// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

package obsconsumer_test

import (
	"context"
	"errors"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.opentelemetry.io/otel/attribute"
	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
	"go.opentelemetry.io/otel/sdk/metric/metricdata"

	"go.opentelemetry.io/collector/consumer"
	"go.opentelemetry.io/collector/consumer/consumererror"
	"go.opentelemetry.io/collector/consumer/consumertest"
	"go.opentelemetry.io/collector/pdata/ptrace"
	"go.opentelemetry.io/collector/service/internal/obsconsumer"
)

type mockTracesConsumer struct {
	err          error
	capabilities consumer.Capabilities
}

func (m *mockTracesConsumer) ConsumeTraces(_ context.Context, _ ptrace.Traces) error {
	return m.err
}

func (m *mockTracesConsumer) Capabilities() consumer.Capabilities {
	return m.capabilities
}

func TestTracesNopWhenGateDisabled(t *testing.T) {
	setGateForTest(t, false)

	mp := sdkmetric.NewMeterProvider()
	meter := mp.Meter("test")
	itemCounter, err := meter.Int64Counter("item_counter")
	require.NoError(t, err)
	sizeCounter, err := meter.Int64Counter("size_counter")
	require.NoError(t, err)

	cons := consumertest.NewNop()
	require.Equal(t, cons, obsconsumer.NewTraces(cons, itemCounter, sizeCounter))
}

func TestTracesItemsOnly(t *testing.T) {
	setGateForTest(t, true)

	ctx := context.Background()
	mockConsumer := &mockTracesConsumer{}

	reader := sdkmetric.NewManualReader()
	mp := sdkmetric.NewMeterProvider(sdkmetric.WithReader(reader))
	meter := mp.Meter("test")

	itemCounter, err := meter.Int64Counter("item_counter")
	require.NoError(t, err)
	sizeCounter, err := meter.Int64Counter("size_counter")
	require.NoError(t, err)
	sizeCounterDisabled := newDisabledCounter(sizeCounter)

	consumer := obsconsumer.NewTraces(mockConsumer, itemCounter, sizeCounterDisabled)

	td := ptrace.NewTraces()
	r := td.ResourceSpans().AppendEmpty()
	ss := r.ScopeSpans().AppendEmpty()
	ss.Spans().AppendEmpty()

	err = consumer.ConsumeTraces(ctx, td)
	require.NoError(t, err)

	var metrics metricdata.ResourceMetrics
	err = reader.Collect(ctx, &metrics)
	require.NoError(t, err)
	require.Len(t, metrics.ScopeMetrics, 1)
	require.Len(t, metrics.ScopeMetrics[0].Metrics, 1)

	metric := metrics.ScopeMetrics[0].Metrics[0]
	require.Equal(t, "item_counter", metric.Name)

	data := metric.Data.(metricdata.Sum[int64])
	require.Len(t, data.DataPoints, 1)
	require.Equal(t, int64(1), data.DataPoints[0].Value)

	attrs := data.DataPoints[0].Attributes
	require.Equal(t, 1, attrs.Len())
	val, ok := attrs.Value(attribute.Key(obsconsumer.ComponentOutcome))
	require.True(t, ok)
	require.Equal(t, "success", val.Emit())
}

func TestTracesConsumeSuccess(t *testing.T) {
	setGateForTest(t, true)

	ctx := context.Background()
	mockConsumer := &mockTracesConsumer{}

	reader := sdkmetric.NewManualReader()
	mp := sdkmetric.NewMeterProvider(sdkmetric.WithReader(reader))
	meter := mp.Meter("test")

	itemCounter, err := meter.Int64Counter("item_counter")
	require.NoError(t, err)
	sizeCounter, err := meter.Int64Counter("size_counter")
	require.NoError(t, err)

	consumer := obsconsumer.NewTraces(mockConsumer, itemCounter, sizeCounter)

	td := ptrace.NewTraces()
	r := td.ResourceSpans().AppendEmpty()
	ss := r.ScopeSpans().AppendEmpty()
	ss.Spans().AppendEmpty()

	err = consumer.ConsumeTraces(ctx, td)
	require.NoError(t, err)

