// ── The demo's rig and versions (docs/website/DEMO_MODE.md §7.2, §7.5) ──────
//
// One script, four commands, run by the demo workflows on the `demo-site` host
// inside a stock Node container (so the host needs Docker and nothing else):
//
//   node rig.mjs plan      decide the versions for this cycle (§7.5)
//   node rig.mjs restore   put the rig back to the baseline, updating its plugins
//                          and sidecar first when the bundle changed (§7.2)
//   node rig.mjs baseline  capture the rig's current state as the baseline (§7.2)
//   node rig.mjs smoke     wait for the site, then for the rig to report in (§7.3.6)
//
// State lives in $STATE_DIR (the deploy directory's `state/`):
//   bundle.json  the bundle last written onto the rig
//   modules.env  MODULES=rust@<version>=<manifest>, read by docker-compose.yml
//   plan.json    this cycle's decision, written by `plan`, read by `restore`
//
// Environment:
//   PTERODACTYL_URL         the panel, e.g. http://192.168.0.12
//   PTERODACTYL_SERVER      the rig's short identifier, e.g. e6758c06
//   PTERODACTYL_CLIENT_KEY  the demo subuser's client key (file + power only)
//   PTERODACTYL_IDENTITY    optional: the folder under /server holding the save;
//                           found by listing /server when unset
//   GITEA_URL               default https://gitea.whitlocktech.com
//   SITE_URL                for `smoke`, e.g. http://app:3000
//   SMOKE_TIMEOUT_SECONDS   for `smoke`, default 900 (a Rust boot is ~9 minutes)
//
// Dependency-free on purpose: Node's own fetch and crypto, and the image's tar.

import { createHash } from 'node:crypto'
import { execFileSync } from 'node:child_process'
import fs from 'node:fs'
import os from 'node:os'
import path from 'node:path'
import { fileURLToPath, pathToFileURL } from 'node:url'

const GITEA = (process.env.GITEA_URL || 'https://gitea.whitlocktech.com').replace(/\/+$/, '')
const STATE_DIR = process.env.STATE_DIR || path.join(path.dirname(fileURLToPath(import.meta.url)), 'state')
const BASELINE = 'demo-baseline.tar.gz'
const MODULE_REPO = 'RunicGateway/Module-Rust'
const BUNDLE_PATH = 'RunicGateway/installer/contents/v2/rust/current.json?ref=bundles'

const log = (...a) => console.log(...a)
const warn = (msg) => console.log(`::warning::${msg}`)
const sleep = (ms) => new Promise((r) => setTimeout(r, ms))

function need(name) {
  const v = process.env[name]
  if (!v) throw new Error(`${name} is not set`)
  return v
}

const statePath = (f) => path.join(STATE_DIR, f)
function readJson(file, fallback = null) {
  try {
    return JSON.parse(fs.readFileSync(file, 'utf8'))
  } catch {
    return fallback
  }
}
function writeFile(file, text) {
  fs.mkdirSync(path.dirname(file), { recursive: true })
  fs.writeFileSync(file, text)
}

// ── Gitea ──────────────────────────────────────────────────────────────────

// The JSON API, never /raw/: /raw/ is CDN-cached for hours on this instance, and
// a stale current.json would pin the demo to an old bundle without a word.
async function gitea(apiPath) {
  const res = await fetch(`${GITEA}/api/v1/repos/${apiPath}`, { headers: { Accept: 'application/json' } })
  if (!res.ok) throw new Error(`GET ${apiPath}: HTTP ${res.status}`)
  return res.json()
}

async function currentBundle() {
  const file = await gitea(BUNDLE_PATH)
  return JSON.parse(Buffer.from(file.content, 'base64').toString('utf8'))
}

async function download(url, sha256) {
  const res = await fetch(url)
  if (!res.ok) throw new Error(`GET ${url}: HTTP ${res.status}`)
  const buf = Buffer.from(await res.arrayBuffer())
  if (sha256) {
    const got = createHash('sha256').update(buf).digest('hex')
    if (got !== sha256) throw new Error(`${url}: sha256 ${got} does not match the bundle's ${sha256}`)
  }
  return buf
}

const semver = (v) => String(v).replace(/^v/, '').split('.').map((n) => Number.parseInt(n, 10) || 0)
function newerFirst(a, b) {
  const x = semver(a)
  const y = semver(b)
  for (let i = 0; i < 3; i += 1) if (x[i] !== y[i]) return y[i] - x[i]
  return 0
}

