PSAirTable.psm1

Set-StrictMode -Version Latest

$WorkingDir = $MyInvocation.MyCommand.Path | Split-Path -Parent
$EndPointUri = 'https://api.airtable.com/v0'

function Get-AirTableApiKey {
    <#
        .SYNOPSIS
            Queries the API key configuration to return the API key set earlier via the Save-AirTableApiKey command.
    
        .EXAMPLE
            PS> Get-AirTableApiKey

            This example pulls the API key from the configuration file.

    
    #>

    [CmdletBinding()]
    param
    (
        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [string]$ApiKey
    )
    
    $ErrorActionPreference = 'Stop'

    function decrypt([string]$TextToDecrypt) {
        $secure = ConvertTo-SecureString $TextToDecrypt
        $hook = New-Object system.Management.Automation.PSCredential("test", $secure)
        $plain = $hook.GetNetworkCredential().Password
        return $plain
    }

    try {
        if ($PSBoundParameters.ContainsKey('ApiKey')) {
            $script:AirTableApiKey = $ApiKey
            $ApiKey
        } elseif (Get-Variable -Name AirTableApiKey -Scope Script -ErrorAction 'Ignore') {
            $script:AirTableApiKey
        } elseif (-not ($encApiKey = (Get-PSAirTableConfiguration).Application.ApiKey)) {
            throw 'No API key found in configuration.'
        } else {
            $atKey = decrypt $encApiKey
            $script:AirTableApiKey = $atKey
            $script:AirTableApiKey
        }
    } catch {
        $PSCmdlet.ThrowTerminatingError($_)
    }
}

function Save-AirTableApiKey {
    <#
        .SYNOPSIS
            Saves the API key to the configuration file obtained from your AirTable account at https://airtable.com/account.
    
        .EXAMPLE
            PS> Save-AirTableApiKey -ApiKey foobar

            Saves the value 'foobar' in the configuration APIKey value.
    
    #>

    [CmdletBinding()]
    param (
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string]$ApiKey
    )

    function encrypt([string]$TextToEncrypt) {
        $secure = ConvertTo-SecureString $TextToEncrypt -AsPlainText -Force
        $encrypted = $secure | ConvertFrom-SecureString
        return $encrypted
    }
    
    $config = Get-PSAirTableConfiguration
    $config.Application.ApiKey = encrypt($ApiKey)
    $config | ConvertTo-Json | Set-Content -Path "$WorkingDir\Configuration.json"
}

function Get-PSAirTableConfiguration {
    <#
        .SYNOPSIS
            Queries the configuration stored as a JSON file in the module directory and returns as a PowerShell object.
    
        .EXAMPLE
            PS> Get-PSAirTableConfiguration

            Queries the configuration JSON file and returns values.
    
    #>

    [OutputType('string')]
    [CmdletBinding()]
    param
    ()

    $ErrorActionPreference = 'Stop'

    try {
        $configJsonPath = "$WorkingDir\Configuration.json"
        if (-not (Test-Path -Path $configJsonPath)) {
            throw 'The required Configuration.json file could not be found.'
        }

        Get-Content -Path $configJsonPath -Raw | ConvertFrom-Json
    } catch {
        $PSCmdlet.ThrowTerminatingError($_)
    }
}

function Find-Record {
    <#
        .SYNOPSIS
            Queries an AirTable table for one or more records.
    
        .EXAMPLE
            PS> Find-Record -BaseName foo -Table bar

            Returns all records in the bar table within the foo base.

        .EXAMPLE
            PS> Find-Record -BaseName foo -Table bar -FilterFormula '{Name}="adam"'

            Returns all records in the bar table within the foo base that have a Name value of 'adam'.

        .PARAMETER BaseName
            A string value representing the AirTable base that contains the table to query.

        .PARAMETER Table
            A string value representing the AirTable table containing the records to query.

        .PARAMETER FilterFormula
            A string value representing an AirTable-specific filter to limit the number of records returned. For
            full explanation of this query language, refer to
            https://support.airtable.com/hc/en-us/articles/203255215-Formula-field-reference.
    
