import { describe, it } from 'node:test';
import assert from 'node:assert/strict';
import {
  assessSkillListingBudget,
  DESCRIPTION_CAP,
  AGGREGATE_BUDGET_TOKENS,
  CONTEXT_WINDOW_ANCHOR,
  LARGE_CONTEXT_WINDOW,
  LARGE_CONTEXT_BUDGET_TOKENS,
  withCommas,
  BUDGET_CALIBRATION_NOTE,
} from '../../scanners/lib/skill-listing-budget.mjs';

// This lib is the single source of truth for the skill-listing budget that both
// the SKL scanner (diagnoses overflow) and the GAP scanner (recommends the
// disableBundledSkills lever) consume. The constants and aggregate math here
// must match what SKL shipped in v5.2.0 — these tests pin that contract.

describe('skill-listing-budget — constants', () => {
  it('DESCRIPTION_CAP is the verified 1536-char listing cap (CC 2.1.105)', () => {
    assert.equal(DESCRIPTION_CAP, 1536);
  });

  it('AGGREGATE_BUDGET_TOKENS is 2% of the conservative 200k anchor', () => {
    assert.equal(CONTEXT_WINDOW_ANCHOR, 200_000);
    assert.equal(AGGREGATE_BUDGET_TOKENS, 4000);
  });

  it('LARGE_CONTEXT_BUDGET_TOKENS is 2% of the 1M window', () => {
    assert.equal(LARGE_CONTEXT_WINDOW, 1_000_000);
    assert.equal(LARGE_CONTEXT_BUDGET_TOKENS, 20000);
  });
});

describe('withCommas', () => {
  it('inserts thousands separators', () => {
    assert.equal(withCommas(1_000_000), '1,000,000');
    assert.equal(withCommas(4000), '4,000');
    assert.equal(withCommas(999), '999');
    assert.equal(withCommas(0), '0');
  });
});

describe('BUDGET_CALIBRATION_NOTE', () => {
  it('discloses the 1M-context scaling and flags this as an estimate, not telemetry', () => {
    assert.match(BUDGET_CALIBRATION_NOTE, /1,000,000/);
    assert.match(BUDGET_CALIBRATION_NOTE, /20,000/);
    assert.match(BUDGET_CALIBRATION_NOTE, /estimate/i);
  });
});

describe('assessSkillListingBudget — aggregate math', () => {
  it('sums each description length capped at the 1536 cap', () => {
    // 1000 + 1000 + min(5000,1536) = 3536
    const r = assessSkillListingBudget([1000, 1000, 5000]);
    assert.equal(r.aggregateChars, 3536);
  });

  it('scanned counts every entry, including empty descriptions', () => {
    const r = assessSkillListingBudget([0, 0, 100]);
    assert.equal(r.scanned, 3);
    assert.equal(r.aggregateChars, 100);
  });

  it('aggregateTokens mirrors estimateTokens markdown (ceil chars/4)', () => {
    const r = assessSkillListingBudget([16]); // 16 chars -> 4 tokens
    assert.equal(r.aggregateTokens, 4);
  });

  it('is NOT over budget exactly at the budget (16×1000 chars -> 4000 tok)', () => {
    const r = assessSkillListingBudget(Array(16).fill(1000));
    assert.equal(r.aggregateChars, 16000);
    assert.equal(r.aggregateTokens, 4000);
    assert.equal(r.overBudget, false);
    assert.equal(r.overBy, 0);
  });

  it('is over budget one skill past the budget (17×1000 chars -> 4250 tok)', () => {
    const r = assessSkillListingBudget(Array(17).fill(1000));
    assert.equal(r.aggregateTokens, 4250);
    assert.equal(r.overBudget, true);
    assert.equal(r.overBy, 250);
  });

  it('exposes budgetTokens and handles the empty case', () => {
    const r = assessSkillListingBudget([]);
    assert.equal(r.budgetTokens, AGGREGATE_BUDGET_TOKENS);
    assert.equal(r.scanned, 0);
    assert.equal(r.aggregateChars, 0);
    assert.equal(r.aggregateTokens, 0);
    assert.equal(r.overBudget, false);
    assert.equal(r.overBy, 0);
  });

  it('treats negative or non-finite lengths as zero contribution', () => {
    const r = assessSkillListingBudget([-5, NaN, 100]);
    assert.equal(r.aggregateChars, 100);
    assert.equal(r.scanned, 3);
  });
});