BeforeAll {
    $script:RepoRoot = Split-Path $PSScriptRoot -Parent
    . "$script:RepoRoot/Scripts/GUI/Ui-Preferences.ps1"
    . "$script:RepoRoot/Scripts/GUI/Get-SystemUsesDarkMode.ps1"
    . "$script:RepoRoot/Scripts/FileIO/Import-JsonFile.ps1"
    . "$script:RepoRoot/Scripts/FileIO/Import-LanguageFile.ps1"
    $script:LanguagesPath = Join-Path $script:RepoRoot 'Config/Languages'
}

Describe 'UI preference initialization' {
    BeforeEach {
        $script:UiPreferencesFilePath = "$TestDrive/preferences.json"
        Save-UiPreferences -Preferences @{ Theme = 'Dark'; Language = 'nl-NL' }
    }

    It 'loads the saved language and theme' {
        Initialize-UiPreferences
        $script:UiPreferences.Theme | Should -Be 'Dark'
        $script:UiPreferences.Language | Should -Be 'nl-NL'
        $script:Lang.LanguageCode | Should -Be 'nl-NL'
    }

    It 'honors an explicit language without persisting the override' {
        Initialize-UiPreferences -Language 'pt-BR'
        $script:UiPreferences.Language | Should -Be 'pt-BR'
        $script:Lang.LanguageCode | Should -Be 'pt-BR'
        (Get-UiPreferences).Language | Should -Be 'nl-NL'
    }

    It 'keeps Auto as a preference while resolving the system language' {
        Initialize-UiPreferences -Language 'Auto'
        $script:UiPreferences.Language | Should -Be 'Auto'
        $script:Lang.LanguageCode | Should -Be (Import-LanguageFile).LanguageCode
    }

    It 'normalizes <Language> to the resolved folder' -ForEach @(
        @{ Language = 'nl-BE'; Expected = 'nl-NL' }
        @{ Language = 'fr-FR'; Expected = 'en-US' }
    ) {
        Initialize-UiPreferences -Language $Language
        $script:UiPreferences.Language | Should -Be $Expected
        $script:Lang.LanguageCode | Should -Be $Expected
    }

    It 'leaves language failure handling to the caller' {
        Mock Get-UiLanguage { $null }
        Initialize-UiPreferences
        $script:Lang | Should -BeNullOrEmpty
    }
}

Describe 'UI preference persistence and theme resolution' {
    It 'defaults to system settings when no preferences exist' {
        $result = Get-UiPreferences -Path "$TestDrive/missing.json"
        $result.Theme | Should -Be 'Auto'
        $result.Language | Should -Be 'Auto'
    }
    It 'round trips explicit preferences' {
        Save-UiPreferences -Preferences @{Theme='Dark'; Language='pt-BR'} -Path "$TestDrive/preferences.json"
        $result = Get-UiPreferences -Path "$TestDrive/preferences.json"
        $result.Theme | Should -Be 'Dark'
        $result.Language | Should -Be 'pt-BR'
    }
    It 'ignores unsupported preferences' {
        '{"Theme":"Unknown","Language":"../other"}' | Set-Content "$TestDrive/invalid.json"
        $result = Get-UiPreferences -Path "$TestDrive/invalid.json"
        $result.Theme | Should -Be 'Auto'
        $result.Language | Should -Be 'Auto'
    }
    It 'keeps the previous settings when writing fails' {
        Save-UiPreferences -Preferences @{Theme='Light'; Language='en-US'} -Path "$TestDrive/safe.json"
        Mock Set-Content { throw 'Disk full' }
        { Save-UiPreferences -Preferences @{Theme='Dark'; Language='pt-BR'} -Path "$TestDrive/safe.json" } | Should -Throw
        (Get-UiPreferences -Path "$TestDrive/safe.json").Theme | Should -Be 'Light'
    }
    It 'honors explicit themes and resolves Auto from Windows' {
        Mock Get-SystemUsesDarkMode { $true }
        $script:UiPreferences = @{Theme='Light'}
        Get-AppUsesDarkMode | Should -BeFalse
        $script:UiPreferences.Theme = 'Dark'
        Get-AppUsesDarkMode | Should -BeTrue
        $script:UiPreferences.Theme = 'Auto'
        Get-AppUsesDarkMode | Should -BeTrue
        Should -Invoke Get-SystemUsesDarkMode -Times 1 -Exactly
    }
}