<#
.SYNOPSIS
  Builds the ERP frontend (Next.js) and packages it into a deployable zip.

.DESCRIPTION
  1. Installs dependencies (npm ci) when node_modules is missing or -CleanInstall is set
  2. Runs `npm run build`
  3. Copies the runtime files into dist/ and zips them

  The /api/* rewrite to the backend is resolved at BUILD time (next.config.ts ->
  routes-manifest.json), so BACKEND_ORIGIN must be correct for the target environment
  when you build, not when you start the server.

.PARAMETER BackendOrigin
  Origin of the ERPCore backend, e.g. http://127.0.0.1:6701. Overrides BACKEND_ORIGIN
  from the environment / .env.local for this build only.

.PARAMETER CleanInstall
  Delete node_modules and reinstall from package-lock.json.

.PARAMETER NoZip
  Build and stage the files in dist/erp-frontend but do not create the zip.

.EXAMPLE
  .\build.ps1 -BackendOrigin http://127.0.0.1:6701
#>
[CmdletBinding()]
param(
  [string]$BackendOrigin,
  [switch]$CleanInstall,
  [switch]$NoZip
)

$ErrorActionPreference = "Stop"
Set-Location $PSScriptRoot

function Step($msg) { Write-Host "`n==> $msg" -ForegroundColor Cyan }

function Invoke-Npm {
  & npm @args
  if ($LASTEXITCODE -ne 0) { throw "npm $($args -join ' ') failed (exit $LASTEXITCODE)" }
}

if (-not (Get-Command node -ErrorAction SilentlyContinue)) { throw "Node.js is not installed or not on PATH." }
if (-not (Get-Command npm -ErrorAction SilentlyContinue)) { throw "npm is not installed or not on PATH." }

$env:NEXT_TELEMETRY_DISABLED = "1"
if ($BackendOrigin) { $env:BACKEND_ORIGIN = $BackendOrigin }

# --- Install -----------------------------------------------------------------
if ($CleanInstall -and (Test-Path node_modules)) {
  Step "Removing node_modules"
  Remove-Item node_modules -Recurse -Force
}
if (-not (Test-Path node_modules)) {
  Step "Installing dependencies (npm ci)"
  Invoke-Npm ci
}
else {
  Write-Host "node_modules found, skipping install (use -CleanInstall to reinstall)." -ForegroundColor DarkGray
}

# --- Build -------------------------------------------------------------------
$origin = if ($env:BACKEND_ORIGIN) { $env:BACKEND_ORIGIN } else { "(from .env.local, else http://127.0.0.1:6701)" }
Step "Building (BACKEND_ORIGIN = $origin)"
Invoke-Npm run build

# --- Package -----------------------------------------------------------------
Step "Packaging"
$dist = Join-Path $PSScriptRoot "dist"
$stage = Join-Path $dist "erp-frontend"
if (Test-Path $stage) { Remove-Item $stage -Recurse -Force }
New-Item -ItemType Directory -Force $stage | Out-Null

# .next without the build cache and dev output (hundreds of MB, not needed at runtime)
& robocopy ".next" (Join-Path $stage ".next") /E /NFL /NDL /NJH /NJS /NP /XD cache dev diagnostics | Out-Null
if ($LASTEXITCODE -ge 8) { throw "robocopy .next failed (exit $LASTEXITCODE)" }

& robocopy "public" (Join-Path $stage "public") /E /NFL /NDL /NJH /NJS /NP | Out-Null
if ($LASTEXITCODE -ge 8) { throw "robocopy public failed (exit $LASTEXITCODE)" }

foreach ($f in "package.json", "package-lock.json", "next.config.ts") {
  Copy-Item $f $stage
}

if ($NoZip) {
  Write-Host "`nStaged at: $stage" -ForegroundColor Green
  exit 0
}

$stamp = Get-Date -Format "yyyyMMdd-HHmmss"
$zip = Join-Path $dist "erp-frontend-$stamp.zip"
# bsdtar (built into Windows 10+) writes forward-slash entry names. Windows PowerShell 5.1's
# ZipFile/Compress-Archive write backslashes, which unzip on Linux as literal "a\b" filenames.
& tar.exe -a -c -f $zip -C $stage .
if ($LASTEXITCODE -ne 0) { throw "tar failed (exit $LASTEXITCODE)" }

$sizeMb = [math]::Round((Get-Item $zip).Length / 1MB, 1)
Write-Host "`nBuild OK: $zip ($sizeMb MB)" -ForegroundColor Green
Write-Host @"

To run on the server:
  unzip, then in the folder:
    npm ci --omit=dev
    PORT=6702 npm start
"@