. $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 = ""

<#
There are three potential use-cases in this exercise
We modify external state and the caller will respond differently depending on that external state
If nothing was ever wrong, we should see case #1
In the case the third party is busted outside of our interaction, we should see case #2
In the event that this function did the job it was intended to do, and everybody is happy, we should see case #3

Run   first call    second call
#1    pass
#2    throw         throw
#3    throw         pass
#>

Describe "Start-FileBeatsService" {
    Mock -ModuleName $moduleForMock -CommandName Get-LogLeadName -MockWith { return "UUT" }
    Mock -ModuleName $moduleForMock -CommandName Get-WindowsServiceApplicationPath -MockWith { return $env:TEMP }
    Mock -ModuleName $moduleForMock -CommandName Stop-AlkamiService -MockWith { return $null }
    Mock -ModuleName $moduleForMock -CommandName Remove-FileSystemItem -MockWith { return $null }
    Mock -ModuleName $moduleForMock -CommandName Start-AlkamiService -MockWith { return $null }
    Mock -ModuleName $moduleForMock -CommandName Write-Warning -MockWith { }
    Mock -ModuleName $moduleForMock -CommandName Write-Host -MockWith { }
    Mock -ModuleName $moduleForMock -CommandName Test-Path -MockWith { return $false }
    Mock -ModuleName $moduleForMock -CommandName Split-Path -MockWith { return "dummy path" }
    Mock -ModuleName $moduleForMock -CommandName Join-Path -MockWith { return "dummy path" }
    Mock -ModuleName $moduleForMock -CommandName New-Item -MockWith { return $null }

    Context "Happiest Path" {
        Mock -ModuleName $moduleForMock -CommandName Get-FileBeatsService -MockWith {
            return @( @{
                Name        = 'Filebeat (Haystack)'
                DisplayName = 'Filebeat (Haystack)'
                State       = 'Running'
                StartMode   = 'Auto'
                ExePath     = '"C:\Tools\Beats\FileBeat\tools\\filebeat.exe"'
            } )
        }
        Mock -ModuleName $moduleForMock -CommandName Start-AlkamiService -MockWith { return $null }

        It "Exits cleanly with no throws" {
            { Start-FileBeatsService } | Should -Not -Throw
        }
    }

    Context "Start-AlkamiService throws every time (worst path)" {
        Mock -ModuleName $moduleForMock -CommandName Get-FileBeatsService -MockWith {
            return @( @{
                Name        = 'Filebeat (Haystack)'
                DisplayName = 'Filebeat (Haystack)'
                State       = 'Running'
                StartMode   = 'Auto'
                ExePath     = '"C:\Tools\Beats\FileBeat\tools\\filebeat.exe"'
            } )
        }
        # assume the external program just hates us and fails every time no matter what we do
        Mock -ModuleName $moduleForMock -CommandName Start-AlkamiService -MockWith { throw 'expected exception' }

        It "Tries to start service twice then throws an exception" {
            { Start-FileBeatsService } | Should -Throw
            Assert-MockCalled -CommandName Start-AlkamiService -ModuleName $moduleForMock -Times 2 -Exactly -Scope It
        }

    }

    Context "Start-AlkamiService throws the first time but works the next time (expected path)" {

        Mock -ModuleName $moduleForMock -CommandName Get-FileBeatsService -MockWith {
            return @( @{
                    Name        = 'Filebeat (Haystack)'
                    DisplayName = 'Filebeat (Haystack)'
                    State       = 'Running'
                    StartMode   = 'Auto'
                    ExePath     = '"C:\Tools\Beats\FileBeat\tools\\filebeat.exe"'
                },
                @{
                    Name        = 'Filebeat_os (Haystack)'
                    DisplayName = 'Filebeat_os (Haystack)'
                    State       = 'Running'
                    StartMode   = 'Auto'
                    ExePath     = '"C:\Tools\Beats\FileBeat_os\tools\\filebeat.exe"'
                })
        }
        $script:firstPassCompleted = $false
        $script:secondPassCompleted = $false
        $script:thirdPassCompleted = $false
        Mock -ModuleName $moduleForMock -CommandName Start-AlkamiService -MockWith {
            # track external state as tho we were actively making changes to the full system instead of mocking things
            # the actual target application will have two response states so we need to recognize that
            if ($script:firstPassCompleted -eq $false) {
                $script:firstPassCompleted = $true
                Write-Host "PESTER: threw the first time"
                throw 'expected exception'
            } elseif ($script:firstPassCompleted -eq $true -and $script:secondPassCompleted -eq $false) {
                $script:secondPassCompleted = $true
                Write-Host "PESTER: did not throw the second time"
                return
            } elseif ($script:firstPassCompleted -eq $true -and $script:secondPassCompleted -eq $true -and $script:thirdPassCompleted -eq $false) {
                $script:thirdPassCompleted = $true
                Write-Host "PESTER: threw the third time"
                throw 'expected exception'
            } elseif ($script:firstPassCompleted -eq $true -and $script:secondPassCompleted -eq $true -and $script:thirdPassCompleted -eq $true) {
                Write-Host "PESTER: did not throw the forth time"
                return
            } else {
                Write-Host "PESTER: Found unexpected flag state, check brain"
                return
            }
        }

        It "Tries to start each service twice for a total of four tries and does not throw an error" {
            { Start-FileBeatsService } | Should -Not -Throw
            Assert-MockCalled -CommandName Start-AlkamiService -ModuleName $moduleForMock -Times 4 -Exactly
        }

    }
}