/** Local gateway bootstrap for the Ink TUI: run ui-tui's `gateway_bootstrap.py` on the install's
interpreter and parse its grant (or its named terminal failure). Kept out of the transport class;
`GatewayClient` takes it as its injected `bootstrap`. */
import { execFile } from 'node:child_process'
import { resolve } from 'node:path'
import { promisify } from 'node:util'

import { pythonHelperPath } from './lib/pythonHelpers.js'

const resolvePython = () => {
  // Trust HERMES_PYTHON only. The launcher guarantees it: hermes_cli/main.py
  // validates it and falls back to its own sys.executable, and the Nix
  // wrapper sets it too. So a TUI started the normal way already knows its
  // interpreter, and scanning VIRTUAL_ENV / .venv here can only find a
  // DIFFERENT python than the parent process runs on — with the pm store,
  // a stale venv path is actively dangerous (the interpreter a gateway
  // child gets must match the one that spawned it).
  const configured = process.env.HERMES_PYTHON?.trim()

  if (configured) {
    return configured
  }

  // The one case with no launcher above it: `npm run dev` / `npm start`
  // straight out of ui-tui/. A developer doing that runs inside their own
  // activated environment, so PATH is the right question there.
  return process.platform === 'win32' ? 'python' : 'python3'
}

export interface LocalGatewayGrant { url: string; protocols: string[]; profile_id: string; instance_id: string }

/** gateway_bootstrap.py's verdict for an interpreter that cannot load Hermes or its dependencies. */
// execFile's error text is `Command failed: …` followed by the child's stderr, hence the line match.
export const isTerminalBootstrapFailure = (message: string) => /^gateway unavailable: /m.test(message)

export const bootstrapLocalGateway = async (start: boolean, recover = false): Promise<LocalGatewayGrant> => {
  const root = process.env.HERMES_PYTHON_SRC_ROOT ?? resolve(import.meta.dirname, '../../')

  const { stdout } = await promisify(execFile)(resolvePython(),
    [pythonHelperPath('gateway_bootstrap.py', root), ...(start ? ['--start'] : recover ? ['--recover'] : [])],
    { cwd: root, env: { ...process.env, PYTHONPATH: root, HERMES_PYTHON_SRC_ROOT: root }, timeout: 40_000, maxBuffer: 1024 * 1024 })

  return JSON.parse(stdout) as LocalGatewayGrant
}