dotnet-installer/src/Microsoft.DotNet.Configurer/DotnetFirstTimeUseConfigurer.cs

// Copyright (c) .NET Foundation and contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System.IO;
using Microsoft.DotNet.Cli.Utils;
using Microsoft.Extensions.EnvironmentAbstractions;

namespace Microsoft.DotNet.Configurer
{
    public class DotnetFirstTimeUseConfigurer
    {
        private IEnvironmentProvider _environmentProvider;
        private INuGetCachePrimer _nugetCachePrimer;
        private INuGetCacheSentinel _nugetCacheSentinel;

        public DotnetFirstTimeUseConfigurer(
            INuGetCachePrimer nugetCachePrimer,
            INuGetCacheSentinel nugetCacheSentinel,
            IEnvironmentProvider environmentProvider)
        {
            _nugetCachePrimer = nugetCachePrimer;
            _nugetCacheSentinel = nugetCacheSentinel;
            _environmentProvider = environmentProvider;
        }

        public void Configure()
        {
            if(ShouldPrimeNugetCache())
            {
                PrintFirstTimeUseNotice();

                _nugetCachePrimer.PrimeCache();
            }
        }

        private void PrintFirstTimeUseNotice()
        {
            const string firstTimeUseWelcomeMessage = @"Welcome to .NET Core!
---------------------
Learn more about .NET Core @ https://aka.ms/dotnet-docs. Use dotnet --help to see available commands or go to https://aka.ms/dotnet-cli-docs.

Telemetry
--------------
The .NET Core tools collect usage data in order to improve your experience. The data is anonymous and does not include command-line arguments. The data is collected by Microsoft and shared with the community.
You can opt out of telemetry by setting a DOTNET_CLI_TELEMETRY_OPTOUT environment variable to 1 using your favorite shell.
You can read more about .NET Core tools telemetry @ https://aka.ms/dotnet-cli-telemetry.

Configuring...
-------------------
A command is running to initially populate your local package cache, to improve restore speed and enable offline access. This command will take up to a minute to complete and will only happen once.";

            Reporter.Output.WriteLine();
            Reporter.Output.WriteLine(firstTimeUseWelcomeMessage);
        }

        private bool ShouldPrimeNugetCache()
        {
            var skipFirstTimeExperience = 
                _environmentProvider.GetEnvironmentVariableAsBool("DOTNET_SKIP_FIRST_TIME_EXPERIENCE", false);

            return !skipFirstTimeExperience &&
                !_nugetCacheSentinel.Exists() &&
                !_nugetCacheSentinel.InProgressSentinelAlreadyExists();
        }
    }
}