// Hidden vars (os, actorsym, init, core_path, shop_path, json, args) come from env
// Engine is self-sufficient: defines its own compilation pipeline
var ACTORDATA = actorsym
var native_mode = false
var SYSYM = '__SYSTEM__'

var _cell = {}
var need_stop = false

var cases = {
  Windows: '.dll',
  macOS: '.dylib',
  Linux: '.so'
}

var dylib_ext = cases[os.platform()]

var MOD_EXT = '.cm'
var ACTOR_EXT = '.ce'

var load_internal = os.load_internal
function use_embed(name) {
  return load_internal("js_core_" + name + "_use")
}

var fd = use_embed('internal_fd')
var js = use_embed('js')
var crypto = use_embed('crypto')

// core_path and shop_path come from env (C runtime passes them through)
// shop_path may be null if --core was used without --shop
var packages_path = shop_path ? shop_path + '/packages' : null

// Self-sufficient initialization: content-addressed cache
var use_cache = {}

function content_hash(content) {
  return text(crypto.blake2(content), 'h')
}

function cache_path(hash) {
  if (!shop_path) return null
  return shop_path + '/build/' + hash
}

function ensure_build_dir() {
  if (!shop_path) return null
  var dir = shop_path + '/build'
  if (!fd.is_dir(dir)) fd.mkdir(dir)
  return dir
}

// Load a boot seed module (for compiling pipeline modules on cache miss)
function boot_load(name) {
  var mcode_path = core_path + '/boot/' + name + '.cm.mcode'
  var mcode_blob = null
  var mach_blob = null
  if (!fd.is_file(mcode_path)) {
    print("error: missing boot seed: " + name + "\n")
    disrupt
  }
  mcode_blob = fd.slurp(mcode_path)
  mach_blob = mach_compile_mcode_bin(name, text(mcode_blob))
  return mach_load(mach_blob, stone({use: use_embed}))
}

// Load a pipeline module from cache; on miss compile from source via boot chain
function load_pipeline_module(name, env) {
  var source_path = core_path + '/' + name + '.cm'
  var source_blob = null
  var hash = null
  var cached = null
  var mcode_path = null
  var mcode_blob = null
  var mach_blob = null
  var src = null
  var boot_tok = null
  var boot_par = null
  var boot_fld = null
  var boot_mc = null
  var boot_sl = null
  var tok_result = null
  var ast = null
  var compiled = null
  var mcode_json = null
  if (fd.is_file(source_path)) {
    source_blob = fd.slurp(source_path)
    hash = content_hash(source_blob)
    cached = cache_path(hash)
    if (cached && fd.is_file(cached))
      return mach_load(fd.slurp(cached), env)

    // Cache miss: compile from source using boot seed pipeline
    mcode_path = core_path + '/boot/' + name + '.cm.mcode'
    if (fd.is_file(mcode_path)) {
      boot_tok = boot_load("tokenize")
      boot_par = boot_load("parse")
      boot_fld = boot_load("fold")
      boot_mc = boot_load("mcode")
      src = text(source_blob)
      tok_result = boot_tok(src, source_path)
      ast = boot_par(tok_result.tokens, src, source_path, boot_tok)
      if (ast.errors != null && length(ast.errors) > 0) {
        print("error: failed to compile pipeline module: " + name + "\n")
        disrupt
      }
      ast = boot_fld(ast)
      compiled = boot_mc(ast)
      boot_sl = boot_load("streamline")
      compiled = boot_sl(compiled)
      mcode_json = json.encode(compiled)
      mach_blob = mach_compile_mcode_bin(name, mcode_json)
      if (cached) {
        ensure_build_dir()
        fd.slurpwrite(cached, mach_blob)
      }
      return mach_load(mach_blob, env)
    }
  }
  // Last resort: boot seed as runtime (no source file found)
  mcode_path = core_path + '/boot/' + name + '.cm.mcode'
  if (fd.is_file(mcode_path)) {
    mcode_blob = fd.slurp(mcode_path)
    mach_blob = mach_compile_mcode_bin(name, text(mcode_blob))
    return mach_load(mach_blob, env)
  }
  print("error: cannot load pipeline module: " + name + "\n")
  disrupt
}

// Load compilation pipeline
var pipeline_env = stone({use: use_embed})
var tokenize_mod = load_pipeline_module('tokenize', pipeline_env)
var parse_mod = load_pipeline_module('parse', pipeline_env)
var fold_mod = load_pipeline_module('fold', pipeline_env)
var mcode_mod = load_pipeline_module('mcode', pipeline_env)
var streamline_mod = load_pipeline_module('streamline', pipeline_env)

use_cache['tokenize'] = tokenize_mod
use_cache['parse'] = parse_mod
use_cache['fold'] = fold_mod
use_cache['mcode'] = mcode_mod
use_cache['core/mcode'] = mcode_mod
use_cache['streamline'] = streamline_mod
use_cache['core/streamline'] = streamline_mod

