# Regenerate index.json for THIS gallery repository (PLT\Gallery).
#
# 为什么自带一份：
#   主仓库 build\regen-gallery-index.ps1 写死了 "<脚本父目录的父目录>\gallery"，
#   只能服务 TeamAAS-2.1\gallery，无法指向这里。
#
# 格式：对齐远端 Gallery 仓库的 GalleryPackage schema（含多版本 versions[]），
#   以保持内容为准：字段全部来自包内 manifest.json，不再手写，避免 index 与包不一致。
#   版本历史会继承旧 index 中同 id 的其它版本条目（releasedAt / status / notes 不丢）。
#
# 用法（改了 packages\ 下任何 zip 之后执行）：
#   powershell -NoProfile -ExecutionPolicy Bypass -File .\regen-index.ps1
#
# 布局约定：packages\<host>\<id>\<id>-<version>.zip（zip 根目录必须含 manifest.json）
$ErrorActionPreference = 'Stop'

$galleryDir  = $PSScriptRoot
$packagesDir = Join-Path $galleryDir 'packages'
$indexPath   = Join-Path $galleryDir 'index.json'

if (-not (Test-Path $packagesDir)) {
    throw "packages directory not found: $packagesDir"
}

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

# 旧 index：仅用于继承版本历史
$history = @{}
if (Test-Path $indexPath) {
    try {
        $old = (Get-Content $indexPath -Raw -Encoding UTF8) | ConvertFrom-Json
        foreach ($p in $old.packages) {
            foreach ($v in $p.versions) {
                $history["$($p.id)@$($v.version)"] = @{
                    releasedAt = $v.releasedAt
                    status     = if ($v.status) { $v.status } else { 'stable' }
                    notes      = $v.notes
                }
            }
        }
    } catch {
        Write-Warning "旧 index.json 解析失败，版本历史不继承：$($_.Exception.Message)"
    }
}

$today   = (Get-Date).ToString('yyyy-MM-dd')
$sha     = [System.Security.Cryptography.SHA256]::Create()
$entries = New-Object System.Collections.Generic.List[object]
$seen    = @{}

foreach ($zipFile in (Get-ChildItem -Path $packagesDir -Recurse -Filter '*.zip' | Sort-Object FullName)) {
    $zip = [System.IO.Compression.ZipFile]::OpenRead($zipFile.FullName)
    try {
        $manifestEntry = $zip.Entries |
            Where-Object { $_.FullName -replace '\\', '/' -eq 'manifest.json' } |
            Select-Object -First 1
        if (-not $manifestEntry) {
            Write-Warning "skip (no manifest.json at root): $($zipFile.Name)"
            continue
        }

        $reader = New-Object System.IO.StreamReader($manifestEntry.Open(), [System.Text.Encoding]::UTF8)
        try { $manifest = $reader.ReadToEnd() } finally { $reader.Dispose() }

        $j = $manifest | ConvertFrom-Json
        if (-not $j.id -or -not $j.version) {
            Write-Warning "skip (manifest missing id/version): $($zipFile.Name)"
            continue
        }

        $key = "$($j.id)@$($j.version)"
        if ($seen.ContainsKey($key)) {
            Write-Warning "skip duplicate: $key ($($zipFile.Name))"
            continue
        }
        $seen[$key] = $true

        $fs = [System.IO.File]::OpenRead($zipFile.FullName)
        try {
            $hashBytes = $sha.ComputeHash($fs)
            $size = $fs.Length
        } finally { $fs.Dispose() }
        $hashHex = ([System.BitConverter]::ToString($hashBytes) -replace '-', '').ToLowerInvariant()

        # downloadUrl 存相对路径：GalleryClient 会按实际源根拼接，源换域名也不用改包。
        $relativeUrl = $zipFile.FullName.Substring($galleryDir.Length + 1) -replace '\\', '/'

        $hostName = if ($j.host) { [string]$j.host } else { 'platform' }
        $kind     = if ($j.kind) { [string]$j.kind } else { 'extension' }
        $requires = $null
        if ($j.requiresHost) {
            $requires = if ($j.requiresHost.minVersion) {
                "$($j.requiresHost.id)>=$($j.requiresHost.minVersion)"
            } else { [string]$j.requiresHost.id }
        }

