import test from "node:test";
import assert from "node:assert/strict";
import { deriveLaneState, LANE_WORD } from "./laneState";

// THE FOUR STATES, AS LITERALS, and the precedence between them.
//
// It used to pin a second function beside this one — `sweepLaneNote`, the
// sentence a sweep lane gave for not working. That retired with the sweeps in
// slice 1.3: every lane is dispatched by a runner now, so the reason a lane is
// not working is the runner's own `idleReason`, which the console and the
// Active Jobs strip both map through `idleReasonText` / `autoIdleNote`. What is
// left here is the state itself, which all four lanes still share.

test("the gate decides before anything else", () => {
  // A running lane behind a shut gate is HOLDING, not running and not stopped:
  // its limit() returns 0 and the pool idle-waits, which looks exactly like
  // wedged unless something says otherwise. That state is the reason this is
  // four strings rather than a boolean.
  assert.equal(deriveLaneState({ gateHeld: true }), "holding");
  assert.equal(deriveLaneState({ gateHeld: true, activeCount: 3 }), "holding");
});

test("unavailable beats the gate", () => {
  // With no operation switched on there is nothing to hold, and "Holding" would
  // send an operator to the wrong control.
  assert.equal(deriveLaneState({ available: false, gateHeld: true }), "unavailable");
  assert.equal(
    deriveLaneState({ available: false, gateHeld: false, activeCount: 2 }),
    "unavailable",
  );
});

test("work in flight is the only thing that reads as running", () => {
  assert.equal(deriveLaneState({ gateHeld: false, activeCount: 1 }), "running");
  assert.equal(deriveLaneState({ gateHeld: false, activeCount: 0 }), "idle");
  assert.equal(deriveLaneState({ gateHeld: false }), "idle");
});

test("every state has a word, and Off is not Idle", () => {
  // The word beside the dot is what assistive tech reads, so it has to stand on
  // its own — and "Off" must never be spelled "Idle": an idle-looking lane
  // claims "all caught up" where the truth is "nothing would run this".
  assert.equal(LANE_WORD[deriveLaneState({ available: false, gateHeld: false })], "Off");
  assert.equal(LANE_WORD[deriveLaneState({ gateHeld: true })], "Holding");
  assert.equal(LANE_WORD[deriveLaneState({ gateHeld: false })], "Idle");
  assert.equal(
    LANE_WORD[deriveLaneState({ gateHeld: false, activeCount: 1 })],
    "Running",
  );
});