package sessions

import (
	"net/http"
	"net/url"
	"testing"

	"github.com/oauth2-proxy/mockoidc"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"github.com/xlgmokha/x/pkg/serde"
	"github.com/xlgmokha/x/pkg/test"
	"github.com/xlgmokha/x/pkg/x"
	xcfg "gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/app/cfg"
	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/app/domain"
	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/pkg/oidc"
	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/pkg/pls"
	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/pkg/web"
)

func TestSessions(t *testing.T) {
	srv := oidc.NewTestServer(t)
	defer srv.Close()

	clientID := srv.MockOIDC.Config().ClientID
	clientSecret := srv.MockOIDC.Config().ClientSecret
	cfg, err := oidc.New(
		t.Context(),
		srv.Issuer(),
		clientID,
		clientSecret,
		"callback_url",
	)
	require.NoError(t, err)
	controller := New(cfg, http.DefaultClient)
	mux := http.NewServeMux()
	controller.MountTo(mux)

	t.Run("GET /session/new", func(t *testing.T) {
		t.Run("without an authenticated session", func(t *testing.T) {
			r, w := test.RequestResponse("GET", "/session/new")

			mux.ServeHTTP(w, r)

			t.Run("redirect to the OIDC Provider", func(t *testing.T) {
				require.Equal(t, http.StatusFound, w.Code)
				require.NotEmpty(t, w.Header().Get("Location"))
				redirectURL, err := url.Parse(w.Header().Get("Location"))
				require.NoError(t, err)
				assert.Equal(t, srv.AuthorizationEndpoint(), redirectURL.Scheme+"://"+redirectURL.Host+redirectURL.Path)
				assert.NotEmpty(t, redirectURL.Query().Get("state"))
				assert.Equal(t, srv.MockOIDC.Config().ClientID, redirectURL.Query().Get("client_id"))
				assert.Equal(t, "openid profile email", redirectURL.Query().Get("scope"))
				assert.Equal(t, cfg.Config.ClientID, redirectURL.Query().Get("audience"))
				assert.Equal(t, cfg.Config.RedirectURL, redirectURL.Query().Get("redirect_uri"))
				assert.Equal(t, "code", redirectURL.Query().Get("response_type"))
			})

			t.Run("generates a CSRF token", func(t *testing.T) {
				cookieHeader := w.Header().Get("Set-Cookie")
				require.NotEmpty(t, cookieHeader)

				cookie, err := http.ParseSetCookie(w.Header().Get("Set-Cookie"))
				require.NoError(t, err)
				require.NotZero(t, cookie)

				assert.Equal(t, xcfg.CSRFCookie, cookie.Name)
			})
		})

		t.Run("with an active authenicated session", func(t *testing.T) {
			t.Run("redirects to the dashboard", func(t *testing.T) {
				user := &domain.User{}
				r, w := test.RequestResponse(
					"GET",
					"/session/new",
					test.WithContextKeyValue(t.Context(), xcfg.CurrentUser, user),
				)

				mux.ServeHTTP(w, r)

				require.Equal(t, http.StatusFound, w.Code)
				assert.Equal(t, "/dashboard", w.Header().Get("Location"))
			})
		})
	})

	t.Run("GET /session/callback", func(t *testing.T) {
		t.Run("with an invalid csrf token", func(t *testing.T) {
			user := mockoidc.DefaultUser()
			code := srv.CreateAuthorizationCodeFor(user)
			nonce := pls.GenerateRandomHex(32)

			r, w := test.RequestResponse(
				"GET",
				"/session/callback?code="+code+"&state=invalid",
				test.WithCookie(web.NewCookie(xcfg.CSRFCookie, nonce)),
			)

			mux.ServeHTTP(w, r)

			require.Equal(t, http.StatusBadRequest, w.Code)
		})

		t.Run("with an invalid authorization code grant", func(t *testing.T) {
			r, w := test.RequestResponse("GET", "/session/callback?code=invalid")

			mux.ServeHTTP(w, r)

			assert.Equal(t, http.StatusBadRequest, w.Code)
		})

		t.Run("when already logged in", func(t *testing.T) {
			t.Run("redirects to the dashboard", func(t *testing.T) {
				user := &domain.User{}
				r, w := test.RequestResponse(
					"GET",
					"/session/callback?code=valid",
					test.WithContextKeyValue(t.Context(), xcfg.CurrentUser, user),
				)

				mux.ServeHTTP(w, r)

				require.Equal(t, http.StatusFound, w.Code)
				assert.Equal(t, "/dashboard", w.Header().Get("Location"))
			})
		})

		t.Run("with a valid authorization code grant", func(t *testing.T) {
			user := mockoidc.DefaultUser()
			code := srv.CreateAuthorizationCodeFor(user)
			nonce := pls.GenerateRandomHex(32)

