#Requires -Version 5.1
<#
.SYNOPSIS
    Build boringtun (Cloudflare WireGuard FFI library) for Windows.

.DESCRIPTION
    Clones or updates the boringtun repository, builds it with Cargo in
    release mode, and copies the resulting static library + C header to
    deps/boringtun/.

    Output:
        deps/boringtun/boringtun.lib        — static library (MSVC target)
        deps/boringtun/wireguard_ffi.h      — C ABI header
        deps/boringtun/wireguard.dll        — thin DLL shim (optional, not used)

.PARAMETER Target
    Rust target triple.  Defaults to x86_64-pc-windows-msvc.
    Use aarch64-pc-windows-msvc for ARM64.

.EXAMPLE
    pwsh scripts/build-boringtun-win.ps1
    pwsh scripts/build-boringtun-win.ps1 -Target aarch64-pc-windows-msvc

.NOTES
    Prerequisites:
        • Rust toolchain (https://rustup.rs) with the target installed:
              rustup target add x86_64-pc-windows-msvc
        • Visual Studio Build Tools 2019+ (for link.exe / lib.exe)
        • Git (for cloning boringtun)
#>

param(
    [string]$Target = "x86_64-pc-windows-msvc"
)

Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"

$Root      = Split-Path -Parent (Split-Path -Parent $PSCommandPath)
$DepsDir   = Join-Path $Root "deps\boringtun"
$CloneDir  = Join-Path $Root "build\boringtun-src"
$RepoURL   = "https://github.com/cloudflare/boringtun.git"
$CrateName = "boringtun-cli"   # the FFI-enabled crate lives under boringtun-cli

function Info($msg)  { Write-Host "  $msg"          -ForegroundColor Cyan  }
function Ok($msg)    { Write-Host "  ✓ $msg"         -ForegroundColor Green }
function Fail($msg)  { Write-Host "  ✗ $msg"         -ForegroundColor Red; exit 1 }

# ── Validate prerequisites ────────────────────────────────────────────────────

Info "Checking prerequisites..."

if (-not (Get-Command cargo -ErrorAction SilentlyContinue)) {
    Fail "cargo not found. Install Rust from https://rustup.rs"
}
if (-not (Get-Command git -ErrorAction SilentlyContinue)) {
    Fail "git not found. Install Git from https://git-scm.com"
}

# Ensure target is installed
$installed = rustup target list --installed 2>&1
if ($installed -notmatch [regex]::Escape($Target)) {
    Info "Installing Rust target $Target..."
    rustup target add $Target
}
Ok "Prerequisites satisfied"

# ── Clone / update boringtun ──────────────────────────────────────────────────

if (-not (Test-Path $CloneDir)) {
    Info "Cloning boringtun..."
    git clone --depth 1 $RepoURL $CloneDir
} else {
    Info "Updating boringtun..."
    Push-Location $CloneDir
    git pull --ff-only
    Pop-Location
}
Ok "Source ready at $CloneDir"

# ── Build ─────────────────────────────────────────────────────────────────────

Info "Building boringtun (--release, target=$Target)..."
Push-Location $CloneDir
cargo build --release --target $Target --features ffi-bindings 2>&1 | Write-Host
if ($LASTEXITCODE -ne 0) { Fail "cargo build failed" }
Pop-Location
Ok "Build complete"

# ── Copy artifacts ────────────────────────────────────────────────────────────

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

# The static library produced by Cargo for MSVC targets is named *.lib
$LibSrc = Join-Path $CloneDir "target\$Target\release\boringtun.lib"
if (-not (Test-Path $LibSrc)) {
    # Cargo sometimes names the lib after the crate package
    $LibSrc = Join-Path $CloneDir "target\$Target\release\boringtun_cli.lib"
}
if (-not (Test-Path $LibSrc)) {
    Fail "Could not find boringtun.lib in $CloneDir\target\$Target\release\"
}
Copy-Item $LibSrc (Join-Path $DepsDir "boringtun.lib") -Force
Ok "Copied boringtun.lib"

# Copy the FFI header (already lives in app/vpn/boringtun_ffi.h in our repo,
# but also copy the upstream version for reference)
$HdrSrc = Join-Path $CloneDir "boringtun\src\ffi\wireguard_ffi.h"
if (Test-Path $HdrSrc) {
    Copy-Item $HdrSrc (Join-Path $DepsDir "wireguard_ffi.h") -Force
    Ok "Copied wireguard_ffi.h"
}

Write-Host ""
Write-Host "  Build successful.  Output in:" -ForegroundColor Green
Write-Host "    $DepsDir" -ForegroundColor White
Write-Host ""
Write-Host "  Next steps:" -ForegroundColor Yellow
Write-Host "    1. Place wintun.dll (x64) next to DragonMoonlight.exe" -ForegroundColor White
Write-Host "       Download from https://www.wintun.net" -ForegroundColor White
Write-Host "    2. cmake -B build -DCMAKE_BUILD_TYPE=Release" -ForegroundColor White
Write-Host "    3. cmake --build build --config Release" -ForegroundColor White