enum State {
    Started
    Finished
    Failed
}

function GetVMName {
    param (
        [string]$Rest
    )
    $tokens = $Rest -split "'"
    return $tokens[1]
}

function ConvertDate {
    param (
        [string]$DateString
    )
    return [DateTime]$DateString
}

function DeterminState {
    param (
        [String]$Rest
    )
    if($Rest.IndexOf("Erfolgreiche") -cge 0){
        return 'Finished'
    } elseif ($Rest.IndexOf("gestartet") -cge 0) {
        return 'Started'
    } else {
        return 'Failed'
    }
}

function ProduceHashMap {
    param (
        $Elements
    )
    $HashTable =@{}
    foreach ($elem in $Elements){
        $indexOfFirst = $elem.IndexOf(" ")
        if($indexOfFirst -le 0){
            continue
        }
        $date = $elem.SubString(0,$elem.IndexOf(" ",($indexOfFirst + 1)))
        $rest = $elem.Substring($elem.IndexOf(" ",($indexOfFirst + 1))+1)
        $vmName = GetVMName($rest)
        $backUpState = DeterminState($rest)
        $timeStamp
        if($HashTable.ContainsKey($vmName)){
            $array = $HashTable[$vmName]
            $lastState=($array[$array.Count-1]).state
            #Write-Host $lastState
            #Write-Host $backUpState
            if (($lastState -eq $backUpState) -or ($backUpState -eq 'Finished' -and $lastState -ne 'Started') -or ($backUpState -eq 'Failed' -and $lastState -ne 'Started')) {
                #Write-Host "skipping"
                continue
            }
            #Write-Host "continuing"
            try {
                $timeStamp = ConvertDate($date)
                $array += New-Object psobject -Property @{
                    state = $backUpState
                    ts = $timeStamp
                }
            }
            catch {
                $timeStamp = ($array[$array.Count-1]).ts
                $array += New-Object psobject -Property @{
                    state = $backUpState
                    ts = $timeStamp
                }
            }
            $HashTable[$vmName]=$array
        } else {
            try {
                $timeStamp = ConvertDate($date)
                $HashTable += @{$vmName=@(New-Object psobject -Property @{
                    state = $backUpState
                    ts = $timeStamp
                    })}
            }
            catch {
                <#Do nothing as key is empty and failed state#>
            }
        }  
    }
    return $HashTable
}

function getElems {
    param (
        $Path
    )
    $lines = Get-Content -Path $Path | ForEach-Object {$_.SubString($_.IndexOf(":")+1)}
    $elems = $lines | Out-String -Stream | Select-String -Pattern "VMware-Maschine" | Out-String -Stream
    return $elems
}

function ProcessLogToHash {
    param (
        $Path
    )
    ProduceHashMap -Elements $(getElems -Path $Path)
}

function buildIntervals {
    param (
        $hash
    )
    $array = @()
    foreach ($key in $hash.Keys){
        #Write-Host $key
        $list = $hash.$key
        #Write-Host $list
        $lastState = $null
        $lastTS = $null
        foreach ($elem in $list){
            #Write-Host $elem
            if (($elem.state -eq 'Started') -and ($null -eq $lastState)) {
                $lastState=$elem.state
                $lastTS=$elem.ts
            }
            if (($elem.state -ne 'Started') -and ($lastState -eq 'Started')) {
                $array += @(New-Object psobject -Property @{
                    begining=$lastTS
                    ending=$elem.ts
                    state=$elem.state
                    vm=$key
                })
                $lastState=$null
                $lastTS=$null
            }
            #Write-Host "$array"
        }
    }
    return $array
}