import { describe, it } from "node:test";
import assert from "node:assert/strict";
import { declToUtil, snapBase } from "../src/generate/tailwind.js";

// Zero-value gating. A named `-0` step only exists for props on Tailwind's spacing (or numeric)
// scales; for the rest the class compiles to NOTHING — a silent no-op that ships the wrong style
// (a map label captured at font-size:0 painted at the inherited 20px because `text-0` isn't a
// utility). Zeros for scale-less props must stay arbitrary so the declaration really compiles.
describe("declToUtil zero values", () => {
  it("emits arbitrary text-[0px] for font-size:0 (no text-0 utility in v4)", () => {
    assert.equal(declToUtil("font-size", "0px"), "text-[0px]");
    assert.equal(declToUtil("font-size", "0"), "text-[0px]");
  });

  it("emits arbitrary tracking-[0px] for letter-spacing:0 (no tracking-0 utility in v4)", () => {
    assert.equal(declToUtil("letter-spacing", "0px"), "tracking-[0px]");
    assert.equal(declToUtil("letter-spacing", "0"), "tracking-[0px]");
  });

  it("emits arbitrary rounded corners for radius:0 (radius scale has no numeric 0)", () => {
    assert.equal(declToUtil("border-top-left-radius", "0px"), "rounded-tl-[0px]");
  });

  it("keeps the named -0 for spacing-scale props", () => {
    assert.equal(declToUtil("width", "0px"), "w-0");
    assert.equal(declToUtil("width", "0"), "w-0");
    assert.equal(declToUtil("top", "0px"), "top-0");
    assert.equal(declToUtil("margin-left", "0px"), "ml-0");
    assert.equal(declToUtil("line-height", "0px"), "leading-0");
  });

  it("keeps the named -0 for numeric scales that include 0", () => {
    assert.equal(declToUtil("flex-grow", "0"), "grow-0");
    assert.equal(declToUtil("flex-shrink", "0"), "shrink-0");
    assert.equal(declToUtil("order", "0"), "order-0");
    assert.equal(declToUtil("z-index", "0"), "z-0");
  });

  it("leaves non-zero values untouched", () => {
    assert.equal(declToUtil("font-size", "20px"), "text-[20px]");
    assert.equal(declToUtil("letter-spacing", "-0.5px"), "tracking-[-0.5px]");
  });
});

// BUG B — the spacing-scale snap must only fire when a value lands ESSENTIALLY ON a step (≤0.25px).
// The scale is 2px-granular (`p-0.5`=2px, `p-1.5`=6px), so 3.5px is BETWEEN steps — snapping it up to
// p-1 (4px) adds +0.5px per side, which accumulates across a fixed-width flex row until items overflow
// and wrap. On-step values (2px→p-0.5, 4px→p-1) still snap.
describe("snapBase spacing-scale snapping", () => {
  it("keeps a between-steps value arbitrary (3.5px does NOT snap to p-1)", () => {
    assert.equal(snapBase("p-[3.5px]"), "p-[3.5px]");
  });

  it("does not snap the same sub-step delta on other spacing props", () => {
    assert.equal(snapBase("pl-[3.5px]"), "pl-[3.5px]");
    assert.equal(snapBase("gap-[3.5px]"), "gap-[3.5px]");
    assert.equal(snapBase("mt-[13.5px]"), "mt-[13.5px]"); // between p-3 (12px) and p-3.5 (14px)
  });

  it("still snaps a value that sits on a 0.5-step (2px → p-0.5, 6px → p-1.5)", () => {
    assert.equal(snapBase("p-[2px]"), "p-0.5");
    assert.equal(snapBase("p-[6px]"), "p-1.5");
  });

  it("still snaps a near-exact on-step value within the tight budget (3.98px → p-1)", () => {
    assert.equal(snapBase("p-[3.98px]"), "p-1");
  });

  it("leaves an already-clean scale utility unchanged and snaps 16px → mx-4", () => {
    assert.equal(snapBase("p-1"), "p-1");
    assert.equal(snapBase("mx-[16px]"), "mx-4");
  });
});