// analyze: tokenize + parse + fold, check for errors
function analyze(src, filename) {
  var tok_result = tokenize_mod(src, filename)
  var _ast = parse_mod(tok_result.tokens, src, filename, tokenize_mod)
  var _i = 0
  var prev_line = -1
  var prev_msg = null
  var e = null
  var msg = null
  var line = null
  var col = null
  var has_errors = _ast.errors != null && length(_ast.errors) > 0
  if (has_errors) {
    while (_i < length(_ast.errors)) {
      e = _ast.errors[_i]
      msg = e.message
      line = e.line
      col = e.column
      if (msg != prev_msg || line != prev_line) {
        if (line != null && col != null)
          print(`${filename}:${text(line)}:${text(col)}: error: ${msg}`)
        else
          print(`${filename}: error: ${msg}`)
      }
      prev_line = line
      prev_msg = msg
      _i = _i + 1
    }
    disrupt
  }
  return fold_mod(_ast)
}

// Lazy-loaded verify_ir module (loaded on first use)
var _verify_ir_mod = null

// Run AST through mcode pipeline -> register VM
function run_ast_fn(name, ast, env) {
  var compiled = mcode_mod(ast)
  if (os._verify_ir) {
    if (_verify_ir_mod == null) {
      _verify_ir_mod = load_pipeline_module('verify_ir', pipeline_env)
    }
    compiled._verify = true
    compiled._verify_mod = _verify_ir_mod
  }
  var optimized = streamline_mod(compiled)
  if (optimized._verify) {
    delete optimized._verify
    delete optimized._verify_mod
  }
  var mcode_json = json.encode(optimized)
  var mach_blob = mach_compile_mcode_bin(name, mcode_json)
  return mach_load(mach_blob, env)
}

// Run AST through mcode pipeline WITHOUT optimization -> register VM
function run_ast_noopt_fn(name, ast, env) {
  var compiled = mcode_mod(ast)
  var mcode_json = json.encode(compiled)
  var mach_blob = mach_compile_mcode_bin(name, mcode_json)
  return mach_load(mach_blob, env)
}

// Compile AST to blob without loading (for caching)
function compile_to_blob(name, ast) {
  var compiled = mcode_mod(ast)
  var optimized = streamline_mod(compiled)
  return mach_compile_mcode_bin(name, json.encode(optimized))
}

// If loaded directly by C runtime (not via bootstrap), convert args -> init
var _program = null
var _user_args = []
var _j = 1
var _init = init

// Inherit native_mode from init (set by C for --native, or by parent actor)
if (_init != null && _init.native_mode)
  native_mode = true

// CLI path: convert args to init record
if (args != null && (_init == null || !_init.program)) {
  _program = args[0]
  while (_j < length(args)) {
    push(_user_args, args[_j])
    _j = _j + 1
  }
  if (_init == null) {
    _init = {program: _program, arg: _user_args}
  } else {
    _init.program = _program
    _init.arg = _user_args
  }
}

use_cache['core/os'] = os

// Extra env properties added as engine initializes (log, runtime fns, etc.)
var core_extras = {}

// Load a core module from the file system
function use_core(path) {
  var cache_key = 'core/' + path
  var env = null
  if (use_cache[cache_key])
    return use_cache[cache_key]

  var sym = use_embed(replace(path, '/', '_'))
  var result = null
  var script = null
  var ast = null
  var _load_mod = null

  // Build env: merge core_extras
  env = {use: use_core}
  arrfor(array(core_extras), function(k) { env[k] = core_extras[k] })
  env = stone(env)

  var hash = null
  var cached_path = null
  var mach_blob = null
  var source_blob = null
  var file_path = null

  // Compile from source .cm file
  file_path = core_path + '/' + path + MOD_EXT
  if (fd.is_file(file_path)) {
    _load_mod = function() {
      source_blob = fd.slurp(file_path)
      hash = content_hash(source_blob)
      cached_path = cache_path(hash)
      if (cached_path && fd.is_file(cached_path)) {
        result = mach_load(fd.slurp(cached_path), env)
      } else {
        script = text(source_blob)
        ast = analyze(script, file_path)
        mach_blob = compile_to_blob('core:' + path, ast)
        if (cached_path) {
          ensure_build_dir()
          fd.slurpwrite(cached_path, mach_blob)
        }
        result = mach_load(mach_blob, env)
      }
    } disruption {
      print("use('" + path + "'): failed to compile or load " + file_path + "\n")
      disrupt
    }
    _load_mod()
    use_cache[cache_key] = result
    return result
  }

