2008 Scripting Games, Solution 10

# Advanced Event 10: Blackjack!
# http://www.microsoft.com/technet/scriptcenter/funzone/games/games08/aevent10.mspx

# -ShowValue is an aid in testing the script
param([switch]$showValues,$dealerColor=$host.ui.RawUI.ForegroundColor,$playerColor=$host.ui.RawUI.ForegroundColor)

# Define cards and their values, prepare for double-value cards (the Ace), but I did not implement the
# logic for playing with it
$cards="Hearts","Diamonds","Spades","Clubs" | % { 
    $suite=$_
    "Ace,11,1","Two,2","Three,3","Four,4","Five,5","Six,6","Seven,7","Eight,8","Nine,9","Ten,10","Jack,10","Queen,10","King,10" | % {
        $card="" | select Name,Rank,Suite,Value,Value2
        $Card.Rank,$Card.Value,$Card.Value2=$_.split(",")
        $card.Name=$Card.Rank + " of $suite"
        $card.Suite=$suite
        $card
    }
}


# Shuffle (using sort-random) and place in stack - love the ability to use .net :D

[Collections.Stack] $cards=$cards | sort {(new-object random).next()}

# Show a hand
function ShowCards([switch]$dealer) {
    begin {
        ""
        if ($dealer.ispresent) {
            $color=$dealerColor
            write-host -foreground $color "Dealer's cards:"
        }
        else {
            $color=$playerColor
            write-host -foreground $color "Your cards:"
        }
        $sum=0
    }
    process {
        if ($showValues.ispresent) {
            write-host -foreground $color ("{0} ({1})" -f $_.name,$_.value)
        }
        else {
            write-host -foreground $color $_.name
        }
        $sum+=$_.value
    }
    end {
        if ($showValues.ispresent) {
            write-host -foreground $color ("Total {0}" -f $sum)
        }
    }
}

# Stay or hit function
function Ask{
    write-host -nonewline "Stay (s) or hit (h) ?"
    do {
        $key=$host.ui.rawui.ReadKey("noecho,includekeydown").character
    } until ($key -eq "s" -or $key -eq "h")
    write-host $key
    $key
}

# Sum up the hand
function value{
    begin {
        $sum=0
    }
    process {
        $sum+=$_.value
    }
    end {
        $sum
    }
}

$player=@()
$dealer=@()

# Start dealing
$player+=$cards.pop()
$player+=$cards.pop()
$player | ShowCards
$playervalue=$player | value

# And the dealer
$dealer+=$cards.pop()
$dealer | ShowCards -dealer
# Second card is hidden
$dealer+=$cards.pop()
$dealervalue=$dealer | value

# Player's turn

# Continue dealing until gt 21 or 'stay'
while ((ask) -eq "h") {
    $player+=$cards.pop()
    $player | ShowCards
    $playervalue=$player | value
    if ($playervalue -ge 21) {
        break
    }
}

"You have $playervalue"
""
$dealer | ShowCards -dealer
""

if ($playervalue -gt 21) {
    "Over 21. Sorry you loose"
}
elseif ($playervalue -eq 21) {
    "Black Jack. You win"
}
elseif ($dealervalue -ge $playervalue) {
    "Dealer has $dealervalue. Sorry you loose"
}
else {
    # Dealer playes, must continue until player is defeated, black jack or exceeds 21
    while ($dealervalue -lt $playervalue) {
        $dealer+=$cards.pop()
        $dealer | ShowCards -dealer
        $dealervalue=$dealer | value
    }
    if ($dealervalue -gt 21) {
        "Dealer has over 21. You win"
    }
    elseif ($dealervalue -eq 21) {
        "Dealer has Black Jack. Sorry you loose"
    }
    elseif ($dealervalue -ge $playervalue) {
        "Dealer has $dealervalue. Sorry you loose"
    }
    else {
        "Dealer has $dealervalue. You win"
    }
}