YT_Run

# Initialize Variables
$terminate= $true                                   #Exit variable for the DoUntil Loop
$simulate = $false                                  #Variable to prevent yt execution
$count = 0                                          #Counter for the Link Parser
$usercount = 0                                      #Counter for the User link to Vid link converter
$confcnt = 0                                        #Counter for Configuration File items
$allowedthreads = 4                                 #Total number of Userdownloads that can happen concurrently Set to 0 for unlimited
$wrlinks = New-Object System.Collections.ArrayList  #The Arraylist that is passed to Youtube-DL
$userlinks = New-Object System.Collections.ArrayList #The Arraylist used for user items

$DEBUG = $false                                     #Debug Bool
$rootdir = $PSScriptRoot                            #finds the root directory
$rootdri = ((Get-Location).Path.Split(":")).Get(0)+':'  #builds a driveletter for pathing

$dldate = 19691231                                  #This is backup in case dldate is not specified in $config
$dlrelpath                                          #this is the variable from scriptconf.txt that specifies where to put videos
$dlpath                                             #This variable is built from config file terms and the rootpath
$saveform                                           #this variable contains the format to save files in
$oscarflag                                          #this is the complete -o flag for ytdl

$today = Get-Date -UFormat "%Y%m%d"                 #This contains the date the script is being run on
$userlinkspull = $null                              #This array contains links pulled from user channels

#Check for, then set various config files
if (Test-Path "$rootdir\alwaysdl")
{$userlinks = Get-Content "$rootdir\alwaysdl" }     #This array has links for Users that are always downloaded

if (Test-Path "$rootdir\scriptconf.txt") {
    $config = Get-Content "$rootdir\scriptconf.txt" #Grabs the config file, or makes it null
}else { $PS
    $config = $null
    $DEBUG = $true
}


#Set important variables from the config file
if ($config -ne $null) {
    ForEach ($item in $config) {
        if (($item -match '=') -and ($item -notmatch '#')) {
            $cmd = $item
            if ($DEBUG) {Write-Host "Executing Script Configuration: "; Write-Host "Running $cmd"}
            try {Invoke-Expression $cmd}
            catch {$failed.Add($cmd)}
        }
    }
    Write-Host
}
else {
    $config = "#I'm an empty config file. You can initialize user adjustable variables here"
    $dlpath = "$rootdir\downloads"
    $doupdate = $true
    $douser = $false
    $dolinks = $true
    $saveform = '%(uploader)s\%(uploader)s - %(upload_date)s - %(title)s.%(ext)s'

}
#Debug Header
if ($DEBUG){
    Write-Host "\\\\>>INITIALIZING DEBUG MODE>>"
    Write-Host "Currently operating from $rootdir"
}

if ($DEBUG -and ($failed -ne $null)) { Write-Host "Debug: `$failed Commands include: $failed" }

$confcnt ++

#Build $oscarflag from various variables
#Sample: -o "..\dlvideos\%(uploader)s\%(uploader)s - %(upload_date)s - %(title)s.%(ext)s"
$oscarflag = " -o `"$dlpath\$saveform`""

#Grab New and Reference Content from information files
if (Test-Path "$rootdir\currentlinks") { $newlinks = Get-Content "$rootdir\currentlinks"}
else{ $newlinks = $null; Write-Host "The currentlinks file is empty!`n"}
if (Test-Path "$rootdir\SystemArchive") {$oldlinks = Get-Content "$rootdir\SystemArchive" }
else {$oldlinks = $null; Write-Host "No archive availible!"}

# Check for new version of Youtube-DL
if ($doupdate) {
    Write-Host "Checking for new Youtube-DL Version`n"
    Start-Process -Filepath $rootdir\youtube-dl.exe -ArgumentList ("-U") -NoNewWindow -Wait
    Write-Host "`nCheck Complete`n"
}

#This needs to be changed to include the alwaysdl options
if (($newlinks -ne $null) -or ($userlinks -ne $null)) {
    #Backs up links. This may end up being a debug option
    if($newlinks -ne $null) {
        $newlinks | Out-File -FilePath "$rootdir\backuplinks";
        if ($DEBUG) {Write-Host "Debug: Backed up currentlinks"}
    }
    else {Write-Host "Failed to backup currentlinks, as there are no currentlinks" }


    # Clears link arraylist to allow fresh links to be written
    $wrlinks.Clear()

    # Add links not in SystemArchive from currentlinks
    if ($dolinks) {
        ForEach ($newlink in $newlinks) {
            $newlink = $newlink -replace '&index=\d{1,3}&list=\w{1,34}',''
            $newlink = $newlink.Replace('https://www.youtube.com/watch?v=', 'youtube ')
            if ($oldlinks -contains $newlink) {$count ++}
            else {
                $newlink = $newlink.Replace("youtube ", "https://www.youtube.com/watch?v=")
                $wrlinks.Add($newlink) | Out-Null
            }
        }

        if ($count -ne 0) {Write-Host "Successfully Removed $count Links"}
        else {Write-Host "No Links Removed"}
        $wrlinks | Out-File -FilePath "$rootdir\currentlinks"
    }
    else {Write-Host "Currentlinks disabled in scriptconf.txt"}

    # Launch Youtube-DL
    $doytdl = ($dldate -ne $today) -or ($wrlinks.Count -gt 0)
    if ($dldate -ne 19691231) {Write-Host "Last Downloaded users on $dldate"}
    else {Write-Host "Never Downloaded users before"}
    if($doytdl) {Write-Host "Launching Youtube-DL`n"}

        # Mechanism for downloading channel videos
    if ($douser -and ($dldate -ne $today)) {
        Write-Host "Downloading User Videos"
        $counter = 0
        ForEach ($user in $userlinks) {
            if ($allowedthreads -eq 0) {$allowedthreads = $userlinks.Count}
            $args = "$user -i --config-location $rootdir\ytdlconf --dateafter $dldate $oscarflag"

            if ($counter -lt $allowedthreads) {
                Start-Process -Filepath $rootdir\youtube-dl.exe -ArgumentList ($args)
            } elseif ($counter -eq $allowedthreads) {
                $counter = 0
                Start-Process -Filepath $rootdir\youtube-dl.exe -ArgumentList ($args) -Wait
                Write-Host "Pausing Script."
            } elseif ($counter -eq ($allowedthreads - 1)) {
                Start-Process -Filepath $rootdir\youtube-dl.exe -ArgumentList ($args) -Wait
                Write-Host "Running User download Threads"
            }
            $counter ++
        }
        $config[4] = '$dldate = ' + $today
        $config | Out-File "$rootdir\scriptconf.txt"
    }

        # Mechanism for downloading individual videos
    if ($dolinks -and ($wrlinks.Count -gt 0)){
        Write-Host "Downloading Individual Videos`n"
        if ($DEBUG) {Write-Host "%%   $wrlinks   %%"}
        $args = "$wrlinks --config-location $rootdir\ytdlconf $oscarflag"
        Start-Process -Filepath $rootdir\youtube-dl.exe -ArgumentList ($args) -NoNewWindow -Wait
    }
    if (-not ($dolinks -and $douser)) { Write-Host "No Links Set to download!" }
    if($doytdl) {Write-Host "`nYoutube-DL Terminated`n"}
}
else {Write-Host "`nNo links set for download!`n"}