  // Embedded C module only
  use_cache[cache_key] = sym
  return sym
}

// Load full modules via use_core (extends C embeds with .cm additions, and caches)
fd = use_core('fd')
use_core('js')
var blob = use_core('blob')

function actor() {

}

var actor_mod = use_core('actor')
var wota = use_core('wota')
var nota = use_core('nota')


var ENETSERVICE = 0.1
var REPLYTIMEOUT = 60 // seconds before replies are ignored

// --- Logging system (bootstrap phase) ---
// Early log: prints to console before toml/time/json are loaded.
// Upgraded to full sink-based system after config loads (see load_log_config below).

var log_config = null
var channel_sinks = {}
var wildcard_sinks = []
var warned_channels = {}
var stack_channels = {}

function log(name, args) {
  var msg = args[0]
  if (msg == null) msg = ""
  os.print(`[${text(_cell.id, 0, 5)}] [${name}]: ${msg}\n`)
}

function actor_die(err)
{
  var reason = null
  var unders = null

  if (err && is_function(err.toString)) {
    os.print(err.toString())
    os.print("\n")
    if (err.stack) os.print(err.stack)
  }

  if (overling) {
    if (err) {
      // with an err, this is a forceful disrupt
      reason = err
      report_to_overling({type:'disrupt', reason})
    } else
      report_to_overling({type:'stop'})
  }

  if (underlings) {
    unders = array(underlings)
    arrfor(unders, function(id, index) {
      log.console(`calling on ${id} to disrupt too`)
      $_.stop(create_actor({id}))
    })
  }

  if (err) {
    if (err.message)
      log.console(err.message)
    if (err.stack)
      log.console(err.stack)
  }

  actor_mod["disrupt"]()
}



actor_mod.on_exception(actor_die)

_cell.args = _init != null ? _init : {}

function create_actor(desc) {
  var _desc = desc == null ? {id:guid()} : desc
  var actor = {}
  actor[ACTORDATA] = _desc
  stone(actor)
  return actor
}

var $_ = {}

use_cache['core/json'] = json

// Create runtime_env early (empty) -- filled after pronto loads.
// Shop accesses it lazily (in inject_env, called at module-use time, not load time)
// so it sees the filled version.
var runtime_env = {}

// Populate core_extras with everything shop (and other core modules) need
core_extras.use_cache = use_cache
core_extras.core_path = core_path
core_extras.shop_path = shop_path
core_extras.analyze = analyze
core_extras.run_ast_fn = run_ast_fn
core_extras.run_ast_noopt_fn = run_ast_noopt_fn
os.analyze = analyze
os.run_ast_fn = run_ast_fn
os.run_ast_noopt_fn = run_ast_noopt_fn
core_extras.core_json = json
core_extras.actor_api = $_
core_extras.log = log
core_extras.runtime_env = runtime_env
core_extras.content_hash = content_hash
core_extras.cache_path = cache_path
core_extras.ensure_build_dir = ensure_build_dir
core_extras.compile_to_blob = compile_to_blob
core_extras.native_mode = native_mode

// NOW load shop -- it receives all of the above via env
var shop = use_core('internal/shop')
if (native_mode) use_core('build')
var time = use_core('time')
var toml = use_core('toml')

// --- Logging system (full version) ---
// Now that toml, time, fd, and json are available, upgrade the log function
// from the bootstrap version to a configurable sink-based system.

function ensure_log_dir(path) {
  var parts = array(path, '/')
  var current = starts_with(path, '/') ? '/' : ''
  var i = 0
  // ensure parent dir (skip last element which is the filename)
  for (i = 0; i < length(parts) - 1; i++) {
    if (parts[i] == '') continue
    current = current + parts[i] + '/'
    if (!fd.is_dir(current)) fd.mkdir(current)
  }
}

function build_sink_routing() {
  channel_sinks = {}
  wildcard_sinks = []
  stack_channels = {}
  var names = array(log_config.sink)
  arrfor(names, function(name) {
    var sink = log_config.sink[name]
    sink._name = name
    if (!is_array(sink.channels)) sink.channels = []
    if (is_text(sink.exclude)) sink.exclude = [sink.exclude]
    if (!is_array(sink.exclude)) sink.exclude = []
    if (is_text(sink.stack)) sink.stack = [sink.stack]
    if (!is_array(sink.stack)) sink.stack = []
    if (sink.type == "file" && sink.path) ensure_log_dir(sink.path)
    arrfor(sink.stack, function(ch) {
      stack_channels[ch] = true
    })
    arrfor(sink.channels, function(ch) {
      if (ch == "*") {
        wildcard_sinks[] = sink
        return
      }
      if (!channel_sinks[ch]) channel_sinks[ch] = []
      channel_sinks[ch][] = sink
    })
  })
}