/** The newest Module-Rust release whose install manifest says `protocol` (DM12). */
async function moduleFor(protocol) {
  const releases = (await gitea(`${MODULE_REPO}/releases?limit=50`))
    .filter((r) => !r.draft && !r.prerelease)
    .sort((a, b) => newerFirst(a.tag_name, b.tag_name))
  for (const r of releases) {
    const asset = (r.assets || []).find((a) => /^module-rust-.+\.json$/.test(a.name))
    if (!asset) continue
    const res = await fetch(asset.browser_download_url)
    if (!res.ok) continue
    const manifest = await res.json()
    // Releases from before §7.5 carry no `protocol`; they never match.
    if (manifest.protocol === protocol) {
      return { version: manifest.version, manifestUrl: asset.browser_download_url }
    }
  }
  return null
}

// ── Pterodactyl (client API: files + power only) ─────────────────────────

function ptero() {
  const base = `${need('PTERODACTYL_URL').replace(/\/+$/, '')}/api/client/servers/${need('PTERODACTYL_SERVER')}`
  const key = need('PTERODACTYL_CLIENT_KEY')

  async function call(method, sub, { json, body, type, raw = false } = {}) {
    const headers = { Authorization: `Bearer ${key}`, Accept: 'application/json' }
    let payload
    if (json !== undefined) {
      headers['Content-Type'] = 'application/json'
      payload = JSON.stringify(json)
    } else if (body !== undefined) {
      headers['Content-Type'] = type || 'application/octet-stream'
      payload = body
    }
    const res = await fetch(`${base}${sub}`, { method, headers, body: payload })
    const text = await res.text()
    if (!res.ok) throw new Error(`${method} ${sub}: HTTP ${res.status} ${text.slice(0, 300)}`)
    if (raw) return text
    return text ? JSON.parse(text) : null
  }

  return {
    state: async () => (await call('GET', '/resources')).attributes.current_state,
    power: (signal) => call('POST', '/power', { json: { signal } }),
    list: async (dir) =>
      (await call('GET', `/files/list?directory=${encodeURIComponent(dir)}`)).data.map((f) => f.attributes),
    remove: (files) => call('POST', '/files/delete', { json: { root: '/', files } }),
    decompress: (file) => call('POST', '/files/decompress', { json: { root: '/', file } }),
    compress: async (files) => (await call('POST', '/files/compress', { json: { root: '/', files } })).attributes,
    rename: (from, to) => call('PUT', '/files/rename', { json: { root: '/', files: [{ from, to }] } }),
    read: (file) => call('GET', `/files/contents?file=${encodeURIComponent(file)}`, { raw: true }),
    write: (file, body, type) => call('POST', `/files/write?file=${encodeURIComponent(file)}`, { body, type }),
    // One file per call: a chmod naming two applies only the first, silently.
    chmod: (dir, file, mode) => call('POST', '/files/chmod', { json: { root: dir, files: [{ file, mode }] } }),
  }
}

async function waitFor(p, wanted, seconds) {
  const until = Date.now() + seconds * 1000
  for (;;) {
    const s = await p.state()
    if (s === wanted) return
    if (Date.now() > until) throw new Error(`the rig is "${s}" after ${seconds}s, expected "${wanted}"`)
    await sleep(5000)
  }
}

/** The folder under /server holding the world save and cfg/. */
async function identity(p) {
  if (process.env.PTERODACTYL_IDENTITY) return process.env.PTERODACTYL_IDENTITY
  const dirs = (await p.list('/server')).filter((f) => !f.is_file).map((f) => f.name)
  if (dirs.length !== 1) {
    throw new Error(`cannot tell the server identity: /server holds ${JSON.stringify(dirs)}; set PTERODACTYL_IDENTITY`)
  }
  return dirs[0]
}

const baselineDirs = (id) => ['oxide/data', 'oxide/config', `server/${id}`]