	var rm metricdata.ResourceMetrics
	err = reader.Collect(ctx, &rm)
	require.NoError(t, err)
	require.Len(t, rm.ScopeMetrics, 1)
	require.Len(t, rm.ScopeMetrics[0].Metrics, 2)

	var itemMetric, sizeMetric metricdata.Metrics
	for _, m := range rm.ScopeMetrics[0].Metrics {
		switch m.Name {
		case "item_counter":
			itemMetric = m
		case "size_counter":
			sizeMetric = m
		}
	}
	require.NotNil(t, itemMetric)
	require.NotNil(t, sizeMetric)

	itemData := itemMetric.Data.(metricdata.Sum[int64])
	require.Len(t, itemData.DataPoints, 1)
	require.Equal(t, int64(1), itemData.DataPoints[0].Value)

	itemAttrs := itemData.DataPoints[0].Attributes
	require.Equal(t, 1, itemAttrs.Len())
	val, ok := itemAttrs.Value(attribute.Key(obsconsumer.ComponentOutcome))
	require.True(t, ok)
	require.Equal(t, "success", val.Emit())

	sizeData := sizeMetric.Data.(metricdata.Sum[int64])
	require.Len(t, sizeData.DataPoints, 1)
	require.Positive(t, sizeData.DataPoints[0].Value)

	sizeAttrs := sizeData.DataPoints[0].Attributes
	require.Equal(t, 1, sizeAttrs.Len())
	val, ok = sizeAttrs.Value(attribute.Key(obsconsumer.ComponentOutcome))
	require.True(t, ok)
	require.Equal(t, "success", val.Emit())
}

func TestTracesConsumeFailure(t *testing.T) {
	setGateForTest(t, true)

	ctx := context.Background()
	expectedErr := errors.New("test error")
	downstreamErr := consumererror.NewDownstream(expectedErr)
	mockConsumer := &mockTracesConsumer{err: expectedErr}

	reader := sdkmetric.NewManualReader()
	mp := sdkmetric.NewMeterProvider(sdkmetric.WithReader(reader))
	meter := mp.Meter("test")

	itemCounter, err := meter.Int64Counter("item_counter")
	require.NoError(t, err)
	sizeCounter, err := meter.Int64Counter("size_counter")
	require.NoError(t, err)

	consumer := obsconsumer.NewTraces(mockConsumer, itemCounter, sizeCounter)

	td := ptrace.NewTraces()
	r := td.ResourceSpans().AppendEmpty()
	ss := r.ScopeSpans().AppendEmpty()
	ss.Spans().AppendEmpty()

	err = consumer.ConsumeTraces(ctx, td)
	assert.Equal(t, downstreamErr, err)

	var rm metricdata.ResourceMetrics
	err = reader.Collect(ctx, &rm)
	require.NoError(t, err)
	require.Len(t, rm.ScopeMetrics, 1)
	require.Len(t, rm.ScopeMetrics[0].Metrics, 2)

	var itemMetric, sizeMetric metricdata.Metrics
	for _, m := range rm.ScopeMetrics[0].Metrics {
		switch m.Name {
		case "item_counter":
			itemMetric = m
		case "size_counter":
			sizeMetric = m
		}
	}
	require.NotNil(t, itemMetric)
	require.NotNil(t, sizeMetric)

	itemData := itemMetric.Data.(metricdata.Sum[int64])
	require.Len(t, itemData.DataPoints, 1)
	require.Equal(t, int64(1), itemData.DataPoints[0].Value)

	itemAttrs := itemData.DataPoints[0].Attributes
	require.Equal(t, 1, itemAttrs.Len())
	val, ok := itemAttrs.Value(attribute.Key(obsconsumer.ComponentOutcome))
	require.True(t, ok)
	require.Equal(t, "failure", val.Emit())

	sizeData := sizeMetric.Data.(metricdata.Sum[int64])
	require.Len(t, sizeData.DataPoints, 1)
	require.Positive(t, sizeData.DataPoints[0].Value)

	sizeAttrs := sizeData.DataPoints[0].Attributes
	require.Equal(t, 1, sizeAttrs.Len())
	val, ok = sizeAttrs.Value(attribute.Key(obsconsumer.ComponentOutcome))
	require.True(t, ok)
	require.Equal(t, "failure", val.Emit())
}

