#!/usr/bin/env bun
/**
 * Builds isolate-compatible bundles for the document-generation libraries.
 *
 * Each library is bundled with `target=browser, format=iife` so it can be
 * evaluated inside a V8 isolate that has no Node APIs (`require`, `process`,
 * `fs`). The emitted files attach their exports to `globalThis.__bundles[name]`
 * and are checked in so production images don't need the bundler at runtime.
 *
 * Run via: `bun run build:sandbox-bundles`.
 */

import { mkdirSync, rmSync, writeFileSync } from 'node:fs'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'
import { createLogger } from '@sim/logger'

const logger = createLogger('SandboxBundleBuild')

interface BunBuildResult {
  success: boolean
  logs: unknown[]
  outputs: Array<{ text: () => Promise<string> }>
}
interface BunBuildOptions {
  entrypoints: string[]
  target: string
  format: string
  minify: boolean
  sourcemap: string
  root: string
}
declare const Bun: { build: (opts: BunBuildOptions) => Promise<BunBuildResult> }

const HERE = dirname(fileURLToPath(import.meta.url))
const BUNDLES_DIR = HERE
const ENTRIES_DIR = join(HERE, '.entries')
const APP_SIM_ROOT = join(HERE, '..', '..', '..', '..')

interface BundleSpec {
  /** Key on `globalThis.__bundles`. */
  name: string
  /** Short filename written under `bundles/<file>.cjs`. */
  outFile: string
  /** Source of the entry file bun will bundle. */
  entry: string
}

const POLYFILLS_PATH = join(HERE, '_polyfills.ts')
const POLYFILL_PRELUDE = `
// Isolate-side polyfills must execute BEFORE any other import (process/browser
// captures setTimeout at module-init time). Keep this as the first import.
import '${POLYFILLS_PATH}'
import { Buffer as __BufferPolyfill } from 'buffer'
import * as __processPolyfill from 'process/browser'
if (typeof globalThis.Buffer === 'undefined') globalThis.Buffer = __BufferPolyfill
if (typeof globalThis.process === 'undefined') globalThis.process = __processPolyfill
`

const BUNDLES: ReadonlyArray<BundleSpec> = [
  {
    name: 'pdf-lib',
    outFile: 'pdf-lib.cjs',
    entry: `
${POLYFILL_PRELUDE}
import * as mod from 'pdf-lib'
globalThis.__bundles = globalThis.__bundles || {}
globalThis.__bundles['pdf-lib'] = mod
`,
  },
  {
    name: 'docx',
    outFile: 'docx.cjs',
    entry: `
${POLYFILL_PRELUDE}
import * as mod from 'docx'
globalThis.__bundles = globalThis.__bundles || {}
globalThis.__bundles['docx'] = mod
`,
  },
  {
    name: 'pptxgenjs',
    outFile: 'pptxgenjs.cjs',
    entry: `
${POLYFILL_PRELUDE}
import PptxGenJS from 'pptxgenjs'
globalThis.__bundles = globalThis.__bundles || {}
globalThis.__bundles['pptxgenjs'] = PptxGenJS
`,
  },
]

async function main(): Promise<void> {
  rmSync(ENTRIES_DIR, { recursive: true, force: true })
  mkdirSync(ENTRIES_DIR, { recursive: true })
  mkdirSync(BUNDLES_DIR, { recursive: true })

  for (const spec of BUNDLES) {
    const entryPath = join(ENTRIES_DIR, `${spec.name}.entry.ts`)
    writeFileSync(entryPath, spec.entry, 'utf-8')

    const result = await Bun.build({
      entrypoints: [entryPath],
      target: 'browser',
      format: 'iife',
      minify: true,
      sourcemap: 'none',
      root: APP_SIM_ROOT,
    })

    if (!result.success) {
      for (const log of result.logs) {
        logger.error(String(log))
      }
      throw new Error(`Failed to build sandbox bundle: ${spec.name}`)
    }

    if (result.outputs.length === 0) {
      throw new Error(`No output produced for sandbox bundle: ${spec.name}`)
    }

    const code = await result.outputs[0].text()
    const banner = `// sandbox bundle: ${spec.name}\n// generated by apps/sim/lib/execution/sandbox/bundles/build.ts\n// do not edit by hand. run \`bun run build:sandbox-bundles\` to regenerate.\n`
    writeFileSync(join(BUNDLES_DIR, spec.outFile), banner + code, 'utf-8')
    logger.info(`built ${spec.outFile} (${code.length.toLocaleString()} chars)`)
  }

  rmSync(ENTRIES_DIR, { recursive: true, force: true })
}

main().catch((err) => {
  logger.error('sandbox bundle build failed', err)
  process.exit(1)
})