// 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.Diagnostics.CodeAnalysis;
using System.Globalization;
using Xunit;

namespace Microsoft.AspNetCore.Testing;

public class CultureReplacer : IDisposable
{
    private const string _defaultCultureName = "en-GB";
    private const string _defaultUICultureName = "en-US";
    private static readonly CultureInfo _defaultCulture = new CultureInfo(_defaultCultureName);
    private readonly CultureInfo _originalCulture;
    private readonly CultureInfo _originalUICulture;
    private readonly long _threadId;

    // Culture => Formatting of dates/times/money/etc, defaults to en-GB because en-US is the same as InvariantCulture
    // We want to be able to find issues where the InvariantCulture is used, but a specific culture should be.
    //
    // UICulture => Language
    [SuppressMessage("ApiDesign", "RS0027:Public API with optional parameter(s) should have the most parameters amongst its public overloads", Justification = "Required to maintain compatibility")]
    public CultureReplacer(string culture = _defaultCultureName, string uiCulture = _defaultUICultureName)
        : this(new CultureInfo(culture), new CultureInfo(uiCulture))
    {
    }

    public CultureReplacer(CultureInfo culture, CultureInfo uiCulture)
    {
        _originalCulture = CultureInfo.CurrentCulture;
        _originalUICulture = CultureInfo.CurrentUICulture;
        _threadId = Environment.CurrentManagedThreadId;
        CultureInfo.CurrentCulture = culture;
        CultureInfo.CurrentUICulture = uiCulture;
    }

    /// <summary>
    /// The name of the culture that is used as the default value for CultureInfo.DefaultThreadCurrentCulture when CultureReplacer is used.
    /// </summary>
    public static string DefaultCultureName
    {
        get { return _defaultCultureName; }
    }

    /// <summary>
    /// The name of the culture that is used as the default value for [Thread.CurrentThread(NET45)/CultureInfo(K10)].CurrentUICulture when CultureReplacer is used.
    /// </summary>
    public static string DefaultUICultureName
    {
        get { return _defaultUICultureName; }
    }

    /// <summary>
    /// The culture that is used as the default value for [Thread.CurrentThread(NET45)/CultureInfo(K10)].CurrentCulture when CultureReplacer is used.
    /// </summary>
    public static CultureInfo DefaultCulture
    {
        get { return _defaultCulture; }
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    private void Dispose(bool disposing)
    {
        if (disposing)
        {
            Assert.True(Environment.CurrentManagedThreadId == _threadId,
                "The current thread is not the same as the thread invoking the constructor. This should never happen.");
            CultureInfo.CurrentCulture = _originalCulture;
            CultureInfo.CurrentUICulture = _originalUICulture;
        }
    }
}
