<#
.SYNOPSIS
    Moves movies and TV show folders into flat A-Z "bucket" folders.
.DESCRIPTION
    Looks at every top-level folder and video file in a source folder and moves it into
    a bucket folder under the destination, based on the first character of its name:
    A through Z, "0-9" for titles that start with a number, and "#" for everything else.
    Leading articles ("The", "A", "An") can be ignored so "The Wire" lands in W.
    Nothing is overwritten. If the target already exists, the item is skipped and reported.
    Supports -WhatIf and -Confirm, returns one object per item, and can log to CSV.
.PARAMETER SourcePath
    The messy folder to sort. Only its top-level items are moved; what's inside a show or
    movie folder is left alone.
.PARAMETER DestinationPath
    Where the bucket folders live. Can be the same as SourcePath to sort a folder in place.
.PARAMETER Scheme
    Letter gives one bucket per letter (A, B, C...). Range gives five wider buckets
    (A-E, F-J, K-O, P-T, U-Z) for smaller libraries.
.PARAMETER IgnoreArticle
    Skip a leading "The", "A" or "An" when picking the bucket. The name itself isn't changed.
.PARAMETER Extension
    Loose files with these extensions are treated as movies. Anything else is left in place.
.PARAMETER LogPath
    Optional CSV file for the results. Written even during -WhatIf, so you can review the plan.
.EXAMPLE
    .\Move-MediaToBucket.ps1 -SourcePath D:\Incoming\TV -DestinationPath D:\TV -IgnoreArticle -WhatIf
.EXAMPLE
    .\Move-MediaToBucket.ps1 -SourcePath D:\Movies -DestinationPath D:\Movies -LogPath .\movies.csv
#>
[CmdletBinding(SupportsShouldProcess)]
param(
    [Parameter(Mandatory)]
    [ValidateScript({ Test-Path -LiteralPath $_ -PathType Container })]
    [string]$SourcePath,

    [Parameter(Mandatory)]
    [string]$DestinationPath,

    [ValidateSet('Letter', 'Range')]
    [string]$Scheme = 'Letter',

    [switch]$IgnoreArticle,

    [string[]]$Extension = @('.mkv', '.mp4', '.m4v', '.avi'),

    [string]$LogPath
)

function Get-BucketName {
    param([string]$Name)

    $sortName = $Name.Trim()
    if ($IgnoreArticle) { $sortName = $sortName -replace '^(the|an|a)\s+', '' }
    $sortName = $sortName.TrimStart("'", '"', '(', '[', '.', '-', '_', ' ')
    if (-not $sortName) { return '#' }

    # "Élite" should land in E, so strip accents before looking at the first letter.
    $first = ([string]$sortName[0]).Normalize([Text.NormalizationForm]::FormD)[0]
    $first = [char]::ToUpperInvariant($first)

    if ($first -ge [char]'0' -and $first -le [char]'9') { return '0-9' }
    if ($first -lt [char]'A' -or $first -gt [char]'Z') { return '#' }
    if ($Scheme -eq 'Letter') { return [string]$first }

    foreach ($range in 'A-E', 'F-J', 'K-O', 'P-T', 'U-Z') {
        if ($first -ge $range[0] -and $first -le $range[2]) { return $range }
    }
}

$source      = (Resolve-Path -LiteralPath $SourcePath).ProviderPath.TrimEnd('\', '/')
$destination = [IO.Path]::GetFullPath($DestinationPath).TrimEnd('\', '/')
$bucketNames = @('0-9', '#') + $(if ($Scheme -eq 'Letter') { [char[]](65..90) | ForEach-Object { [string]$_ } } else { 'A-E', 'F-J', 'K-O', 'P-T', 'U-Z' })
$sortInPlace = $source -eq $destination

$items = Get-ChildItem -LiteralPath $source | Where-Object {
    if ($_.PSIsContainer) {
        # Don't try to sort the buckets themselves, or the destination if it sits inside the source.
        -not ($sortInPlace -and $bucketNames -contains $_.Name) -and $_.FullName.TrimEnd('\', '/') -ne $destination
    }
    else {
        $Extension -contains $_.Extension.ToLowerInvariant()
    }
}

$results = foreach ($item in $items) {
    $bucket = Get-BucketName -Name $item.Name
    $target = Join-Path (Join-Path $destination $bucket) $item.Name
    $result = [pscustomobject]@{
        Name        = $item.Name
        Type        = if ($item.PSIsContainer) { 'Folder' } else { 'File' }
        Bucket      = $bucket
        Status      = $null
        Source      = $item.FullName
        Destination = $target
        Message     = $null
    }

    if (Test-Path -LiteralPath $target) {
        $result.Status  = 'Skipped'
        $result.Message = 'Something with this name is already in the bucket.'
        Write-Warning "Skipped '$($item.Name)': already exists in $bucket"
    }
    elseif ($PSCmdlet.ShouldProcess($item.FullName, "Move to $bucket")) {
        try {
            $bucketPath = Join-Path $destination $bucket
            if (-not (Test-Path -LiteralPath $bucketPath)) {
                New-Item -Path $bucketPath -ItemType Directory -Force -ErrorAction Stop | Out-Null
            }
            Move-Item -LiteralPath $item.FullName -Destination $target -ErrorAction Stop
            $result.Status = 'Moved'
            Write-Verbose "Moved '$($item.Name)' to $bucket"
        }
        catch {
            $result.Status  = 'Error'
            $result.Message = $_.Exception.Message
            Write-Warning "Failed on '$($item.Name)': $($_.Exception.Message)"
        }
    }
    else {
        $result.Status = if ($WhatIfPreference) { 'WhatIf' } else { 'Declined' }
    }

    $result
}

if ($LogPath -and $results) {
    $results | Export-Csv -LiteralPath $LogPath -NoTypeInformation -WhatIf:$false -Confirm:$false
}

$results