﻿/*
 * 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.
 */

namespace DotPulsar.Internal;

using DotPulsar.Abstractions;
using System.Collections.Generic;
using System.Diagnostics;

public static class DotPulsarActivitySource
{
    private const string _traceParent = "traceparent";
    private const string _traceState = "tracestate";

    static DotPulsarActivitySource()
    {
        ActivitySource = new ActivitySource(Constants.ClientName, Constants.ClientVersion);
    }

    public static ActivitySource ActivitySource { get; }

    public static Activity? StartConsumerActivity(IMessage message, string operationName, KeyValuePair<string, object?>[] tags)
    {
        if (!ActivitySource.HasListeners())
            return null;

        var properties = message.Properties;

        if (properties.TryGetValue(_traceParent, out var traceparent))
        {
            var tracestate = properties.ContainsKey(_traceState) ? properties[_traceState] : null;
            if (ActivityContext.TryParse(traceparent, tracestate, out var activityContext))
                return ActivitySource.StartActivity(operationName, ActivityKind.Consumer, activityContext, tags);
        }

        var activity = ActivitySource.StartActivity(operationName, ActivityKind.Consumer);

        if (activity is not null && activity.IsAllDataRequested)
        {
            for (var i = 0; i < tags.Length; ++i)
            {
                var tag = tags[i];
                activity.SetTag(tag.Key, tag.Value);
            }
        }

        return activity;
    }

    public static Activity? StartProducerActivity(MessageMetadata metadata, string operationName, KeyValuePair<string, object?>[] tags)
    {
        if (!ActivitySource.HasListeners())
            return null;

        var activity = ActivitySource.StartActivity(operationName, ActivityKind.Producer);

        if (activity is not null && activity.IsAllDataRequested)
        {
            metadata[_traceParent] = activity.TraceId.ToHexString();
            metadata[_traceState] = activity.TraceStateString;

            for (var i = 0; i < tags.Length; ++i)
            {
                var tag = tags[i];
                activity.SetTag(tag.Key, tag.Value);
            }
        }

        return activity;
    }
}