// Copyright 2019 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package integration

import (
	"bytes"
	"context"
	"crypto/sha256"
	"encoding/base64"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"testing"

	auth_model "code.gitea.io/gitea/models/auth"
	"code.gitea.io/gitea/models/unittest"
	user_model "code.gitea.io/gitea/models/user"
	"code.gitea.io/gitea/modules/json"
	"code.gitea.io/gitea/modules/setting"
	"code.gitea.io/gitea/modules/test"
	"code.gitea.io/gitea/routers/web/auth"
	"code.gitea.io/gitea/tests"

	"github.com/markbates/goth"
	"github.com/stretchr/testify/assert"
)

func TestAuthorizeNoClientID(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequest(t, "GET", "/login/oauth/authorize")
	ctx := loginUser(t, "user2")
	resp := ctx.MakeRequest(t, req, http.StatusBadRequest)
	assert.Contains(t, resp.Body.String(), "Client ID not registered")
}

func TestAuthorizeUnregisteredRedirect(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequest(t, "GET", "/login/oauth/authorize?client_id=da7da3ba-9a13-4167-856f-3899de0b0138&redirect_uri=UNREGISTERED&response_type=code&state=thestate")
	ctx := loginUser(t, "user1")
	resp := ctx.MakeRequest(t, req, http.StatusBadRequest)
	assert.Contains(t, resp.Body.String(), "Unregistered Redirect URI")
}

func TestAuthorizeUnsupportedResponseType(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequest(t, "GET", "/login/oauth/authorize?client_id=da7da3ba-9a13-4167-856f-3899de0b0138&redirect_uri=a&response_type=UNEXPECTED&state=thestate")
	ctx := loginUser(t, "user1")
	resp := ctx.MakeRequest(t, req, http.StatusSeeOther)
	u, err := resp.Result().Location()
	assert.NoError(t, err)
	assert.Equal(t, "unsupported_response_type", u.Query().Get("error"))
	assert.Equal(t, "Only code response type is supported.", u.Query().Get("error_description"))
}

func TestAuthorizeUnsupportedCodeChallengeMethod(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequest(t, "GET", "/login/oauth/authorize?client_id=da7da3ba-9a13-4167-856f-3899de0b0138&redirect_uri=a&response_type=code&state=thestate&code_challenge_method=UNEXPECTED")
	ctx := loginUser(t, "user1")
	resp := ctx.MakeRequest(t, req, http.StatusSeeOther)
	u, err := resp.Result().Location()
	assert.NoError(t, err)
	assert.Equal(t, "invalid_request", u.Query().Get("error"))
	assert.Equal(t, "unsupported code challenge method", u.Query().Get("error_description"))
}

func TestAuthorizeLoginRedirect(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequest(t, "GET", "/login/oauth/authorize")
	assert.Contains(t, MakeRequest(t, req, http.StatusSeeOther).Body.String(), "/user/login")
}

func TestAuthorizeShow(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequest(t, "GET", "/login/oauth/authorize?client_id=da7da3ba-9a13-4167-856f-3899de0b0138&redirect_uri=a&response_type=code&state=thestate")
	ctx := loginUser(t, "user4")
	resp := ctx.MakeRequest(t, req, http.StatusOK)

	htmlDoc := NewHTMLParser(t, resp.Body)
	htmlDoc.AssertElement(t, "#authorize-app", true)
	htmlDoc.GetCSRF()
}

func TestAuthorizeRedirectWithExistingGrant(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequest(t, "GET", "/login/oauth/authorize?client_id=da7da3ba-9a13-4167-856f-3899de0b0138&redirect_uri=https%3A%2F%2Fexample.com%2Fxyzzy&response_type=code&state=thestate")
	ctx := loginUser(t, "user1")
	resp := ctx.MakeRequest(t, req, http.StatusSeeOther)
	u, err := resp.Result().Location()
	assert.NoError(t, err)
	assert.Equal(t, "thestate", u.Query().Get("state"))
	assert.Truef(t, len(u.Query().Get("code")) > 30, "authorization code '%s' should be longer then 30", u.Query().Get("code"))
	u.RawQuery = ""
	assert.Equal(t, "https://example.com/xyzzy", u.String())
}

