package server

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"net/url"
	"path"
	"testing"
	"time"

	gosundheit "github.com/AppsFlyer/go-sundheit"
	"github.com/AppsFlyer/go-sundheit/checks"
	"github.com/coreos/go-oidc/v3/oidc"
	"github.com/stretchr/testify/require"
	"golang.org/x/oauth2"

	"github.com/dexidp/dex/storage"
)

func TestHandleHealth(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	httpServer, server := newTestServer(ctx, t, nil)
	defer httpServer.Close()

	rr := httptest.NewRecorder()
	server.ServeHTTP(rr, httptest.NewRequest("GET", "/healthz", nil))
	if rr.Code != http.StatusOK {
		t.Errorf("expected 200 got %d", rr.Code)
	}
}

func TestHandleHealthFailure(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	httpServer, server := newTestServer(ctx, t, func(c *Config) {
		c.HealthChecker = gosundheit.New()

		c.HealthChecker.RegisterCheck(
			&checks.CustomCheck{
				CheckName: "fail",
				CheckFunc: func(_ context.Context) (details interface{}, err error) {
					return nil, errors.New("error")
				},
			},
			gosundheit.InitiallyPassing(false),
			gosundheit.ExecutionPeriod(1*time.Second),
		)
	})
	defer httpServer.Close()

	rr := httptest.NewRecorder()
	server.ServeHTTP(rr, httptest.NewRequest("GET", "/healthz", nil))
	if rr.Code != http.StatusInternalServerError {
		t.Errorf("expected 500 got %d", rr.Code)
	}
}

type emptyStorage struct {
	storage.Storage
}

func (*emptyStorage) GetAuthRequest(string) (storage.AuthRequest, error) {
	return storage.AuthRequest{}, storage.ErrNotFound
}

func TestHandleInvalidOAuth2Callbacks(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	httpServer, server := newTestServer(ctx, t, func(c *Config) {
		c.Storage = &emptyStorage{c.Storage}
	})
	defer httpServer.Close()

	tests := []struct {
		TargetURI    string
		ExpectedCode int
	}{
		{"/callback", http.StatusBadRequest},
		{"/callback?code=&state=", http.StatusBadRequest},
		{"/callback?code=AAAAAAA&state=BBBBBBB", http.StatusBadRequest},
	}

	rr := httptest.NewRecorder()

	for i, r := range tests {
		server.ServeHTTP(rr, httptest.NewRequest("GET", r.TargetURI, nil))
		if rr.Code != r.ExpectedCode {
			t.Fatalf("test %d expected %d, got %d", i, r.ExpectedCode, rr.Code)
		}
	}
}

func TestHandleInvalidSAMLCallbacks(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	httpServer, server := newTestServer(ctx, t, func(c *Config) {
		c.Storage = &emptyStorage{c.Storage}
	})
	defer httpServer.Close()

	type requestForm struct {
		RelayState string
	}
	tests := []struct {
		RequestForm  requestForm
		ExpectedCode int
	}{
		{requestForm{}, http.StatusBadRequest},
		{requestForm{RelayState: "AAAAAAA"}, http.StatusBadRequest},
	}

	rr := httptest.NewRecorder()

	for i, r := range tests {
		jsonValue, err := json.Marshal(r.RequestForm)
		if err != nil {
			t.Fatal(err.Error())
		}
		server.ServeHTTP(rr, httptest.NewRequest("POST", "/callback", bytes.NewBuffer(jsonValue)))
		if rr.Code != r.ExpectedCode {
			t.Fatalf("test %d expected %d, got %d", i, r.ExpectedCode, rr.Code)
		}
	}
}

// TestHandleAuthCode checks that it is forbidden to use same code twice
func TestHandleAuthCode(t *testing.T) {
	tests := []struct {
		name       string
		handleCode func(*testing.T, context.Context, *oauth2.Config, string)
	}{
		{
			name: "Code Reuse should return invalid_grant",
			handleCode: func(t *testing.T, ctx context.Context, oauth2Config *oauth2.Config, code string) {
				_, err := oauth2Config.Exchange(ctx, code)
				require.NoError(t, err)

				_, err = oauth2Config.Exchange(ctx, code)
				require.Error(t, err)

				oauth2Err, ok := err.(*oauth2.RetrieveError)
				require.True(t, ok)

				var errResponse struct{ Error string }
				err = json.Unmarshal(oauth2Err.Body, &errResponse)
				require.NoError(t, err)

