/**
# Copyright (c) 2022, NVIDIA CORPORATION.  All rights reserved.
#
# 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 modifier

import (
	"fmt"
	"testing"

	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
	"github.com/NVIDIA/nvidia-container-toolkit/internal/discover"
	"github.com/NVIDIA/nvidia-container-toolkit/internal/oci"
	"github.com/opencontainers/runtime-spec/specs-go"
	testlog "github.com/sirupsen/logrus/hooks/test"
	"github.com/stretchr/testify/require"
)

func TestNewExperimentalModifier(t *testing.T) {
	logger, _ := testlog.NewNullLogger()

	testCases := []struct {
		description    string
		cfg            *config.Config
		spec           oci.Spec
		visibleDevices string
		expectedError  error
		expectedNil    bool
	}{
		{
			description: "spec load error returns error",
			spec: &oci.SpecMock{
				LoadFunc: func() error {
					return fmt.Errorf("load failed")
				},
			},
			expectedError: fmt.Errorf("load failed"),
		},
		{
			description:    "visible devices not set returns nil",
			visibleDevices: "NOT_SET",
			expectedNil:    true,
		},
		{
			description:    "visible devices empty returns nil",
			visibleDevices: "",
			expectedNil:    true,
		},
		{
			description:    "visible devices 'void' returns nil",
			visibleDevices: "void",
			expectedNil:    true,
		},
		{
			description: "empty config raises error",
			cfg: &config.Config{
				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{},
			},
			visibleDevices: "all",
			expectedError:  fmt.Errorf("invalid discover mode"),
		},
		{
			description: "non-legacy discover mode raises error",
			cfg: &config.Config{
				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
					DiscoverMode: "non-legacy",
				},
			},
			visibleDevices: "all",
			expectedError:  fmt.Errorf("invalid discover mode"),
		},
		{
			description: "legacy discover mode returns modifier",
			cfg: &config.Config{
				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
					DiscoverMode: "legacy",
				},
			},
			visibleDevices: "all",
		},
		{
			description: "csv discover mode returns modifier",
			cfg: &config.Config{
				NVIDIAContainerRuntimeConfig: config.RuntimeConfig{
					DiscoverMode: "csv",
				},
			},
			visibleDevices: "all",
		},
	}

	for _, tc := range testCases {
		t.Run(tc.description, func(t *testing.T) {
			spec := tc.spec
			if spec == nil {
				spec = &oci.SpecMock{
					LookupEnvFunc: func(s string) (string, bool) {
						if tc.visibleDevices != "NOT_SET" && s == visibleDevicesEnvvar {
							return tc.visibleDevices, true
						}
						return "", false
					},
				}
			}

			m, err := NewExperimentalModifier(logger, tc.cfg, spec)
			if tc.expectedError != nil {
				require.Error(t, err)
			} else {
				require.NoError(t, err)
			}

			if tc.expectedNil || tc.expectedError != nil {
				require.Nil(t, m)
			} else {
				require.NotNil(t, m)
			}
		})
	}
}

func TestExperimentalModifier(t *testing.T) {
	logger, _ := testlog.NewNullLogger()

