Version.targets

<Project>
 <PropertyGroup>
    <NightlyTag>nightly</NightlyTag>
    <RegexPre>pre\d</RegexPre>
 </PropertyGroup>
 <PropertyGroup>
    <GitBranch Condition="'$(SYSTEM_PULLREQUEST_TARGETBRANCH)' != ''">$(SYSTEM_PULLREQUEST_TARGETBRANCH)</GitBranch>
    <GitBranch Condition="'$(SYSTEM_PULLREQUEST_TARGETBRANCH)' == '' and '$(BUILD_SOURCEBRANCHNAME)' != ''">$(BUILD_SOURCEBRANCHNAME)</GitBranch>
  </PropertyGroup>

  <Target Name="SetVersions"
          BeforeTargets="PrepareForBuild;GetAssemblyVersion;GetPackageVersion;Pack"
          DependsOnTargets="GitVersion"
          Returns="$(Version)"
         >
    <PropertyGroup>
      <PreOut>$([System.Text.RegularExpressions.Regex]::Match($(GitTag), $(RegexPre)))</PreOut>
      <GitSemVerLabel Condition=" '$(GitTag)' != '' and '$(GitTag)' == '$(GitBranch)' and $([System.Text.RegularExpressions.Regex]::IsMatch('$(GitTag)', $(RegexPre))) ">$(PreOut)</GitSemVerLabel>
      <GitSemVerLabel  Condition="$(CI) and '$(BUILD_REASON)' == 'Schedule'">$(NightlyTag)</GitSemVerLabel>
      <GitSemVerDashLabel Condition="'$(GitSemVerLabel)' != ''" >-$(GitSemVerLabel)</GitSemVerDashLabel>
    </PropertyGroup>
    <ItemGroup>
      <VersionMetadata Include="$(GitCommits)" Condition="'$(GitSemVerDashLabel)' == ''" />

      <VersionMetadata Condition="$(CI) and '$(BUILD_REASON)' == 'PullRequest'"
                       Include="pr.$(SYSTEM_PULLREQUEST_PULLREQUESTNUMBER)"/>

      <VersionMetadata Include="sha.$(GitCommit)"/>

      <VersionMetadata Condition="$(CI)"
                       Include="azdo.$(BUILD_BUILDID)"/>
    </ItemGroup>

    <PropertyGroup>
      <VersionMetadataLabel>@(VersionMetadata -> '%(Identity)', '-')</VersionMetadataLabel>
      <VersionMetadataPlusLabel Condition="'$(VersionMetadataLabel)' != ''">+$(VersionMetadataLabel)</VersionMetadataPlusLabel>
      <Version>$(GitBaseVersionMajor).$(GitBaseVersionMinor).$(GitBaseVersionPatch)</Version>
      <PackageVersion>$(GitSemVerMajor).$(GitSemVerMinor).$(GitSemVerPatch)$(GitSemVerDashLabel)$(VersionMetadataPlusLabel)</PackageVersion>

      <PackageVersion Condition="$(CI)">$(GitSemVerMajor).$(GitSemVerMinor).$(GitBaseVersionPatch).$(BUILDVERSION)$(GitSemVerDashLabel)$(VersionMetadataPlusLabel)</PackageVersion>
      <PackageVersion Condition="$(CI) and '$(GitBaseVersion)' == '4.2.0'">$(GitSemVerMajor).$(GitSemVerMinor).$(GitBaseVersionPatch).$(BUILDVERSION42)$(GitSemVerDashLabel)$(VersionMetadataPlusLabel)</PackageVersion>
      <PackageVersion Condition="$(CI) and '$(GitBaseVersion)' == '4.3.0'">$(GitSemVerMajor).$(GitSemVerMinor).$(GitBaseVersionPatch).$(BUILDVERSION43)$(GitSemVerDashLabel)$(VersionMetadataPlusLabel)</PackageVersion>
      <PackageVersion Condition="$(CI) and '$(GitBaseVersion)' == '4.4.0'">$(GitSemVerMajor).$(GitSemVerMinor).$(GitBaseVersionPatch).$(BUILDVERSION44)$(GitSemVerDashLabel)$(VersionMetadataPlusLabel)</PackageVersion>
    </PropertyGroup>

    <PropertyGroup>
      <InformationalVersion>$(PackageVersion)</InformationalVersion>
      <FileVersion>$(Version).$(GitCommits)</FileVersion>
      <AssemblyVersion>2.0.0.0</AssemblyVersion> <!-- THIS SHALL REMAIN 2.0.0.0 -->
    </PropertyGroup>

    <ItemGroup>
      <AssemblyAttribute Include="System.Reflection.AssemblyMetadata">
        <_Parameter1>Version</_Parameter1>
        <_Parameter2>2.0.0.0</_Parameter2> <!-- THIS SHALL REMAIN 2.0.0.0 -->
      </AssemblyAttribute>
      <AssemblyAttribute Include="System.Reflection.AssemblyMetadata">
        <_Parameter1>PackageVersion</_Parameter1>
        <_Parameter2>$(PackageVersion)</_Parameter2>
      </AssemblyAttribute>
    </ItemGroup>

    <Message Condition="$(CI) and '$(BUILD_REASON)' == 'Schedule'" Importance="high" Text="##vso[build.addbuildtag]$(NightlyTag)"/>
    <ItemGroup>
       <XamarinFormsVersionFile Include="../.XamarinFormsVersionFile.txt"/>
       <XamarinFormsVersionLine Include="$(PackageVersion)"/>
    </ItemGroup>
    
    <!-- Occasionally this throws an error from parallel builds writing to this file. It's fine if only one of them wins. -->
    <WriteLinesToFile ContinueOnError="WarnAndContinue" File="@(XamarinFormsVersionFile)" Lines="@(XamarinFormsVersionLine)" Overwrite="true" />
    <Message Condition="$(CI)" Importance="high" Text="##vso[build.updatebuildnumber]$(PackageVersion)"/>
    <Message Condition="$(CI)" Importance="high" Text="##vso[task.setvariable variable=XamarinFormsPackageVersion;isOutput=true;]$(PackageVersion)"/>
  </Target>

  <Target Name="VersionInfoReport" DependsOnTargets="SetVersions" AfterTargets="GitInfoReport">
   <ItemGroup>
		<Message Importance="$(GitInfoReportImportance)" Text="Version Info:
  AssemblyVersion:        $(AssemblyVersion)
  FileVersion:            $(FileVersion)
  InformationalVersion:   $(InformationalVersion)
  PackageVersion:         $(PackageVersion)
  Version:        $(Version)
  VersionPrefix:  $(VersionPrefix)
  VersionSuffix:  $(VersionSuffix)
"/>
   </ItemGroup>
	</Target>

</Project>