package db

import (
	"context"
	"encoding/json"
	"errors"
	"io/ioutil"
	"os"
	"testing"
	"time"

	"github.com/aquasecurity/trivy/pkg/github"
	"github.com/aquasecurity/trivy/pkg/indicator"

	"github.com/spf13/afero"

	"github.com/stretchr/testify/require"

	"golang.org/x/xerrors"

	"k8s.io/utils/clock"
	clocktesting "k8s.io/utils/clock/testing"

	"github.com/aquasecurity/trivy-db/pkg/db"
	"github.com/stretchr/testify/assert"
)

func TestClient_NeedsUpdate(t *testing.T) {
	timeNextUpdateDay1 := time.Date(2019, 9, 1, 0, 0, 0, 0, time.UTC)
	timeNextUpdateDay2 := time.Date(2019, 10, 2, 0, 0, 0, 0, time.UTC)

	testCases := []struct {
		name          string
		light         bool
		skip          bool
		clock         clock.Clock
		metadata      db.Metadata
		expected      bool
		expectedError error
	}{
		{
			name:  "happy path",
			light: false,
			clock: clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{
				Version:    1,
				Type:       db.TypeFull,
				NextUpdate: timeNextUpdateDay1,
			},
			expected: true,
		},
		{
			name:     "happy path for first run",
			light:    false,
			clock:    clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{},
			expected: true,
		},
		{
			name:  "happy path with different type",
			light: true,
			clock: clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{
				Version:    1,
				Type:       db.TypeFull,
				NextUpdate: timeNextUpdateDay1,
			},
			expected: true,
		},
		{
			name:  "happy path with old schema version",
			light: true,
			clock: clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{
				Version:    0,
				Type:       db.TypeFull,
				NextUpdate: timeNextUpdateDay1,
			},
			expected: true,
		},
		{
			name:  "happy path with --skip-update",
			light: false,
			clock: clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{
				Version:    1,
				Type:       db.TypeFull,
				NextUpdate: timeNextUpdateDay1,
			},
			skip:     true,
			expected: false,
		},
		{
			name:  "skip downloading DB",
			light: false,
			clock: clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{
				Version:    1,
				Type:       db.TypeFull,
				NextUpdate: timeNextUpdateDay2,
			},
			expected: false,
		},
		{
			name:  "newer schema version",
			light: false,
			clock: clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{
				Version:    2,
				Type:       db.TypeFull,
				NextUpdate: timeNextUpdateDay2,
			},
			expectedError: xerrors.New("the version of DB schema doesn't match. Local DB: 2, Expected: 1"),
		},
		{
			name:          "--skip-update on the first run",
			light:         false,
			clock:         clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata:      db.Metadata{},
			skip:          true,
			expectedError: xerrors.New("--skip-update cannot be specified on the first run"),
		},
		{
			name:  "--skip-update with different schema version",
			light: false,
			clock: clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{
				Version:    0,
				Type:       db.TypeFull,
				NextUpdate: timeNextUpdateDay1,
			},
			skip:          true,
			expectedError: xerrors.New("--skip-update cannot be specified with the old DB"),
		},
		{
			name:  "happy with old DownloadedAt",
			light: false,
			clock: clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{
				Version:      1,
				Type:         db.TypeFull,
				NextUpdate:   timeNextUpdateDay1,
				DownloadedAt: time.Date(2019, 9, 30, 22, 30, 0, 0, time.UTC),
			},
			expected: true,
		},
		{
			name:  "skip downloading DB with recent DownloadedAt",
			light: false,
			clock: clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC)),
			metadata: db.Metadata{
				Version:      1,
				Type:         db.TypeFull,
				NextUpdate:   timeNextUpdateDay1,
				DownloadedAt: time.Date(2019, 9, 30, 23, 30, 0, 0, time.UTC),
			},
			expected: false,
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			fs := afero.NewMemMapFs()
			metadata := NewMetadata(fs, "/cache")
			if tc.metadata != (db.Metadata{}) {
				b, err := json.Marshal(tc.metadata)
				require.NoError(t, err)
				err = afero.WriteFile(fs, metadata.filePath, b, 0600)
				require.NoError(t, err)
			}

			client := Client{
				clock:    tc.clock,
				metadata: metadata,
			}

			needsUpdate, err := client.NeedsUpdate("test", tc.light, tc.skip)

			switch {
			case tc.expectedError != nil:
				assert.EqualError(t, err, tc.expectedError.Error(), tc.name)
			default:
				assert.NoError(t, err, tc.name)
			}

			assert.Equal(t, tc.expected, needsUpdate)
		})
	}
}

func TestClient_Download(t *testing.T) {
	testCases := []struct {
		name            string
		light           bool
		downloadDB      []github.DownloadDBExpectation
		expectedContent []byte
		expectedError   error
	}{
		{
			name:  "happy path",
			light: false,
			downloadDB: []github.DownloadDBExpectation{
				{
					Args: github.DownloadDBInput{FileName: fullDB},
					ReturnArgs: github.DownloadDBOutput{
						FileName: "testdata/test.db.gz",
					},
				},
			},
		},
		{
			name:  "DownloadDB returns an error",
			light: false,
			downloadDB: []github.DownloadDBExpectation{
				{
					Args: github.DownloadDBInput{FileName: fullDB},
					ReturnArgs: github.DownloadDBOutput{
						Err: xerrors.New("download failed"),
					},
				},
			},
			expectedError: xerrors.New("failed to download vulnerability DB: download failed"),
		},
		{
			name:  "invalid gzip",
			light: false,
			downloadDB: []github.DownloadDBExpectation{
				{
					Args: github.DownloadDBInput{FileName: fullDB},
					ReturnArgs: github.DownloadDBOutput{
						FileName: "testdata/invalid.db.gz",
					},
				},
			},
			expectedError: xerrors.New("invalid gzip file: unexpected EOF"),
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			mockConfig := new(mockDbOperation)

