import { readFileSync } from "node:fs";
import { describe, expect, it } from "vitest";

// The limits a clip is marked to, held in two languages: the clip panel's handles, fields and keys
// keep a range the server takes, and a crop frame no smaller than it cuts. Neither side can see the
// other's copy, so the gate reads both (as `api/downloads.contract.test.ts` does for the name bound).
// A cap moved on one side alone makes the panel offer what the server refuses — or clamp below
// what it would take — with every other test green.
//
// Read as TEXT: the modules are plain constants, but reading the source is what makes a renamed or
// moved constant fail here instead of comparing two undefineds.
const src = (u: string) => readFileSync(new URL(u, import.meta.url), "utf-8");
const backend = src("../../../backend/app/downloads/clip.py");

function pyConst(name: string): number {
  const m = backend.match(new RegExp(`^${name}\\s*=\\s*([\\d.]+)`, "m"));
  expect(m, `backend/app/downloads/clip.py no longer defines ${name}`).toBeTruthy();
  return Number(m![1]);
}

function tsConst(file: string, name: string): number {
  const m = src(file).match(new RegExp(`^(?:export )?const ${name} = ([\\d.]+);`, "m"));
  expect(m, `${file} no longer defines ${name}`).toBeTruthy();
  return Number(m![1]);
}

describe("clip limits", () => {
  it.each([
    ["./clipRange.ts", "MIN_CLIP_S"],
    ["./clipRange.ts", "MAX_CLIP_S"],
    ["./cropGeometry.ts", "MIN_CROP"],
  ])("%s %s is the server's", (file, name) => {
    expect(tsConst(file, name)).toBe(pyConst(name));
  });
});