#Requires -Version 5.1
<#
.SYNOPSIS
  Builds the Behavision Windows package: engine, app, agent, installer.

.DESCRIPTION
  This script must run ON WINDOWS. Everything else in this repository
  cross-compiles from a Mac - the Go binaries with GOOS=windows, the web bundle
  with npm - but the ENGINE cannot. PyInstaller freezes the interpreter and the
  native wheels (onnxruntime, OpenCV) of the machine it runs on; there is no
  cross-target flag, and there never has been. So the engine .exe is built here
  or it is not built at all.

  Output: dist\Behavision-Setup-<version>.exe, plus dist\Behavision\ which is
  the unpacked tree the installer copies (useful for testing without
  installing).

.PARAMETER Version
  Stamped into the installer and shown in Add/Remove Programs.

.PARAMETER SkipInstaller
  Build the payload but not the setup .exe. Use when Inno Setup is absent.
#>
param(
  [string]$Version = "0.1.0",
  [switch]$SkipInstaller
)

$ErrorActionPreference = "Stop"
$root = Split-Path -Parent $PSScriptRoot
$dist = Join-Path $root "dist"
$stage = Join-Path $dist "Behavision"

function Step($msg) { Write-Host "`n=== $msg ===" -ForegroundColor Cyan }
function Need($exe, $hint) {
  if (-not (Get-Command $exe -ErrorAction SilentlyContinue)) {
    throw "$exe not found on PATH. $hint"
  }
}

# Run a NATIVE command and stop if it fails.
#
# $ErrorActionPreference = "Stop" does not do this. It governs PowerShell
# errors; a .exe returning non-zero is not one, so the script sails past it.
# That is not theoretical here: `npm ci` failing on a fresh Windows box would
# have let the build continue, and `go build` would then have embedded the
# STALE frontend/dist that is committed to this repository - producing an
# installer that works, opens, and shows last month's UI, with nothing
# anywhere saying so. The silent-wrong outcome, from the most likely failure.
#
# Output is NOT swallowed. `| Out-Null` on a failing install is how
# run-local.sh once exited with no output at all, which took three runs to
# diagnose; the same mistake is not worth repeating in a script that will be
# run on a machine nobody is sitting at.
function Run($exe) {
  $rest = $args
  & $exe @rest
  if ($LASTEXITCODE -ne 0) {
    throw "$exe $($rest -join ' ') failed with exit code $LASTEXITCODE"
  }
}

Need python "Install Python 3.11+ and tick 'Add to PATH'."
Need go      "Install Go 1.21+ from https://go.dev/dl/."
Need npm     "Install Node.js LTS from https://nodejs.org/."

Step "Python environment"
Push-Location $root
if (-not (Test-Path ".venv")) { Run python -m venv .venv }
Run .\.venv\Scripts\python -m pip install --upgrade pip
Run .\.venv\Scripts\python -m pip install -r requirements.txt pyinstaller

Step "Engine tests"
# The package is not worth building if the engine is broken, and finding that
# out after the installer is signed is the expensive order to do it in.
Run .\.venv\Scripts\python -m pytest tests -q

Step "Engine (PyInstaller, one-folder)"
if (Test-Path (Join-Path $root "build")) { Remove-Item -Recurse -Force (Join-Path $root "build") }
Run .\.venv\Scripts\pyinstaller behavision.spec --noconfirm --distpath (Join-Path $dist "engine-build")

