Describe 'Install-IPerf3' {
    BeforeAll {
        function Uninstall-IPerf3 {
            param (
                [string]$DestinationPath = 'C:\Program Files\iPerf3'
            )

            # Stop and remove the service if it exists
            if (Get-Service -Name iperf3server -ErrorAction SilentlyContinue) {
                Stop-Service -Name iperf3server -Force
                Remove-Service -Name iperf3server
            }

            # Remove the installation directory
            if (Test-Path -Path $DestinationPath) {
                Remove-Item -Path $DestinationPath -Recurse -Force
            }

            # Remove firewall rule
            if ('Allow iPerf3' -in (Get-NetFirewallRule).DisplayName) {
                Remove-NetFirewallRule -DisplayName 'Allow iPerf3'
            }

            # Remove from PATH
            $env:PATH = $env:PATH -replace [regex]::Escape("$DestinationPath\"), ''
            [Environment]::SetEnvironmentVariable("Path", $env:PATH, [System.EnvironmentVariableTarget]::Machine)
        }

        # Clean up any existing iPerf3 installation
        Uninstall-IPerf3 -DestinationPath 'C:\Program Files\iPerf3'
    
        # Load the Install-iPerf3 function
        Set-Item function:Install-IPerf3 ([ScriptBlock]::Create((Get-Content -Raw $PSCommandPath.Replace('.Tests.ps1', '.ps1'))))
    }

    It 'Has the correct parameters' {
        $params = (Get-Command Install-iPerf3).Parameters

        $params.ContainsKey('DestinationPath') | Should -Be $true
        $params['DestinationPath'].ParameterType.Name | Should -Be 'String'

        $params.ContainsKey('ServerService') | Should -Be $true
        $params['ServerService'].ParameterType.Name | Should -Be 'SwitchParameter'
    }

    Context 'Without ServerService parameter' {
        It 'Should download and install iPerf3 without errors' {
            { Install-iPerf3 -DestinationPath 'C:\Program Files\iPerf3' } | Should -Not -Throw
        }

        It 'Should add iPerf3 to the system PATH' {
            $env:PATH | Should -Match 'C:\\Program Files\\iPerf3\\'
        }

        It 'Should create the iPerf3 installation directory' {
            Test-Path -Path 'C:\Program Files\iPerf3' | Should -Be $true
        }

        It 'Should create the iPerf3 executable in the installation directory' {
            Test-Path -Path 'C:\Program Files\iPerf3\iperf3.exe' | Should -Be $true
        }

        It 'Should add a firewall rule for iPerf3' {
            $firewallRule = Get-NetFirewallRule -DisplayName 'Allow iPerf3' -ErrorAction SilentlyContinue
            $firewallRule | Should -Not -Be $null
        }
    }

    Context 'With ServerService parameter' {
        It 'Should install iPerf3 as a Windows service when ServerService is specified' {
            { Install-iPerf3 -DestinationPath 'C:\Program Files\iPerf3' -ServerService } | Should -Not -Throw
            $service = Get-Service -Name iperf3server -ErrorAction SilentlyContinue
            $service | Should -Not -Be $null
            $service.Status | Should -Be 'Running'
        }
    }

    AfterAll {
        Uninstall-IPerf3 -DestinationPath 'C:\Program Files\iPerf3'
    }
}