# Build .skill archives from skills/<name>/ into dist/<name>.skill
# Usage: build.ps1 [-Names <name1>,<name2>] [-Prune]
#   no args        = build all skills/* into dist/<name>.skill
#   -Prune         = after build, remove dist/<name>.skill files whose <name>
#                    is NOT in skills/* (analogue of install.ps1 -Prune).
#                    Prune always scans the full dist/, ignores -Names filter.
#
# Uses .NET System.IO.Compression.ZipArchive directly to produce
# spec-compliant ZIPs with forward-slash entry names (Windows PowerShell 5.1's
# Compress-Archive writes backslashes, which break extraction on Linux/Mac).

[CmdletBinding()]
param(
    [string[]]$Names = @(),
    [switch]$Prune
)

$ErrorActionPreference = 'Stop'

$root = Split-Path -Parent $PSScriptRoot
$src  = Join-Path $root 'skills'
$dist = Join-Path $root 'dist'

if (-not (Test-Path $dist)) { New-Item -Type Directory -Path $dist | Out-Null }

if ($Names.Count -eq 0) {
    $Names = Get-ChildItem -Path $src -Directory | Sort-Object Name | Select-Object -ExpandProperty Name
}

Add-Type -AssemblyName System.IO.Compression
Add-Type -AssemblyName System.IO.Compression.FileSystem

function New-SkillArchive {
    param(
        [string]$SkillName,
        [string]$SourceDir,
        [string]$OutPath
    )
    if (Test-Path $OutPath) { Remove-Item $OutPath -Force }

    $sourceFull = (Resolve-Path $SourceDir).ProviderPath.TrimEnd('\','/')
    $archive = [System.IO.Compression.ZipFile]::Open(
        $OutPath,
        [System.IO.Compression.ZipArchiveMode]::Create
    )
    try {
        $files = Get-ChildItem -Path $sourceFull -Recurse -File
        foreach ($file in $files) {
            $rel = $file.FullName.Substring($sourceFull.Length + 1) -replace '\\','/'
            $entryName = "$SkillName/$rel"
            [System.IO.Compression.ZipFileExtensions]::CreateEntryFromFile(
                $archive,
                $file.FullName,
                $entryName,
                [System.IO.Compression.CompressionLevel]::Optimal
            ) | Out-Null
        }
    } finally {
        $archive.Dispose()
    }
}

foreach ($name in $Names) {
    $srcDir = Join-Path $src $name
    if (-not (Test-Path $srcDir -PathType Container)) {
        Write-Warning "skip: $name (not found in skills/)"
        continue
    }
    if (-not (Test-Path (Join-Path $srcDir 'SKILL.md'))) {
        Write-Warning "skip: $name (missing SKILL.md)"
        continue
    }
    $out = Join-Path $dist "$name.skill"
    New-SkillArchive -SkillName $name -SourceDir $srcDir -OutPath $out
    Write-Host "built: dist/$name.skill"
}

if ($Prune) {
    $sourceNames = @(Get-ChildItem -Path $src -Directory | Select-Object -ExpandProperty Name)
    $skillArchives = Get-ChildItem -Path $dist -Filter "*.skill" -File -ErrorAction SilentlyContinue
    foreach ($archive in $skillArchives) {
        $archiveName = [System.IO.Path]::GetFileNameWithoutExtension($archive.Name)
        if ($sourceNames -notcontains $archiveName) {
            Write-Host "pruning: $archiveName (not in skills/) -> $($archive.FullName)"
            Remove-Item -Force $archive.FullName
        }
    }
}