# Sync standards snapshot to project root.
# - Copies <snapshot>/.agents -> <project-root>/.agents/tsl
# - Copies <snapshot>/.gitattributes -> <project-root>/.gitattributes
# Existing targets are backed up before overwrite.
$ErrorActionPreference = "Stop"

$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
$Src = (Resolve-Path (Join-Path $ScriptDir "..")).Path

$Root = (git -C $ScriptDir rev-parse --show-toplevel 2>$null)
if (-not $Root) { $Root = (Get-Location).Path }
$Root = (Resolve-Path $Root).Path

$AgentsSrc = Join-Path $Src ".agents"
$GitAttrSrc = Join-Path $Src ".gitattributes"

if (-not (Test-Path $AgentsSrc)) {
  throw "Standards snapshot not found at $AgentsSrc. Run git subtree add first (choose any prefix)."
}

$timestamp = Get-Date -Format "yyyyMMddHHmmss"

$AgentsNs = $env:AGENTS_NS
if (-not $AgentsNs) { $AgentsNs = "tsl" }
if ($AgentsNs -match '[\\/]' -or $AgentsNs -match '\.\.') {
  throw "Invalid AGENTS_NS=$AgentsNs"
}
$AgentsRoot = Join-Path $Root ".agents"
$AgentsDst = Join-Path $AgentsRoot $AgentsNs

if ($Src -ieq $Root) {
  Write-Host "Skip: snapshot root equals project root."
  Write-Host "Done."
  exit 0
}

New-Item -ItemType Directory -Path $AgentsRoot -Force | Out-Null

if (Test-Path $AgentsDst) {
  $bak = (Join-Path $AgentsRoot "$AgentsNs.bak.$timestamp")
  Move-Item $AgentsDst $bak
  Write-Host "Backed up existing $AgentsNs agents -> $(Split-Path -Leaf $bak)"
}

New-Item -ItemType Directory -Path $AgentsDst -Force | Out-Null
Copy-Item (Join-Path $AgentsSrc "*") $AgentsDst -Recurse -Force
Write-Host "Synced .agents/$AgentsNs from standards."

$AgentsIndex = Join-Path $AgentsRoot "index.md"
if (-not (Test-Path $AgentsIndex)) {
@"
# .agents（多语言）

本目录用于存放仓库级/语言级的代理规则集。

建议约定：

- `.agents/tsl/`：TSL 相关标准（由 `sync_standards.*` 同步）
- `.agents/cpp/`、`.agents/python/` 等：其他语言的规则集（按需增加）

规则发生冲突时，建议以“更靠近代码的目录规则更具体”为准。
"@ | Set-Content -Path $AgentsIndex -Encoding UTF8
  Write-Host "Created .agents/index.md"
}

$GitAttrDst = Join-Path $Root ".gitattributes"
if (Test-Path $GitAttrSrc) {
  if ($GitAttrSrc -ieq $GitAttrDst) {
    Write-Host "Skip: .gitattributes source equals destination."
    Write-Host "Done."
    exit 0
  }
  if (Test-Path $GitAttrDst) {
    $bak = "$GitAttrDst.bak.$timestamp"
    Move-Item $GitAttrDst $bak
    Write-Host "Backed up existing .gitattributes -> $bak"
  }
  Copy-Item $GitAttrSrc $GitAttrDst -Force
  Write-Host "Synced .gitattributes from standards."
}

Write-Host "Done."