#Requires -Version 5.1
[CmdletBinding()]
param(
    [datetime]$Since = (Get-Date).AddDays(-183),
    [datetime]$Until = (Get-Date),
    [string]$UserName,
    [string]$ComputerName,
    [string]$MonitoringRoot = 'C:\ProgramData\SGU\Monitoring',
    [string]$OutputCsv
)

$ErrorActionPreference = 'Stop'
$eventIds = @(4624,4625,4634,4647,4778,4779,6005,6006,6008)
$events = [Collections.Generic.List[object]]::new()

try {
    # Windows Server 2025 can crash the Windows Event Log service when a
    # structured query is evaluated against ForwardedEvents (wevtsvc.dll,
    # exception 0xc0000420). Read the channel without a server-side query and
    # apply every predicate in this process instead.
    Get-WinEvent -LogName 'ForwardedEvents' -ErrorAction Stop |
        Where-Object {
            $_.Id -in $eventIds -and
            $_.TimeCreated -ge $Since -and
            $_.TimeCreated -le $Until
        } |
        ForEach-Object { $events.Add($_) }
}
catch [System.Exception] {
    if ($_.FullyQualifiedErrorId -notlike 'NoMatchingEventsFound*') {
        Write-Verbose $_.Exception.Message
    }
}

$archiveRoot = Join-Path $MonitoringRoot 'Archive'
Get-ChildItem -LiteralPath $archiveRoot -Filter '*.evtx' -File -ErrorAction SilentlyContinue |
    Where-Object LastWriteTime -ge $Since.AddDays(-1) |
    ForEach-Object {
        try {
            Get-WinEvent -Path $_.FullName -Oldest -ErrorAction Stop |
                Where-Object { $_.Id -in $eventIds -and $_.TimeCreated -ge $Since -and $_.TimeCreated -le $Until } |
                ForEach-Object { $events.Add($_) }
        }
        catch {
            Write-Warning "Could not read archive $($_.FullName): $($_.Exception.Message)"
        }
    }

function Get-EventData {
    param([Parameter(Mandatory)]$EventRecord)

    $xml = [xml]$EventRecord.ToXml()
    $data = @{}
    foreach ($item in @($xml.Event.EventData.Data)) {
        if ($item.Name) {
            $data[[string]$item.Name] = [string]$item.'#text'
        }
    }
    [pscustomobject]@{
        Computer = [string]$xml.Event.System.Computer
        Data = $data
    }
}

$openSessions = @{}
$rows = [Collections.Generic.List[object]]::new()
$ignoredUsers = @('ANONYMOUS LOGON','DWM-1','DWM-2','DWM-3','LOCAL SERVICE','NETWORK SERVICE','SYSTEM','UMFD-0','UMFD-1','UMFD-2','UMFD-3')

foreach ($eventRecord in @($events | Sort-Object TimeCreated,RecordId)) {
    $parsed = Get-EventData -EventRecord $eventRecord
    $machine = ($parsed.Computer -split '\.')[0].ToUpperInvariant()
    $data = $parsed.Data

    if ($eventRecord.Id -in 6005,6006,6008) {
        foreach ($key in @($openSessions.Keys | Where-Object { $_ -like "$machine|*" })) {
            $session = $openSessions[$key]
            $rows.Add([pscustomobject]@{
                User = $session.User
                Computer = $machine
                StartedAt = $session.StartedAt
                EndedAt = $eventRecord.TimeCreated
                Duration = $eventRecord.TimeCreated - $session.StartedAt
                DurationMinutes = [math]::Round(($eventRecord.TimeCreated - $session.StartedAt).TotalMinutes, 2)
                LogonType = $session.LogonType
                Result = 'Interrumpida por apagado o reinicio'
                FailureStatus = $null
            })
            $openSessions.Remove($key)
        }
        continue
    }

    if ($eventRecord.Id -eq 4625) {
        $failedUser = [string]$data.TargetUserName
        if ($failedUser -and $failedUser -notlike '*$' -and $failedUser.ToUpperInvariant() -notin $ignoredUsers) {
            $rows.Add([pscustomobject]@{
                User = if ($data.TargetDomainName) { "$($data.TargetDomainName)\$failedUser" } else { $failedUser }
                Computer = $machine
                StartedAt = $eventRecord.TimeCreated
                EndedAt = $eventRecord.TimeCreated
                Duration = [timespan]::Zero
                DurationMinutes = 0
                LogonType = [string]$data.LogonType
                Result = 'Fallida'
                FailureStatus = "$($data.Status)/$($data.SubStatus)"
            })
        }
        continue
    }

    if ($eventRecord.Id -eq 4624) {
        $logonType = [string]$data.LogonType
        $targetUser = [string]$data.TargetUserName
        if ($logonType -notin @('2','10','11') -or -not $targetUser -or $targetUser -like '*$' -or
            $targetUser.ToUpperInvariant() -in $ignoredUsers) {
            continue
        }
        $logonId = [string]$data.TargetLogonId
        $key = "$machine|$logonId"
        $openSessions[$key] = [pscustomobject]@{
            User = if ($data.TargetDomainName) { "$($data.TargetDomainName)\$targetUser" } else { $targetUser }
            StartedAt = $eventRecord.TimeCreated
            LogonType = $logonType
        }
        continue
    }

    if ($eventRecord.Id -in 4634,4647) {
        $logonId = if ($eventRecord.Id -eq 4634) { [string]$data.TargetLogonId } else { [string]$data.SubjectLogonId }
        $key = "$machine|$logonId"
        if ($openSessions.ContainsKey($key)) {
            $session = $openSessions[$key]
            $rows.Add([pscustomobject]@{
                User = $session.User
                Computer = $machine
                StartedAt = $session.StartedAt
                EndedAt = $eventRecord.TimeCreated
                Duration = $eventRecord.TimeCreated - $session.StartedAt
                DurationMinutes = [math]::Round(($eventRecord.TimeCreated - $session.StartedAt).TotalMinutes, 2)
                LogonType = $session.LogonType
                Result = 'Completada'
                FailureStatus = $null
            })
            $openSessions.Remove($key)
        }
    }
}

foreach ($key in $openSessions.Keys) {
    $session = $openSessions[$key]
    $machine = ($key -split '\|', 2)[0]
    $rows.Add([pscustomobject]@{
        User = $session.User
        Computer = $machine
        StartedAt = $session.StartedAt
        EndedAt = $null
        Duration = $Until - $session.StartedAt
        DurationMinutes = [math]::Round(($Until - $session.StartedAt).TotalMinutes, 2)
        LogonType = $session.LogonType
        Result = 'Sesión posiblemente activa'
        FailureStatus = $null
    })
}

$result = @($rows | Where-Object {
    (-not $UserName -or $_.User -like "*$UserName*") -and
    (-not $ComputerName -or $_.Computer -like "*$ComputerName*")
} | Sort-Object StartedAt -Descending)

if ($OutputCsv) {
    $resolvedOutput = [IO.Path]::GetFullPath($OutputCsv)
    New-Item -ItemType Directory -Path (Split-Path $resolvedOutput -Parent) -Force | Out-Null
    $result | Export-Csv -LiteralPath $resolvedOutput -NoTypeInformation -Encoding UTF8
}

$result