using namespace System.Management.Automation
using namespace System.Management.Automation.Language

Register-ArgumentCompleter -Native -CommandName 'triton-tui' -ScriptBlock {
    param($wordToComplete, $commandAst, $cursorPosition)

    $commandElements = $commandAst.CommandElements
    $command = @(
        'triton-tui'
        for ($i = 1; $i -lt $commandElements.Count; $i++) {
            $element = $commandElements[$i]
            if ($element -isnot [StringConstantExpressionAst] -or
                $element.StringConstantType -ne [StringConstantType]::BareWord -or
                $element.Value.StartsWith('-') -or
                $element.Value -eq $wordToComplete) {
                break
        }
        $element.Value
    }) -join ';'

    $completions = @(switch ($command) {
        'triton-tui' {
            [CompletionResult]::new('-i', '-i', [CompletionResultType]::ParameterName, 'File containing public input')
            [CompletionResult]::new('--input', '--input', [CompletionResultType]::ParameterName, 'File containing public input')
            [CompletionResult]::new('-n', '-n', [CompletionResultType]::ParameterName, 'JSON file containing all non-determinism')
            [CompletionResult]::new('--non-determinism', '--non-determinism', [CompletionResultType]::ParameterName, 'JSON file containing all non-determinism')
            [CompletionResult]::new('--initial-state', '--initial-state', [CompletionResultType]::ParameterName, 'JSON file containing entire initial state')
            [CompletionResult]::new('--interrupt-cycle', '--interrupt-cycle', [CompletionResultType]::ParameterName, 'The maximum number of cycles to run after any interaction, preventing a frozen TUI in infinite loops')
            [CompletionResult]::new('-h', '-h', [CompletionResultType]::ParameterName, 'Print help')
            [CompletionResult]::new('--help', '--help', [CompletionResultType]::ParameterName, 'Print help')
            [CompletionResult]::new('-V', '-V ', [CompletionResultType]::ParameterName, 'Print version')
            [CompletionResult]::new('--version', '--version', [CompletionResultType]::ParameterName, 'Print version')
            break
        }
    })

    $completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
        Sort-Object -Property ListItemText
}