func TestAuthorizePKCERequiredForPublicClient(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequest(t, "GET", "/login/oauth/authorize?client_id=ce5a1322-42a7-11ed-b878-0242ac120002&redirect_uri=http%3A%2F%2F127.0.0.1&response_type=code&state=thestate")
	ctx := loginUser(t, "user1")
	resp := ctx.MakeRequest(t, req, http.StatusSeeOther)
	u, err := resp.Result().Location()
	assert.NoError(t, err)
	assert.Equal(t, "invalid_request", u.Query().Get("error"))
	assert.Equal(t, "PKCE is required for public clients", u.Query().Get("error_description"))
}

func TestAccessTokenExchange(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "a",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp := MakeRequest(t, req, http.StatusOK)
	type response struct {
		AccessToken  string `json:"access_token"`
		TokenType    string `json:"token_type"`
		ExpiresIn    int64  `json:"expires_in"`
		RefreshToken string `json:"refresh_token"`
	}
	parsed := new(response)

	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsed))
	assert.True(t, len(parsed.AccessToken) > 10)
	assert.True(t, len(parsed.RefreshToken) > 10)
}

func TestAccessTokenExchangeWithPublicClient(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     "ce5a1322-42a7-11ed-b878-0242ac120002",
		"redirect_uri":  "http://127.0.0.1",
		"code":          "authcodepublic",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp := MakeRequest(t, req, http.StatusOK)
	type response struct {
		AccessToken  string `json:"access_token"`
		TokenType    string `json:"token_type"`
		ExpiresIn    int64  `json:"expires_in"`
		RefreshToken string `json:"refresh_token"`
	}
	parsed := new(response)

	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsed))
	assert.True(t, len(parsed.AccessToken) > 10)
	assert.True(t, len(parsed.RefreshToken) > 10)
}

func TestAccessTokenExchangeJSON(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequestWithJSON(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "a",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp := MakeRequest(t, req, http.StatusOK)
	type response struct {
		AccessToken  string `json:"access_token"`
		TokenType    string `json:"token_type"`
		ExpiresIn    int64  `json:"expires_in"`
		RefreshToken string `json:"refresh_token"`
	}
	parsed := new(response)

	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsed))
	assert.True(t, len(parsed.AccessToken) > 10)
	assert.True(t, len(parsed.RefreshToken) > 10)
}

func TestAccessTokenExchangeWithoutPKCE(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "a",
		"code":          "authcode",
	})
	resp := MakeRequest(t, req, http.StatusBadRequest)
	parsedError := new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "unauthorized_client", string(parsedError.ErrorCode))
	assert.Equal(t, "failed PKCE code challenge", parsedError.ErrorDescription)
}

func TestAccessTokenExchangeWithInvalidCredentials(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	// invalid client id
	req := NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     "???",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "a",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp := MakeRequest(t, req, http.StatusBadRequest)
	parsedError := new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "invalid_client", string(parsedError.ErrorCode))
	assert.Equal(t, "cannot load client with client id: '???'", parsedError.ErrorDescription)

	// invalid client secret
	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "???",
		"redirect_uri":  "a",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError = new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "unauthorized_client", string(parsedError.ErrorCode))
	assert.Equal(t, "invalid client secret", parsedError.ErrorDescription)

	// invalid redirect uri
	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "???",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError = new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "unauthorized_client", string(parsedError.ErrorCode))
	assert.Equal(t, "unexpected redirect URI", parsedError.ErrorDescription)

	// invalid authorization code
	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "a",
		"code":          "???",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError = new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "unauthorized_client", string(parsedError.ErrorCode))
	assert.Equal(t, "client is not authorized", parsedError.ErrorDescription)

	// invalid grant_type
	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "???",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "a",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError = new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "unsupported_grant_type", string(parsedError.ErrorCode))
	assert.Equal(t, "Only refresh_token or authorization_code grant type is supported", parsedError.ErrorDescription)
}

func TestAccessTokenExchangeWithBasicAuth(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"redirect_uri":  "a",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	req.Header.Add("Authorization", "Basic ZGE3ZGEzYmEtOWExMy00MTY3LTg1NmYtMzg5OWRlMGIwMTM4OjRNSzhOYTZSNTVzbWRDWTBXdUNDdW1aNmhqUlBuR1k1c2FXVlJISGpKaUE9")
	resp := MakeRequest(t, req, http.StatusOK)
	type response struct {
		AccessToken  string `json:"access_token"`
		TokenType    string `json:"token_type"`
		ExpiresIn    int64  `json:"expires_in"`
		RefreshToken string `json:"refresh_token"`
	}
	parsed := new(response)