				// invalid_grant must be returned for invalid values
				// https://tools.ietf.org/html/rfc6749#section-5.2
				require.Equal(t, errInvalidGrant, errResponse.Error)
			},
		},
		{
			name: "No Code should return invalid_request",
			handleCode: func(t *testing.T, ctx context.Context, oauth2Config *oauth2.Config, _ string) {
				_, err := oauth2Config.Exchange(ctx, "")
				require.Error(t, err)

				oauth2Err, ok := err.(*oauth2.RetrieveError)
				require.True(t, ok)

				var errResponse struct{ Error string }
				err = json.Unmarshal(oauth2Err.Body, &errResponse)
				require.NoError(t, err)

				require.Equal(t, errInvalidRequest, errResponse.Error)
			},
		},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			ctx, cancel := context.WithCancel(context.Background())
			defer cancel()

			httpServer, s := newTestServer(ctx, t, func(c *Config) { c.Issuer += "/non-root-path" })
			defer httpServer.Close()

			p, err := oidc.NewProvider(ctx, httpServer.URL)
			require.NoError(t, err)

			var oauth2Client oauth2Client
			oauth2Client.server = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				if r.URL.Path != "/callback" {
					http.Redirect(w, r, oauth2Client.config.AuthCodeURL(""), http.StatusSeeOther)
					return
				}

				q := r.URL.Query()
				require.Equal(t, q.Get("error"), "", q.Get("error_description"))

				code := q.Get("code")
				tc.handleCode(t, ctx, oauth2Client.config, code)

				w.WriteHeader(http.StatusOK)
			}))
			defer oauth2Client.server.Close()

			redirectURL := oauth2Client.server.URL + "/callback"
			client := storage.Client{
				ID:           "testclient",
				Secret:       "testclientsecret",
				RedirectURIs: []string{redirectURL},
			}
			err = s.storage.CreateClient(client)
			require.NoError(t, err)

			oauth2Client.config = &oauth2.Config{
				ClientID:     client.ID,
				ClientSecret: client.Secret,
				Endpoint:     p.Endpoint(),
				Scopes:       []string{oidc.ScopeOpenID, "email", "offline_access"},
				RedirectURL:  redirectURL,
			}

			resp, err := http.Get(oauth2Client.server.URL + "/login")
			require.NoError(t, err)

			resp.Body.Close()
		})
	}
}

func mockConnectorDataTestStorage(t *testing.T, s storage.Storage) {
	c := storage.Client{
		ID:           "test",
		Secret:       "barfoo",
		RedirectURIs: []string{"foo://bar.com/", "https://auth.example.com"},
		Name:         "dex client",
		LogoURL:      "https://goo.gl/JIyzIC",
	}

	err := s.CreateClient(c)
	require.NoError(t, err)

	c1 := storage.Connector{
		ID:   "test",
		Type: "mockPassword",
		Name: "mockPassword",
		Config: []byte(`{
"username": "test",
"password": "test"
}`),
	}

	err = s.CreateConnector(c1)
	require.NoError(t, err)
}

func TestPasswordConnectorDataNotEmpty(t *testing.T) {
	t0 := time.Now()

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	// Setup a dex server.
	httpServer, s := newTestServer(ctx, t, func(c *Config) {
		c.PasswordConnector = "test"
		c.Now = func() time.Time { return t0 }
	})
	defer httpServer.Close()

	mockConnectorDataTestStorage(t, s.storage)

	u, err := url.Parse(s.issuerURL.String())
	require.NoError(t, err)

	u.Path = path.Join(u.Path, "/token")
	v := url.Values{}
	v.Add("scope", "openid offline_access email")
	v.Add("grant_type", "password")
	v.Add("username", "test")
	v.Add("password", "test")

	req, _ := http.NewRequest("POST", u.String(), bytes.NewBufferString(v.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded; param=value")
	req.SetBasicAuth("test", "barfoo")

	rr := httptest.NewRecorder()
	s.ServeHTTP(rr, req)

	require.Equal(t, 200, rr.Code)

	// Check that we received expected refresh token
	var ref struct {
		Token string `json:"refresh_token"`
	}
	err = json.Unmarshal(rr.Body.Bytes(), &ref)
	require.NoError(t, err)

	newSess, err := s.storage.GetOfflineSessions("0-385-28089-0", "test")
	require.NoError(t, err)
	require.Equal(t, `{"test": "true"}`, string(newSess.ConnectorData))
}