$scriptTitle = 'Example Script'

$scriptFileName = 'Example.ps1'

$scriptDesc = 'Example script description'

$version = '0.1.0'

$commands = @{

'example-command' = @{

Description = 'Example description'

# Order is used in the help menu

Order = 0

# Arguments are prefixed by --

Arguments = @{

# Define an argument like this

'required' = @{

Description = 'Example basic required argument'

Order = 0

Required = $true

# (THIS IS OPTIONAL) Type can either be 'STRING', 'BOOLEAN', 'NUMBER', or 'PATH' for built in parsing supported by the framework, you can also specify a custom one as seen below in "custom-type"

Type = 'STRING'

}

'optional' = @{

Description = 'Example basic optional argument'

Order = 1

Required = $false

Type = 'STRING'

}

'path-argument' = @{

Description = 'Example path argument'

Order = 2

Required = $false

# Path arguments are resolved at parse-time. This means if you specify something like a local path (.\ or ./), it will resolve it to the full path before running the command incase you change the working dir

Type = 'PATH'

}

'string-list' = @{

Description = 'Example string list argument'

Order = 3

Required = $false

Type = 'STRING'

# If you want to take a list, specify the List property, it will try and parse a comma seperated list: "1,2,3" (no spaces)

# This works for any of the built in types specified above, and will produce a strongly typed array like: "int[]"

# If the user provides only one item, it will be an array of length 1

List = $true

}

'number-list' = @{

Description = 'Example number list argument'

Order = 4

Required = $false

Type = 'NUMBER'

List = $true

}

'default-argument' = @{

Description = 'Argument with default value'

Order = 5

Required = $false

Type = 'STRING'

# Define a basic default argument

Default = 'This is a default value!'

}

'custom-default' = @{

Description = 'Argument with default value'

Order = 6

Required = $false

Type = 'STRING'

# Use this with the below to provide extra detail in the help menu

DefaultDescription = 'Defaults to show if "example-flag-2" was set'

# Default can also be a script block that calculates a default from the rest of the arguments and flags

# Note that defaults are applied all at once after the rest of the arguments are parsed, meaning you cannot make one default argument rely on another

Default = {

param(

[hashtable]$Arguments,

[hashtable]$Flags

)

if ($Flags['example-flag-2']) {

return 'The example flag 2 was set'

}

else {

return 'The example flag 2 was not set'

}

}

}

# Use this when you have complex requirements, takes Arguments and Flags as params, wow! (make sure to return a boolean)

'custom-requirements' = @{

Description = 'This command has a custom requirement block'

Order = 7

# Optionally you can provide a description for your custom script block

RequiredDescription = 'Checks if the -example-flag is set'

Required = {

param(

[Hashtable]$Arguments,

[Hashtable]$Flags

)

# Simply returns if the flag exists, could be whatever you want though

return $Flags['example-flag']

}

Type = 'STRING'

}

'custom-type' = @{

Description = 'Example basic optional argument'

Order = 8

Required = $false

# You can specify any string name you want for the type (this is just for display)

Type = 'NAME/VALUE'

# If you want to actually do custom type parsing, specify the CustomType property with a script block, takes the argument value as a parameter

CustomType = @{

# If you want the argument value to be created with strong typing, set the intended return type here, if you do not, it will simply return it as an Object[] with no garuntees about the types held

ReturnType = [hashtable]

Parser = {

param(

[System.Object]$Value

)

# Checks if argument can be split in two by a slash

$parts = $value -split '/'

if ($parts.Length -eq 2) {

$parsedArgument = @{}

$parsedArgument['name'] = $parts[0]

$parsedArgument['value'] = $parts[1]

# If it can be parsed, return whatever custom parsed type you want

return $parsedArgument

}

# Implicit null return

}

}

# This also works with the list property like below, the custom rules will be applied to each element

# List = $true

}

# Define a group like this

# Use this when you want a group where AT LEAST ONE option is required

'Required Group' = @{

# When making a group, set this to true

Group = $true

# You can also set custom requirement script blocks here like above

Required = $true

Exclusive = $false

Order = 9

Arguments = @{

'required-group-1' = @{

Description = 'Either this or required-group-2 are required (or both)'

# Group order is independant of normal argument order

Order = 1

Type = 'STRING'

}

'required-group-2' = @{

Description = 'Either this or required-group-1 are required (or both)'

Order = 2

Type = 'STRING'