	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsed))
	assert.True(t, len(parsed.AccessToken) > 10)
	assert.True(t, len(parsed.RefreshToken) > 10)

	// use wrong client_secret
	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"redirect_uri":  "a",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	req.Header.Add("Authorization", "Basic ZGE3ZGEzYmEtOWExMy00MTY3LTg1NmYtMzg5OWRlMGIwMTM4OmJsYWJsYQ==")
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError := new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "unauthorized_client", string(parsedError.ErrorCode))
	assert.Equal(t, "invalid client secret", parsedError.ErrorDescription)

	// missing header
	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"redirect_uri":  "a",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError = new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "invalid_client", string(parsedError.ErrorCode))
	assert.Equal(t, "cannot load client with client id: ''", parsedError.ErrorDescription)

	// client_id inconsistent with Authorization header
	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":   "authorization_code",
		"redirect_uri": "a",
		"code":         "authcode",
		"client_id":    "inconsistent",
	})
	req.Header.Add("Authorization", "Basic ZGE3ZGEzYmEtOWExMy00MTY3LTg1NmYtMzg5OWRlMGIwMTM4OjRNSzhOYTZSNTVzbWRDWTBXdUNDdW1aNmhqUlBuR1k1c2FXVlJISGpKaUE9")
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError = new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "invalid_request", string(parsedError.ErrorCode))
	assert.Equal(t, "client_id in request body inconsistent with Authorization header", parsedError.ErrorDescription)

	// client_secret inconsistent with Authorization header
	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"redirect_uri":  "a",
		"code":          "authcode",
		"client_secret": "inconsistent",
	})
	req.Header.Add("Authorization", "Basic ZGE3ZGEzYmEtOWExMy00MTY3LTg1NmYtMzg5OWRlMGIwMTM4OjRNSzhOYTZSNTVzbWRDWTBXdUNDdW1aNmhqUlBuR1k1c2FXVlJISGpKaUE9")
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError = new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "invalid_request", string(parsedError.ErrorCode))
	assert.Equal(t, "client_secret in request body inconsistent with Authorization header", parsedError.ErrorDescription)
}

func TestRefreshTokenInvalidation(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	req := NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "authorization_code",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "a",
		"code":          "authcode",
		"code_verifier": "N1Zo9-8Rfwhkt68r1r29ty8YwIraXR8eh_1Qwxg7yQXsonBt",
	})
	resp := MakeRequest(t, req, http.StatusOK)
	type response struct {
		AccessToken  string `json:"access_token"`
		TokenType    string `json:"token_type"`
		ExpiresIn    int64  `json:"expires_in"`
		RefreshToken string `json:"refresh_token"`
	}
	parsed := new(response)

	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsed))

	// test without invalidation
	setting.OAuth2.InvalidateRefreshTokens = false

	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type": "refresh_token",
		"client_id":  "da7da3ba-9a13-4167-856f-3899de0b0138",
		// omit secret
		"redirect_uri":  "a",
		"refresh_token": parsed.RefreshToken,
	})
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError := new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "invalid_client", string(parsedError.ErrorCode))
	assert.Equal(t, "invalid empty client secret", parsedError.ErrorDescription)

	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "refresh_token",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "a",
		"refresh_token": "UNEXPECTED",
	})
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError = new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "unauthorized_client", string(parsedError.ErrorCode))
	assert.Equal(t, "unable to parse refresh token", parsedError.ErrorDescription)

	req = NewRequestWithValues(t, "POST", "/login/oauth/access_token", map[string]string{
		"grant_type":    "refresh_token",
		"client_id":     "da7da3ba-9a13-4167-856f-3899de0b0138",
		"client_secret": "4MK8Na6R55smdCY0WuCCumZ6hjRPnGY5saWVRHHjJiA=",
		"redirect_uri":  "a",
		"refresh_token": parsed.RefreshToken,
	})

	bs, err := io.ReadAll(req.Body)
	assert.NoError(t, err)

	req.Body = io.NopCloser(bytes.NewReader(bs))
	MakeRequest(t, req, http.StatusOK)

	req.Body = io.NopCloser(bytes.NewReader(bs))
	MakeRequest(t, req, http.StatusOK)