function load_log_config() {
  var log_path = null
  if (shop_path) {
    log_path = shop_path + '/log.toml'
    if (fd.is_file(log_path)) {
      log_config = toml.decode(text(fd.slurp(log_path)))
    }
  }
  if (!log_config || !log_config.sink) {
    log_config = {
      sink: {
        terminal: {
          type: "console",
          format: "pretty",
          channels: ["console", "error", "system"],
          stack: ["error"]
        }
      }
    }
  }
  build_sink_routing()
}

function pretty_format(rec) {
  var aid = text(rec.actor_id, 0, 5)
  var src = ""
  var ev = null
  var out = null
  var i = 0
  var fr = null
  if (rec.source && rec.source.file)
    src = rec.source.file + ":" + text(rec.source.line)
  ev = is_text(rec.event) ? rec.event : json.encode(rec.event, false)
  out = `[${aid}] [${rec.channel}] ${src} ${ev}\n`
  if (rec.stack && length(rec.stack) > 0) {
    for (i = 0; i < length(rec.stack); i = i + 1) {
      fr = rec.stack[i]
      out = out + `    at ${fr.fn} (${fr.file}:${text(fr.line)}:${text(fr.col)})\n`
    }
  }
  return out
}

function bare_format(rec) {
  var aid = text(rec.actor_id, 0, 5)
  var ev = is_text(rec.event) ? rec.event : json.encode(rec.event, false)
  var out = `[${aid}] ${ev}\n`
  var i = 0
  var fr = null
  if (rec.stack && length(rec.stack) > 0) {
    for (i = 0; i < length(rec.stack); i = i + 1) {
      fr = rec.stack[i]
      out = out + `    at ${fr.fn} (${fr.file}:${text(fr.line)}:${text(fr.col)})\n`
    }
  }
  return out
}

function sink_excluded(sink, channel) {
  var excluded = false
  if (!sink.exclude || length(sink.exclude) == 0) return false
  arrfor(sink.exclude, function(ex) {
    if (ex == channel) excluded = true
  })
  return excluded
}

function dispatch_to_sink(sink, rec) {
  var line = null
  if (sink_excluded(sink, rec.channel)) return
  if (sink.type == "console") {
    if (sink.format == "json")
      os.print(json.encode(rec, false) + "\n")
    else if (sink.format == "bare")
      os.print(bare_format(rec))
    else
      os.print(pretty_format(rec))
  } else if (sink.type == "file") {
    line = json.encode(rec, false) + "\n"
    fd.slurpappend(sink.path, stone(blob(line)))
  }
}

load_log_config()

log = function(name, args) {
  var sinks = channel_sinks[name]
  var event = args[0]
  var caller = null
  var stack = null
  var rec = null

  if (!sinks && length(wildcard_sinks) == 0) {
    if (!warned_channels[name]) {
      warned_channels[name] = true
      os.print(`[warn] log channel '${name}' has no sinks configured\n`)
    }
    return
  }

  caller = caller_info(2)
  if (stack_channels[name]) stack = os.stack(1)
  rec = {
    actor_id: _cell.id,
    timestamp: time.number(),
    channel: name,
    event: event,
    source: caller
  }
  if (stack) rec.stack = stack

  if (sinks) arrfor(sinks, function(sink) { dispatch_to_sink(sink, rec) })
  arrfor(wildcard_sinks, function(sink) { dispatch_to_sink(sink, rec) })
}

var pronto = use_core('pronto')
var fallback = pronto.fallback
var parallel = pronto.parallel
var race = pronto.race
var sequence = pronto.sequence

runtime_env.actor = actor
runtime_env.log = log
runtime_env.send = send
runtime_env.shop_path = shop_path
runtime_env.fallback = fallback
runtime_env.parallel = parallel
runtime_env.race = race
runtime_env.sequence = sequence

// Make runtime functions available to modules loaded via use_core
arrfor(array(runtime_env), function(k) { core_extras[k] = runtime_env[k] })

