class SourceDirs {
    static $MixxxConfig = "$env:USERPROFILE\AppData\Local\Mixxx"
    static $Test        = "C:\tmp\Test With Spaces"

    static $Desktop_ITunes = "$env:USERPROFILE\Music\iTunes\iTunes Media\Music"
    
    static $Music_MixxxConfig  = "M:\Config\Mixxx"
    static $Music_ITunes       = "M:\Music\ITUNES"
    static $Music_ZipDJ        = "M:\Music\ZipDJ Tracks"
    static $Music_Music        = "M:\Music"
    
    static $Drive_MixxxConfig  = "D:\Config\Mixxx"
    static $Drive_ITunes       = "D:\Music\ITUNES"
    static $Drive_ZipDJ        = "D:\Music\ZipDJ Tracks"
    static $Drive_Music        = "D:\Music"
}

class Choice {
    [string] $DisplayName
    [string] $Source
    [string] $Dest
    [boolean] $MakeBackup
    [boolean] $IgnoreTimestamps

    Choice($displayName, $source, $dest, $makeBackup, $ignoreTimestamps) {
        $this.Source = $source
        $this.Dest = $dest
        $this.DisplayName = $displayName
        $this.MakeBackup = $makeBackup
        $this.IgnoreTimestamps = $ignoreTimestamps
    }
}

$CHOICES = @(
    ############
    # Mixxx
    [Choice]::new(
        "Mixxx:   Desktop --> Server",
        [SourceDirs]::MixxxConfig,
        [SourceDirs]::Music_MixxxConfig,
        $false, # Make Backup
        $false  # Ignore Timestamps
    ),
    [Choice]::new(
        "Mixxx:   Desktop --> Drive",
        [SourceDirs]::MixxxConfig,
        [SourceDirs]::Drive_MixxxConfig,
        $false, # Make Backup
        $false  # Ignore Timestamps
    ),
    [Choice]::new(
        "Mixxx:   Drive   --> Laptop",
        [SourceDirs]::Music_MixxxConfig,
        [SourceDirs]::MixxxConfig,
        $true,  # Make Backup
        $false  # Ignore Timestamps
    ),
    [Choice]::new(
        "Mixxx:   Drive   --> Desktop",
        [SourceDirs]::Drive_MixxxConfig,
        [SourceDirs]::MixxxConfig,
        $true,  # Make Backup
        $false  # Ignore Timestamps
    ),
    [Choice]::new(
        "Mixxx:   Laptop  --> Drive",
        [SourceDirs]::MixxxConfig,
        [SourceDirs]::Music_MixxxConfig,
        $false, # Make Backup
        $false  # Ignore Timestamps
    ),

    ##########
    # iTunes
    [Choice]::new(
        "iTunes:  Desktop --> Server",
        [SourceDirs]::Desktop_ITunes,
        [SourceDirs]::Music_ITunes,
        $false,  # Make Backup
        $true  # Ignore Timestamps
    ),
    [Choice]::new(
        "iTunes:  Drive   --> Server",
        [SourceDirs]::Drive_ITunes,
        [SourceDirs]::Music_ITunes,
        $false,  # Make Backup
        $true  # Ignore Timestamps
    ),
    [Choice]::new(
        "iTunes:  Server  --> Desktop",
        [SourceDirs]::Music_ITunes,
        [SourceDirs]::Desktop_ITunes,
        $false,  # Make Backup
        $true  # Ignore Timestamps
    ),

    ##########
    # Music
    [Choice]::new(
        "Music:   Server  --> Drive",
        [SourceDirs]::Music_MixxxConfig,
        [SourceDirs]::MixxxConfig,
        $false,  # Make Backup
        $true  # Ignore Timestamps
    ),
    
    ##########
    # Zip DJ
    [Choice]::new(
        "ZipDJ:  Drive   --> Server",
        [SourceDirs]::Drive_ZipDJ,
        [SourceDirs]::Music_ZipDJ,
        $false,  # Make Backup
        $true  # Ignore Timestamps
    )
)