        $prev = $history[$key]
        $versionEntry = [ordered]@{
            version     = [string]$j.version
            downloadUrl = $relativeUrl
            sha256      = $hashHex
            size        = $size
            releasedAt  = if ($prev) { $prev.releasedAt } else { $today }
            status      = if ($prev) { $prev.status } else { 'stable' }
            # 本版特性优先取被发布物料自己的 manifest.notes（每个版本各自的说明），
            # 其次继承旧 index 里的同版本记录，最后才是兜底文案。
            notes       = if ($j.notes) { [string]$j.notes } elseif ($prev -and $prev.notes) { $prev.notes } else { '首次收录' }
        }

        $entry = [ordered]@{
            id              = [string]$j.id
            name            = [string]$j.name
            version         = [string]$j.version
            publisher       = if ($j.publisher) { [string]$j.publisher } else { $null }
            kind            = $kind
            host            = $hostName
            description     = if ($j.description) { [string]$j.description } else { $null }
            notes           = if ($j.notes) { [string]$j.notes } else { $null }
            downloadUrl     = $relativeUrl
            sha256          = $hashHex
            size            = $size
            references      = @($j.references)
            targetFramework = if ($j.targetFramework) { [string]$j.targetFramework } else { $null }
            requiresHost    = $requires
            arch            = @($j.arch)
            dependencies    = @($j.dependencies)
            versions        = @($versionEntry)
        }

        $entries.Add([PSCustomObject]$entry)
        Write-Host ("indexed {0} {1} [{2}]  {3} bytes  {4}" -f $j.id, $j.version, $hostName, $size, $hashHex)
    } finally {
        $zip.Dispose()
    }
}
$sha.Dispose()

# ---------------------------------------------------------------------------
# 合并同 id 的多条为单一条目：
#   index.json 的契约是 packages[] 每个 id 只出现一次，多版本装在 versions[] 里
#   （SDK 侧 GalleryPackage.AllVersions 就按这个读）。
#   若同 id 各版本各占一条，平台按 id 取一条展示 —— 表现为"版本下拉只有最新一版"，
#   旧版本永远选不到。这里按 id 归并，并把顶层字段对齐到最高版本。
# ---------------------------------------------------------------------------
$byId = [ordered]@{}
foreach ($e in $entries) {
    $id = [string]$e.id
    if ($byId.Contains($id)) {
        $byId[$id].versions = @($byId[$id].versions) + @($e.versions)
        if (-not $byId[$id].notes -and $e.notes) { $byId[$id].notes = $e.notes }
    } else {
        $byId[$id] = $e
    }
}

$merged = New-Object System.Collections.Generic.List[object]
foreach ($id in $byId.Keys) {
    $p = $byId[$id]
    $versions = @($p.versions | Sort-Object -Property @{ Expression = {
        $v = $null
        if ([version]::TryParse([string]$_.version, [ref]$v)) { $v } else { [version]'0.0' }
    } } -Descending)
    if ($versions.Count -eq 0) { continue }
    $top = $versions[0]
    $p.versions    = $versions
    $p.version     = [string]$top.version
    $p.downloadUrl = $top.downloadUrl
    $p.sha256      = $top.sha256
    $p.size        = $top.size
    $p.notes       = if ($p.notes) { $p.notes } else { $top.notes }
    $merged.Add([PSCustomObject]$p)
}

# Stable order: host (platform first), then id.
$sorted = @($merged | Sort-Object @{ Expression = { $_.host } }, @{ Expression = { $_.id } })

$index = [ordered]@{
    schemaVersion = 1
    generatedAt   = (Get-Date).ToUniversalTime().ToString('yyyy-MM-ddTHH:mm:ssZ')
    packages      = $sorted
}

$json = $index | ConvertTo-Json -Depth 12
# ConvertTo-Json 会把 ">" 转义成 \u003e（合法 JSON 但可读性差，且与线上文件不一致），还原。
$json = $json -replace '\\u003e', '>' -replace '\\u003c', '<' -replace '\\u0026', '&'
[System.IO.File]::WriteAllText($indexPath, $json, (New-Object System.Text.UTF8Encoding($false)))
Write-Host "REGEN DONE: $($sorted.Count) package(s) -> $indexPath"