$_.time_limit = function(requestor, seconds)
{
  if (!pronto.is_requestor(requestor)) {
    log.error('time_limit: first argument must be a requestor')
    disrupt
  }
  if (!is_number(seconds) || seconds <= 0) {
    log.error('time_limit: seconds must be a positive number')
    disrupt
  }

  return function time_limit_requestor(callback, value) {
    pronto.check_callback(callback, 'time_limit')
    var finished = false
    var requestor_cancel = null
    var timer_cancel = null

    function cancel(reason) {
      if (finished) return
      finished = true
      if (timer_cancel) {
        timer_cancel()
        timer_cancel = null
      }
      if (requestor_cancel) {
        requestor_cancel(reason)
        requestor_cancel = null
      }
    }

    function safe_cancel_requestor(reason) {
      if (requestor_cancel) {
        requestor_cancel(reason)
        requestor_cancel = null
      }
    }

    timer_cancel = $_.delay(function() {
      if (finished) return
      def reason = make_reason(factory, 'Timeout.', seconds)
      safe_cancel_requestor(reason)
      finished = true
      callback(null, reason)
    }, seconds)

    function do_request() {
      requestor_cancel = requestor(function(val, reason) {
        if (finished) return
        finished = true
        if (timer_cancel) {
          timer_cancel()
          timer_cancel = null
        }
        callback(val, reason)
      }, value)
    } disruption {
      cancel('requestor failed')
      callback(null, 'requestor failed')
    }
    do_request()

    return function(reason) {
      safe_cancel_requestor(reason)
    }
  }
}

var config = {
  ar_timer: 60,
  actor_memory:0,
  net_service:0.1,
  reply_timeout:60,
  main: true
}

_cell.config = config

ENETSERVICE = config.net_service
REPLYTIMEOUT = config.reply_timeout



/*
  When handling a message, the message appears like this:
  {
    type: type of message
      - contact: used for contact messages
      - stop: used to issue stop command
      - etc
    reply: ID this message will respond to (callback saved on the actor)
    replycc: the actor that is waiting for the reply
    target: ID of the actor that's supposed to receive the message. Only added to non direct sends (out of portals)
    return: reply ID so the replycc actor can know what callback to send the message to

    data: the actual content of the message
  }

  actors look like
  {
    id: the GUID of this actor
    address: the IP this actor can be found at
    port: the port of the IP the actor can be found at
  }
*/

function guid(bits)
{
  var _bits = bits == null ? 256 : bits
  var guid = blob(_bits, os.random)
  stone(guid)
  return text(guid,'h')
}

var HEADER = {}

// takes a function input value that will eventually be called with the current time in number form.
$_.clock = function(fn) {
  actor_mod.clock(_ => {
    fn(time.number())
    send_messages()
  })
}

var underlings = {} // this is more like "all actors that are notified when we die"
var overling = null
var root = null

var receive_fn = null
var greeters = {} // Router functions for when messages are received for a specific actor

var peers = {}
var id_address = {}
var peer_queue = {}
var portal = null
var portal_fn = null

function peer_connection(peer) {
  return {
    latency: peer.rtt,
    bandwidth: {
      incoming: peer.incoming_bandwidth,
      outgoing: peer.outgoing_bandwidth
    },
    activity: {
      last_sent: peer.last_send_time,
      last_received: peer.last_receive_time
    },
    mtu: peer.mtu,
    data: {
      incoming_total: peer.incoming_data_total,
      outgoing_total: peer.outgoing_data_total,
      reliable_in_transit: peer.reliable_data_in_transit
    },
    latency_variance: peer.rtt_variance,
    packet_loss: peer.packet_loss,
    state: peer.state
  }
}

// takes a callback function, an actor object, and a configuration record for getting information about the status of a connection to the actor. The configuration record is used to request the sort of information that needs to be communicated. This can include latency, bandwidth, activity, congestion, cost, partitions. The callback is given a record containing the requested information.
$_.connection = function(callback, actor, config) {
  var peer = peers[actor[ACTORDATA].id]
  if (peer) {
    callback(peer_connection(peer))
    return
  }
  if (actor_mod.mailbox_exist(actor[ACTORDATA].id)) {
    callback({type:"local"})
    return
  }

  callback()
}

// takes a function input value that will eventually be called with the current time in number form.
$_.portal = function(fn, port) {
  if (portal) {
    log.error(`Already started a portal listening on ${portal.port}`)
    disrupt
  }
  if (!port) {
    log.error("Requires a valid port.")
    disrupt
  }
  log.system(`starting a portal on port ${port}`)
  portal = enet.create_host({address: "any", port})
  portal_fn = fn
}

