[CmdletBinding(SupportsShouldProcess,ConfirmImpact='Medium')]param(
    [Parameter(Mandatory,ParameterSetName="RemoteSrc")]
    [string]$RemoteSrc,
    [Parameter(Mandatory,ParameterSetName="Local",Position=1)]
    [Parameter(Mandatory,ParameterSetName="RemoteSrc",Position=1)]
    [Parameter(Mandatory,ParameterSetName="RemoteDst",Position=1)]
    [string]$SrcBase,
    [Parameter(Mandatory,ParameterSetName="Local",Position=2)]
    [Parameter(Mandatory,ParameterSetName="RemoteSrc",Position=2)]
    [Parameter(Mandatory,ParameterSetName="RemoteDst",Position=2)]
    [string]$DstBase,
    [Parameter(Mandatory,ParameterSetName="RemoteDst")]
    [string]$RemoteDst,
    [Parameter(Position=4)]
    [string]$Path=".",
    [switch]$NoPassThru,
    [int]$Depth=-1,
    [int]$Limit,
    [Alias("Do")]
    [switch]$NoSimulate
)
Write-Host -ForegroundColor Cyan ( $PSCmdlet | Out-String )
Write-Host -ForegroundColor Yellow ( $PSBoundParameters | Out-String )

function GetLocalPath{
[CmdletBinding(SupportsShouldProcess,ConfirmImpact='Low')]param(
    [string]$LocalBase,
    [string]$Path = "."
)
    return ([System.IO.Path]::GetFullPath((Join-Path $LocalBase $Path),"/"))
}

function GetRemotePath{
[CmdletBinding(SupportsShouldProcess,ConfirmImpact='Low')]param(
    [string]$RemoteAddr,
    [string]$RemoteBase,
    [string]$Path = "."
)
    return "$RemoteAddr`:$(
        [Management.Automation.WildcardPattern]::Escape(
            [System.IO.Path]::GetFullPath((Join-Path $RemoteBase $Path),"/")
        ) -replace '([&\[\(\)\\])','\$1'
    )"
}

function GetSubstituedPath{
[CmdletBinding(SupportsShouldProcess,ConfirmImpact='Low')]param(
    [string]$OriginalPath,
    [string]$Base,
    [string]$ReplaceBase,
    [string]$RemotePrefix
)

    $local:newPath = $OriginalPath -replace "^$([regex]::Escape($Base))",($ReplaceBase -replace '\$(\d)','\$$1')
    if( $RemotePrefix ) {
        $newPath = GetRemotePath $RemotePrefix $newPath
    }
    return $newPath
}


$local:SrcPath = GetLocalPath $SrcBase $Path
$local:DstPath = GetLocalPath $DstBase $Path
$local:LocalPath = [string]::Empty

if( -not $RemoteSrc ) {
    $LocalPath = $SrcPath
} else {
    $LocalPath = $DstPath
}

function GetSortedDirsDepthFirst {
    param([string]$Path,$StopDepth=-1,$CurrentDepth=0)

    $local:dirs = Get-ChildItem $Path -Directory |
        Sort-Object Name
    foreach( $local:d in $dirs ) {
        if( $StopDepth -lt 0 -or $CurrentDepth -lt $StopDepth ) {
            GetSortedDirsDepthFirst $d.FullName $StopDepth ($CurrentDepth + 1)
        }
        $d
    }
}

$local:limitParam = @{}
if( $Limit -gt 0 ) {
    $limitParam.First = $Limit
}
$local:Pairs = @()
if( -not $RemoteSrc ) {
    $Pairs = GetSortedDirsDepthFirst $LocalPath -StopDepth $Depth |
        Select-Object @limitParam |
        ForEach-Object {
            [PSCustomObject]([ordered]@{
                SrcGB = -1
                Src = GetLocalPath $_.FullName
                Dst = GetSubstituedPath $_.FullName $SrcPath $DstPath $RemoteDst
            })
        }
} else {
    $Pairs = , ([PSCustomObject]([ordered]@{
                Src = GetRemotePath $RemoteSrc $SrcPath
                Dst = $DstPath
            }))
}

$local:sw = [System.Diagnostics.Stopwatch]::StartNew();
$Pairs | ForEach-Object {
    $local:s = $_.Src -replace "'",'${Q}'
    $local:d = $_.Dst -replace "'",'\\${Q}'
    $local:skip = $false
    if( $_.SrcGB ) { 
        $_.SrcGB = [Math]::Round( (
                        Get-ChildItem -Recurse -File $_.Src | Measure-Object -Sum Length
                    ).Sum / 1000000000, 2)
        if( -not $_.SrcGB ) {
            $_.SrcGB = "Skip"
        } else {
            $_.SrcGB = "$($_.SrcGB) GB"
        }
    }
    Write-Host -ForegroundColor Cyan ($($_ | Format-Table -HideTableHeaders | Out-String).Trim())
    $local:exp = "Q=\`"'\`"; rsync -avzh --remove-source-files --progress \`"$s/\`" \`"$d/\`""

    $sw.Restart()
    if( -not $_.SrcGB -or $_.SrcGB -ne "Skip" ) {
        $exp | Out-Host

        sh -c $exp | Out-Host
    }
    
    Write-Host -Cyan "Cleanup '$s'..."
    $exp = "Q=\`"'\`"; find \`"$s\`" -type d -empty -delete"
    sh -c $exp | Out-Host

    [PSCustomObject]([ordered]@{
        PSTypeName = 'RsyncReport'
        SrcGB = $_.SrcGB
        Elapsed = $sw.Elapsed
        Src = $_.Src
        Dst = $_.Dst
    })
}