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

BeforeAll {
    $repoRoot = Split-Path (Split-Path $PSScriptRoot -Parent) -Parent
    foreach ($f in @(
            'src/Normalization/New-PersonaMembershipRecord.ps1'
            'src/Normalization/New-PersonaUserRecord.ps1'
            'src/RuleEngine/Test-PersonaCondition.ps1'
            'src/RuleEngine/Test-PersonaConditionGroup.ps1'
            'src/RuleEngine/Test-PersonaRule.ps1'
            'src/RuleEngine/Resolve-UserPersona.ps1'
        )) { . (Join-Path $repoRoot $f) }

    $script:tier0 = '00000000-0000-0000-0000-0000000000a0'

    function New-UserWithFailedLookup {
        param([string] $StoredPersona = 'Employee')
        New-PersonaUserRecord `
            -AccountObjectId '00000000-0000-0000-0000-000000000101' `
            -UserPrincipalName 'alex.employee@example.invalid' `
            -Properties @{ Department = 'Finance' } `
            -StoredPersona $StoredPersona `
            -Membership (New-PersonaMembershipRecord -DirectFailureReason 'Graph 503 after 5 attempts')
    }

    function New-UserWithGoodLookup {
        New-PersonaUserRecord `
            -AccountObjectId '00000000-0000-0000-0000-000000000102' `
            -UserPrincipalName 'blair.ok@example.invalid' `
            -Properties @{ Department = 'Finance' } `
            -StoredPersona 'Employee' `
            -Membership (New-PersonaMembershipRecord -AllRetrieved)
    }

    $script:membershipRule = [pscustomobject]@{
        id = 'R-030'; priority = 30; persona = 'Tier0-Admin'; enabled = $true
        match = [pscustomobject]@{
            operator = 'all'
            conditions = @([pscustomobject]@{ type = 'membership'; operator = 'memberOf'; groupObjectIds = @($tier0) })
        }
    }

    $script:catchAllRule = [pscustomobject]@{
        id = 'R-900'; priority = 900; persona = 'Employee'; enabled = $true
        match = [pscustomobject]@{
            operator = 'all'
            conditions = @([pscustomobject]@{ type = 'property'; property = 'Department'; operator = 'isNotNull' })
        }
    }
}

Describe 'EvaluationError outcome (FR-013, FR-014)' {

    It 'is produced when required membership data could not be retrieved' {
        $result = Resolve-UserPersona -UserRecord (New-UserWithFailedLookup) -Rules @($membershipRule)
        $result.Outcome | Should -Be 'EvaluationError'
    }

    It 'preserves the stored persona' {
        $result = Resolve-UserPersona -UserRecord (New-UserWithFailedLookup -StoredPersona 'Tier0-Admin') -Rules @($membershipRule)
        $result.StoredPersona | Should -Be 'Tier0-Admin'
    }

    It 'leaves CalculatedPersona null so nothing can be written' {
        $result = Resolve-UserPersona -UserRecord (New-UserWithFailedLookup) -Rules @($membershipRule)
        $result.CalculatedPersona | Should -BeNullOrEmpty
    }

    It 'records a reason naming the rule that could not be evaluated' {
        $result = Resolve-UserPersona -UserRecord (New-UserWithFailedLookup) -Rules @($membershipRule)
        $result.EvaluationErrorReason | Should -Not -BeNullOrEmpty
        $result.EvaluationErrorReason | Should -BeLike '*R-030*'
    }

    It 'stops evaluation rather than falling through to a lower-priority rule' {
        # The critical case. Falling through would assign Employee to an account
        # that may in truth be a Tier 0 administrator — a silent privilege
        # downgrade, which is exactly what FR-013 exists to prevent.
        $result = Resolve-UserPersona -UserRecord (New-UserWithFailedLookup) -Rules @($membershipRule, $catchAllRule)

        $result.Outcome | Should -Be 'EvaluationError'
        $result.CalculatedPersona | Should -Not -Be 'Employee'
        $result.RulesEvaluated | Should -Be 1
    }

    It 'still matches when a higher-priority rule resolves before the unknown one' {
        # An unknown rule at priority 30 is irrelevant if priority 10 already matched.
        $earlyMatch = [pscustomobject]@{
            id = 'R-010'; priority = 10; persona = 'Guest'; enabled = $true
            match = [pscustomobject]@{ operator = 'all'; conditions = @([pscustomobject]@{ type = 'property'; property = 'Department'; operator = 'equals'; value = 'Finance' }) }
        }

        $result = Resolve-UserPersona -UserRecord (New-UserWithFailedLookup) -Rules @($earlyMatch, $membershipRule)
        $result.Outcome | Should -Be 'Matched'
        $result.CalculatedPersona | Should -Be 'Guest'
    }

    It 'does not affect a user whose lookup succeeded' {
        # Per-user isolation: one account's data failure must not contaminate another.
        $result = Resolve-UserPersona -UserRecord (New-UserWithGoodLookup) -Rules @($membershipRule, $catchAllRule)
        $result.Outcome | Should -Be 'Matched'
        $result.CalculatedPersona | Should -Be 'Employee'
    }

    It 'processes a mixed population without one failure stopping the others' {
        $population = @((New-UserWithFailedLookup), (New-UserWithGoodLookup))
        $results = $population | ForEach-Object { Resolve-UserPersona -UserRecord $_ -Rules @($membershipRule, $catchAllRule) }

        $results | Should -HaveCount 2
        ($results | Where-Object Outcome -EQ 'EvaluationError') | Should -HaveCount 1
        ($results | Where-Object Outcome -EQ 'Matched') | Should -HaveCount 1
    }

    It 'is produced when the condition tree exceeds the depth limit' {
        $deep = [pscustomobject]@{
            id = 'R-050'; priority = 50; persona = 'Employee'; enabled = $true
            match = [pscustomobject]@{
                operator = 'all'
                conditions = @([pscustomobject]@{
                        operator = 'all'
                        conditions = @([pscustomobject]@{
                                operator = 'all'
                                conditions = @([pscustomobject]@{ type = 'property'; property = 'Department'; operator = 'equals'; value = 'Finance' })
                            })
                    })
            }
        }

        $result = Resolve-UserPersona -UserRecord (New-UserWithGoodLookup) -Rules @($deep) -MaxDepth 2
        $result.Outcome | Should -Be 'EvaluationError'
    }
}