function handle_host(e) {
  var queue = null
  var data = null

  if (e.type == "connect") {
    log.system(`connected a new peer: ${e.peer.address}:${e.peer.port}`)
    peers[`${e.peer.address}:${e.peer.port}`] = e.peer
    queue = peer_queue.get(e.peer)
    if (queue) {
      arrfor(queue, (msg, index) => e.peer.send(nota.encode(msg)))
      log.system(`sent queue out of queue`)
      peer_queue.delete(e.peer)
    }
  } else if (e.type == "disconnect") {
    peer_queue.delete(e.peer)
    arrfor(array(peers), function(id, index) {
      if (peers[id] == e.peer) delete peers[id]
    })
    log.system('portal got disconnect from ' + e.peer.address + ":" + e.peer.port)
  } else if (e.type == "receive") {
    data = nota.decode(e.data)
    if (data.replycc && !data.replycc.address) {
      data.replycc[ACTORDATA].address = e.peer.address
      data.replycc[ACTORDATA].port = e.peer.port
    }
    if (data.data) populate_actor_addresses(data.data, e)
    turn(data)
  }
}

function populate_actor_addresses(obj, e) {
  if (!is_object(obj)) return
  if (obj[ACTORDATA] && !obj[ACTORDATA].address) {
    obj[ACTORDATA].address = e.peer.address
    obj[ACTORDATA].port = e.peer.port
  }
  arrfor(array(obj), function(key, index) {
    if (key in obj)
      populate_actor_addresses(obj[key], e)
  })
}

// takes a callback function, an actor object, and a configuration record for getting information about the status of a connection to the actor. The configuration record is used to request the sort of information that needs to be communicated. This can include latency, bandwidth, activity, congestion, cost, partitions. The callback is given a record containing the requested information.
$_.contact = function(callback, record) {
  send(create_actor(record), record, callback)
}

// registers a function that will receive all messages...
$_.receiver = function receiver(fn) {
  receive_fn = fn
}

// Holds all messages queued during the current turn.
var message_queue = []

$_.start = function start(cb, program) {
    if (!program) return

    var id = guid()
    var oid = $_.self[ACTORDATA].id
    var startup = {
      id,
      overling_id: oid,
      root_id: root ? root[ACTORDATA].id : null,
      program,
      native_mode: native_mode,
    }
    greeters[id] = cb
    push(message_queue, { startup })
}

// stops an underling or self.
$_.stop = function stop(actor) {
  if (!actor) {
    need_stop = true
    return
  }
  if (!is_actor(actor)) {
    log.error('Can only call stop on an actor.')
    disrupt
  }
  if (is_null(underlings[actor[ACTORDATA].id])) {
    log.error('Can only call stop on an underling or self.')
    disrupt
  }

  sys_msg(actor, {kind:"stop"})
}

// schedules the removal of an actor after a specified amount of time.
$_.unneeded = function unneeded(fn, seconds) {
  actor_mod.unneeded(fn, seconds)
}

// schedules the invocation of a function after a specified amount of time.
$_.delay = function delay(fn, seconds) {
  var _seconds = seconds == null ? 0 : seconds
  function delay_turn() {
    fn()
    send_messages()
  }
  var id = actor_mod.delay(delay_turn, _seconds)
  return function() { actor_mod.removetimer(id) }
}

var enet = use_core('enet')

// causes this actor to stop when another actor stops.
var couplings = {}
$_.couple = function couple(actor) {
  if (actor == $_.self) return // can't couple to self
  couplings[actor[ACTORDATA].id] = true
  sys_msg(actor, {kind:'couple', from_id: _cell.id})
  log.system(`coupled to ${actor}`)
}

function actor_prep(actor, send) {
  push(message_queue, {actor,send});
}

// Send a message immediately without queuing
function actor_send_immediate(actor, send) {
  actor_send(actor, send)
}

function actor_send(actor, message) {
  var wota_blob = null
  var peer = null

  if (actor[HEADER] && !actor[HEADER].replycc) // attempting to respond to a message but sender is not expecting; silently drop
    return

  if (!is_actor(actor) && !is_actor(actor.replycc)) {
    log.error(`Must send to an actor object. Attempted send to ${actor}`)
    disrupt
  }

  if (!is_object(message)) {
    log.error('Must send an object record.')
    disrupt
  }

  // message to self
  if (actor[ACTORDATA].id == _cell.id) {
    if (receive_fn) receive_fn(message.data)
    return
  }