# Print the given message preceded by the name of the calling function.
function out($message) {
    $caller = (Get-PSCallStack)[1].Command
    Write-Host "${caller}: $message"
}

# Print the given message, preceded by the name of the calling function,
# prompt the user to hit a key, and exit.
function fail($message) {
    $caller = (Get-PSCallStack)[1].Command
    Write-Host "ERROR: ${caller}: $message"
    Read-Host -Prompt "Press Enter to exit"
    exit -1
}

function pause($message) {
    $caller = (Get-PSCallStack)[1].Command
    Write-Host "${caller}: $message`n`n"
    Read-Host -Prompt "Press Enter to continue, or CTRL+C to exit"
}

function GetModifiedDate($dirPath) {
    $dir = Get-Item $dirPath
    $date = Get-Date $dir.LastWriteTime
    return $date.ToShortDateString()
}

# Rename the specified directory to have a suffix based on the
# last modified time.
function makeDatedBackup($dirPath) {
    if (-not(Test-Path $dirPath)) {
        # Not an error, but nothing we can do.
        out "Directory does no exist: ${dirPath}"
        return
    }

    $modifiedDate = GetModifiedDate($dirPath)
    $newPath = "$dirPath-$modifiedDate"
    
    if (Test-Path $newPath) {
        $num = 2
        $newNewPath = "$newPath-$num"
        while (Test-Path $newNewPath) {
            $num++
        }
        out "$newPath already exists. Using $newNewPath"
        $newPath = $newNewPath
    }

    $dirName = [io.path]::GetFileName($newPath)
    pause "Moving $dirPath to $dirName"

    Move-Item -Path $dirPath -Destination $newPath
}

# Synchronize the contents of two directories.
# -NoBackup: Skip moving the existing destination to a dated backup path.
# -IgnoreTimestamps: Skip re-copying files if only timestamps are different.
function syncDirs {
    param (
        [string] $Source,
        [string] $Destination,
        [boolean] $MakeBackup,
        [boolean] $IgnoreTimestamps
    )

    if (($Source.Length -eq 0) -or ($Destination.Length -eq 0)) {
        fail "Both Source and Destination need to be specified."
    }

    if (-not(Test-Path $Source)) {
        fail "Source does not exist: $Source"
    }

    if ($MakeBackup) {
        out "Backing up $Destination"
        makeDatedBackup $Destination
    }

    # Docs: https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/robocopy
    $roboWhat = @("/s", "/copy:DAT", "/dcopy:DAT")
    $roboOptions = @("/v", "/j")
    $roboExclude = @("/xo", "/xx")
    $roboAdditionalExcludes = @()

    if ($IgnoreTimestamps) {
        $roboAdditionalExcludes = @("/xn")
    }

    pause "Copying contents of: `n`t${Source}`nTo:`n`t${Destination}"

    robocopy $Source $Destination $roboWhat $roboOptions $roboExclude
}

function chooseSyncOption() {
    $num = 1
    Write-Host "`nPick an option to run:"
    ForEach ($o in $CHOICES) {
        Write-Host ([string]::Format("{0}) {1}", $num, $o.DisplayName))
        $num++
    }
    Write-Host "`n`n"

    Write-Host "Before an event: 1, 2, 6, 9"
    Write-Host "During an event: 3"
    Write-host "After an event:  5, 7, 8, 10, 4"
    $input = Read-Host -Prompt "Enter option number"
    $choice = [int]$input

    if (($choice -lt 1) -or ($choice -gt $CHOICES.Length + 1)) {
        fail 'Invalid choice!'
    }

    return $CHOICES[$choice-1]
}

function Main() {
    [Choice] $option = chooseSyncOption
    $option
    syncDirs `
        -Source $option.Source `
        -Destination $option.Dest `
        -MakeBackup $option.MakeBackup `
        -IgnoreTimestamps $option.IgnoreTimestamps
    #syncDirs -Source ([SourceDirs]::MixxxConfig) -Destination ([SourceDirs]::Test) -NoBackup -IgnoreTimestamps

    pause ([string]::Format("Done running {0}!", $option.DisplayName))
}

Main