/**
 * A node's height against the ports it has to fit.
 *
 * Run: `bun src/components/Flow/layout.check.ts` (there is no unit runner; the
 * suite in `tests/` drives a running stack). Typechecked with the rest of
 * `src` and imported by nothing, so it is not in the bundle.
 */
import assert from "node:assert/strict"

import { layoutGraph, nodeHeight, PORT_SPAN } from "./layout"

/** Handles are 12px across — see `.react-flow__handle` in `flow.css`. */
const HANDLE = 12

// Two ports fit the plain box, so most nodes are unchanged.
assert.equal(nodeHeight(0), 56)
assert.equal(nodeHeight(1), 56)
assert.equal(nodeHeight(2), 56)
assert.ok(nodeHeight(3) > 56)

for (let ports = 2; ports <= 12; ports += 1) {
  const height = nodeHeight(ports)
  // `handleOffset` spreads the ports over `PORT_SPAN` of the edge, so that is
  // the room they actually get. Two handles must not touch.
  const between = (PORT_SPAN * height) / (ports - 1)
  assert.ok(
    between > HANDLE,
    `${ports} ports on a ${height}px node leave ${between}px between handles`,
  )
  // Growing, never shrinking: one more port can only need more room.
  assert.ok(height >= nodeHeight(ports - 1))
}

// The layout places top-left corners, so a taller node has to be lifted by its
// own half-height rather than by the default box's.
const tall = nodeHeight(8)
const placed = layoutGraph(
  ["a", "b"],
  [{ source: "a", target: "b" }],
  "LR",
  new Map([["b", tall]]),
)
const a = placed.get("a")
const b = placed.get("b")
assert.ok(a && b)
// Dagre centres the two on one rank line, so the taller one starts higher up
// by exactly the difference in half-heights.
assert.equal(Math.round(a.y - b.y), Math.round((tall - 56) / 2))

console.log("layout: ok")