func TestTracesWithStaticAttributes(t *testing.T) {
	setGateForTest(t, true)

	ctx := context.Background()
	mockConsumer := &mockTracesConsumer{}

	reader := sdkmetric.NewManualReader()
	mp := sdkmetric.NewMeterProvider(sdkmetric.WithReader(reader))
	meter := mp.Meter("test")

	itemCounter, err := meter.Int64Counter("item_counter")
	require.NoError(t, err)
	sizeCounter, err := meter.Int64Counter("size_counter")
	require.NoError(t, err)

	staticAttr := attribute.String("test", "value")
	consumer := obsconsumer.NewTraces(mockConsumer, itemCounter, sizeCounter,
		obsconsumer.WithStaticDataPointAttribute(staticAttr))

	td := ptrace.NewTraces()
	r := td.ResourceSpans().AppendEmpty()
	ss := r.ScopeSpans().AppendEmpty()
	ss.Spans().AppendEmpty()

	err = consumer.ConsumeTraces(ctx, td)
	require.NoError(t, err)

	var rm metricdata.ResourceMetrics
	err = reader.Collect(ctx, &rm)
	require.NoError(t, err)
	require.Len(t, rm.ScopeMetrics, 1)
	require.Len(t, rm.ScopeMetrics[0].Metrics, 2)

	var itemMetric, sizeMetric metricdata.Metrics
	for _, m := range rm.ScopeMetrics[0].Metrics {
		switch m.Name {
		case "item_counter":
			itemMetric = m
		case "size_counter":
			sizeMetric = m
		}
	}
	require.NotNil(t, itemMetric)
	require.NotNil(t, sizeMetric)

	itemData := itemMetric.Data.(metricdata.Sum[int64])
	require.Len(t, itemData.DataPoints, 1)
	require.Equal(t, int64(1), itemData.DataPoints[0].Value)

	itemAttrs := itemData.DataPoints[0].Attributes
	require.Equal(t, 2, itemAttrs.Len())
	val, ok := itemAttrs.Value(attribute.Key("test"))
	require.True(t, ok)
	require.Equal(t, "value", val.Emit())
	val, ok = itemAttrs.Value(attribute.Key(obsconsumer.ComponentOutcome))
	require.True(t, ok)
	require.Equal(t, "success", val.Emit())

	sizeData := sizeMetric.Data.(metricdata.Sum[int64])
	require.Len(t, sizeData.DataPoints, 1)
	require.Positive(t, sizeData.DataPoints[0].Value)

	sizeAttrs := sizeData.DataPoints[0].Attributes
	require.Equal(t, 2, sizeAttrs.Len())
	val, ok = sizeAttrs.Value(attribute.Key("test"))
	require.True(t, ok)
	require.Equal(t, "value", val.Emit())
	val, ok = sizeAttrs.Value(attribute.Key(obsconsumer.ComponentOutcome))
	require.True(t, ok)
	require.Equal(t, "success", val.Emit())
}

func TestTracesMultipleItemsMixedOutcomes(t *testing.T) {
	setGateForTest(t, true)

	ctx := context.Background()
	expectedErr := errors.New("test error")
	downstreamErr := consumererror.NewDownstream(expectedErr)
	mockConsumer := &mockTracesConsumer{}

	reader := sdkmetric.NewManualReader()
	mp := sdkmetric.NewMeterProvider(sdkmetric.WithReader(reader))
	meter := mp.Meter("test")

	itemCounter, err := meter.Int64Counter("item_counter")
	require.NoError(t, err)
	sizeCounter, err := meter.Int64Counter("size_counter")
	require.NoError(t, err)

	consumer := obsconsumer.NewTraces(mockConsumer, itemCounter, sizeCounter)

	// First batch: 2 successful items
	td1 := ptrace.NewTraces()
	for range 2 {
		r := td1.ResourceSpans().AppendEmpty()
		ss := r.ScopeSpans().AppendEmpty()
		ss.Spans().AppendEmpty()
	}
	err = consumer.ConsumeTraces(ctx, td1)
	require.NoError(t, err)

