[CmdletBinding(SupportsShouldProcess = $true, DefaultParameterSetName = 'List')]
param(
    [Parameter(ParameterSetName = 'List')][switch]$List,
    [Parameter(Mandatory = $true, ParameterSetName = 'Selected')][string[]]$Skill,
    [Parameter(Mandatory = $true, ParameterSetName = 'All')][switch]$All
)
Set-StrictMode -Version Latest
$ErrorActionPreference = 'Stop'
try {
    Import-Module (Join-Path $PSScriptRoot 'scripts/XasSkills.psm1') -Force
    $catalog = @(Get-XasSkillCatalog -RepositoryRoot $PSScriptRoot)
    if ($PSCmdlet.ParameterSetName -eq 'List') {
        if ($catalog.Count -eq 0) { Write-Host 'No installable skills found.' }
        $catalog | Select-Object Name, Description | Format-Table -AutoSize
        Write-Host 'Usage: .\skills install <name> | .\skills install --all (add --preview to inspect first)'
        exit 0
    }
    if ($All) { $Skill = @($catalog | ForEach-Object { $_.Name }) }
    if (@($Skill).Count -eq 0) { Write-Host 'No installable skills found.'; exit 0 }
    $skillsRoot = Get-XasDefaultSkillsRoot
    if ($WhatIfPreference) {
        Invoke-XasInstall -RepositoryRoot $PSScriptRoot -SkillsRoot $skillsRoot -Skill $Skill -Preview | Format-Table -AutoSize
        Write-Host "Preview only. Destination: $skillsRoot"
    } elseif ($PSCmdlet.ShouldProcess($skillsRoot, 'Install selected xas-skills')) {
        Invoke-XasInstall -RepositoryRoot $PSScriptRoot -SkillsRoot $skillsRoot -Skill $Skill | ForEach-Object {
            Write-Host ("{0}: {1}" -f $_.Name, $_.Status)
        }
        Write-Host 'Skills are available on the next turn. If they do not appear, restart Codex.'
    }
    exit 0
} catch {
    Write-Error $_ -ErrorAction Continue
    exit 1
}