			mockGitHubClient, err := github.NewMockClient(tc.downloadDB)
			require.NoError(t, err, tc.name)

			fs := afero.NewMemMapFs()
			metadata := NewMetadata(fs, "/cache")

			dir, err := ioutil.TempDir("", "db")
			require.NoError(t, err, tc.name)
			defer os.RemoveAll(dir)

			pb := indicator.NewProgressBar(true)
			client := NewClient(mockConfig, mockGitHubClient, pb, nil, metadata)
			ctx := context.Background()
			err = client.Download(ctx, dir, tc.light)

			switch {
			case tc.expectedError != nil:
				assert.EqualError(t, err, tc.expectedError.Error(), tc.name)
			default:
				assert.NoError(t, err, tc.name)
			}

			mockGitHubClient.AssertExpectations(t)
		})
	}
}

func TestClient_UpdateMetadata(t *testing.T) {
	timeDownloadedAt := clocktesting.NewFakeClock(time.Date(2019, 10, 1, 0, 0, 0, 0, time.UTC))
	testCases := []struct {
		name                     string
		clock                    clock.Clock
		getMetadataExpectation   dbOperationGetMetadataExpectation
		storeMetadataExpectation dbOperationStoreMetadataExpectation
		expectedError            error
	}{
		{
			name:  "happy path",
			clock: timeDownloadedAt,
			getMetadataExpectation: dbOperationGetMetadataExpectation{
				Returns: dbOperationGetMetadataReturns{
					Metadata: db.Metadata{
						Version:    1,
						Type:       1,
						NextUpdate: time.Date(2020, 4, 30, 23, 59, 59, 0, time.UTC),
						UpdatedAt:  time.Date(2006, 4, 30, 23, 59, 59, 0, time.UTC),
					},
					Err: nil,
				},
			},
			storeMetadataExpectation: dbOperationStoreMetadataExpectation{
				Metadata: db.Metadata{
					Version:      1,
					Type:         1,
					NextUpdate:   time.Date(2020, 4, 30, 23, 59, 59, 0, time.UTC),
					UpdatedAt:    time.Date(2006, 4, 30, 23, 59, 59, 0, time.UTC),
					DownloadedAt: timeDownloadedAt.Now(),
				},
			},
		},
		{
			name:  "sad path, get metadata fails",
			clock: timeDownloadedAt,
			getMetadataExpectation: dbOperationGetMetadataExpectation{
				Returns: dbOperationGetMetadataReturns{
					Err: errors.New("get metadata failed"),
				},
			},
			expectedError: errors.New("unable to get metadata: get metadata failed"),
		},
		{
			name:  "sad path, store metadata fails",
			clock: timeDownloadedAt,
			getMetadataExpectation: dbOperationGetMetadataExpectation{
				Returns: dbOperationGetMetadataReturns{
					Metadata: db.Metadata{
						Version:    1,
						Type:       1,
						NextUpdate: time.Date(2020, 4, 30, 23, 59, 59, 0, time.UTC),
						UpdatedAt:  time.Date(2006, 4, 30, 23, 59, 59, 0, time.UTC),
					},
					Err: nil,
				},
			},
			storeMetadataExpectation: dbOperationStoreMetadataExpectation{
				Metadata: db.Metadata{
					Version:      1,
					Type:         1,
					NextUpdate:   time.Date(2020, 4, 30, 23, 59, 59, 0, time.UTC),
					UpdatedAt:    time.Date(2006, 4, 30, 23, 59, 59, 0, time.UTC),
					DownloadedAt: timeDownloadedAt.Now(),
				},
				Returns: dbOperationStoreMetadataReturns{
					Err: errors.New("store metadata failed"),
				},
			},
			expectedError: errors.New("failed to store metadata: store metadata failed"),
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			mockConfig := new(mockDbOperation)
			mockConfig.ApplyGetMetadataExpectation(tc.getMetadataExpectation)
			mockConfig.ApplyStoreMetadataExpectation(tc.storeMetadataExpectation)

			fs := afero.NewMemMapFs()
			metadata := NewMetadata(fs, "/cache")

			dir, err := ioutil.TempDir("", "db")
			require.NoError(t, err, tc.name)
			defer os.RemoveAll(dir)

			pb := indicator.NewProgressBar(true)
			client := NewClient(mockConfig, nil, pb, tc.clock, metadata)

			err = client.UpdateMetadata(dir)
			switch {
			case tc.expectedError != nil:
				assert.EqualError(t, err, tc.expectedError.Error(), tc.name)
			default:
				assert.NoError(t, err, tc.name)
			}
		})
	}
}