9_Writing and Using Functions.ps1

# -------------------------------------------------------
# Writing and Using Functions
# -------------------------------------------------------

# Simple Function
Function BoolToReadable {
    "No"
}

BoolToReadable

# Simple Function with Arguments
Function BoolToReadable($current, $test) {
    if($current){
        return "Yes"
    }
    $test
    "No"
}

BoolToReadable $false "bob"

# Function with Parameters
Function BoolToReadable {
    param(
        [bool] $Current,
        [bool] $Test
    )
    
    if($Current) {
        
        return "Yes"
    }

    "No"
}

BoolToReadable -Current $true

# Function with Advanced Parameters
Function BoolToReadable {
    param(
        [Parameter(Mandatory = $true)]
        [bool] $Current = $false
    )
    Write-Verbose "Current Value is: $($Current.ToString())" -Verbose
    if($Current) {
        
        return "Yes"
    }

    "No"
}

BoolToReadable
BoolToReadable -Current $false

#Function with Advanced Parameter + Common Parameters
Function BoolToReadable {
    [CmdletBinding()]

    param(
        [Parameter(Mandatory = $true)]
        [bool] $Current
    )
    Write-Host "Verbose Var: $($VerbosePreference)"
    Write-Verbose "Current Value is: $($Current.ToString())"

    if($Current) {
        
        return "Yes"
    }

    "No"
}

BoolToReadable
BoolToReadable -Current $false
BoolToReadable -Current $true -Verbose

# -------------------------------------------------------
# Example of Using
# -------------------------------------------------------

$userData = '[
    {
        "AccountExpires":  null,
        "Description":  "Built-in account for administering the computer/domain",
        "Enabled":  true,
        "FullName":  "",
        "PasswordChangeableDate":  null,
        "PasswordExpires":  null,
        "UserMayChangePassword":  true,
        "PasswordRequired":  true,
        "PasswordLastSet":  null,
        "LastLogon":  "\/Date(1605771872777)\/",
        "Name":  "Administrator",
        "SID":  {
                    "BinaryLength":  28,
                    "AccountDomainSid":  "S-1-5-21-1627568633-850217724-3435047281",
                    "Value":  "S-1-5-21-1627568633-850217724-3435047281-500"
                },
        "PrincipalSource":  1,
        "ObjectClass":  "User"
    },
    {
        "AccountExpires":  null,
        "Description":  "A user account managed by the system.",
        "Enabled":  false,
        "FullName":  "",
        "PasswordChangeableDate":  null,
        "PasswordExpires":  null,
        "UserMayChangePassword":  true,
        "PasswordRequired":  false,
        "PasswordLastSet":  null,
        "LastLogon":  null,
        "Name":  "DefaultAccount",
        "SID":  {
                    "BinaryLength":  28,
                    "AccountDomainSid":  "S-1-5-21-1627568633-850217724-3435047281",
                    "Value":  "S-1-5-21-1627568633-850217724-3435047281-503"
                },
        "PrincipalSource":  1,
        "ObjectClass":  "User"
    },
    {
        "AccountExpires":  null,
        "Description":  "Built-in account for guest access to the computer/domain",
        "Enabled":  false,
        "FullName":  "",
        "PasswordChangeableDate":  null,
        "PasswordExpires":  null,
        "UserMayChangePassword":  false,
        "PasswordRequired":  false,
        "PasswordLastSet":  null,
        "LastLogon":  null,
        "Name":  "Guest",
        "SID":  {
                    "BinaryLength":  28,
                    "AccountDomainSid":  "S-1-5-21-1627568633-850217724-3435047281",
                    "Value":  "S-1-5-21-1627568633-850217724-3435047281-501"
                },
        "PrincipalSource":  1,
        "ObjectClass":  "User"
    },
    {
        "AccountExpires":  null,
        "Description":  "shared",
        "Enabled":  false,
        "FullName":  "shared",
        "PasswordChangeableDate":  "\/Date(-11644387200000)\/",
        "PasswordExpires":  null,
        "UserMayChangePassword":  false,
        "PasswordRequired":  true,
        "PasswordLastSet":  null,
        "LastLogon":  null,
        "Name":  "shared",
        "SID":  {
                    "BinaryLength":  28,
                    "AccountDomainSid":  "S-1-5-21-1627568633-850217724-3435047281",
                    "Value":  "S-1-5-21-1627568633-850217724-3435047281-1002"
                },
        "PrincipalSource":  1,
        "ObjectClass":  "User"
    },
    {
        "AccountExpires":  null,
        "Description":  "A user account managed and used by the system for Windows Defender Application Guard scenarios.",
        "Enabled":  false,
        "FullName":  "",
        "PasswordChangeableDate":  "\/Date(1605858056395)\/",
        "PasswordExpires":  "\/Date(1609400456395)\/",
        "UserMayChangePassword":  true,
        "PasswordRequired":  true,
        "PasswordLastSet":  "\/Date(1605771656395)\/",
        "LastLogon":  null,
        "Name":  "WDAGUtilityAccount",
        "SID":  {
                    "BinaryLength":  28,
                    "AccountDomainSid":  "S-1-5-21-1627568633-850217724-3435047281",
                    "Value":  "S-1-5-21-1627568633-850217724-3435047281-504"
                },
        "PrincipalSource":  1,
        "ObjectClass":  "User"
    }
]'

$users = $userData | ConvertFrom-Json
$adminGroup = "Administrator", "Tim Davis"

# Step 1, run lines 1-104 to populate $users with User data (Local User Accounts from a PC)
# and Administrators Group data.  
# Using user data, generate a collection of custom user objects with the following properties
# Name
# Enabled (Yes|No)
# PasswordRequired (Yes|No)
# UserCanChangePassword (Yes|No)
# IsAdmin (Yes|No) (Can compare to users in $adminGroup)
# IsBuiltInAdmin (Yes|No)

# One a collection of custom objects have been created, display them by piping to Format-Table

# Results will look like
#
#Name               PasswordRequired IsBuiltInAdmin IsAdmin UserMayChangePassword Enabled
#----               ---------------- -------------- ------- --------------------- -------
#Administrator      Yes              Yes            Yes     Yes                   Yes
#DefaultAccount     No               No             No      Yes                   No
#Guest              No               No             No      No                    No
#shared             Yes              No             No      No                    No
#WDAGUtilityAccount Yes              No             No      Yes                   No

# In this exercise you will use Loops, Conditionals, could potentially use a Function,
# HashTable, as well as creaing an object from a Hashtable, and Lists

$results = New-Object -TypeName System.Collections.Generic.List[PSCustomObject]

# Function to convert True/False to Yes/No
Function BoolToReadable {
    param(
        [bool] $Current
    )

    if($Current) {
        return "Yes"
    }

    return "No"
}

# Loop through each user
foreach($user in $users) {

    # Create a new Hashtable with the properties we want
    $hash = @{
        Name = $user.Name 
        Enabled = BoolToReadable -Current $user.Enabled    # <- Use function to do conversion over and over again
        PasswordRequired = BoolToReadable -Current $user.PasswordRequired
        UserMayChangePassword = BoolToReadable -Current $user.UserMayChangePassword
        IsAdmin = BoolToReadable -Current ($user.Name -in $adminGroup)   # <- Since function is expecting T/F we can use Conditionals
        IsBuiltInAdmin = BoolToReadable -Current ($user.Name -eq "Administrator")
    }

    # Create our new Object from the Hashtable
    $obj = New-Object -TypeName PSCustomObject -Property $hash
    # Add Object to results colleciton
    $results.Add($obj)
}

$results | Format-Table