# DeployCenter - Log management
# Compatible with Windows PowerShell 5.1

function Initialize-DeployCenterLogging {
    [CmdletBinding()]
    param(
        [AllowNull()]
        [string]$IPv4 = $null
    )

    $tempRoot = [Environment]::GetEnvironmentVariable('TEMP')
    if ([string]::IsNullOrWhiteSpace($tempRoot)) {
        throw 'The TEMP environment variable is not defined.'
    }
    $script:LogRoot = Join-Path $tempRoot 'DeployCenter'
    if (-not (Test-Path -LiteralPath $script:LogRoot -PathType Container)) {
        New-Item -Path $script:LogRoot -ItemType Directory -Force -ErrorAction Stop | Out-Null
    }

    # The IPv4 address is provided by Modules\\Network.psm1.
    $script:LogIPv4 = $IPv4

    $logIpTag = if ([string]::IsNullOrWhiteSpace($script:LogIPv4)) {
        'no-ip'
    } else {
        $script:LogIPv4 -replace '[^0-9A-Za-z.-]', '_'
    }
    $script:LogFile = Join-Path $script:LogRoot (
        'DeployCenter_{0}_{1}.log' -f $logIpTag, (Get-Date -Format 'yyyyMMdd_HHmmss')
    )
}

function Write-Log {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $true)]
        [string]$Message,

        [ValidateSet('INFO', 'SUCCESS', 'WARNING', 'ERROR')]
        [string]$Level = 'INFO'
    )

    $line = '{0} [{1}] {2}' -f (Get-Date -Format 'yyyy-MM-dd HH:mm:ss'), $Level, $Message

    try {
        [System.IO.File]::AppendAllText(
            $script:LogFile,
            $line + [Environment]::NewLine,
            [System.Text.Encoding]::UTF8
        )
    } catch {
        # The graphical log remains available if the file cannot be accessed.
    }

    if ($null -ne $script:txtLog -and -not $script:txtLog.IsDisposed) {
        $script:txtLog.AppendText($line + [Environment]::NewLine)
        $script:txtLog.SelectionStart = $script:txtLog.TextLength
        $script:txtLog.ScrollToCaret()
    }
}

function Copy-DeployCenterLog {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)][string]$DestinationRoot
    )

    if ([string]::IsNullOrWhiteSpace([string]$script:LogFile) -or
        -not (Test-Path -LiteralPath $script:LogFile -PathType Leaf)) {
        Write-Log -Message (ConvertTo-DeployCenterLocalizedLogMessage -Message 'Log copy skipped: no log file is available.') -Level 'WARNING'
        return $null
    }

    try {
        if (-not (Test-Path -LiteralPath $DestinationRoot -PathType Container)) {
            throw "Destination folder is not accessible: $DestinationRoot"
        }
        $destinationPath = Join-Path $DestinationRoot ([System.IO.Path]::GetFileName($script:LogFile))
        Write-Log -Message (ConvertTo-DeployCenterLocalizedLogMessage -Message "Copying the log to $destinationPath.") -Level 'INFO'
        Copy-Item -LiteralPath $script:LogFile -Destination $destinationPath -Force -ErrorAction Stop | Out-Null
        return $destinationPath
    } catch {
        Write-Log -Message (ConvertTo-DeployCenterLocalizedLogMessage -Message "Unable to copy the log to '$DestinationRoot' : $($_.Exception.Message)") -Level 'WARNING'
        return $null
    }
}