// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Globalization;
using System.Text;
 
namespace Microsoft.Extensions.Logging.AzureAppServices;
 
internal sealed class BatchingLogger : ILogger
{
    private readonly BatchingLoggerProvider _provider;
    private readonly string _category;
 
    public BatchingLogger(BatchingLoggerProvider loggerProvider, string categoryName)
    {
        _provider = loggerProvider;
        _category = categoryName;
    }
 
    public IDisposable BeginScope<TState>(TState state)
    {
        return null;
    }
 
    public bool IsEnabled(LogLevel logLevel)
    {
        return _provider.IsEnabled;
    }
 
    public void Log<TState>(DateTimeOffset timestamp, LogLevel logLevel, EventId _, TState state, Exception exception, Func<TState, Exception, string> formatter)
    {
        if (!IsEnabled(logLevel))
        {
            return;
        }
 
        var builder = new StringBuilder();
        builder.Append(timestamp.ToString("yyyy-MM-dd HH:mm:ss.fff zzz", CultureInfo.InvariantCulture));
        builder.Append(" [");
        builder.Append(logLevel.ToString());
        builder.Append("] ");
        builder.Append(_category);
 
        var scopeProvider = _provider.ScopeProvider;
        if (scopeProvider != null)
        {
            scopeProvider.ForEachScope((scope, stringBuilder) =>
            {
                stringBuilder.Append(" => ").Append(scope);
            }, builder);
 
            builder.AppendLine(":");
        }
        else
        {
            builder.Append(": ");
        }
 
        builder.AppendLine(formatter(state, exception));
 
        if (exception != null)
        {
            builder.AppendLine(exception.ToString());
        }
 
        _provider.AddMessage(timestamp, builder.ToString());
    }
 
    public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
    {
        Log(DateTimeOffset.Now, logLevel, eventId, state, exception, formatter);
    }
}