    #>

    [OutputType('pscustomobject')]
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [Alias('BaseName', 'BaseId')]
        [string]$BaseIdentity,

        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string]$Table,

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [string]$FilterFormula
        
    )

    $ErrorActionPreference = 'Stop'

    $baseId = GetBaseId -Identity $BaseIdentity

    $uri = BuildUriString -BaseId $baseId -Table $Table
    $invParams = @{
        Uri = $Uri
    }
    if ($PSBoundParameters.ContainsKey('FilterFormula')) {
        $invParams.HttpBody = @{ 'filterByFormula' = $FilterFormula }
    }
    
    InvokeAirTableApiCall @invParams
    
}

function Update-Record {
    <#
        .SYNOPSIS
            Updated an AirTable table record field value(s).
    
        .EXAMPLE
            PS> Find-Record -BaseName foo -Table bar -Name 'old' | Update-Record -Fields { 'Name' = 'new' }

            Updates any records in the 'bar' table with a field Name value of 'old' to 'new'.

        .EXAMPLE
            PS> Update-Record -BaseName foo -Table bar -Id recXXXXXXXXX -Fields { 'Name' = 'new' }

            Updates any records in the 'bar' table with a field Name value of 'old' to 'new'.
        
        .PARAMETER InputObject
            A pscustomobject value representing the record to update. This is typically used via the pipeline.

        .PARAMETER Id
            A string value representing the record ID of the record to update.

        .PARAMETER BaseName
            A string value representing the AirTable base that contains the table to query.

        .PARAMETER Table
            A string value representing the AirTable table containing the records to query.

        .PARAMETER Fields
            A hashtable value representing all of the record's fields to update. Each key in the hashtable is the
            field name and each corresponding value is the value to update the field to.
    
    #>

    [OutputType('void')]
    [CmdletBinding(SupportsShouldProcess, DefaultParameterSetName = 'Default')]
    param
    (
        [Parameter(Mandatory, ValueFromPipeline, ParameterSetName = 'ByObject')]
        [ValidateNotNullOrEmpty()]
        [pscustomobject]$InputObject,

        [Parameter(Mandatory, ParameterSetName = 'ById')]
        [ValidateNotNullOrEmpty()]
        [ValidatePattern('^rec')]
        [string]$Id,

        [Parameter(Mandatory, ParameterSetName = 'ById')]
        [ValidateNotNullOrEmpty()]
        [Alias('BaseName', 'BaseId')]
        [string]$BaseIdentity,

        [Parameter(Mandatory, ParameterSetName = 'ById')]
        [ValidateNotNullOrEmpty()]
        [string]$Table,

        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [hashtable]$Fields
    )


    $ErrorActionPreference = 'Stop'

    if ($PSCmdlet.ParameterSetName -eq 'ById') {
        $filterFormula = 'RECORD_ID()="{0}"' -f $Id
        $InputObject = Find-Record -BaseName $BaseIdentity -Table $Table -FilterFormula $filterFormula
    } else {

    }
    $uri = BuildUriString -BaseId $InputObject.'Base ID' -Table $InputObject.Table -RecordId $InputObject.'Record ID'

    $invParams = @{
        Uri      = $uri
        Method   = 'PATCH'
        HttpBody = @{ 'fields' = $Fields }
    }

    $targetMsg = "AirTable Record ID [$($InputObject.'Record ID')] in table [$($InputObject.Table)]"
    $actionMsg = "Update fields [$($Fields.Keys -join ',')] to [$($Fields.Values -join ',')]"
    if ($PSCmdlet.ShouldProcess($targetMsg, $actionMsg)) {
        InvokeAirTableApiCall @invParams
    }
}

function Remove-Record {
    <#
        .SYNOPSIS
            Removes an AirTable table record.
    
        .EXAMPLE
            PS> Find-Record -BaseName foo -Table bar -Name 'old' | Remove-Record

            Removes any records in the 'bar' table with a field Name value of 'old'.
        
        .PARAMETER InputObject
            A pscustomobject value representing the record to remove. This is typically used via the pipeline.
    