}

}

}

# Use this when you want a group that ONLY takes one option but is required

'Exclusive Group' = @{

Group = $true

Required = $false

Exclusive = $true

Order = 10

Arguments = @{

'exclusive-group-1' = @{

Description = 'Either this or exclusive-group-2 are required (not both)'

Order = 1

Type = 'STRING'

}

'exclusive-group-2' = @{

Description = 'Either this or exclusive-group-1 are required (not both)'

Order = 2

Type = 'STRING'

}

}

}

}

# Flags are prefixed by -

Flags = @{

'example-flag' = @{

Description = 'Example flag'

Order = 0

}

'example-flag-2' = @{

Description = 'See what happens to "custom-default" when you set this!'

Order = 1

}

}

}

}

function example-command {

param(

[Hashtable]$Arguments,

[Hashtable]$Flags

)

# Arguments received in here are simply name-value, they are NOT the same format as you specified above (does not include the extra info) so you simply access them as seen below for the value

# Make sure to check if arguments are specified, they are possibly null!

if ($arguments.ContainsKey('required')) {

Write-Host "Value for required argument: $($arguments['required'])"

}

if ($arguments.ContainsKey('path-argument')) {

Write-Host "Resolved path argument: $($arguments['path-argument'])"

}

# List was set, we can iterate over it now

if ($arguments.ContainsKey('string-list')) {

foreach ($item in $arguments['string-list']) {

Write-Host "String list item: $item"

}

}

# Lists are strongly typed based on the set type

if ($arguments.ContainsKey('number-list')) {

Write-Host "String list is strongly typed: $($arguments['number-list'].GetType())"

}

# Group arguments are flattened into the arguments here, so they are all accessed at the root level

if ($arguments.ContainsKey('required-group-1')) {

Write-Host "Value for required-group-1 argument: $($arguments['required-group-1'])"

}

if ($arguments.ContainsKey('custom-type')) {

# Our custom type is parsed into the object from above, we can use it as such

$customType = $arguments['custom-type']

Write-Host "Custom type was set!"

Write-Host "Custom type name: $($customType['name'])"

Write-Host "Custom type value: $($customType['value'])"

}

if ($arguments.ContainsKey('default-argument')) {

Write-Host "Found default argument: $($arguments['default-argument'])"

}

if ($arguments.ContainsKey('custom-default')) {

Write-Host "Found default argument, this was calculated dynamically: $($arguments['custom-default'])"

}

# Flags do not need to be checked with "ContainsKey" as the ones not specified are all initialized to $false, simply check them as booleans

if ($flags['example-flag']) {

Write-Host 'Example flag is set!'

}

}

function Get-FlatArguments {

param (

[string]$CommandName

)

$flatArguments = @{}

if ($commands[$commandName].ContainsKey('Arguments')) {

foreach ($argument in $commands[$commandName]['Arguments'].GetEnumerator()) {

if ($argument.Value.ContainsKey('Group') -and $argument.Value['Group']) {

$group = $argument.Value

if ($group.ContainsKey('Arguments')) {

foreach ($groupArgument in $group['Arguments'].GetEnumerator()) {

$flatArguments[$groupArgument.Key] = $groupArgument.Value

}

}

}

else {

$flatArguments[$argument.Key] = $argument.Value

}

}

}

return $flatArguments

}

function Show-Argument {

param (

[System.Collections.DictionaryEntry]$Argument,

[int]$Padding

)

$argumentOutputString = " --$("$($argument.Key) <$($argument.Value['Type'])>".PadRight($padding)) $($argument.Value['Description'])"

if ($argument.Value.ContainsKey('Default')) {

if ($argument.Value['Default'] -is [System.Management.Automation.ScriptBlock]) {

if ($argument.Value.ContainsKey('DefaultDescription')) {

$argumentOutputString = $argumentOutputString + " (default: $($argument.Value['DefaultDescription']))"

}

else {

$argumentOutputString = $argumentOutputString + " (default: <not specified>)"

}

}

else {

$argumentOutputString = $argumentOutputString + " (default: $($argument.Value['Default']))"

}

}

Write-Host $argumentOutputString

}

function Show-HelpMenu {

param (

[Parameter(Mandatory = $False)]

[string]$SelectedCommand

)

# Header of help menu, all defined at the top of the file

Write-Host "=== $scriptTitle ==="

Write-Host $scriptDesc

Write-Host "Version: $version"

Write-Host ''