// ── plan ──────────────────────────────────────────────────────────────────

async function plan() {
  const bundle = await currentBundle()
  const applied = readJson(statePath('bundle.json'))
  const previousModules = fs.existsSync(statePath('modules.env'))
  log(`bundle ${bundle.bundle} (protocol ${bundle.protocol}); on the rig: ${applied ? applied.bundle : 'none recorded'}`)

  const module = await moduleFor(bundle.protocol)
  if (!module) {
    // §7.5: a half-released protocol bump never takes the demo down.
    if (!previousModules) {
      throw new Error(`no Module-Rust release speaks protocol ${bundle.protocol}, and there is no previous set to keep`)
    }
    warn(`no Module-Rust release speaks protocol ${bundle.protocol} yet; keeping the previous bundle and module`)
    writeFile(statePath('plan.json'), JSON.stringify({ bundle: null }, null, 2))
    return
  }

  log(`module rust ${module.version} (protocol ${bundle.protocol})`)
  writeFile(statePath('modules.env'), `MODULES=rust@${module.version}=${module.manifestUrl}\n`)
  const changed = !applied || applied.bundle !== bundle.bundle
  writeFile(statePath('plan.json'), JSON.stringify({ bundle: changed ? bundle : null }, null, 2))
  log(changed ? 'the rig gets the new bundle at this wipe' : 'the rig is already on this bundle')
}

// ── restore ───────────────────────────────────────────────────────────────

async function writeBundle(p, bundle) {
  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'bundle-'))
  try {
    const plugins = []
    for (const part of [bundle.payload, bundle.npc].filter(Boolean)) {
      const tarball = path.join(tmp, part.asset.name)
      fs.writeFileSync(tarball, await download(part.asset.url, part.asset.sha256))
      const out = path.join(tmp, `${part.asset.name}.d`)
      fs.mkdirSync(out)
      execFileSync('tar', ['-xzf', tarball, '-C', out])
      for (const dir of fs.readdirSync(out)) {
        for (const f of fs.readdirSync(path.join(out, dir))) {
          if (f.endsWith('.cs')) plugins.push({ name: f, text: fs.readFileSync(path.join(out, dir, f)) })
        }
      }
    }
    if (!plugins.length) throw new Error(`bundle ${bundle.bundle} carries no plugin files`)

    const sidecar = bundle.sidecar.assets['linux-x86_64']
    const binary = await download(sidecar.url, sidecar.sha256)
    const launcher = await download(bundle.sidecar.launcher.url, bundle.sidecar.launcher.sha256)

    for (const f of plugins) {
      await p.write(`/oxide/plugins/${f.name}`, f.text, 'text/plain')
      log(`  wrote oxide/plugins/${f.name}`)
    }
    await p.write('/rust-link/rust-link-sidecar', binary)
    await p.write('/rust-link/with-sidecar.sh', launcher, 'text/plain')
    await p.chmod('/rust-link', 'rust-link-sidecar', '755')
    await p.chmod('/rust-link', 'with-sidecar.sh', '755')
    log(`  wrote the sidecar ${bundle.sidecar.version} and its launcher`)

    // The rig's own record of what it runs, in the shape the rig push writes, so
    // anyone reading the rig sees the bundle the wipe put there.
    const prior = JSON.parse((await p.read('/rust-link/bundle.json').catch(() => null)) || '{}')
    const record = {
      bundle: bundle.bundle,
      protocol: bundle.protocol,
      framework: prior.framework || 'oxide',
      installed: new Date().toISOString().replace(/\.\d+Z$/, 'Z'),
      sidecar: { tag: bundle.sidecar.tag },
      plugin: { tag: bundle.payload.tag, commit: bundle.payload.commit },
      ...(bundle.npc ? { runicnpc: { tag: bundle.npc.tag, api: bundle.npc.api } } : {}),
    }
    await p.write('/rust-link/bundle.json', `${JSON.stringify(record, null, 2)}\n`, 'text/plain')
  } finally {
    fs.rmSync(tmp, { recursive: true, force: true })
  }
}

async function restore() {
  const p = ptero()
  const decided = readJson(statePath('plan.json'))
  if (!decided) throw new Error('no plan.json; run `plan` first')