	// test with invalidation
	setting.OAuth2.InvalidateRefreshTokens = true
	req.Body = io.NopCloser(bytes.NewReader(bs))
	MakeRequest(t, req, http.StatusOK)

	// repeat request should fail
	req.Body = io.NopCloser(bytes.NewReader(bs))
	resp = MakeRequest(t, req, http.StatusBadRequest)
	parsedError = new(auth.AccessTokenError)
	assert.NoError(t, json.Unmarshal(resp.Body.Bytes(), parsedError))
	assert.Equal(t, "unauthorized_client", string(parsedError.ErrorCode))
	assert.Equal(t, "token was already used", parsedError.ErrorDescription)
}

func TestSignInOAuthCallbackSignIn(t *testing.T) {
	defer tests.PrepareTestEnv(t)()

	//
	// OAuth2 authentication source GitLab
	//
	gitlabName := "gitlab"
	gitlab := addAuthSource(t, authSourcePayloadGitLabCustom(gitlabName))

	//
	// Create a user as if it had been previously been created by the GitLab
	// authentication source.
	//
	userGitLabUserID := "5678"
	userGitLab := &user_model.User{
		Name:        "gitlabuser",
		Email:       "gitlabuser@example.com",
		Passwd:      "gitlabuserpassword",
		Type:        user_model.UserTypeIndividual,
		LoginType:   auth_model.OAuth2,
		LoginSource: gitlab.ID,
		LoginName:   userGitLabUserID,
	}
	defer createUser(context.Background(), t, userGitLab)()

	//
	// A request for user information sent to Goth will return a
	// goth.User exactly matching the user created above.
	//
	defer mockCompleteUserAuth(func(res http.ResponseWriter, req *http.Request) (goth.User, error) {
		return goth.User{
			Provider: gitlabName,
			UserID:   userGitLabUserID,
			Email:    userGitLab.Email,
		}, nil
	})()
	req := NewRequest(t, "GET", fmt.Sprintf("/user/oauth2/%s/callback?code=XYZ&state=XYZ", gitlabName))
	resp := MakeRequest(t, req, http.StatusSeeOther)
	assert.Equal(t, test.RedirectURL(resp), "/")
	userAfterLogin := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: userGitLab.ID})
	assert.Greater(t, userAfterLogin.LastLoginUnix, userGitLab.LastLoginUnix)
}

func TestSignInOAuthCallbackPKCE(t *testing.T) {
	defer tests.PrepareTestEnv(t)()

	// Setup authentication source
	gitlabName := "gitlab"
	gitlab := addAuthSource(t, authSourcePayloadGitLabCustom(gitlabName))
	// Create a user as if it had been previously been created by the authentication source.
	userGitLabUserID := "5678"
	userGitLab := &user_model.User{
		Name:        "gitlabuser",
		Email:       "gitlabuser@example.com",
		Passwd:      "gitlabuserpassword",
		Type:        user_model.UserTypeIndividual,
		LoginType:   auth_model.OAuth2,
		LoginSource: gitlab.ID,
		LoginName:   userGitLabUserID,
	}
	defer createUser(context.Background(), t, userGitLab)()

	// initial redirection (to generate the code_challenge)
	session := emptyTestSession(t)
	req := NewRequest(t, "GET", fmt.Sprintf("/user/oauth2/%s", gitlabName))
	resp := session.MakeRequest(t, req, http.StatusTemporaryRedirect)
	dest, err := url.Parse(resp.Header().Get("Location"))
	assert.NoError(t, err)
	assert.Equal(t, "S256", dest.Query().Get("code_challenge_method"))
	codeChallenge := dest.Query().Get("code_challenge")
	assert.NotEmpty(t, codeChallenge)

