$script:ModuleRoot = Split-Path -Parent $PSScriptRoot
$script:ModuleManifest = Join-Path -Path $script:ModuleRoot -ChildPath 'Merge-DSCConfigurationData.psd1'

Import-Module $script:ModuleManifest -Force

Describe 'Merge-DSCConfigurationData Extends' {
    It 'keeps the existing hashtable merge behavior' {
        $Template = @{
            Parameters = @{
                DomainFQDN = @{
                    Type = 'string'
                    Required = $true
                    DefaultValue = 'example.local'
                }
            }
        }

        $Deployment = @{
            Parameters = @{
                DomainFQDN = @{
                    Value = 'contoso.local'
                }
            }
        }

        $Result = Merge-DSCConfigurationData -Template $Template -Deployment $Deployment

        $Result.Parameters.DomainFQDN.Type | Should Be 'string'
        $Result.Parameters.DomainFQDN.Required | Should Be $true
        $Result.Parameters.DomainFQDN.Value | Should Be 'contoso.local'
    }

    It 'merges a child template with Metadata.Extends' {
        $DefaultPath = Join-Path -Path $TestDrive -ChildPath 'Default.psd1'
        $ChildPath = Join-Path -Path $TestDrive -ChildPath 'Contoso.psd1'

        @'
@{
    Metadata = @{
        TemplateType = 'Environment'
        Name = 'Default'
    }
    Parameters = @{
        DomainFQDN = @{
            Type = 'string'
            Required = $true
            DefaultValue = 'example.local'
        }
        DomainNetBIOS = @{
            Type = 'string'
            Required = $true
        }
    }
    Resources = @{
        NonNodeData = @{
            RequiredModules = @(
                @{
                    Name = 'ActiveDirectoryDsc'
                    Version = '6.7.1'
                }
            )
        }
    }
}
'@ | Set-Content -Path $DefaultPath -Encoding UTF8

        @'
@{
    Metadata = @{
        TemplateType = 'Environment'
        Name = 'Contoso'
        Extends = './Default.psd1'
    }
    Parameters = @{
        DomainFQDN = @{
            Value = 'contoso.local'
        }
        DomainNetBIOS = @{
            Value = 'CONTOSO'
        }
    }
}
'@ | Set-Content -Path $ChildPath -Encoding UTF8

        $Result = Merge-DSCConfigurationData -Path $ChildPath -PassThru

        $Result.Files.Count | Should Be 2
        [System.IO.Path]::GetFileName($Result.Files[0]) | Should Be 'Default.psd1'
        [System.IO.Path]::GetFileName($Result.Files[1]) | Should Be 'Contoso.psd1'
        $Result.ConfigurationData.Parameters.DomainFQDN.Type | Should Be 'string'
        $Result.ConfigurationData.Parameters.DomainFQDN.Value | Should Be 'contoso.local'
        $Result.ConfigurationData.Parameters.DomainNetBIOS.Required | Should Be $true
        $Result.ConfigurationData.Parameters.DomainNetBIOS.Value | Should Be 'CONTOSO'
        $Result.ConfigurationData.Resources.NonNodeData.RequiredModules[0].Name | Should Be 'ActiveDirectoryDsc'
        $Result.ConfigurationData.ContainsKey('Metadata') | Should Be $false
    }

    It 'detects circular Metadata.Extends references' {
        $APath = Join-Path -Path $TestDrive -ChildPath 'A.psd1'
        $BPath = Join-Path -Path $TestDrive -ChildPath 'B.psd1'

        @'
@{
    Metadata = @{
        Extends = './B.psd1'
    }
}
'@ | Set-Content -Path $APath -Encoding UTF8

        @'
@{
    Metadata = @{
        Extends = './A.psd1'
    }
}
'@ | Set-Content -Path $BPath -Encoding UTF8

        { Merge-DSCConfigurationData -Path $APath } | Should Throw
    }
}