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

<#
    FR-027: the interactive editor can add a new rule, and rejects a colliding id or
    priority before the rule is added.

    Add-PersonaConfigRule is exercised directly rather than through the interactive
    script - it is the pure function the [A] command calls, and pure functions are
    what this suite can test without driving Read-Host through a subprocess (see
    NonInteractive.Tests.ps1 for why that path is reserved for hang/prompt proof, not
    ordinary behaviour).
#>

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

    function New-TestRule {
        param(
            [string] $Id = 'RULE-0500-TEST',
            [int] $Priority = 500,
            [string] $Persona = 'Employee'
        )

        [pscustomobject]@{
            id          = $Id
            name        = 'Test rule'
            description = 'A rule added by a test.'
            enabled     = $true
            priority    = $Priority
            persona     = $Persona
            match       = [pscustomobject]@{
                operator   = 'all'
                conditions = @([pscustomobject]@{ type = 'property'; property = 'Department'; operator = 'isNotNull' })
            }
        }
    }
}

Describe 'Add-PersonaConfigRule (FR-027)' {

    It 'appends the new rule to the collection' {
        $existing = @((New-TestRule -Id 'RULE-0010-GUEST' -Priority 10))
        $new = New-TestRule -Id 'RULE-0500-TEST' -Priority 500

        $result = Add-PersonaConfigRule -Rules $existing -Rule $new

        $result.Count | Should -Be 2
        ($result | Where-Object { [string]$_.id -eq 'RULE-0500-TEST' }).Count | Should -Be 1
    }

    It 'does not mutate the input collection' {
        $existing = @((New-TestRule -Id 'RULE-0010-GUEST' -Priority 10))
        $new = New-TestRule -Id 'RULE-0500-TEST' -Priority 500

        Add-PersonaConfigRule -Rules $existing -Rule $new | Out-Null

        $existing.Count | Should -Be 1
    }

    It 'always returns an array, even when the result has exactly one rule' {
        # The single-element case is the one PowerShell silently collapses to a
        # scalar unless the function guards against it (see Add-PersonaConfigRule's
        # `, (...)` return) - assigning the call's result directly, with no extra
        # @() at this call site, is what proves the function's own guard is doing
        # the work rather than an @() here masking a function that does not.
        $new = New-TestRule -Id 'RULE-0500-TEST' -Priority 500

        $result = Add-PersonaConfigRule -Rules @() -Rule $new

        , $result | Should -BeOfType [array]
        $result.Count | Should -Be 1
    }

    It 'rejects a duplicate id before adding' {
        $existing = @((New-TestRule -Id 'RULE-0010-GUEST' -Priority 10))
        $colliding = New-TestRule -Id 'RULE-0010-GUEST' -Priority 999

        { Add-PersonaConfigRule -Rules $existing -Rule $colliding } | Should -Throw '*RULE-0010-GUEST*'
    }

    It 'rejects a duplicate priority before adding' {
        $existing = @((New-TestRule -Id 'RULE-0010-GUEST' -Priority 10))
        $colliding = New-TestRule -Id 'RULE-0500-TEST' -Priority 10

        { Add-PersonaConfigRule -Rules $existing -Rule $colliding } | Should -Throw '*10*'
    }

    It 'leaves the original collection unchanged when the add is rejected' {
        $existing = @((New-TestRule -Id 'RULE-0010-GUEST' -Priority 10))
        $colliding = New-TestRule -Id 'RULE-0010-GUEST' -Priority 999

        try { Add-PersonaConfigRule -Rules $existing -Rule $colliding } catch { }

        $existing.Count | Should -Be 1
    }

    It 'rejects a blank id' {
        $existing = @((New-TestRule -Id 'RULE-0010-GUEST' -Priority 10))
        $blank = New-TestRule -Id '' -Priority 999

        { Add-PersonaConfigRule -Rules $existing -Rule $blank } | Should -Throw
    }

    It 'the added rule survives a full validation pass' {
        $document = New-TestConfigurationDocument
        $new = @{
            id          = 'RULE-0500-TEST'
            name        = 'Test rule'
            description = 'A rule added by a test.'
            enabled     = $true
            priority    = 500
            persona     = 'Employee'
            match       = @{
                operator   = 'all'
                conditions = @(@{ type = 'property'; property = 'Department'; operator = 'isNotNull' })
            }
        }

        $document.rules = Add-PersonaConfigRule -Rules $document.rules -Rule $new
        $path = Save-TestConfiguration -Document $document -Directory ([System.IO.Path]::GetTempPath())

        try {
            $result = Test-PersonaConfiguration -Path $path
            $result.IsValid | Should -BeTrue
            @($result.Document.rules).Count | Should -Be 3
        }
        finally {
            Remove-Item -LiteralPath $path -Force -ErrorAction SilentlyContinue
        }
    }
}