    #>

    [OutputType('void')]
    [CmdletBinding(SupportsShouldProcess)]
    param
    (
        [Parameter(Mandatory, ValueFromPipeline, ParameterSetName = 'ByObject')]
        [ValidateNotNullOrEmpty()]
        [pscustomobject]$InputObject
    )


    $ErrorActionPreference = 'Stop'

    $uri = BuildUriString -BaseId $InputObject.'Base ID' -Table $InputObject.Table -RecordId $InputObject.'Record ID'

    $invParams = @{
        Uri    = $uri
        Method = 'DELETE'
    }

    $targetMsg = "AirTable Record ID [$($InputObject.'Record ID')] in table [$($InputObject.Table)]"
    $actionMsg = 'Remove'
    if ($PSCmdlet.ShouldProcess($targetMsg, $actionMsg)) {
        InvokeAirTableApiCall @invParams
    }
}

function New-Record {
    <#
        .SYNOPSIS
            Creates a new AirTable table record.
    
        .EXAMPLE
            PS> New-Record -BaseName foo -Table bar -Fields { 'Name' = 'new' }

            Creates a new record in the 'bar' table with a field Name value of 'new'.

        .PARAMETER BaseName
            A string value representing the AirTable base that contains the table to query.

        .PARAMETER Table
            A string value representing the AirTable table containing the records to query.

        .PARAMETER Fields
            A hashtable value representing all of the new record's fields. Each key in the hashtable is the
            field name and each corresponding value is the value to update the field to.
    
    #>

    [OutputType('void')]
    [CmdletBinding(SupportsShouldProcess)]
    param
    (
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [Alias('BaseName', 'BaseId')]
        [string]$BaseIdentity,

        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string]$Table,

        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [hashtable]$Fields
    )


    $ErrorActionPreference = 'Stop'

    $baseId = GetBaseId -Identity $BaseIdentity

    $uri = BuildUriString -BaseId $baseId -Table $Table

    $invParams = @{
        Uri      = $uri
        Method   = 'POST'
        HttpBody = @{ 'fields' = $Fields }
    }

    $targetMsg = "New AirTable Record in table [$($Table)]"
    $actionMsg = "Fields [$($Fields.Keys -join ',')] to [$($Fields.Values -join ',')]"
    if ($PSCmdlet.ShouldProcess($targetMsg, $actionMsg)) {
        InvokeAirTableApiCall @invParams
    }
}

function InvokeAirTableApiCall {
    <#
        .SYNOPSIS
            A private function that crafts the REST call to AirTable.
    
        .EXAMPLE
            PS> InvokeAirTableApiCall -Uri 'https://api.airtable.com/v0/Fruit' -HttpBody @{ filterByFormula = "{Name}='Apple'" }

            Queries the AirTable URI and passes the HTTP body to the API using the GET method.

        .EXAMPLE
            PS> InvokeAirTableApiCall -Uri 'https://api.airtable.com/v0/Fruit' -HttpBody @{ filterByFormula = "{Name}='Apple'" } -Method POST

            Queries the AirTable URI and passes the HTTP body to the API using the POST method.

        .PARAMETER Uri
            A string value representing the API endpoint URI.

        .PARAMETER HttpBody
            A hashtable value representing the HTTP body to send to the API.

        .PARAMETER Method
            A string value representing the HTTP verb (method) to send to the API. This defaults to using GET.
    
    #>

    [OutputType('pscustomobject')]
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string]$Uri,

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [hashtable]$HttpBody,

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [string]$Method = 'GET',

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [string]$ApiKey = (Get-AirTableApiKey)
    )

    $ErrorActionPreference = 'Stop'

    try {
        $headers = @{
            'Authorization' = "Bearer $ApiKey"
        }
        
        $invRestParams = @{
            Method  = $Method
            Headers = $headers
            Uri     = $Uri
        }

        switch ($Method) {
            'GET' {
                if ($PSBoundParameters.ContainsKey('HttpBody')) {
                    $invRestParams.Body = $HttpBody
                }
                break
            }
            { $_ -in 'PATCH', 'POST', 'DELETE' } {
                $invRestParams.ContentType = 'application/json'
                if ($PSBoundParameters.ContainsKey('HttpBody')) {
                    $invRestParams.Body = (ConvertTo-Json $HttpBody)
                }
                break
            }
            default {
                throw "Unrecognized input: [$_]"
            }
        }

