$WorkItemAssociatedURL = "$($env:SYSTEM_TEAMFOUNDATIONCOLLECTIONURI)$env:SYSTEM_TEAMPROJECTID/_apis/build/builds/$($env:BUILD_BUILDID)/workitems?api-version=2.0"
$WorkItemQueryURL = "$($env:SYSTEM_TEAMFOUNDATIONCOLLECTIONURI)$env:SYSTEM_TEAMPROJECTID/_apis/wit/wiql?api-version=2.0"

$headers = @{
 Authorization = "Bearer $env:SYSTEM_ACCESSTOKEN"
}
$ResponseJSON = Invoke-RestMethod -Uri $WorkItemAssociatedURL -ContentType "application/json" -Method GET -Headers $headers

$CountWorkitems = $ResponseJSON.count
$WorkitemUrlArray = $ResponseJSON.value

for($i = 0; $i -lt $CountWorkitems ; $i++) {
	$WorkItemId = $WorkitemUrlArray[$i].id

	$query = "Select [System.Id], [System.WorkItemType], [System.Title], [System.AssignedTo], [System.State] From WorkItemLinks WHERE (Source.[System.Id] = $WorkItemId and  Source.[System.WorkItemType] = 'User Story'  and Source.[System.State] <> 'Closed') and ([System.Links.LinkType] = 'System.LinkTypes.Hierarchy-Forward') and (Target.[System.WorkItemType] = 'Task' and Target.[System.State] <> 'Closed') mode(Recursive)"

	$wiqlBody = '{ "query": "' + $query + '"}'

	Write-Host "WIQL is: $wiqlBody"
	$workItemsOpenTasks = Invoke-RestMethod -Uri $WorkItemQueryURL -Body $wiqlBody -ContentType "application/json" -Method Post -Headers $headers

	# WIQL returns User Story itself and its open Tasks. We expect all tasks are closed and WIQL returns only User Story, so workItemRelations count should be 1
	$relationCount = $workItemsOpenTasks.workItemRelations.count
	Write-Host "Work item and its tasks count: " $relationCount

	if ($relationCount -gt 1) {
		Write-Host "Work item has open tasks, skipped updating state"
	}
	else {
		$body =
			'[
				{
					"op": "add",
					"path": "/fields/System.State",
					"value":"ReadyToTest"
				}
			]'

		Write-Host "body to post: $body"
		$WorkitemUpdateURL = $WorkitemUrlArray[$i].url + "?api-version=2.0"
		Invoke-RestMethod -Uri $WorkitemUpdateURL -Body $body -ContentType "application/json-patch+json" -Method Patch -Headers $headers

		Write-Host "Updating WorkItem's (#$WorkItemId) state to ReadyToTest"
	}


}