dir.targets

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="12.0" InitialTargets="_RestoreBuildToolsWrapper" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

  <!-- Inline task to bootstrap the build to enable downloading nuget.exe -->
  <UsingTask TaskName="DownloadFile" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v12.0.dll">
    <ParameterGroup>
      <Address ParameterType="System.String" Required="true"/>
      <FileName ParameterType="System.String" Required="true" />
    </ParameterGroup>
    <Task>
      <Reference Include="System" />
      <Reference Include="System.IO" />
      <Code Type="Fragment" Language="cs">
        <![CDATA[
            var directory = System.IO.Path.GetDirectoryName(FileName);
            Directory.CreateDirectory(directory);

            var tempFile = Path.Combine(directory, Path.GetRandomFileName());
            var client = new System.Net.WebClient();
            client.DownloadFile(Address, tempFile);

            try
            {
                if (!File.Exists(FileName))
                    File.Move(tempFile, FileName);
            }
            finally
            {
                if (File.Exists(tempFile))
                    File.Delete(tempFile);
            }
        ]]>
      </Code>
    </Task>
  </UsingTask>

  <!-- 
    Needed to avoid the IntialTargets from having an Output which ends up getting
    added to the output references when you have a project to project reference.
  -->
  <Target Name="_RestoreBuildToolsWrapper" DependsOnTargets="_RestoreBuildTools" />

  <Target Name="_RestoreBuildTools"
          Inputs="$(MSBuildThisFileDirectory)dir.props;$(SourceDir).nuget\packages.config"
          Outputs="$(ToolsDir)Microsoft.DotNet.Build.Tasks.dll;$(NugetToolPath)">
    <Message Importance="High" Text="Restoring build tools..." />

    <!-- Download latest nuget.exe -->
    <DownloadFile FileName="$(NuGetToolPath)"
                  Address="https://www.nuget.org/nuget.exe"
                  Condition="!Exists('$(NuGetToolPath)')" />

    <!-- Restore build tools -->
    <Exec Command="$(NugetRestoreCommand) &quot;$(SourceDir).nuget\packages.config&quot;" StandardOutputImportance="Low" />
    
    <Error Condition="'$(ErrorIfBuildToolsRestoredFromIndividualProject)'=='true'"
           Text="The build tools package was just restored and so we cannot continue the build of an individual project because targets from the build tools package were not able to be imported. Please retry the build the individual project again." />

    <!--
      There are cases where the inputs could be newer than the outputs but the
      download or restore may not need to update. In such cases we need to touch
      these files otherwise we continually run this target over and over for
      every project until these files are cleaned (if the are ever cleaned).
    -->
    <Touch Files="$(ToolsDir)Microsoft.DotNet.Build.Tasks.dll;$(NugetToolPath)" />
  </Target>

  <!-- Provide default empty targets for BuildAndTest and Test which can be hooked onto or overridden as necessary -->
  <Target Name="BuildAndTest" DependsOnTargets="Build;Test" />

  <Target Name="Test" />

</Project>