Write-Host "Usage: $scriptFileName [COMMAND] [ARGUMENTS] [FLAGS]"

Write-Host ''

# Iterate over all the commands and args/flags to dynamically calculate the padding needed to make all of the text line up in the help menu

$helpMenuCommandPadding = 0

$helpMenuArgsAndFlagsPadding = 0

foreach ($commandName in $commands.Keys) {

if ($commandName.Length -gt $helpMenuCommandPadding) {

$helpMenuCommandPadding = $commandName.Length

}

$flatArguments = Get-FlatArguments -CommandName $commandName

foreach ($argument in $flatArguments.GetEnumerator()) {

$fullArgument = $argument.Key

if ($argument.Value.ContainsKey('Type')) {

$fullArgument = "$fullArgument <$($argument.Value['Type'])>"

}

if ($fullArgument.Length -gt $helpMenuArgsAndFlagsPadding) {

$helpMenuArgsAndFlagsPadding = $fullArgument.Length

}

}

foreach ($flagName in $commands[$commandName]['Flags'].Keys) {

if ($flagName.Length -gt $helpMenuArgsAndFlagsPadding) {

$helpMenuArgsAndFlagsPadding = $flagName.Length

}

}

}

# Add a gap

$helpMenuCommandPadding += 2

$helpMenuArgsAndFlagsPadding += 2

if (-not $selectedCommand) {

Write-Host '[COMMANDS]'

}

$sortedCommands = $commands.GetEnumerator() | Sort-Object { $_.Value['Order'] }

foreach ($command in $sortedCommands) {

# Provides sub-menu for a selected command instead of printing all

if ($selectedCommand -and ($selectedCommand -ne ($command.Key))) {

continue

}

Write-Host " $($command.Key.PadRight($helpMenuCommandPadding)) $($command.Value['Description'])"

Write-Host ''

if ($command.Value.ContainsKey('Arguments')) {

Write-Host ' [ARGUMENTS]'

# Get args and sort by the Order property

$arguments = $command.Value['Arguments']

$sortedArguments = $arguments.GetEnumerator() | Sort-Object { $_.Value['Order'] }

# We use this to make sure we have standardized spacing of newlines between arguments, which needs to happen differently if we last printed a group or just an argument

$lastItemWasGroup = $false

foreach ($argument in $sortedArguments) {

# Check if the argument is a group

if ($argument.Value.ContainsKey('Group') -and $argument.Value['Group']) {

$lastItemWasGroup = $true

Write-Host ''

$group = $argument.Value

if ($group.ContainsKey('Arguments')) {

$groupTitleString = " {$($argument.Key)}"

if ($group.ContainsKey('Required') -and $group['Required']) {

$groupTitleString += ' (Required)'

}

if ($group.ContainsKey('Exclusive') -and $group['Exclusive']) {

$groupTitleString += ' (Exclusive)'

}

Write-Host $groupTitleString

$groupArguments = $group['Arguments'].GetEnumerator() | Sort-Object { $_.Value['Order'] }

foreach ($groupArgument in $groupArguments) {

Show-Argument -Argument $groupArgument -Padding $helpMenuArgsAndFlagsPadding

}

}

}

else {

if ($lastItemWasGroup) {

Write-Host ''

}

Show-Argument -Argument $argument -Padding $helpMenuArgsAndFlagsPadding + 2

}

}

Write-Host ''

}

if ($command.Value.ContainsKey('Flags')) {

Write-Host ' [FLAGS]'

$flags = $command.Value['Flags'].GetEnumerator() | Sort-Object { $_.Value['Order'] }

foreach ($flagName in $flags.Key) {

$flagValue = $command.Value['Flags'][$flagName]

Write-Host " -$($flagName.PadRight($helpMenuArgsAndFlagsPadding + 1)) $($flagValue['Description'])"

}

Write-Host ''

}

}

Write-Host ''

}

if ($Args.Count -eq 0 -or $Args[0] -eq '-h' -or $Args[0] -eq '--help') {

Show-HelpMenu

exit 0

}

if (-not $commands.ContainsKey($Args[0])) {

throw 'Invalid command selected (Use -h or --help for help)'

}

$selectedCommand = $null

$flattenedCommandArguments = $null

$selectedArguments = @{}

$selectedFlags = @{}

for ($i = 0; $i -lt $Args.Count; $i++) {

if ($i -eq 0) {

# First cmd arg is the command

$selectedCommand = $Args[0]

$flattenedCommandArguments = Get-FlatArguments -CommandName $Args[0]

