// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: MIT

package host

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.opentelemetry.io/collector/component"
	"go.opentelemetry.io/collector/confmap"

	"github.com/aws/amazon-cloudwatch-agent/internal/util/collections"
	"github.com/aws/amazon-cloudwatch-agent/translator/translate/otel/common"
)

type testTranslator struct {
	id component.ID
}

var _ common.Translator[component.Config] = (*testTranslator)(nil)

func (t testTranslator) Translate(_ *confmap.Conf) (component.Config, error) {
	return nil, nil
}

func (t testTranslator) ID() component.ID {
	return t.id
}

func TestTranslator(t *testing.T) {
	type want struct {
		pipelineID string
		receivers  []string
		processors []string
		exporters  []string
	}
	testCases := map[string]struct {
		input        map[string]interface{}
		pipelineName string
		want         *want
		wantErr      error
	}{
		"WithoutMetricsKey": {
			input:        map[string]interface{}{},
			pipelineName: common.PipelineNameHost,
			wantErr: &common.MissingKeyError{
				ID:      component.NewIDWithName(component.DataTypeMetrics, common.PipelineNameHost),
				JsonKey: common.MetricsKey,
			},
		},
		"WithMetricsKey": {
			input: map[string]interface{}{
				"metrics": map[string]interface{}{},
			},
			pipelineName: common.PipelineNameHost,
			want: &want{
				pipelineID: "metrics/host",
				receivers:  []string{"nop", "other"},
				processors: []string{},
				exporters:  []string{"awscloudwatch"},
			},
		},
		"WithMetricsKeyNet": {
			input: map[string]interface{}{
				"metrics": map[string]interface{}{
					"metrics_collected": map[string]interface{}{
						"net": map[string]interface{}{},
					},
				},
			},
			pipelineName: common.PipelineNameHostDeltaMetrics,
			want: &want{
				pipelineID: "metrics/hostDeltaMetrics",
				receivers:  []string{"nop", "other"},
				processors: []string{"cumulativetodelta/hostDeltaMetrics"},
				exporters:  []string{"awscloudwatch"},
			},
		},
		"WithMetricDecoration": {
			input: map[string]interface{}{
				"metrics": map[string]interface{}{
					"metrics_collected": map[string]interface{}{
						"cpu": map[string]interface{}{
							"measurement": []interface{}{
								map[string]interface{}{
									"name":   "cpu_usage_idle",
									"rename": "CPU_USAGE_IDLE",
								},
							},
						},
					},
				},
			},
			pipelineName: common.PipelineNameHost,
			want: &want{
				pipelineID: "metrics/host",
				receivers:  []string{"nop", "other"},
				processors: []string{"transform"},
				exporters:  []string{"awscloudwatch"},
			},
		},
		"WithoutMetricDecoration": {
			input: map[string]interface{}{
				"metrics": map[string]interface{}{
					"metrics_collected": map[string]interface{}{
						"cpu": map[string]interface{}{
							"measurement": []interface{}{
								"cpu_usage_guest",
							},
						},
					},
				},
			},
			pipelineName: common.PipelineNameHost,
			want: &want{
				pipelineID: "metrics/host",
				receivers:  []string{"nop", "other"},
				processors: []string{},
				exporters:  []string{"awscloudwatch"},
			},
		},
	}
	for name, testCase := range testCases {
		t.Run(name, func(t *testing.T) {
			ht := NewTranslator(testCase.pipelineName, common.NewTranslatorMap[component.Config](
				&testTranslator{id: component.NewID("nop")},
				&testTranslator{id: component.NewID("other")},
			))
			conf := confmap.NewFromStringMap(testCase.input)
			got, err := ht.Translate(conf)
			require.Equal(t, testCase.wantErr, err)
			if testCase.want == nil {
				require.Nil(t, got)
			} else {
				require.NotNil(t, got)
				require.EqualValues(t, testCase.want.pipelineID, ht.ID().String())
				assert.Equal(t, testCase.want.receivers, collections.MapSlice(got.Receivers.Keys(), component.ID.String))
				assert.Equal(t, testCase.want.processors, collections.MapSlice(got.Processors.Keys(), component.ID.String))
				assert.Equal(t, testCase.want.exporters, collections.MapSlice(got.Exporters.Keys(), component.ID.String))
			}
		})
	}
}