out.User)
	}
	// wrong code 401s
	if rec := do(t, h, "POST", "/api/auth/device/poll", map[string]string{"code": "nope"}); rec.Code != http.StatusUnauthorized {
		t.Fatalf("bad code: %d, want 401", rec.Code)
	}
}

// Reset without SMTP: the link is logged for the admin; the token itself
// must update the password exactly once.
func TestPasswordReset(t *testing.T) {
	srv, auth, _ := authHub(t, true)
	h := srv.Handler()
	signupAndSession(t, h, "r@x.io", "R", "oldpassword")

	form := url.Values{"email": {"r@x.io"}}
	req := httptest.NewRequest("POST", "/auth/reset", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rec := httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "reset link is on its way") {
		t.Fatalf("reset request: %d", rec.Code)
	}
	// grab the pending reset token (in production it arrives by email/log)
	var tok string
	auth.mu.Lock()
	for id, g := range auth.pending {
		if g.kind == "reset" {
			tok = id
		}
	}
	auth.mu.Unlock()
	if tok == "" {
		t.Fatal("no reset token minted")
	}

	form = url.Values{"token": {tok}, "password": {"newpassword9"}}
	req = httptest.NewRequest("POST", "/auth/reset/confirm", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "password is updated") {
		t.Fatalf("reset confirm: %d %s", rec.Code, rec.Body)
	}
	if auth.verifyPassword("r@x.io", "oldpassword") != nil {
		t.Fatal("old password still works")
	}
	if auth.verifyPassword("r@x.io", "newpassword9") == nil {
		t.Fatal("new password does not work")
	}
	// token is single-use
	req = httptest.NewRequest("POST", "/auth/reset/confirm", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if !strings.Contains(rec.Body.String(), "invalid or expired") {
		t.Fatal("reset token must be single-use")
	}
	// unknown emails get the same neutral answer (no account probing)
	form = url.Values{"email": {"ghost@x.io"}}
	req = httptest.NewRequest("POST", "/auth/reset", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	rec = httptest.NewRecorder()
	h.ServeHTTP(rec, req)
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "reset link is on its way") {
		t.Fatalf("reset for unknown email must look identical: %d", rec.Code)
	}
}

// Accounts and tokens survive a server restart; revocation sticks.
func TestAuthPersistence(t *testing.T) {
	path := filepath.Join(t.TempDir(), "auth.json")
	a1, err := OpenBuiltinAuth(path, true, nil)
	if err != nil {
		t.Fatal(err)
	}
	u, err := a1.signup("p@x.io", "P", "password1")
	if err != nil {
		t.Fatal(err)
	}
	tok, err := a1.issueToken(u.ID, "laptop")
	if err != nil {
		t.Fatal(err)
	}

	a2, err := OpenBuiltinAuth(path, true, nil) // "restart"
	if err != nil {
		t.Fatal(err)
	}
	if got, ok := a2.userForToken(tok); !ok || got.Email != "p@x.io" {
		t.Fatalf("token after reload = %+v %v", got, ok)
	}
	if a2.verifyPassword("p@x.io", "password1") == nil {
		t.Fatal("password lost across reload")
	}
	a2.revokeToken(tok)
	a3, err := OpenBuiltinAuth(path, true, nil)
	if err != nil {
		t.Fatal(err)
	}
	if _, ok := a3.userForToken(tok); ok {
		t.Fatal("revoked token still valid after reload")
	}
	// the auth file must never contain the plaintext token or password
	data, _ := readFileString(path)
	if strings.Contains(data, tok) || strings.Contains(data, "password1") {
		t.Fatal("auth.json leaks a plaintext credential")
	}
}

// A syncing device authenticates the same way: token via BDRIVE_TOKEN.
func TestSyncBackendWithToken(t *testing.T) {
	srv, auth, p := authHub(t, true)
	u, err := auth.signup("s@x.io", "S", "password1")
	if err != nil {
		t.Fatal(err)
	}
	tok, err := auth.issueToken(u.ID, "sync-box")
	if err != nil {
		t.Fatal(err)
	}
	ts := httptest.NewServer(srv.Handler())
	defer ts.Close()

	// without a token the backend is rejected
	t.Setenv("BDRIVE_TOKEN", "")
	t.Setenv("BDRIVE_HOME", t.TempDir()) // no settings.json token either
	be, err := remote.Open(context.Background(), ts.URL+"/p/"+p.ID)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := be.List(context.Background(), "journal/"); err == nil || !strings.Contains(err.Error(), "401") {
		t.Fatalf("unauthenticated list = %v, want 401", err)
	}
	be.Close()

	// with the token everything works
	t.Setenv("BDRIVE_TOKEN", tok)
	be, err = remote.Open(context.Background(), ts.URL+"/p/"+p.ID)
	if err != nil {
		t.Fatal(err)
	}
	defer be.Close()
	if _, err := be.List(context.Background(), "journal/"); err != nil {
		t.Fatalf("authenticated list: %v", err)
	}
	content := "authed content"
	if err := be.Put(context.Background(), "blobs/"+shaOf(content), strings.NewReader(content), int64(len(content))); err != nil {
		t.Fatalf("authenticated put: %v", err)
	}
}

func readFileString(path string) (string, error) {
	data, err := os.ReadFile(path)
	return string(data), err
}