. $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 = ""
# We need to use their stupid [Amazon.EC2.Model.Tag], so we have to import their module.
Import-Module AWSPowerShell

Mock -CommandName Get-LogLeadName -ModuleName $moduleForMock -MockWith { return 'Get-TerminatedComputersReport.tests' }
Mock -CommandName Write-Progress -ModuleName $moduleForMock -MockWith {}
Mock -CommandName Import-Module -ModuleName $moduleForMock -MockWith {}
Mock -CommandName Get-Date -ModuleName $moduleForMock -MockWith {return ([datetime]::Now)}
Mock -CommandName Write-Error -ModuleName $moduleForMock -MockWith {}
Mock -CommandName Test-IsTeamCityProcess -ModuleName $moduleForMock -MockWith { return $false }


$credential = ([pscredential]::new("test",("test1" | ConvertTo-SecureString -AsPlainText -Force)))

Describe "Get-TerminatedComputersReport" {
    Context "When a parameter value is not valid or missing" {
        It "Throws an exception if Credential parameter is blank" {
            { Get-TerminatedComputersReport -Credential -Domain fh.local } | Should -Throw
        }

        It "Throws an exception if Domain parameter is blank" {
            { Get-TerminatedComputersReport -Credential $credential -Domain } | Should -Throw
        }

        It "Throws an exception if OU is not provided a value" {
            { Get-TerminatedComputersReport -OU } | Should -Throw
        }

        It "Throws an exception if NumberOfDays is not provided a value" {
            { Get-TerminatedComputersReport -NumberOfDays } | Should -Throw
        }

        It "Throws an exception if NumberOfDays is outside of the valid range" {
            { Get-TerminatedComputersReport -NumberOfDays 366 } | Should -Throw
        }
    }

    Context "Error Handling"{
        It "Writes an error if AWSPowerShell cannot be loaded" {
            Mock -CommandName Get-Module -ModuleName $moduleForMock -MockWith {[pscustomobject]@{"Name" = "NotAWSPowerShell"}}
            Mock -CommandName Import-Module -ModuleName $moduleForMock -MockWith { throw "Module not found."}

            Get-TerminatedComputersReport -CheckAWS

            Assert-MockCalled -CommandName Write-Error -Times 1 -Exactly -ModuleName $moduleForMock -Scope It -ParameterFilter { $Message -like "*Unable to load the AWSPowerShell module*"}
        }

        It "Writes an error if DNS for the domain cannot be resolved" {
            Mock -CommandName Resolve-DnsName -ModuleName $moduleForMock -MockWith { throw "It's always DNS."}

            Get-TerminatedComputersReport -Credential $credential -Domain fh.local

            Assert-MockCalled -CommandName Write-Error -Times 1 -Exactly -ModuleName $moduleForMock -Scope It -ParameterFilter { $Message -like "*Error when resolving DNS for*"}
        }

        It "Writes an error if bad credentials are supplied" {
            Mock -CommandName Resolve-DnsName -ModuleName $moduleForMock -MockWith { return [pscustomobject]@{"IPAddress"="10.0.0.1"} }
            Mock -CommandName Test-Connection -ModuleName $moduleForMock -MockWith { return [pscustomobject]@{"Address"="10.0.0.1";"ResponseTime" = 25} }
            Mock -CommandName Get-ADComputer -ModuleName $moduleForMock -MockWith { throw [System.Security.Authentication.AuthenticationException]::new("The server has rejected the client credentials.") }

            Get-TerminatedComputersReport -Credential $credential -Domain fh.local

            Assert-MockCalled -CommandName Write-Error -Times 1 -Exactly -ModuleName $moduleForMock -Scope It -ParameterFilter { $Message -like "*Unable to connect to the target domain, invalid credentials*"}
        }

        It "Writes an error if unable to retrieve AD Computer objects" {
            Mock -CommandName Resolve-DnsName -ModuleName $moduleForMock -MockWith { return [pscustomobject]@{"IPAddress"="10.0.0.1"} }
            Mock -CommandName Test-Connection -ModuleName $moduleForMock -MockWith { return [pscustomobject]@{"Address"="10.0.0.1";"ResponseTime" = 25} }
            Mock -CommandName Get-ADComputer -ModuleName $moduleForMock -MockWith { throw "Something bad happened"}

            Get-TerminatedComputersReport -Credential $credential -Domain fh.local

            Assert-MockCalled -CommandName Write-Error -Times 1 -Exactly -ModuleName $moduleForMock -Scope It -ParameterFilter { $Message -like "*Unable to retrieve Computer objects from AD*"}
        }

        It "Writes an error if unable to retrieve EC2 instances from us-east-1" {
            Mock -CommandName Get-Module -ModuleName $moduleForMock -MockWith {[pscustomobject]@{"Name" = "AWSPowerShell"}}
            Mock -CommandName Get-ADComputer -ModuleName $moduleForMock -MockWith {}
            Mock -CommandName Get-EC2Instance -ModuleName $moduleForMock -ParameterFilter { $Region -eq "us-east-1"} -MockWith {throw "Error getting EC2 in us-east-1"}

            Get-TerminatedComputersReport -CheckAWS

            Assert-MockCalled -CommandName Write-Error -Times 4 -Exactly -ModuleName $moduleForMock -Scope It -ParameterFilter { $Message -like "*An error occurred while retrieving EC2 instances in us-east-1*"}
        }