	testCases := []struct {
		description   string
		discover      *discover.DiscoverMock
		spec          *specs.Spec
		expectedError error
		expectedSpec  *specs.Spec
	}{
		{
			description: "empty discoverer does not modify spec",
			discover:    &discover.DiscoverMock{},
		},
		{
			description: "failed hooks discoverer returns error",
			discover: &discover.DiscoverMock{
				HooksFunc: func() ([]discover.Hook, error) {
					return nil, fmt.Errorf("discover.Hooks error")
				},
			},
			expectedError: fmt.Errorf("discover.Hooks error"),
		},
		{
			description: "discovered hooks are injected into spec",
			spec:        &specs.Spec{},
			discover: &discover.DiscoverMock{
				HooksFunc: func() ([]discover.Hook, error) {
					hooks := []discover.Hook{
						{
							Lifecycle: "prestart",
							Path:      "/hook/a",
							Args:      []string{"/hook/a", "arga"},
						},
						{
							Lifecycle: "createContainer",
							Path:      "/hook/b",
							Args:      []string{"/hook/b", "argb"},
						},
					}
					return hooks, nil
				},
			},
			expectedSpec: &specs.Spec{
				Hooks: &specs.Hooks{
					Prestart: []specs.Hook{
						{
							Path: "/hook/a",
							Args: []string{"/hook/a", "arga"},
						},
					},
					CreateContainer: []specs.Hook{
						{
							Path: "/hook/b",
							Args: []string{"/hook/b", "argb"},
						},
					},
				},
			},
		},
		{
			description: "existing hooks are maintained",
			spec: &specs.Spec{
				Hooks: &specs.Hooks{
					Prestart: []specs.Hook{
						{
							Path: "/hook/a",
							Args: []string{"/hook/a", "arga"},
						},
					},
				},
			},
			discover: &discover.DiscoverMock{
				HooksFunc: func() ([]discover.Hook, error) {
					hooks := []discover.Hook{
						{
							Lifecycle: "prestart",
							Path:      "/hook/b",
							Args:      []string{"/hook/b", "argb"},
						},
					}
					return hooks, nil
				},
			},
			expectedSpec: &specs.Spec{
				Hooks: &specs.Hooks{
					Prestart: []specs.Hook{
						{
							Path: "/hook/a",
							Args: []string{"/hook/a", "arga"},
						},
						{
							Path: "/hook/b",
							Args: []string{"/hook/b", "argb"},
						},
					},
				},
			},
		},
		{
			description: "modification fails for existing nvidia-container-runtime-hook",
			spec: &specs.Spec{
				Hooks: &specs.Hooks{
					Prestart: []specs.Hook{
						{
							Path: "/path/to/nvidia-container-runtime-hook",
							Args: []string{"/path/to/nvidia-container-runtime-hook", "prestart"},
						},
					},
				},
			},
			discover: &discover.DiscoverMock{
				HooksFunc: func() ([]discover.Hook, error) {
					hooks := []discover.Hook{
						{
							Lifecycle: "prestart",
							Path:      "/hook/b",
							Args:      []string{"/hook/b", "argb"},
						},
					}
					return hooks, nil
				},
			},
			expectedError: fmt.Errorf("nvidia-container-runtime-hook already exists"),
			expectedSpec: &specs.Spec{
				Hooks: &specs.Hooks{
					Prestart: []specs.Hook{
						{
							Path: "/path/to/nvidia-container-runtime-hook",
							Args: []string{"/path/to/nvidia-container-runtime-hook", "prestart"},
						},
					},
				},
			},
		},
		{
			description: "modification fails for existing nvidia-container-toolkit",
			spec: &specs.Spec{
				Hooks: &specs.Hooks{
					Prestart: []specs.Hook{
						{
							Path: "/path/to/nvidia-container-toolkit",
							Args: []string{"/path/to/nvidia-container-toolkit", "prestart"},
						},
					},
				},
			},
			discover: &discover.DiscoverMock{
				HooksFunc: func() ([]discover.Hook, error) {
					hooks := []discover.Hook{
						{
							Lifecycle: "prestart",
							Path:      "/hook/b",
							Args:      []string{"/hook/b", "argb"},
						},
					}
					return hooks, nil
				},
			},
			expectedError: fmt.Errorf("nvidia-container-toolkit already exists"),
			expectedSpec: &specs.Spec{
				Hooks: &specs.Hooks{
					Prestart: []specs.Hook{
						{
							Path: "/path/to/nvidia-container-toolkit",
							Args: []string{"/path/to/nvidia-container-toolkit", "prestart"},
						},
					},
				},
			},
		},
	}

	for _, tc := range testCases {
		t.Run(tc.description, func(t *testing.T) {
			m, err := newExperimentalModifierFromDiscoverer(logger, tc.discover)
			require.NoError(t, err)

			err = m.Modify(tc.spec)
			if tc.expectedError != nil {
				require.Error(t, err)
			} else {
				require.NoError(t, err)
			}

			require.EqualValues(t, tc.expectedSpec, tc.spec)
		})
	}
}

func TestResolveDiscoverMode(t *testing.T) {
	logger, _ := testlog.NewNullLogger()

	testCases := []struct {
		description  string
		mode         string
		expectedMode string
	}{
		{
			description:  "non-auto resolves to input",
			mode:         "not-auto",
			expectedMode: "not-auto",
		},
		// TODO: The following test is brittle in that it will break on Tegra-based systems.
		// {
		// 	description:  "auto resolves to legacy",
		// 	mode:         "auto",
		// 	expectedMode: "legacy",
		// },
	}

	for _, tc := range testCases {
		t.Run(tc.description, func(t *testing.T) {
			mode := resolveAutoDiscoverMode(logger, tc.mode)
			require.EqualValues(t, tc.expectedMode, mode)
		})
	}
}