	// callback (to check the initial code_challenge)
	defer mockCompleteUserAuth(func(res http.ResponseWriter, req *http.Request) (goth.User, error) {
		codeVerifier := req.URL.Query().Get("code_verifier")
		assert.NotEmpty(t, codeVerifier)
		assert.Greater(t, len(codeVerifier), 40, codeVerifier)

		sha2 := sha256.New()
		io.WriteString(sha2, codeVerifier)
		assert.Equal(t, codeChallenge, base64.RawURLEncoding.EncodeToString(sha2.Sum(nil)))

		return goth.User{
			Provider: gitlabName,
			UserID:   userGitLabUserID,
			Email:    userGitLab.Email,
		}, nil
	})()
	req = NewRequest(t, "GET", fmt.Sprintf("/user/oauth2/%s/callback?code=XYZ&state=XYZ", gitlabName))
	resp = session.MakeRequest(t, req, http.StatusSeeOther)
	assert.Equal(t, "/", test.RedirectURL(resp))
	unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: userGitLab.ID})
}

func TestSignInOAuthCallbackRedirectToEscaping(t *testing.T) {
	defer tests.PrepareTestEnv(t)()

	//
	// OAuth2 authentication source GitLab
	//
	gitlabName := "gitlab"
	gitlab := addAuthSource(t, authSourcePayloadGitLabCustom(gitlabName))

	//
	// Create a user as if it had been previously been created by the GitLab
	// authentication source.
	//
	userGitLabUserID := "5678"
	userGitLab := &user_model.User{
		Name:        "gitlabuser",
		Email:       "gitlabuser@example.com",
		Passwd:      "gitlabuserpassword",
		Type:        user_model.UserTypeIndividual,
		LoginType:   auth_model.OAuth2,
		LoginSource: gitlab.ID,
		LoginName:   userGitLabUserID,
	}
	defer createUser(context.Background(), t, userGitLab)()

	//
	// A request for user information sent to Goth will return a
	// goth.User exactly matching the user created above.
	//
	defer mockCompleteUserAuth(func(res http.ResponseWriter, req *http.Request) (goth.User, error) {
		return goth.User{
			Provider: gitlabName,
			UserID:   userGitLabUserID,
			Email:    userGitLab.Email,
		}, nil
	})()
	req := NewRequest(t, "GET", fmt.Sprintf("/user/oauth2/%s/callback?code=XYZ&state=XYZ", gitlabName))
	req.AddCookie(&http.Cookie{
		Name:  "redirect_to",
		Value: "/login/oauth/authorize?redirect_uri=https%3A%2F%2Ftranslate.example.org",
		Path:  "/",
	})
	resp := MakeRequest(t, req, http.StatusSeeOther)

	hasNewSessionCookie := false
	sessionCookieName := setting.SessionConfig.CookieName
	for _, c := range resp.Result().Cookies() {
		if c.Name == sessionCookieName {
			hasNewSessionCookie = true
			break
		}
		t.Log("Got cookie", c.Name)
	}

	assert.True(t, hasNewSessionCookie, "Session cookie %q is missing", sessionCookieName)
	assert.Equal(t, "/login/oauth/authorize?redirect_uri=https://translate.example.org", test.RedirectURL(resp))
}

func TestSignUpViaOAuthWithMissingFields(t *testing.T) {
	defer tests.PrepareTestEnv(t)()
	// enable auto-creation of accounts via OAuth2
	enableAutoRegistration := setting.OAuth2Client.EnableAutoRegistration
	setting.OAuth2Client.EnableAutoRegistration = true
	defer func() {
		setting.OAuth2Client.EnableAutoRegistration = enableAutoRegistration
	}()

	// OAuth2 authentication source GitLab
	gitlabName := "gitlab"
	addAuthSource(t, authSourcePayloadGitLabCustom(gitlabName))
	userGitLabUserID := "5678"

	// The Goth User returned by the oauth2 integration is missing
	// an email address, so we won't be able to automatically create a local account for it.
	defer mockCompleteUserAuth(func(res http.ResponseWriter, req *http.Request) (goth.User, error) {
		return goth.User{
			Provider: gitlabName,
			UserID:   userGitLabUserID,
		}, nil
	})()
	req := NewRequest(t, "GET", fmt.Sprintf("/user/oauth2/%s/callback?code=XYZ&state=XYZ", gitlabName))
	resp := MakeRequest(t, req, http.StatusSeeOther)
	assert.Equal(t, test.RedirectURL(resp), "/user/link_account")
}