			r, w := test.RequestResponse(
				"GET",
				"/session/callback?code="+code+"&state="+nonce,
				test.WithCookie(web.NewCookie(xcfg.CSRFCookie, nonce)),
			)

			mux.ServeHTTP(w, r)

			cookieValues := w.Header().Values("Set-Cookie")
			cookies := x.Map(cookieValues, func(line string) *http.Cookie {
				ck, err := http.ParseSetCookie(line)
				require.NoError(t, err)
				return ck
			})

			t.Run("stores the id token in a session cookie", func(t *testing.T) {
				cookie := x.Find(cookies, func(item *http.Cookie) bool {
					return item.Name == xcfg.IDTokenCookie
				})

				require.NotNil(t, cookie)

				idToken := srv.Verify(cookie.Value)
				assert.Equal(t, user.Subject, idToken.Subject)
			})

			t.Run("stores the access token in a session cookie", func(t *testing.T) {
				cookie := x.Find(cookies, func(item *http.Cookie) bool {
					return item.Name == xcfg.BearerTokenCookie
				})

				require.NotNil(t, cookie)

				keypair, err := mockoidc.DefaultKeypair()
				require.NoError(t, err)

				token, err := keypair.VerifyJWT(cookie.Value, nil)
				require.NoError(t, err)

				sub, err := token.Claims.GetSubject()
				require.NoError(t, err)
				assert.Equal(t, user.Subject, sub)
			})

			t.Run("stores the refresh token in a session cookie", func(t *testing.T) {
				cookie := x.Find(cookies, func(item *http.Cookie) bool {
					return item.Name == xcfg.RefreshTokenCookie
				})
				require.NotNil(t, cookie)

				keypair, err := mockoidc.DefaultKeypair()
				require.NoError(t, err)

				token, err := keypair.VerifyJWT(cookie.Value, nil)
				require.NoError(t, err)

				sub, err := token.Claims.GetSubject()
				require.NoError(t, err)
				assert.Equal(t, user.Subject, sub)
			})

			t.Run("redirects to the homepage", func(t *testing.T) {
				require.Equal(t, http.StatusFound, w.Code)
				assert.Equal(t, "/dashboard", w.Header().Get("Location"))
			})

			t.Run("applies the appropriate cookie settings", func(t *testing.T) {
				x.Each(cookies, func(cookie *http.Cookie) {
					t.Logf("%v: %v\n", cookie.Name, cookie.Value)
					assert.Equal(t, "/", cookie.Path)
					assert.NotEmpty(t, cookie.Name)
					assert.True(t, cookie.HttpOnly)
					assert.True(t, cookie.Secure)
				})
			})
		})
	})

	t.Run("GET /session", func(t *testing.T) {
		t.Run("with an id_token cookie", func(t *testing.T) {
			user := mockoidc.DefaultUser()
			_, rawIDToken := srv.CreateTokensFor(user)
			cookie := &http.Cookie{Name: xcfg.IDTokenCookie, Value: rawIDToken}
			r, w := test.RequestResponse("GET", "/session", test.WithCookie(cookie))

			mux.ServeHTTP(w, r)

			require.Equal(t, http.StatusOK, w.Code)
			items, err := serde.FromJSON[map[string]interface{}](w.Body)
			require.NoError(t, err)
			assert.Equal(t, srv.Issuer(), items["iss"])
		})

		t.Run("without an id_token cookie", func(t *testing.T) {
			r, w := test.RequestResponse("GET", "/session")

			mux.ServeHTTP(w, r)

			require.Equal(t, http.StatusNotFound, w.Code)
		})
	})

	t.Run("POST /session/destroy", func(t *testing.T) {
		t.Run("clears the session cookie", func(t *testing.T) {
			cookie := web.NewCookie(xcfg.IDTokenCookie, "value")
			r, w := test.RequestResponse("POST", "/session/destroy", test.WithCookie(cookie))

			mux.ServeHTTP(w, r)

			require.Equal(t, http.StatusFound, w.Code)
			assert.Equal(t, "/", w.Header().Get("Location"))

			expected := []string{
				"__csrf=; Path=/; Expires=Thu, 01 Jan 1970 00:00:00 GMT; Max-Age=0; HttpOnly; Secure",
				"id_token=; Path=/; Expires=Thu, 01 Jan 1970 00:00:00 GMT; Max-Age=0; HttpOnly; Secure",
				"bearer_token=; Path=/; Expires=Thu, 01 Jan 1970 00:00:00 GMT; Max-Age=0; HttpOnly; Secure",
				"refresh_token=; Path=/; Expires=Thu, 01 Jan 1970 00:00:00 GMT; Max-Age=0; HttpOnly; Secure",
			}
			assert.ElementsMatch(t, expected, w.Header().Values("Set-Cookie"))
		})
	})
}