#Requires -Version 7.2

[CmdletBinding()]
param (
    [Parameter(Mandatory, Position=0, ValueFromPipeline)]
    [ValidateNotNullOrEmpty()]
    [string]$Inp,

    [Parameter(Position=1)]
    [string]$Out = $PWD.Path
)

function Write-Log {
    param (
        [ValidateSet("INF", "OK", "WRN", "ERR")]
        [string]$Level,
        [string]$Msg
    )
    $time = [datetime]::Now.ToString("HH:mm:ss")
    $lbl = switch ($Level) {
        "INF" { "[INF]" }
        "OK"  { "$($PSStyle.Foreground.Green)[OK] $($PSStyle.Reset)" }
        "WRN" { "$($PSStyle.Foreground.Yellow)[WRN]$($PSStyle.Reset)" }
        "ERR" { "$($PSStyle.Foreground.Red)[ERR]$($PSStyle.Reset)" }
    }
    Write-Host "$time $lbl $Msg"
}

$src = (Resolve-Path -LiteralPath $Inp -ErrorAction Stop).Path
$dest = [System.IO.Path]::GetFullPath($Out)

if (-not (Test-Path -LiteralPath $dest)) {
    $null = New-Item -ItemType Directory -Path $dest -Force
}

function Get-FileOutPath {
    param ([Uri]$Uri, [string]$Dir)

    $raw = [System.IO.Path]::GetFileName($Uri.LocalPath)
    $name = [string]::IsNullOrWhiteSpace($raw) ? [System.IO.Path]::GetRandomFileName() : $raw

    $invalid = [System.IO.Path]::GetInvalidFileNameChars()
    $safe = -join ($name.ToCharArray() | ForEach-Object { $_ -in $invalid ? "_" : $_ })

    $base = [System.IO.Path]::GetFileNameWithoutExtension($safe)
    $ext = [System.IO.Path]::GetExtension($safe)
    $path = Join-Path $Dir $safe

    $i = 1
    while (Test-Path -LiteralPath $path) {
        $path = Join-Path $Dir "$base ($i)$ext"
        $i++
    }
    return $path
}

function Save-FileList {
    param ([string]$Path, [System.Collections.Generic.List[string]]$Data)
    [System.IO.File]::WriteAllLines($Path, $Data)
}

$lines = [System.Collections.Generic.List[string]]::new([System.IO.File]::ReadAllLines($src))
$stats = @{ Succ = 0; Fail = 0; Skip = 0 }
$tmp = $null
$abort = $false

Write-Log INF "Reading $src"
Write-Log INF "Downloading to $dest"

try {
    $i = 0
    while ($i -lt $lines.Count) {
        $line = $lines[$i].Trim()

        if ([string]::IsNullOrWhiteSpace($line) -or $line.StartsWith("#")) {
            $stats.Skip++
            $i++
            continue
        }

        [Uri]$uri = $null
        $valid = [Uri]::TryCreate($line, [System.UriKind]::Absolute, [ref]$uri) -and ($uri.Scheme -in "http", "https")
        if (-not $valid) {
            Write-Log ERR "Malformed URL on line $($i + 1): $line"
            $stats.Fail++
            $i++
            continue
        }

        $target = Get-FileOutPath -Uri $uri -Dir $dest
        $tmp = "$target.tmp"
        Write-Log INF "Downloading: $line"

        try {
            Invoke-WebRequest -Uri $uri.AbsoluteUri `
                              -OutFile $tmp `
                              -TimeoutSec 60 `
                              -ErrorAction Stop
            Move-Item -LiteralPath $tmp -Destination $target
            $tmp = $null
            $lines[$i] = "# $line"
            Save-FileList -Path $src -Data $lines
            Write-Log OK "Saved: $([System.IO.Path]::GetFileName($target))"
            $stats.Succ++
            $i++
        } catch {
            if ($tmp -and (Test-Path -LiteralPath $tmp)) {
                Remove-Item -LiteralPath $tmp -Force -ErrorAction SilentlyContinue
                $tmp = $null
            }
            $msg = ($_.Exception.Message -replace '\s+', " ").Trim()
            Write-Log ERR "'$line': $msg"
            Save-FileList -Path $src -Data $lines
            $stats.Fail++
            $i++
        }
    }
} catch [System.Management.Automation.PipelineStoppedException], [System.Threading.ThreadAbortException] {
    $abort = $true
} finally {
    if ($tmp -and (Test-Path -LiteralPath $tmp)) {
        Remove-Item -LiteralPath $tmp -Force -ErrorAction SilentlyContinue
        $tmp = $null
    }

    if ($abort) {
        Write-Log WRN "Download aborted (direct interrupt)"
    }

    Write-Log OK ""
    Write-Log OK "Summary"
    Write-Log OK "Success: $($stats.Succ)"
    Write-Log OK "Skipped: $($stats.Skip)"
    Write-Log OK "Failed: $($stats.Fail)"
}