}

elseif ($Args -contains '-h' -or $Args -contains '--help') {

if ($selectedCommand) {

# Shows sub-menu for just the selected command

Show-HelpMenu -SelectedCommand $selectedCommand

}

else {

Show-HelpMenu

}

exit 0

}

elseif ($Args[$i].StartsWith('--')) {

# Arguments all start with --

# Parsing, we want to support either "--argument value" or "--argument=value"

$arg = $Args[$i].Substring(2)

$argParts = $arg -split '='

$keyword = $argParts[0]

$value = $null

if (-not $flattenedCommandArguments.ContainsKey($keyword)) {

throw 'Invalid argument (Use -h or --help for help)'

}

# This sets the value if the argument was provided with an equals in between

if ($argParts.Count -eq 2) {

$value = $argParts[1]

}

elseif ($argParts.Count -gt 2 -or $argParts -lt 1) {

# There should not be more than two parts or less than one

throw 'Malformed argument (Use -h or --help for help)'

}

# If the value was provided with a space in between it will be the next arg value, so move it to the next and save it

if (-not $value) {

$i++

$value = $Args[$i]

}

# If one of the above did not work, a value was not provided

if (-not $value) {

throw "No value provided for argument `"$keyword`" (Use -h or --help for help)"

}

# Get the argument type name

$argumentTypeString = $flattenedCommandArguments[$keyword]['Type']

# Default to opaque object for target type and parser just passes the object through

$targetType = [System.Object]

$parser = { param([System.Object]$Value) return $value }

if ($flattenedCommandArguments[$keyword].ContainsKey('CustomType')) {

# Using custom type rules, set those accordingly

if ($flattenedCommandArguments[$keyword].ContainsKey('ReturnType')) {

$targetType = $flattenedCommandArguments[$keyword]['CustomType']['ReturnType']

}

$parser = $flattenedCommandArguments[$keyword]['CustomType']['Parser']

}

else {

# Check if the argument type name matches a built in parser

switch ($argumentTypeString) {

'STRING' {

$targetType = [string]

$parser = { param([System.Object]$Value) return $value -as [string] }

}

'NUMBER' {

$targetType = [int32]

$parser = { param([System.Object]$Value) return $value -as [int32] }

}

'BOOLEAN' {

$targetType = [bool]

$parser = { param([System.Object]$Value) return $value -as [bool] }

}

'PATH' {

$targetType = [string]

$parser = {

param(

[System.Object]$Value

)

if ((-not ($value -match '\\')) -and (-not ($value -match '/'))) {

$value = Join-Path -Path (Get-Location) -ChildPath $value

}

$parentDir = Split-Path -Path $value -Parent

if ((-not $parentDir) -or ($parentDir -and (Test-Path -Path $parentDir))) {

return (Resolve-Path -Path $value).Path -as [string]

}

}

}

}

}

$targetArrayType = $targetType.MakeArrayType()

$shouldBeList = $flattenedCommandArguments[$keyword].ContainsKey('List') -and $flattenedCommandArguments[$keyword]['List']

$parsedValue = $null

# If the value is a list, parse as such

if ($value -is [System.Object[]]) {

if (-not $shouldBeList) {

# The argument is not supposed to be a list, so we error

throw "Argument value for `"$keyword`" cannot be a list (Use -h or --help for help)"

}

# Iterate over the value list in place (do not reallocate) and call the parser on each value

for ($j = 0; $j -lt $value.Length; $j++) {

$parsedListItem = & $parser -Value $value[$j]

if ($null -ne $parsedListItem) {

$value[$j] = $parsedListItem

}

else {

# If we get a null value that means the parsing failed, notify the user and exit

throw "Argument value `"$($value[$j])`" is not a valid $($argumentTypeString.ToLower()) (Use -h or --help for help)"

}

}

# Now that we know we have converted all the elements of the array, it should be safe to cast to the target type

$parsedValue = $value -as $targetArrayType

}

else {

# User provided only one item

if ($shouldBeList) {

# The output should be a list, so we make one with one element and cast it

$parsedItem = & $parser -Value $value

if ($null -ne $parsedItem) {

$parsedValue = @($parsedItem) -as $targetArrayType

}

else {

throw "Argument value `"$value`" is not a valid $($argumentTypeString.ToLower()) (Use -h or --help for help)"