        $response = Invoke-RestMethod @invRestParams
        
        if ('records' -in $response.PSObject.Properties.Name) {
            $baseId = $Uri.split('/')[4]
            $table = $Uri.split('/')[5]
            $response.records.foreach({
                    $output = $_.fields
                    $output | Add-Member -MemberType NoteProperty -Name 'Record ID' -Value $_.id
                    $output | Add-Member -MemberType NoteProperty -Name 'Base ID' -Value $baseId
                    $output | Add-Member -MemberType NoteProperty -Name 'Table' -Value $table -PassThru
                })
            
            while ('offset' -in $response.PSObject.Properties.Name) {
                $invParams = [hashtable]$PSBoundParameters
                if ($invParams['HttpBody'] -and $invParams['HttpBody'].ContainsKey('offset')) {
                    $invParams['HttpBody'].offset = $response.offset
                } else {
                    $invParams['HttpBody'] = $HttpBody + @{ offset = $response.offset  }
                }
                
                InvokeAirTableApiCall @invParams | Tee-Object -Variable response
            }
        }
    } catch {
        $PSCmdlet.ThrowTerminatingError($_)
    }
}

function BuildUriString {
    <#
        .SYNOPSIS
            A pricate helper function to craft the URI necessary to pass to the AirTable API.
    
        .EXAMPLE
            PS> BuildUriString -BaseId XXXXXXXXX -Table Fruit

            Returns the URI. This is typically used by Find-Record and New-Record.
        
        .EXAMPLE
            PS> BuildUriString -BaseId XXXXXXXXX -Table Fruit -RecordId recXXXXXX

            Returns the URI. This is typically used by Update-Record.

        .PARAMETER BaseId
            The ID of the AirTable base that is defined in the module configuration.
        
        .PARAMETER Table
            A string value representing the AirTable table containing the records to query.

        .PARAMETER RecordId
            A string value representing the record ID that will be appended to the end of the URI.
    
    #>

    [OutputType('string')]
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [Alias('BaseName', 'BaseId')]
        [string]$BaseIdentity,

        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string]$Table,

        [Parameter()]
        [ValidateNotNullOrEmpty()]
        [string]$RecordId
    )

    $ErrorActionPreference = 'Stop'

    $baseId = GetBaseId -Identity $BaseIdentity

    $uriParts = @($EndpointUri, $baseId, $Table)
    if ($PSBoundParameters.ContainsKey('RecordId')) {
        $uriParts += $RecordId
    }
    $uriParts -join '/'
}

function GetBaseId {
    <#
        .SYNOPSIS
            A helper function to query the configuration with a base name and return it's ID.
    
        .EXAMPLE
            PS> GetBaseId -Identity foo

            Looks at the module configuration file for a base name defined as 'foo' and returns the ID associated with it.
    
    #>

    [OutputType('string')]
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [string]$Identity
    )

    $ErrorActionPreference = 'Stop'

    $baseIdtype = GetBaseIdentityType -Identity $Identity
    if ($baseIdtype -eq 'Name') {
        $bases = (Get-PSAirTableConfiguration).Bases
        if (-not ($base = @($bases).where({ $_.Name -eq $Identity }))) {
            throw "The base name [$($Identity)] could not be found. Ensure it exists by running (Get-PSAirTableConfiguration).Bases"
        }
        $base.id
    } else {
        $Identity
    }
}

function GetBaseIdentityType {
    <#
        .SYNOPSIS
            A helper function to figure out if the base identity is the name of the base or the ID
    
        .EXAMPLE
            PS> GetBaseIdentityType -Identity 'appXXXXXXXXXXXXXX'
    
    #>

    [OutputType('string')]
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory)]
        [ValidateNotNullOrEmpty()]
        [Alias('BaseName', 'BaseId')]
        [string]$Identity
    )

    $ErrorActionPreference = 'Stop'

    if ($Identity -match '^app[a-zA-Z0-9]{14}$') {
        'ID'
    } else {
        'Name'
    }
}