/*
Copyright 2023 Gravitational, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package auth

import (
	"context"
	"testing"
	"time"

	"github.com/gravitational/trace"
	"github.com/stretchr/testify/require"

	"github.com/gravitational/teleport/api/types"
	"github.com/gravitational/teleport/lib/auth/testauthority"
	"github.com/gravitational/teleport/lib/gitlab"
)

type mockGitLabTokenValidator struct {
	tokens           map[string]gitlab.IDTokenClaims
	lastCalledDomain string
}

func (m *mockGitLabTokenValidator) Validate(
	_ context.Context, domain string, token string,
) (*gitlab.IDTokenClaims, error) {
	m.lastCalledDomain = domain

	claims, ok := m.tokens[token]
	if !ok {
		return nil, errMockInvalidToken
	}

	return &claims, nil
}

func TestAuth_RegisterUsingToken_GitLab(t *testing.T) {
	validIDToken := "test.fake.jwt"
	idTokenValidator := &mockGitLabTokenValidator{
		tokens: map[string]gitlab.IDTokenClaims{
			validIDToken: {
				Sub:            "project_path:octo-org/octo-repo:ref_type:branch:ref:main",
				ProjectPath:    "octo-org/octo-repo",
				NamespacePath:  "octo-org",
				PipelineSource: "web",
				Environment:    "prod",
				UserLogin:      "octocat",
				Ref:            "main",
				RefType:        "branch",
			},
		},
	}
	var withTokenValidator ServerOption = func(server *Server) error {
		server.gitlabIDTokenValidator = idTokenValidator
		return nil
	}
	ctx := context.Background()
	p, err := newTestPack(ctx, t.TempDir(), withTokenValidator)
	require.NoError(t, err)
	auth := p.a

	// helper for creating RegisterUsingTokenRequest
	sshPrivateKey, sshPublicKey, err := testauthority.New().GenerateKeyPair()
	require.NoError(t, err)
	tlsPublicKey, err := PrivateKeyToPublicKeyTLS(sshPrivateKey)
	require.NoError(t, err)
	newRequest := func(idToken string) *types.RegisterUsingTokenRequest {
		return &types.RegisterUsingTokenRequest{
			HostID:       "host-id",
			Role:         types.RoleNode,
			IDToken:      idToken,
			PublicTLSKey: tlsPublicKey,
			PublicSSHKey: sshPublicKey,
		}
	}

	allowRule := func(modifier func(*types.ProvisionTokenSpecV2GitLab_Rule)) *types.ProvisionTokenSpecV2GitLab_Rule {
		rule := &types.ProvisionTokenSpecV2GitLab_Rule{
			Sub:            "project_path:octo-org/octo-repo:ref_type:branch:ref:main",
			ProjectPath:    "octo-org/octo-repo",
			NamespacePath:  "octo-org",
			PipelineSource: "web",
			Environment:    "prod",
			Ref:            "main",
			RefType:        "branch",
		}
		if modifier != nil {
			modifier(rule)
		}
		return rule
	}

	allowRulesNotMatched := require.ErrorAssertionFunc(func(t require.TestingT, err error, i ...interface{}) {
		require.ErrorContains(t, err, "id token claims did not match any allow rules")
		require.True(t, trace.IsAccessDenied(err))
	})
	tests := []struct {
		name        string
		request     *types.RegisterUsingTokenRequest
		tokenSpec   types.ProvisionTokenSpecV2
		assertError require.ErrorAssertionFunc
	}{
		{
			name: "success",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(nil),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: require.NoError,
		},
		{
			name: "domain override",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Domain: "gitlab.example.com",
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(nil),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: require.NoError,
		},
		{
			name: "multiple allow rules",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(func(rule *types.ProvisionTokenSpecV2GitLab_Rule) {
							rule.Sub = "not matching"
						}),
						allowRule(nil),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: require.NoError,
		},
		{
			name: "incorrect sub",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(func(rule *types.ProvisionTokenSpecV2GitLab_Rule) {
							rule.Sub = "not matching"
						}),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: allowRulesNotMatched,
		},
		{
			name: "incorrect project path",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(func(rule *types.ProvisionTokenSpecV2GitLab_Rule) {
							rule.ProjectPath = "not matching"
						}),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: allowRulesNotMatched,
		},
		{
			name: "incorrect namespace path",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(func(rule *types.ProvisionTokenSpecV2GitLab_Rule) {
							rule.NamespacePath = "not matching"
						}),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: allowRulesNotMatched,
		},
		{
			name: "incorrect pipeline source",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(func(rule *types.ProvisionTokenSpecV2GitLab_Rule) {
							rule.PipelineSource = "not matching"
						}),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: allowRulesNotMatched,
		},
		{
			name: "incorrect environment",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(func(rule *types.ProvisionTokenSpecV2GitLab_Rule) {
							rule.Environment = "not matching"
						}),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: allowRulesNotMatched,
		},
		{
			name: "incorrect ref",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(func(rule *types.ProvisionTokenSpecV2GitLab_Rule) {
							rule.Ref = "not matching"
						}),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: allowRulesNotMatched,
		},
		{
			name: "incorrect ref type",
			tokenSpec: types.ProvisionTokenSpecV2{
				JoinMethod: types.JoinMethodGitLab,
				Roles:      []types.SystemRole{types.RoleNode},
				GitLab: &types.ProvisionTokenSpecV2GitLab{
					Allow: []*types.ProvisionTokenSpecV2GitLab_Rule{
						allowRule(func(rule *types.ProvisionTokenSpecV2GitLab_Rule) {
							rule.RefType = "not matching"
						}),
					},
				},
			},
			request:     newRequest(validIDToken),
			assertError: allowRulesNotMatched,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			token, err := types.NewProvisionTokenFromSpec(
				tt.name, time.Now().Add(time.Minute), tt.tokenSpec,
			)
			require.NoError(t, err)
			require.NoError(t, auth.CreateToken(ctx, token))
			tt.request.Token = tt.name

			_, err = auth.RegisterUsingToken(ctx, tt.request)
			tt.assertError(t, err)

			if tt.tokenSpec.GitLab.Domain != "" {
				require.Equal(
					t,
					tt.tokenSpec.GitLab.Domain,
					idTokenValidator.lastCalledDomain,
				)
			}
		})
	}
}