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

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

    $commandElements = $commandAst.CommandElements
    $command = @(
        'snazy'
        for ($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) {
        'snazy' {
            [CompletionResult]::new('-r', 'r', [CompletionResultType]::ParameterName, 'highlight word in a message with a regexp')
            [CompletionResult]::new('--regexp', 'regexp', [CompletionResultType]::ParameterName, 'highlight word in a message with a regexp')
            [CompletionResult]::new('-S', 'S', [CompletionResultType]::ParameterName, 'skip line in a message if matching a regexp')
            [CompletionResult]::new('--skip-line-regexp', 'skip-line-regexp', [CompletionResultType]::ParameterName, 'skip line in a message if matching a regexp')
            [CompletionResult]::new('-f', 'f', [CompletionResultType]::ParameterName, 'filter by levels')
            [CompletionResult]::new('--filter-level', 'filter-level', [CompletionResultType]::ParameterName, 'filter by levels')
            [CompletionResult]::new('--time-format', 'time-format', [CompletionResultType]::ParameterName, 'Time format')
            [CompletionResult]::new('--kail-prefix-format', 'kail-prefix-format', [CompletionResultType]::ParameterName, 'Kail prefix format')
            [CompletionResult]::new('-k', 'k', [CompletionResultType]::ParameterName, 'key to use for json parsing')
            [CompletionResult]::new('--json-keys', 'json-keys', [CompletionResultType]::ParameterName, 'key to use for json parsing')
            [CompletionResult]::new('--action-regexp', 'action-regexp', [CompletionResultType]::ParameterName, 'A regexp to match for action')
            [CompletionResult]::new('--action-command', 'action-command', [CompletionResultType]::ParameterName, 'An action command to launch when action-regexp match')
            [CompletionResult]::new('-c', 'c', [CompletionResultType]::ParameterName, 'When to use colors: never, *auto*, always')
            [CompletionResult]::new('--color', 'color', [CompletionResultType]::ParameterName, 'When to use colors: never, *auto*, always')
            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Print help information')
            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Print help information')
            [CompletionResult]::new('-V', 'V', [CompletionResultType]::ParameterName, 'Print version information')
            [CompletionResult]::new('--version', 'version', [CompletionResultType]::ParameterName, 'Print version information')
            [CompletionResult]::new('--kail-no-prefix', 'kail-no-prefix', [CompletionResultType]::ParameterName, 'Hide container prefix when showing the log with kail')
            [CompletionResult]::new('-l', 'l', [CompletionResultType]::ParameterName, 'Replace log level with pretty symbols')
            [CompletionResult]::new('--level-symbols', 'level-symbols', [CompletionResultType]::ParameterName, 'Replace log level with pretty symbols')
            break
        }
    })

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