}

}

else {

# The output should just be one value, cast it

$parsedValue = & $parser -Value $value

}

}

# If any of our final casts failed, this is null, so we notify the user and exit

if ($null -eq $parsedValue) {

if ($shouldBeList) {

throw "Argument value `"$value`" for `"$keyword`" is not a valid $($argumentTypeString.ToLower()) list (Use -h or --help for help)"

}

else {

throw "Argument value `"$value`" for `"$keyword`" is not a valid $($argumentTypeString.ToLower()) (Use -h or --help for help)"

}

}

# Set the argument

$selectedArguments[$keyword] = $parsedValue

}

elseif ($Args[$i].StartsWith('-')) {

# Flags all start with -

$flag = $Args[$i].Substring(1)

if (-not $commands[$selectedCommand]['Flags'].ContainsKey($flag)) {

throw 'Invalid flag (Use -h or --help for help)'

}

$selectedFlags[$flag] = $True

}

else {

throw 'Invalid input (Use -h or --help for help)'

}

}

foreach ($flagName in $commands[$selectedCommand]['Flags'].Keys) {

if (-not $selectedFlags.ContainsKey($flagName)) {

$selectedFlags[$flagName] = $False

}

}

$defaultArguments = @{}

foreach ($argument in $flattenedCommandArguments.GetEnumerator()) {

if ($argument.Value.ContainsKey('Default')) {

if ($argument.Value['Default'] -is [System.Management.Automation.ScriptBlock]) {

$defaultArguments[$argument.Key] = & $argument.Value['Default'] -Arguments $selectedArguments -Flags $selectedFlags

}

else {

$defaultArguments[$argument.Key] = $argument.Value['Default']

}

}

}

foreach ($defaultArgument in $defaultArguments.GetEnumerator()) {

if (-not $selectedArguments.ContainsKey($defaultArgument.Key)) {

$selectedArguments[$defaultArgument.Key] = $defaultArgument.Value

}

}

foreach ($argument in $flattenedCommandArguments.GetEnumerator()) {

if ($argument.Value.ContainsKey('Group') -and $argument.Value['Group']) {

$group = $argument.Value

if ($group.ContainsKey('Required')) {

if ($group['Required'] -is [bool]) {

$required = $false

if ($group.ContainsKey('Required') -and $group['Required']) {

$required = $true

}

$exclusive = $false

if ($group.ContainsKey('Exclusive') -and $group['Exclusive']) {

$exclusive = $true

}

if ($group.ContainsKey('Arguments')) {

$numberOfArgumentsSelected = 0

foreach ($groupArgument in $group['Arguments'].GetEnumerator()) {

$selectedArguments

if ($selectedArguments.ContainsKey($groupArgument.Key)) {

$numberOfArgumentsSelected++

}

}

if (($numberOfArgumentsSelected -eq 0) -and $required) {

throw "Missing required argument for required group `"$($argument.Key)`" (Use -h or --help for help)"

}

if (($numberOfArgumentsSelected -gt 1) -and $exclusive) {

throw "Multiple arguments specified for exclusive group `"$($argument.Key)`" (Use -h or --help for help)"

}

}

}

elseif ($group['Required'] -is [System.Management.Automation.ScriptBlock]) {

if (-not (& $group['Required'] -Arguments $selectedArguments -Flags $selectedFlags)) {

if ($group.ContainsKey('RequiredDescription')) {

throw "Group `"$($argument.Key)`" did not meet the requirements: $($group['RequiredDescription'])"

}

else {

throw "Group `"$($argument.Key)`" did not meet the requirements, no description was provided."

}

}

}

}

}

else {

if ($argument.Value.ContainsKey('Required')) {

if ($argument.Value['Required'] -is [bool] -and $argument.Value['Required'] -and (-not $selectedArguments.ContainsKey($argument.Key))) {

throw "Missing required argument `"$($argument.Key)`" (Use -h or --help for help)"

}

if ($argument.Value['Required'] -is [System.Management.Automation.ScriptBlock]) {

if (-not (& $argument.Value['Required'] -Arguments $selectedArguments -Flags $selectedFlags)) {

if ($argument.Value.ContainsKey('RequiredDescription')) {

throw "Argument `"$($argument.Key)`" did not meet the requirements: $($argument.Value['RequiredDescription'])"

}

else {

throw "Argument `"$($argument.Key)`" did not meet the requirements, no description was provided."

}

}

}

}

}

}

& (Get-Command $selectedCommand) -Arguments $selectedArguments -Flags $selectedFlags