#Requires -Modules @{ ModuleName = 'Pester'; ModuleVersion = '5.0.0' }

<#
    New-PersonaWriteBody throws for any attribute other than the configured target,
    and for any target absent from the approved list.

    Throwing rather than correcting is the design. A caller that asked to write the
    wrong attribute has a defect; silently substituting the right one hides it until
    the day the substitution is also wrong.
#>

BeforeAll {
    $repoRoot = Split-Path (Split-Path $PSScriptRoot -Parent) -Parent
    . (Join-Path $repoRoot 'tests/TestHelpers.ps1')
    foreach ($file in (Get-PersonaSourceFile -RepoRoot $repoRoot)) { . $file }

    $script:target = 'extension_<EXTENSION-APP-ID>_<PERSONA>'
    $script:approved = @($script:target)
}

Describe 'Rejection of a non-target attribute' -Tag 'Safety' {

    It 'refuses <_>' -ForEach @('department', 'jobTitle', 'userPrincipalName', 'accountEnabled', 'onPremisesImmutableId') {
        { New-PersonaWriteBody -AttributeName $_ -Value 'Employee' `
                -TargetAttribute $script:target -ApprovedWritableAttributes $script:approved } |
            Should -Throw -ExpectedMessage '*only the configured target attribute*'
    }

    It 'refuses a different extension property' {
        { New-PersonaWriteBody -AttributeName 'extension_<EXTENSION-APP-ID>_<SOMETHING-ELSE>' -Value 'Employee' `
                -TargetAttribute $script:target -ApprovedWritableAttributes $script:approved } |
            Should -Throw
    }

    It 'refuses a casing variant of the target' {
        # Extension property names are case-sensitive in Graph, so this is a different
        # attribute, not the same one spelled differently. Accepting it would write to
        # a property nobody approved.
        { New-PersonaWriteBody -AttributeName $script:target.ToUpperInvariant() -Value 'Employee' `
                -TargetAttribute $script:target -ApprovedWritableAttributes $script:approved } |
            Should -Throw
    }
}

Describe 'Rejection of an unapproved target' -Tag 'Safety' {

    It 'refuses a target absent from the approved list' {
        { New-PersonaWriteBody -AttributeName $script:target -Value 'Employee' `
                -TargetAttribute $script:target -ApprovedWritableAttributes @('extension_<EXTENSION-APP-ID>_<OTHER>') } |
            Should -Throw -ExpectedMessage '*not present in approvedWritableAttributes*'
    }

    It 'refuses when the approved list is empty' {
        { New-PersonaWriteBody -AttributeName $script:target -Value 'Employee' `
                -TargetAttribute $script:target -ApprovedWritableAttributes @() } |
            Should -Throw
    }

    It 'refuses when the approved list differs only in casing' {
        { New-PersonaWriteBody -AttributeName $script:target -Value 'Employee' `
                -TargetAttribute $script:target -ApprovedWritableAttributes @($script:target.ToUpperInvariant()) } |
            Should -Throw
    }

    It 'refuses a blank attribute name' {
        { New-PersonaWriteBody -AttributeName '' -Value 'Employee' `
                -TargetAttribute $script:target -ApprovedWritableAttributes $script:approved } |
            Should -Throw
    }
}

Describe 'Resolve-TargetAttribute enforces the same rule earlier' -Tag 'Safety' {

    It 'returns the target when it is approved' {
        $config = [pscustomobject]@{ TargetAttribute = $script:target; ApprovedWritableAttributes = $script:approved }

        Resolve-TargetAttribute -Configuration $config | Should -BeExactly $script:target
    }

    It 'throws rather than returning null for a blank target' {
        # A null return would be indistinguishable from a caller forgetting to check,
        # and that caller writes to whatever name it was holding.
        $config = [pscustomobject]@{ TargetAttribute = '  '; ApprovedWritableAttributes = $script:approved }

        { Resolve-TargetAttribute -Configuration $config } | Should -Throw -ExpectedMessage '*blank*'
    }

    It 'throws for an unapproved target' {
        $config = [pscustomobject]@{ TargetAttribute = 'department'; ApprovedWritableAttributes = $script:approved }

        { Resolve-TargetAttribute -Configuration $config } | Should -Throw
    }
}

Describe 'Set-UserPersonaAttribute refuses an unconfirmed call' -Tag 'Safety' {

    It 'throws when -Confirmed is absent' {
        # Reaching the write adapter without the gate is a control-flow defect. The
        # only safe response is to refuse, not to infer intent.
        Mock Invoke-PersonaGraphRequest { @{} }

        { Set-UserPersonaAttribute -UserObjectId '00000000-0000-0000-0000-000000000101' `
                -AttributeName $script:target -Value 'Employee' `
                -TargetAttribute $script:target -ApprovedWritableAttributes $script:approved } |
            Should -Throw -ExpectedMessage '*without a confirmed ShouldProcess gate*'

        Should -Invoke Invoke-PersonaGraphRequest -Times 0 -Exactly
    }

    It 'returns a failed result rather than throwing when the PATCH fails' {
        # A failed write is a per-user outcome. Throwing would abandon the rest of the
        # population over one account.
        Mock Invoke-PersonaGraphRequest { throw 'Response status code does not indicate success: 403 (Forbidden).' }

        $result = Set-UserPersonaAttribute -UserObjectId '00000000-0000-0000-0000-000000000101' `
            -AttributeName $script:target -Value 'Employee' -PreviousValue 'Guest' `
            -TargetAttribute $script:target -ApprovedWritableAttributes $script:approved -Confirmed

        $result.Succeeded | Should -BeFalse
        $result.FailureReason | Should -Not -BeNullOrEmpty
        $result.PreviousValue | Should -Be 'Guest'
    }

    It 'captures previousValue from the value observed before the write' {
        Mock Invoke-PersonaGraphRequest { @{} }

        $result = Set-UserPersonaAttribute -UserObjectId '00000000-0000-0000-0000-000000000101' `
            -AttributeName $script:target -Value 'Tier0-Admin' -PreviousValue 'Employee' `
            -TargetAttribute $script:target -ApprovedWritableAttributes $script:approved -Confirmed

        $result.Succeeded | Should -BeTrue
        $result.PreviousValue | Should -Be 'Employee'
        $result.Value | Should -Be 'Tier0-Admin'
    }
}