#!/usr/bin/env node
/**
 * Compile native helpers and embed them as base64 into
 * server/native/embedded-helpers.js so bare-pack includes them
 * inside peardata-server.
 *
 *   node scripts/build-native-helpers.cjs
 */
'use strict'

const fs = require('fs')
const path = require('path')
const { spawnSync } = require('child_process')

const root = path.resolve(__dirname, '..')
const src = path.join(root, 'native', 'peardata-ebpf', 'main.c')
const outDir = path.join(root, 'native', 'prebuilds')
const embedOut = path.join(root, 'server', 'native', 'embedded-helpers.js')

function ensureDir(d) {
  fs.mkdirSync(d, { recursive: true })
}

function compile(hostTag) {
  ensureDir(outDir)
  const outBin = path.join(outDir, `peardata-ebpf-${hostTag}`)
  const cc = process.env.CC || 'cc'
  const args = ['-O2', '-Wall', '-o', outBin, src]
  console.log(`[native] ${cc} ${args.join(' ')}`)
  const res = spawnSync(cc, args, { cwd: root, stdio: 'inherit' })
  if (res.status !== 0) {
    console.warn('[native] compile failed — embedding placeholder stub')
    return null
  }
  try {
    fs.chmodSync(outBin, 0o755)
  } catch {
    // ignore
  }
  return outBin
}

function hostTag() {
  const p = process.platform
  const a = process.arch
  return `${p}-${a}`
}

function main() {
  const tag = hostTag()
  let bin = null
  if (process.platform === 'linux') {
    bin = compile(tag)
  } else {
    console.warn(`[native] skip compile on ${process.platform} (Linux helper only)`)
  }

  /** @type {Record<string, string>} */
  const helpers = {}
  if (bin && fs.existsSync(bin)) {
    helpers[`peardata-ebpf-${tag}`] = fs.readFileSync(bin).toString('base64')
    // also copy generic name for current host
    helpers['peardata-ebpf'] = helpers[`peardata-ebpf-${tag}`]
  }

  // Keep any previously embedded linux builds if present
  try {
    const prev = fs.readFileSync(embedOut, 'utf8')
    const m = prev.match(/export const EMBEDDED_HELPERS = (\{[\s\S]*?\})\n/)
    if (m) {
      const old = Function(`return (${m[1]})`)()
      for (const [k, v] of Object.entries(old || {})) {
        if (!helpers[k] && typeof v === 'string' && v.length > 32) helpers[k] = v
      }
    }
  } catch {
    // first run
  }

  ensureDir(path.dirname(embedOut))
  const body = `/* AUTO-GENERATED by scripts/build-native-helpers.cjs — do not edit */
export const EMBEDDED_HELPERS = ${JSON.stringify(helpers, null, 2)}

export const EMBEDDED_HELPER_NAMES = ${JSON.stringify(Object.keys(helpers))}
`
  fs.writeFileSync(embedOut, body)
  console.log(
    `[native] wrote ${embedOut} (${Object.keys(helpers).length} helper(s), ` +
      `${Math.round(JSON.stringify(helpers).length / 1024)} KiB json)`
  )
}

main()