  // message to actor in same flock
  if (actor[ACTORDATA].id && actor_mod.mailbox_exist(actor[ACTORDATA].id)) {
    wota_blob = wota.encode(message)
    actor_mod.mailbox_push(actor[ACTORDATA].id, wota_blob)
    return
  }

  if (actor[ACTORDATA].address) {
    if (actor[ACTORDATA].id)
      message.target = actor[ACTORDATA].id
    else
      message.type = "contact"

    peer = peers[actor[ACTORDATA].address + ":" + actor[ACTORDATA].port]
    if (!peer) {
      if (!portal) {
        log.system(`creating a contactor ...`)
        portal = enet.create_host({address:"any"})
        log.system(`allowing contact to port ${portal.port}`)
      }
      log.system(`no peer! connecting to ${actor[ACTORDATA].address}:${actor[ACTORDATA].port}`)
      peer = portal.connect(actor[ACTORDATA].address, actor[ACTORDATA].port)
      peer_queue.set(peer, [message])
    } else {
      peer.send(nota.encode(message))
    }
    return
  }
  log.system(`Unable to send message to actor ${actor[ACTORDATA]}`)
}

function send_messages() {
   // if we've been flagged to stop, bail out before doing anything
   if (need_stop) {
     actor_die()
     message_queue = []
     return
   }

   var _qi = 0
   var _qm = null
   while (_qi < length(message_queue)) {
     _qm = message_queue[_qi]
     if (_qm.startup) {
       actor_mod.createactor(_qm.startup)
     } else {
       actor_send(_qm.actor, _qm.send)
     }
     _qi = _qi + 1
   }

   message_queue = []
 }

var replies = {}

function send(actor, message, reply) {
  var send_msg = null
  var target = null
  var header = null
  var id = null

  if (!is_object(actor)) {
    log.error(`Must send to an actor object. Provided: ${actor}`)
    disrupt
  }

  if (!is_object(message)) {
    log.error('Message must be an object')
    disrupt
  }
  send_msg = {type:"user", data: message}
  target = actor

  if (actor[HEADER] && actor[HEADER].replycc) {
    header = actor[HEADER]
    if (!header.replycc || !is_actor(header.replycc)) {
      log.error(`Supplied actor had a return, but it's not a valid actor! ${actor[HEADER]}`)
      disrupt
    }

    target = header.replycc
    send_msg.return = header.reply
  }

  if (reply) {
    id = guid()
    replies[id] = reply
    $_.delay(_ => {
      if (replies[id]) {
        replies[id](null, "timeout")
        delete replies[id]
      }
    }, REPLYTIMEOUT)
    send_msg.reply = id
    send_msg.replycc_id = _cell.id
  }

  // Instead of sending immediately, queue it
  actor_prep(target, send_msg);
}

stone(send)

if (!_cell.args.id) _cell.id = guid()
else _cell.id = _cell.args.id

$_.self = create_actor({id: _cell.id})

// Actor's timeslice for processing a single message
function turn(msg)
{
  var mes = wota.decode(msg)
  handle_message(mes)
  send_messages()
}

//log.console(`FIXME: need to get main from config, not just set to true`)
actor_mod.register_actor(_cell.id, turn, true, config.ar_timer)

if (config.actor_memory)
  js.mem_limit(config.actor_memory)

if (config.stack_max)
  js.max_stacksize(config.system.stack_max);

overling = _cell.args.overling_id ? create_actor({id: _cell.args.overling_id}) : null
$_.overling = overling

root = _cell.args.root_id ? create_actor({id: _cell.args.root_id}) : null
if (root == null) root = $_.self

if (overling) {
  $_.couple(overling)
  report_to_overling({type:'greet', actor_id: _cell.id})
}

// sys messages are always dispatched immediately
function sys_msg(actor, msg)
{
  var envelope = {}
  envelope[SYSYM] = msg
  actor_send(actor, envelope)
}

// messages sent to here get put into the cb provided to start
function report_to_overling(msg)
{
  if (!overling) return
  sys_msg(overling, {kind:'underling', message:msg, from_id: _cell.id})
}

// Determine the program to run from command line
var program = _cell.args.program

if (!program) {
  log.error('No program specified. Usage: cell <program> [args...]')
  os.exit(1)
}

function handle_actor_disconnect(id) {
  var greeter = greeters[id]
  if (greeter) {
    greeter({type: "stopped", id})
    delete greeters[id]
  }
  log.system(`actor ${id} disconnected`)
  if (!is_null(couplings[id])) actor_die("coupled actor died") // couplings now disrupts instead of stop
}

function handle_sysym(msg)
{
  var from_id = null
  var from_actor = null
  var greeter = null
  var letter2 = null
  var greet_msg = null

  if (msg.kind == 'stop') {
    actor_die("got stop message")
  } else if (msg.kind == 'underling') {
    from_id = msg.from_id
    greeter = greeters[from_id]
    if (greeter) {
      greet_msg = msg.message
      if (greet_msg.actor_id) {
        greet_msg.actor = create_actor({id: greet_msg.actor_id})
      }
      greeter(greet_msg)
    }
    if (msg.message.type == 'disrupt')
      delete underlings[from_id]
  } else if (msg.kind == 'contact') {
    if (portal_fn) {
      letter2 = msg.data
      letter2[HEADER] = msg
      delete msg.data
      portal_fn(letter2)
    } else {
      log.error('Got a contact message, but no portal is established.')
      disrupt
    }
  } else if (msg.kind == 'couple') {
    from_id = msg.from_id
    underlings[from_id] = true
    log.system(`actor ${from_id} is coupled to me`)
  }
}

