// <copyright file="InMemoryExporterLoggingExtensions.cs" company="OpenTelemetry Authors">
// 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.
// </copyright>

using System.Collections.Generic;
using OpenTelemetry.Exporter;
using OpenTelemetry.Internal;

namespace OpenTelemetry.Logs
{
    public static class InMemoryExporterLoggingExtensions
    {
        /// <summary>
        /// Adds InMemory exporter to the OpenTelemetryLoggerOptions.
        /// </summary>
        /// <param name="loggerOptions"><see cref="OpenTelemetryLoggerOptions"/> options to use.</param>
        /// <param name="exportedItems">Collection which will be populated with the exported <see cref="LogRecord"/>.</param>
        /// <returns>The instance of <see cref="OpenTelemetryLoggerOptions"/> to chain the calls.</returns>
        public static OpenTelemetryLoggerOptions AddInMemoryExporter(this OpenTelemetryLoggerOptions loggerOptions, ICollection<LogRecord> exportedItems)
        {
            Guard.ThrowIfNull(loggerOptions);
            Guard.ThrowIfNull(exportedItems);

            var logExporter = new InMemoryExporter<LogRecord>(
                exportFunc: (in Batch<LogRecord> batch) => ExportLogRecord(in batch, exportedItems));

            return loggerOptions.AddProcessor(new SimpleLogRecordExportProcessor(logExporter));
        }

        private static ExportResult ExportLogRecord(in Batch<LogRecord> batch, ICollection<LogRecord> exportedItems)
        {
            if (exportedItems == null)
            {
                return ExportResult.Failure;
            }

            foreach (var log in batch)
            {
                exportedItems.Add(log.Copy());
            }

            return ExportResult.Success;
        }
    }
}