	// Second batch: 1 failed item
	mockConsumer.err = expectedErr
	td2 := ptrace.NewTraces()
	r := td2.ResourceSpans().AppendEmpty()
	ss := r.ScopeSpans().AppendEmpty()
	ss.Spans().AppendEmpty()
	err = consumer.ConsumeTraces(ctx, td2)
	assert.Equal(t, downstreamErr, err)

	// Third batch: 2 successful items
	mockConsumer.err = nil
	td3 := ptrace.NewTraces()
	for range 2 {
		r = td3.ResourceSpans().AppendEmpty()
		ss = r.ScopeSpans().AppendEmpty()
		ss.Spans().AppendEmpty()
	}
	err = consumer.ConsumeTraces(ctx, td3)
	require.NoError(t, err)

	// Fourth batch: 1 failed item
	mockConsumer.err = expectedErr
	td4 := ptrace.NewTraces()
	r = td4.ResourceSpans().AppendEmpty()
	ss = r.ScopeSpans().AppendEmpty()
	ss.Spans().AppendEmpty()
	err = consumer.ConsumeTraces(ctx, td4)
	assert.Equal(t, downstreamErr, err)

	var rm metricdata.ResourceMetrics
	err = reader.Collect(ctx, &rm)
	require.NoError(t, err)
	require.Len(t, rm.ScopeMetrics, 1)
	require.Len(t, rm.ScopeMetrics[0].Metrics, 2)

	var itemMetric, sizeMetric metricdata.Metrics
	for _, m := range rm.ScopeMetrics[0].Metrics {
		switch m.Name {
		case "item_counter":
			itemMetric = m
		case "size_counter":
			sizeMetric = m
		}
	}
	require.NotNil(t, itemMetric)
	require.NotNil(t, sizeMetric)

	itemData := itemMetric.Data.(metricdata.Sum[int64])
	require.Len(t, itemData.DataPoints, 2)
	sizeData := sizeMetric.Data.(metricdata.Sum[int64])
	require.Len(t, sizeData.DataPoints, 2)

	// Find success and failure data points
	var successDP, failureDP metricdata.DataPoint[int64]
	for _, dp := range itemData.DataPoints {
		val, ok := dp.Attributes.Value(attribute.Key(obsconsumer.ComponentOutcome))
		if ok && val.Emit() == "success" {
			successDP = dp
		} else {
			failureDP = dp
		}
	}
	require.Equal(t, int64(4), successDP.Value)
	require.Equal(t, int64(2), failureDP.Value)

	var successSizeDP, failureSizeDP metricdata.DataPoint[int64]
	for _, dp := range sizeData.DataPoints {
		val, ok := dp.Attributes.Value(attribute.Key(obsconsumer.ComponentOutcome))
		if ok && val.Emit() == "success" {
			successSizeDP = dp
		} else {
			failureSizeDP = dp
		}
	}
	require.Equal(t, int64(72), successSizeDP.Value)
	require.Equal(t, int64(36), failureSizeDP.Value)
}

func TestTracesCapabilities(t *testing.T) {
	setGateForTest(t, true)

	mockConsumer := &mockTracesConsumer{
		capabilities: consumer.Capabilities{MutatesData: true},
	}
	reader := sdkmetric.NewManualReader()
	mp := sdkmetric.NewMeterProvider(sdkmetric.WithReader(reader))
	meter := mp.Meter("test")

	itemCounter, err := meter.Int64Counter("item_counter")
	require.NoError(t, err)
	sizeCounter, err := meter.Int64Counter("size_counter")
	require.NoError(t, err)
	sizeCounterDisabled := newDisabledCounter(sizeCounter)

	// Test with item counter only
	consumer := obsconsumer.NewTraces(mockConsumer, itemCounter, sizeCounterDisabled)
	require.Equal(t, consumer.Capabilities(), mockConsumer.capabilities)

	// Test with both counters
	consumer = obsconsumer.NewTraces(mockConsumer, itemCounter, sizeCounter)
	require.Equal(t, consumer.Capabilities(), mockConsumer.capabilities)
}