function handle_message(msg) {
  var letter = null
  var fn = null

  if (msg[SYSYM]) {
    handle_sysym(msg[SYSYM], msg.from)
    return
  }

  if (msg.type == "user") {
    letter = msg.data // what the sender really sent
    if (msg.replycc_id) {
      msg.replycc = create_actor({id: msg.replycc_id})
    }
    letter[HEADER] = msg
    letter[ACTORDATA] = { reply: msg.reply }

    if (msg.return) {
      fn = replies[msg.return]
      if (fn) fn(letter)
      delete replies[msg.return]
      return
    }

    if (receive_fn) receive_fn(letter)
  } else if (msg.type == "stopped") {
    handle_actor_disconnect(msg.id)
  }
}

function enet_check()
{
  if (portal) portal.service(handle_host)

  $_.delay(enet_check, ENETSERVICE);
}

// enet_check();

// Finally, run the program
actor_mod.setname(_cell.args.program)

var prog = _cell.args.program
if (ends_with(prog, '.cm')) {
  os.print(`error: ${prog} is a module (.cm), not a program (.ce)\n`)
  os.exit(1)
}
if (ends_with(prog, '.ce')) prog = text(prog, 0, -3)

var package = use_core('package')

// Find the .ce file
var prog_path = prog + ".ce"
var pkg_dir = null
var core_dir = null
if (!fd.is_file(prog_path)) {
  pkg_dir = package.find_package_dir(".")
  if (pkg_dir)
    prog_path = pkg_dir + '/' + prog + '.ce'
}
if (!fd.is_file(prog_path)) {
  // Check core packages
  core_dir = core_path
  prog_path = core_dir + '/' + prog + '.ce'
}
if (!fd.is_file(prog_path)) {
  os.print(`Main program ${prog} could not be found\n`)
  os.exit(1)
}

$_.clock(_ => {
  var file_info = shop.file_info ? shop.file_info(prog_path) : null
  var inject = shop.script_inject_for ? shop.script_inject_for(file_info) : []

  // Build env with runtime functions + capability injections
  var env = {}
  arrfor(array(runtime_env), function(k) { env[k] = runtime_env[k] })
  var _ki = 0
  var inj = null
  var key = null
  while (_ki < length(inject)) {
    inj = inject[_ki]
    key = inj
    if (key && key[0] == '$') key = text(key, 1)
    if (key == 'fd') env['$fd'] = fd
    else env['$' + key] = $_[key]
    _ki = _ki + 1
  }

  var pkg = file_info ? file_info.package : null
  env.use = function(path) {
    var ck = 'core/' + path
    if (use_cache[ck]) return use_cache[ck]
    var core_mod = use_core(path)
    if (core_mod) return core_mod
    return shop.use(path, pkg)
  }
  env.args = _cell.args.arg
  env.log  = log
  env = stone(env)

  var native_build = null
  var native_dylib_path = null
  var native_handle = null
  var native_parts = null
  var native_basename = null
  var native_sym = null

  // Native execution path: compile to dylib and run
  if (native_mode) {
    native_build = use_core('build')
    native_dylib_path = native_build.compile_native(prog_path, null, null, pkg)
    native_handle = os.dylib_open(native_dylib_path)
    native_parts = array(prog_path, '/')
    native_basename = native_parts[length(native_parts) - 1]
    native_sym = pkg ? shop.c_symbol_for_file(pkg, native_basename) : null
    if (native_sym)
      os.native_module_load_named(native_handle, native_sym, env)
    else
      os.native_module_load(native_handle, env)
    return
  }

  var source_blob = fd.slurp(prog_path)
  var hash = content_hash(source_blob)
  var cached_path = cache_path(hash)
  var val = null
  var script = null
  var ast = null
  var mach_blob = null
  if (cached_path && fd.is_file(cached_path)) {
    val = mach_load(fd.slurp(cached_path), env)
  } else {
    script = text(source_blob)
    ast = analyze(script, prog_path)
    mach_blob = compile_to_blob(prog, ast)
    if (cached_path) {
      ensure_build_dir()
      fd.slurpwrite(cached_path, mach_blob)
    }
    val = mach_load(mach_blob, env)
  }
  if (val) {
    log.error('Program must not return anything')
    disrupt
  }
})