        It "Writes an error if unable to retrieve EC2 instances from us-west-2"{
            Mock -CommandName Get-Module -ModuleName $moduleForMock -MockWith {[pscustomobject]@{"Name" = "AWSPowerShell"}}
            Mock -CommandName Get-ADComputer -ModuleName $moduleForMock -MockWith {}
            Mock -CommandName Get-EC2Instance -ModuleName $moduleForMock -ParameterFilter { $Region -eq "us-east-1"} -MockWith {}
            Mock -CommandName Get-EC2Instance -ModuleName $moduleForMock -ParameterFilter { $Region -eq "us-west-2"} -MockWith {throw "Error getting EC2 in us-west-2"}

            Get-TerminatedComputersReport -CheckAWS

            Assert-MockCalled -CommandName Get-EC2Instance -Times 5 -Exactly -ModuleName $moduleForMock -Scope It
            Assert-MockCalled -CommandName Write-Error -Times 1 -Exactly -ModuleName $moduleForMock -Scope It -ParameterFilter { $Message -like "*An error occurred while retrieving EC2 instances in us-west-2*"}
        }
    }

    Context "Returns results" {
        $testDate = Get-Date
        It "Returns results without comparing to AWS" {
            Mock -CommandName Get-ADComputer -ModuleName $moduleForMock -MockWith {
                return (
                    [pscustomobject]@{
                        "Name" = "TestComputerName"
                        "Enabled" = $true
                        "IPv4Address" = "10.0.0.2"
                        "lastLogonDate" = $testDate
                        "PasswordLastSet" = $testDate
                        "SID" = "The-Sloth"
                    }
                )
            }

            $adOnlyTest = Get-TerminatedComputersReport
            $expected = [pscustomobject]@{
                "ADName" = "TestComputerName"
                "IsEnabled" = $true
                "ADIPv4Address" = "10.0.0.2"
                "LastLogon" = $testDate
                "PasswordLastSet" = $testDate
                "SID" = "The-Sloth"
                "TerminationConfidence" = [byte](($testDate) -lt ($testDate).AddDays(-90))
            }
            (($adOnlyTest).ADName -eq ($expected).ADName) | Should -BeTrue
            (($adOnlyTest).IsEnabled -eq ($expected).IsEnabled) | Should -BeTrue
            (($adOnlyTest).ADIPv4Address -eq ($expected).ADIPv4Address) | Should -BeTrue
            (($adOnlyTest).LastLogon -eq ($expected).LastLogon) | Should -BeTrue
            (($adOnlyTest).PasswordLastSet -eq ($expected).PasswordLastSet) | Should -BeTrue
            (($adOnlyTest).SID -eq ($expected).SID) | Should -BeTrue
            (($adOnlyTest).TerminationConfidence -eq ($expected).TerminationConfidence) | Should -BeTrue
        }

        It "Returns results comparing to AWS" {
            Mock -CommandName Get-Module -ModuleName $moduleForMock -MockWith {[pscustomobject]@{"Name" = "AWSPowerShell"}}
            $script:mockCalled = 0
            $getEC2InstanceMock = {
                $script:mockCalled++
                if($script:mockCalled -eq 1){
                # This is a hot mess, but we are trying to replicate the blackmagic that AWS has created when returning these objects
                return (
                    @{"Instances"=[pscustomobject]@{
                        "InstanceId" = "i-AmTheSloth"
                        "PrivateIPAddress" = "10.0.0.2"
                        "tags" = @([Amazon.EC2.Model.Tag]::new("alk:hostname","TestComputerName"),[Amazon.EC2.Model.Tag]::new("alk:designation","1000"))
                        }
                    }
                )
                } else {
                    return $null
                }
            }
            Mock -CommandName Get-ADComputer -ModuleName $moduleForMock -MockWith {
                return (
                    [pscustomobject]@{
                        "Name" = "TestComputerName"
                        "Enabled" = $true
                        "IPv4Address" = "10.0.0.2"
                        "lastLogonDate" = $testDate
                        "PasswordLastSet" = $testDate
                        "SID" = "The-Sloth"
                    }
                )
            }
            Mock -CommandName Get-EC2Instance -ModuleName $moduleForMock -MockWith $getEC2InstanceMock

            $awsTest = Get-TerminatedComputersReport -CheckAWS
            $expected = [pscustomobject]@{
                "ADName" = "TestComputerName"
                "IsEnabled" = $true
                "ADIPv4Address" = "10.0.0.2"
                "LastLogon" = $testDate
                "PasswordLastSet" = $testDate
                "SID" = "The-Sloth"
                "InstanceIdByIP" = "i-AmTheSloth"
                "InstanceIdByName" = "i-AmTheSloth"
                "DoesInstanceMatch" = $true
                "Designation" = "1000"
                "TerminationConfidence" = 0
            }

            (($awsTest).ADName -eq ($expected).ADName) | Should -BeTrue
            (($awsTest).IsEnabled -eq ($expected).IsEnabled) | Should -BeTrue
            (($awsTest).ADIPv4Address -eq ($expected).ADIPv4Address) | Should -BeTrue
            (($awsTest).LastLogon -eq ($expected).LastLogon) | Should -BeTrue
            (($awsTest).PasswordLastSet -eq ($expected).PasswordLastSet) | Should -BeTrue
            (($awsTest).SID -eq ($expected).SID) | Should -BeTrue
            (($awsTest).InstanceIdByIP -eq ($expected).InstanceIdByIP) | Should -BeTrue
            (($awsTest).InstanceIdByName -eq ($expected).InstanceIdByName) | Should -BeTrue
            (($awsTest).DoesInstanceMatch -eq ($expected).DoesInstanceMatch) | Should -BeTrue
            (($awsTest).Designation -eq ($expected).Designation) | Should -BeTrue
            (($awsTest).TerminationConfidence -eq ($expected).TerminationConfidence) | Should -BeTrue
        }
    }
}