  // 1. Kill: no save, the world is about to be replaced.
  if ((await p.state()) !== 'offline') {
    await p.power('kill')
    await waitFor(p, 'offline', 120)
  }
  log('the rig is stopped')

  // §7.5: the bundle goes on while the server is stopped.
  if (decided.bundle) {
    log(`writing bundle ${decided.bundle.bundle} onto the rig`)
    await writeBundle(p, decided.bundle)
    writeFile(
      statePath('bundle.json'),
      JSON.stringify({ bundle: decided.bundle.bundle, protocol: decided.bundle.protocol, applied: new Date().toISOString() }, null, 2),
    )
  }

  // 2-3. Delete the three directories and unpack the baseline over them.
  const root = (await p.list('/')).map((f) => f.name)
  if (root.includes(BASELINE)) {
    const id = await identity(p)
    // Only what exists: a visitor cannot delete these, but a half-finished
    // earlier run can have.
    const oxide = new Set((await p.list('/oxide')).map((f) => `oxide/${f.name}`))
    const dirs = baselineDirs(id).filter((d) => oxide.has(d) || d === `server/${id}`)
    await p.remove(dirs)
    log(`  deleted ${dirs.join(', ')}`)
    await p.decompress(BASELINE)
    log(`  unpacked ${BASELINE}`)
  } else {
    warn(`there is no ${BASELINE} on the rig yet; it starts as it is. Capture one with the "Demo baseline" workflow.`)
  }

  // 4. Start. Rust takes minutes to boot; the site does not wait for it.
  await p.power('start')
  log('the rig is starting')
}

// ── baseline ──────────────────────────────────────────────────────────────

async function baseline() {
  const p = ptero()
  // A power stop runs the egg's stop command, `quit`, which writes the save, so
  // the subuser needs no console permission (DM22).
  if ((await p.state()) !== 'offline') {
    await p.power('stop')
    await waitFor(p, 'offline', 300)
  }
  log('the rig is stopped and saved')

  const id = await identity(p)
  const made = await p.compress(baselineDirs(id))
  log(`  compressed ${baselineDirs(id).join(', ')} into ${made.name}`)
  if ((await p.list('/')).some((f) => f.name === BASELINE)) await p.remove([BASELINE])
  await p.rename(made.name, BASELINE)
  log(`  saved as ${BASELINE} (${made.size} bytes)`)

  await p.power('start')
  log('the rig is starting')
}

// ── smoke ─────────────────────────────────────────────────────────────────

async function smoke() {
  const site = need('SITE_URL').replace(/\/+$/, '')
  const until = Date.now() + (Number(process.env.SMOKE_TIMEOUT_SECONDS) || 900) * 1000
  const get = async (p) => {
    try {
      const res = await fetch(`${site}${p}`)
      return res.ok ? await res.json() : null
    } catch {
      return null
    }
  }

  while (!(await get('/api/v1/public/status'))) {
    if (Date.now() > until) throw new Error('the site never answered /api/v1/public/status')
    await sleep(5000)
  }
  log('the site answers')

  for (;;) {
    const list = (await get('/api/v1/public/rust/servers'))?.servers || []
    if (list.length && list.every((s) => s.online)) {
      log(`the rig reports in: ${list.map((s) => s.name || s.id).join(', ')}`)
      return
    }
    if (Date.now() > until) {
      throw new Error(`the rig has not reported in (${JSON.stringify(list.map((s) => ({ id: s.id, online: s.online })))}); the site serves with it shown offline`)
    }
    await sleep(15000)
  }
}

// ── main ──────────────────────────────────────────────────────────────────

export { ptero, identity, baselineDirs, writeBundle, moduleFor, newerFirst, currentBundle, BASELINE }

// Run only when invoked, so a test can import the pieces without running one.
if (process.argv[1] && import.meta.url === pathToFileURL(path.resolve(process.argv[1])).href) {
  const commands = { plan, restore, baseline, smoke }
  const command = commands[process.argv[2]]
  if (!command) {
    console.error(`usage: node rig.mjs ${Object.keys(commands).join('|')}`)
    process.exit(2)
  }
  command().catch((err) => {
    console.log(`::error::${err.message}`)
    process.exit(1)
  })
}