import { describe, it } from 'node:test';
import assert from 'node:assert/strict';
import {
  CONTEXT_WINDOW_ANCHOR,
  LARGE_CONTEXT_WINDOW,
  resolveContextWindow,
  scaleForWindow,
} from '../../scanners/lib/context-window.mjs';

// B8 — context-window calibration. resolveContextWindow turns the raw
// --context-window CLI value into { window, advisory } that SKL/CML calibrate
// their budgets with. The DEFAULT (no flag) must be byte-identical to the
// pre-B8 behavior: the conservative 200k anchor at full severity (advisory=false).

describe('resolveContextWindow — default (no flag) is the conservative anchor', () => {
  it('undefined resolves to the 200k anchor, not advisory (byte-stable default)', () => {
    const r = resolveContextWindow(undefined);
    assert.equal(r.window, CONTEXT_WINDOW_ANCHOR);
    assert.equal(r.advisory, false);
    assert.equal(r.source, 'default');
  });

  it('null resolves to the conservative default', () => {
    const r = resolveContextWindow(null);
    assert.equal(r.window, CONTEXT_WINDOW_ANCHOR);
    assert.equal(r.advisory, false);
  });
});

describe('resolveContextWindow — explicit window', () => {
  it('a numeric string calibrates to that window, not advisory', () => {
    const r = resolveContextWindow('1000000');
    assert.equal(r.window, 1_000_000);
    assert.equal(r.advisory, false);
    assert.equal(r.source, 'explicit');
  });

  it('a plain number is accepted', () => {
    const r = resolveContextWindow(1_000_000);
    assert.equal(r.window, 1_000_000);
    assert.equal(r.advisory, false);
  });
});

describe('resolveContextWindow — auto / unknown downgrades to advisory', () => {
  it('"auto" keeps the conservative anchor but flags advisory (no model probe yet)', () => {
    const r = resolveContextWindow('auto');
    assert.equal(r.window, CONTEXT_WINDOW_ANCHOR, 'window stays the conservative anchor');
    assert.equal(r.advisory, true, 'unknown window -> advisory, not a budget breach');
    assert.equal(r.source, 'auto-unresolved');
  });

  it('"AUTO" is case-insensitive', () => {
    assert.equal(resolveContextWindow('AUTO').advisory, true);
  });

  it('an invalid value falls back to the conservative default (not advisory)', () => {
    for (const bad of ['banana', '0', '-5', '']) {
      const r = resolveContextWindow(bad);
      assert.equal(r.window, CONTEXT_WINDOW_ANCHOR, `"${bad}" -> anchor`);
      assert.equal(r.advisory, false, `"${bad}" -> not advisory`);
    }
  });
});

describe('scaleForWindow — linear scaling off the 200k anchor', () => {
  it('is the identity at the 200k anchor (byte-stable default)', () => {
    assert.equal(scaleForWindow(4000, CONTEXT_WINDOW_ANCHOR), 4000);
    assert.equal(scaleForWindow(40_000, CONTEXT_WINDOW_ANCHOR), 40_000);
  });

  it('scales 5x at the 1M window', () => {
    assert.equal(scaleForWindow(4000, LARGE_CONTEXT_WINDOW), 20_000);
    assert.equal(scaleForWindow(40_000, LARGE_CONTEXT_WINDOW), 200_000);
  });
});