// Copyright The OpenTelemetry Authors
//
// 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 otlpmetricgrpc

import (
	"context"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"google.golang.org/genproto/googleapis/rpc/errdetails"
	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
	"google.golang.org/protobuf/types/known/durationpb"

	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric"
	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/otest"
	"go.opentelemetry.io/otel/sdk/metric"
	"go.opentelemetry.io/otel/sdk/metric/metricdata"
)

func TestThrottleDuration(t *testing.T) {
	c := codes.ResourceExhausted
	testcases := []struct {
		status   *status.Status
		expected time.Duration
	}{
		{
			status:   status.New(c, "NoRetryInfo"),
			expected: 0,
		},
		{
			status: func() *status.Status {
				s, err := status.New(c, "SingleRetryInfo").WithDetails(
					&errdetails.RetryInfo{
						RetryDelay: durationpb.New(15 * time.Millisecond),
					},
				)
				require.NoError(t, err)
				return s
			}(),
			expected: 15 * time.Millisecond,
		},
		{
			status: func() *status.Status {
				s, err := status.New(c, "ErrorInfo").WithDetails(
					&errdetails.ErrorInfo{Reason: "no throttle detail"},
				)
				require.NoError(t, err)
				return s
			}(),
			expected: 0,
		},
		{
			status: func() *status.Status {
				s, err := status.New(c, "ErrorAndRetryInfo").WithDetails(
					&errdetails.ErrorInfo{Reason: "with throttle detail"},
					&errdetails.RetryInfo{
						RetryDelay: durationpb.New(13 * time.Minute),
					},
				)
				require.NoError(t, err)
				return s
			}(),
			expected: 13 * time.Minute,
		},
		{
			status: func() *status.Status {
				s, err := status.New(c, "DoubleRetryInfo").WithDetails(
					&errdetails.RetryInfo{
						RetryDelay: durationpb.New(13 * time.Minute),
					},
					&errdetails.RetryInfo{
						RetryDelay: durationpb.New(15 * time.Minute),
					},
				)
				require.NoError(t, err)
				return s
			}(),
			expected: 13 * time.Minute,
		},
	}

	for _, tc := range testcases {
		t.Run(tc.status.Message(), func(t *testing.T) {
			require.Equal(t, tc.expected, throttleDelay(tc.status))
		})
	}
}

func TestRetryable(t *testing.T) {
	retryableCodes := map[codes.Code]bool{
		codes.OK:                 false,
		codes.Canceled:           true,
		codes.Unknown:            false,
		codes.InvalidArgument:    false,
		codes.DeadlineExceeded:   true,
		codes.NotFound:           false,
		codes.AlreadyExists:      false,
		codes.PermissionDenied:   false,
		codes.ResourceExhausted:  true,
		codes.FailedPrecondition: false,
		codes.Aborted:            true,
		codes.OutOfRange:         true,
		codes.Unimplemented:      false,
		codes.Internal:           false,
		codes.Unavailable:        true,
		codes.DataLoss:           true,
		codes.Unauthenticated:    false,
	}

	for c, want := range retryableCodes {
		got, _ := retryable(status.Error(c, ""))
		assert.Equalf(t, want, got, "evaluate(%s)", c)
	}
}

func TestClient(t *testing.T) {
	factory := func(rCh <-chan otest.ExportResult) (otlpmetric.Client, otest.Collector) {
		coll, err := otest.NewGRPCCollector("", rCh)
		require.NoError(t, err)

		ctx := context.Background()
		addr := coll.Addr().String()
		client, err := newClient(ctx, WithEndpoint(addr), WithInsecure())
		require.NoError(t, err)
		return client, coll
	}

	t.Run("Integration", otest.RunClientTests(factory))
}

func TestConfig(t *testing.T) {
	factoryFunc := func(rCh <-chan otest.ExportResult, o ...Option) (metric.Exporter, *otest.GRPCCollector) {
		coll, err := otest.NewGRPCCollector("", rCh)
		require.NoError(t, err)

		ctx := context.Background()
		opts := append([]Option{
			WithEndpoint(coll.Addr().String()),
			WithInsecure(),
		}, o...)
		exp, err := New(ctx, opts...)
		require.NoError(t, err)
		return exp, coll
	}

	t.Run("WithHeaders", func(t *testing.T) {
		key := "my-custom-header"
		headers := map[string]string{key: "custom-value"}
		exp, coll := factoryFunc(nil, WithHeaders(headers))
		t.Cleanup(coll.Shutdown)
		ctx := context.Background()
		require.NoError(t, exp.Export(ctx, metricdata.ResourceMetrics{}))
		// Ensure everything is flushed.
		require.NoError(t, exp.Shutdown(ctx))

		got := coll.Headers()
		require.Regexp(t, "OTel OTLP Exporter Go/1\\..*", got)
		require.Contains(t, got, key)
		assert.Equal(t, got[key], []string{headers[key]})
	})

	t.Run("WithTimeout", func(t *testing.T) {
		// Do not send on rCh so the Collector never responds to the client.
		rCh := make(chan otest.ExportResult)
		t.Cleanup(func() { close(rCh) })
		exp, coll := factoryFunc(
			rCh,
			WithTimeout(time.Millisecond),
			WithRetry(RetryConfig{Enabled: false}),
		)
		t.Cleanup(coll.Shutdown)
		ctx := context.Background()
		t.Cleanup(func() { require.NoError(t, exp.Shutdown(ctx)) })
		err := exp.Export(ctx, metricdata.ResourceMetrics{})
		assert.ErrorContains(t, err, context.DeadlineExceeded.Error())
	})

	t.Run("WithCustomUserAgent", func(t *testing.T) {
		key := "user-agent"
		customerUserAgent := "custom-user-agent"
		exp, coll := factoryFunc(nil, WithDialOption(grpc.WithUserAgent(customerUserAgent)))
		t.Cleanup(coll.Shutdown)
		ctx := context.Background()
		require.NoError(t, exp.Export(ctx, metricdata.ResourceMetrics{}))
		// Ensure everything is flushed.
		require.NoError(t, exp.Shutdown(ctx))

		got := coll.Headers()
		assert.Contains(t, got[key][0], customerUserAgent)
	})
}