Having difficult creating excel sheet while looping thru names - excel

Question

I have bunch of server names. Then i am looping thru these names and creating sheet by each server name. But getting error. below is my code
create excel spreadsheet
$xlsx = Join-Path -Path (Get-Location).Path -ChildPath "ClusterUsageReport-$(get-date -UFormat '%Y-%m-%d-%H-%M-%S').xlsx"
$xl = new-object -ComObject Excel.Application
$workbook = $xl.Workbooks.Add()
$i = 1
$clusters = ('Hcohesity01','Hcohesity05')
foreach ($vip in $clusters){
### create excel woorksheet
$worksheet = $workbook.Worksheets.Item($i)
$worksheet.Name = "$vip-Storage Growth"
$worksheet.activate | Out-Null
$i ++
### there are more scripts below this line, which create charts in each sheet ####
}
$xl.visible = $true
$worksheet.columns.autofit() | Out-Null
$worksheet.usedRange.rows(1).Font.Bold = $True
$workbook.SaveAs($xlsx,51) | Out-Null
Message i am getting
Invalid index. (Exception from HRESULT: 0x8002000B (DISP_E_BADINDEX))
At C:\raju\scripts\cluster_usage_in_excel.ps1:25 char:1
$worksheet = $workbook.Worksheets.Item($i)
+ CategoryInfo : OperationStopped: (:) [], COMException
+ FullyQualifiedErrorId : System.Runtime.InteropServices.COMException
Message coming from line $worksheet = $workbook.Worksheets.Item($i) , any idea how do i achieve this ?
Below is entire script .. can you point where needs update ??
usage: ./graphStorageGrowth.ps1 -vip mycluster -username myuser [ -domain mydomain.net ] [ -days 60 ]
### process commandline arguments
[CmdletBinding()]
param (
[Parameter(Mandatory = $True)][string]$username,
[Parameter()][int32]$days = 60
)
### constants
$TB = (1024*1024*1024*1024)
$GB = (1024*1024*1024)
### source the cohesity-api helper code
. ./cohesity-api
### create excel spreadsheet
$xlsx = Join-Path -Path (Get-Location).Path -ChildPath "ClusterUsageReport-$(get-date -UFormat '%Y-%m-%d-%H-%M-%S').xlsx"
$xl = new-object -ComObject Excel.Application
$workbook = $xl.Workbooks.Add()
$i = 0
$clusters = ('Hcohesity01','hcohesity03')
foreach ($vip in $clusters){
### create excel woorksheet
while($xlsx.Worksheets.Count -lt $i) { $xlsx.Worksheets.Add() }
#$worksheet = $workbook.Worksheets.Item($i)
$worksheet.Name = "$vip-Storage Growth"
$worksheet.activate()
### headings for data rows
$row = 1
$worksheet.Cells.Item($row,1) = 'Date'
$worksheet.Cells.Item($row,2) = 'Usage in Tib'
$row++
### authenticate
apiauth -vip $vip -username $username -domain corpads.local
### calculate startTimeMsecs
$startTimeMsecs = $(timeAgo $days days)/1000
### get cluster info
$clusterInfo = api get cluster?fetchStats=true
$clusterId = $clusterInfo.id
### collect $days of write throughput stats
#$stats = api get statistics/timeSeriesStats?schemaName=kBridgeClusterStats`&entityId=$clusterId`&metricName=kSystemUsageBytes`&startTimeMsecs=$startTimeMsecs`&rollupFunction=average`&rollupIntervalSecs=86400
$stats = api get "statistics/timeSeriesStats?endTimeMsecs=1662609600000&entityId=$clusterId&metricName=kMorphedUsageBytes&metricUnitType=0&range=day&rollupFunction=average&rollupIntervalSecs=86400&schemaName=kBridgeClusterStats&startTimeMsecs=$startTimeMsecs"
### populate excel worksheet with the throughput stats
foreach ($stat in $stats.dataPointVec){
$day = usecsToDate (($stat.timestampMsecs)*1000)
$consumed = $stat.data.int64Value/$TB
$worksheet.Cells.Item($row,1) = "$day".split()[0]
$worksheet.Cells.Item($row,2) = "{0:N2}" -f $consumed
$row++
}
### create excel chart
$chartData = $worksheet.Range("A1").CurrentRegion
$chart = $worksheet.Shapes.AddChart().Chart
$chart.chartType = 4
$chart.SetSourceData($chartData)
$chart.HasTitle = $true
$chart.ChartTitle.Text = "Storage Consumption Last $days Days"
$chart.Parent.Top = 50
$chart.Parent.Left = 150
$chart.Parent.Width = 600
$i ++
}
$xl.visible = $true
#[System.Runtime.Interopservices.Marshal]::ReleaseComObject($xl)
$worksheet.columns.autofit() | Out-Null
$worksheet.usedRange.rows(1).Font.Bold = $True
$workbook.SaveAs($xlsx,51) | Out-Null