Step "Desktop app (Wails)"
Push-Location (Join-Path $root "desktop\frontend")
# A built dist is COMMITTED to this repository so `go build` type-checks
# without npm (the //go:embed directive requires the directory to exist). That
# convenience is a trap at package time: a silently failed npm build leaves
# the old one in place and it embeds perfectly. So the marker is removed
# first, and its reappearance is what proves this build produced the UI being
# shipped rather than inheriting one.
$marker = Join-Path $root "desktop\frontend\dist\index.html"
if (Test-Path $marker) { Remove-Item -Force $marker }
Run npm ci
Run npm run build
if (-not (Test-Path $marker)) { throw "npm run build reported success and produced no dist\index.html" }
Pop-Location
Push-Location (Join-Path $root "desktop")
# Wails v2 talks to WebView2 through pure-Go bindings, so no cgo and no
# toolchain beyond Go itself. A plain go build is used on purpose: the icon
# and the manifest are compiled in from rsrc_windows_amd64.syso (go-winres,
# from brand/loyaly-icon-512.png), and `wails build` would add a second copy
# of both and fail the link with duplicate resources.
$env:CGO_ENABLED = "0"
Run go build -tags desktop,production -ldflags "-H windowsgui -X main.version=$Version" -o (Join-Path $root "desktop\build\bin\Behavision.exe") .
Pop-Location

Step "Headless agent"
Push-Location (Join-Path $root "agent")
$env:CGO_ENABLED = "0"   # the cgo resolver forces external linking
# `go build -o` does not create the target directory, and on a fresh clone
# dist\ is gitignored and absent. It exists here only because PyInstaller ran
# first and made it - an ordering dependency nothing states, so state it.
New-Item -ItemType Directory -Force -Path $dist | Out-Null
Run go build -o (Join-Path $root "dist\behavision-agent.exe") .
Pop-Location

Step "WebView2 bootstrapper"
# Bundled rather than downloaded at install time: a shop PC being set up often
# has no working internet yet, and the app is a blank white window without it.
$vendor = Join-Path $root "installer\vendor"
New-Item -ItemType Directory -Force -Path $vendor | Out-Null
$wv2 = Join-Path $vendor "MicrosoftEdgeWebview2Setup.exe"
if (-not (Test-Path $wv2)) {
  Invoke-WebRequest -Uri "https://go.microsoft.com/fwlink/p/?LinkId=2124703" -OutFile $wv2
}

Step "Staging"
if (Test-Path $stage) { Remove-Item -Recurse -Force $stage }
New-Item -ItemType Directory -Force -Path $stage | Out-Null
# The engine keeps its own folder: it is a one-folder PyInstaller build with
# ~150 native DLLs beside it, and `behavision.exe` would otherwise collide with
# `Behavision.exe` on a case-insensitive filesystem.
Copy-Item -Recurse (Join-Path $dist "engine-build\behavision") (Join-Path $stage "engine")
Copy-Item (Join-Path $root "desktop\build\bin\Behavision.exe") $stage
Copy-Item (Join-Path $dist "behavision-agent.exe") $stage
Copy-Item (Join-Path $root "LICENSE") $stage -ErrorAction SilentlyContinue

$engineExe = Join-Path $stage "engine\behavision.exe"
if (-not (Test-Path $engineExe)) { throw "engine exe missing at $engineExe" }
# The frozen engine has to START, not merely exist. A PyInstaller build that
# is missing a native DLL links fine and dies on first launch - the classic
# "works in the venv, dies in the bundle" - and finding that out on a shop
# counter is the expensive order to do it in.
Run $engineExe paths

Pop-Location

if ($SkipInstaller) {
  Step "Done (payload only)"
  Write-Host "Unpacked tree: $stage"
  exit 0
}

Step "Installer (Inno Setup)"
$iscc = @(
  "$env:ProgramFiles\Inno Setup 6\ISCC.exe",
  "${env:ProgramFiles(x86)}\Inno Setup 6\ISCC.exe"
) | Where-Object { Test-Path $_ } | Select-Object -First 1
if (-not $iscc) {
  throw "Inno Setup 6 not found. Install it from https://jrsoftware.org/isdl.php, or re-run with -SkipInstaller."
}
& $iscc "/DMyAppVersion=$Version" (Join-Path $root "installer\behavision.iss")
if ($LASTEXITCODE -ne 0) { throw "ISCC failed" }

Step "Done"
Get-ChildItem (Join-Path $dist "Behavision-Setup-*.exe") | ForEach-Object {
  Write-Host ("{0}  ({1:N1} MB)" -f $_.FullName, ($_.Length / 1MB))
}