. $PSScriptRoot\..\..\Load-PesterModules.ps1
$here = Split-Path -Parent $MyInvocation.MyCommand.Path
$sut = (Split-Path -Leaf $MyInvocation.MyCommand.Path) -replace '\.tests\.', '.'
$functionPath = Join-Path -Path $here -ChildPath $sut
Write-Host "Overriding SUT: $functionPath"
Import-Module $functionPath -Force
$moduleForMock = ""

Describe "Get-InstanceHostname" {

    # Load up AWSPowerShell for mocking if available
    $awsPowerShellLoaded = $false
    if ($null -ne (Get-Module -ListAvailable AWSPowerShell)) {

        Import-AWSModule # EC2
        $awsPowerShellLoaded = $true

    } else {

        Write-Warning "AWSPowerShell Module *NOT* installed.  Some tests will not execute."
    }

    Context "Parameter Validation" {

        It "Null Instance Should Throw" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            { Get-InstanceHostname -Instance $null } | Should Throw
        }

        It "Invalid Parameter Type Should Throw" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            { Get-InstanceHostname -Instance 'test' } | Should Throw
        }
    }

    Context "Hostname Determined By Instance Tag" {

        Mock -CommandName Write-Warning -MockWith {} -ModuleName $moduleForMock

        It "Writes Warning When Hostname Tag Does Not Exist" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            $testInstance = (New-Object Amazon.EC2.Model.Instance)
            $testInstance.InstanceId = 'Test'

            Get-InstanceHostname -Instance $testInstance | Out-Null

            Assert-MockCalled -CommandName Write-Warning -Times 1 -Exactly -Scope It `
                -ModuleName $moduleForMock -ParameterFilter { $Message -match "No hostname found" }

        }

        It "Returns Null When Hostname Tag Does Not Exist" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            $testInstance = (New-Object Amazon.EC2.Model.Instance)
            $testInstance.InstanceId = 'Test'

            ( Get-InstanceHostname -Instance $testInstance ) | Should -BeNull
        }

        It "Writes Warning When Hostname Tag Is Null" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            $testTag = (New-Object Amazon.EC2.Model.Tag($Global:AlkamiTagKeyHostName, $null))

            $testInstance = (New-Object Amazon.EC2.Model.Instance)
            $testInstance.Tags.Add($testTag)
            $testInstance.InstanceId = 'Test'

            Get-InstanceHostname -Instance $testInstance | Out-Null

            Assert-MockCalled -CommandName Write-Warning -Times 1 -Exactly -Scope It `
                -ModuleName $moduleForMock -ParameterFilter { $Message -match "No hostname found" }

        }

        It "Returns Null When Hostname Tag Is Null" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            $testTag = (New-Object Amazon.EC2.Model.Tag($Global:AlkamiTagKeyHostName, $null))

            $testInstance = (New-Object Amazon.EC2.Model.Instance)
            $testInstance.Tags.Add($testTag)
            $testInstance.InstanceId = 'Test'

            ( Get-InstanceHostname -Instance $testInstance ) | Should -BeNull
        }

        It "Writes Warning When Hostname Tag Is Null" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            $testTag = (New-Object Amazon.EC2.Model.Tag($Global:AlkamiTagKeyHostName, ''))

            $testInstance = (New-Object Amazon.EC2.Model.Instance)
            $testInstance.Tags.Add($testTag)
            $testInstance.InstanceId = 'Test'

            Get-InstanceHostname -Instance $testInstance | Out-Null

            Assert-MockCalled -CommandName Write-Warning -Times 1 -Exactly -Scope It `
                -ModuleName $moduleForMock -ParameterFilter { $Message -match "No hostname found" }

        }

        It "Returns Null When Hostname Tag Is Null" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            $testTag = (New-Object Amazon.EC2.Model.Tag($Global:AlkamiTagKeyHostName, ''))

            $testInstance = (New-Object Amazon.EC2.Model.Instance)
            $testInstance.Tags.Add($testTag)
            $testInstance.InstanceId = 'Test'

            ( Get-InstanceHostname -Instance $testInstance ) | Should -BeNull
        }

        It "Does Not Write Warning When Hostname Tag Is Valid" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            $testTag = (New-Object Amazon.EC2.Model.Tag($Global:AlkamiTagKeyHostName, 'Test'))

            $testInstance = (New-Object Amazon.EC2.Model.Instance)
            $testInstance.Tags.Add($testTag)
            $testInstance.InstanceId = 'Test'

            Get-InstanceHostname -Instance $testInstance | Out-Null

            Assert-MockCalled -CommandName Write-Warning -Times 0 -Exactly -Scope It `
                -ModuleName $moduleForMock

        }

        It "Returns Uppercased Hostname Tag Value When Hostname Tag Is Valid" {

            if (!($awsPowerShellLoaded)) {

                Set-ItResult -Inconclusive -Because "AWSPowerShell Not Installed"
                continue;
            }

            $testTag = (New-Object Amazon.EC2.Model.Tag($Global:AlkamiTagKeyHostName, 'Test'))

            $testInstance = (New-Object Amazon.EC2.Model.Instance)
            $testInstance.Tags.Add($testTag)
            $testInstance.InstanceId = 'Test'

            ( Get-InstanceHostname -Instance $testInstance ) | Should -BeExactly 'TEST'
        }
    }
}