import { test } from 'node:test';
import assert from 'node:assert/strict';
import { readFileSync } from 'node:fs';
import { fileURLToPath } from 'node:url';
import { dirname, join } from 'node:path';

const here = dirname(fileURLToPath(import.meta.url));
const root = join(here, '..');

test('userscript embeds a copy of src/pure.js that is present and parseable', () => {
  const bundle = readFileSync(join(root, 'torn-attribute-tracker.user.js'), 'utf8');
  // The bundle must reference all four pure function names.
  for (const name of ['parseTarget', 'computeEstimate', 'pruneHistory', 'summary']) {
    assert.ok(bundle.includes('function ' + name), 'missing ' + name + ' in bundle');
  }
  // The bundle must include the Tampermonkey header.
  assert.ok(bundle.includes('// ==UserScript=='), 'missing Tampermonkey header');
  // The bundle must include the @match directive.
  assert.ok(bundle.includes('@match'), 'missing @match');
  assert.ok(bundle.includes('torn.com/gym.php'), 'missing torn.com/gym.php match');
});

test('userscript self-test block is wired to #tat-test', () => {
  const bundle = readFileSync(join(root, 'torn-attribute-tracker.user.js'), 'utf8');
  assert.ok(bundle.includes("location.hash === '#tat-test'"), 'self-test guard missing');
  assert.ok(bundle.includes('runSelfTest'), 'runSelfTest function missing');
});

test('bundle summary behavior matches src/pure.js (catches Math.floor-style regressions)', () => {
  // Read both the source and the bundle.
  const src = readFileSync(join(root, 'src/pure.js'), 'utf8');
  const bundle = readFileSync(join(root, 'torn-attribute-tracker.user.js'), 'utf8');

  // Extract the body of `summary` from src/pure.js between `function summary(` and the next `}`.
  // Use a simple state machine: find the function header, then count braces.
  function extractBody(source, fnName) {
    const start = source.indexOf('function ' + fnName + '(');
    if (start === -1) throw new Error('could not find ' + fnName + ' in source');
    // Find the opening brace of the function body.
    let i = source.indexOf('{', start);
    if (i === -1) throw new Error('no opening brace for ' + fnName);
    let depth = 1;
    i++;
    while (i < source.length && depth > 0) {
      const c = source[i];
      if (c === '{') depth++;
      else if (c === '}') depth--;
      i++;
    }
    return source.slice(start, i);
  }

  // Eval-extract the `summary` function from both sources. The src/pure.js
  // version references the module-level `MS_PER_DAY` constant, so inject
  // it into the eval scope; the bundle inlines the literal value, so the
  // injected binding is a harmless no-op there.
  const srcSummary = eval('(function() { const MS_PER_DAY = 86_400_000; ' + extractBody(src, 'summary') + ' ; return summary; })()');
  const bundleSummary = eval('(function() { const MS_PER_DAY = 86_400_000; ' + extractBody(bundle, 'summary') + ' ; return summary; })()');

  // Run both with a known input that exercises perDay flooring.
  const NOW = 1_700_000_000_000;
  const entries = [
    { ts: NOW - 1000, delta: 247 },
    { ts: NOW - 2000, delta: 247 },
  ];
  const srcResult = srcSummary(entries, NOW);
  const bundleResult = bundleSummary(entries, NOW);

  // The bundle MUST match the source exactly.
  assert.deepEqual(bundleResult, srcResult, 'bundle summary differs from src/pure.js summary');
  // And specifically: perDay must be the floored integer 70, not the float 70.57.
  assert.equal(bundleResult.perDay, 70, 'perDay should be floored to 70');
});

test('bundle parseTarget behavior matches src/pure.js', () => {
  const src = readFileSync(join(root, 'src/pure.js'), 'utf8');
  const bundle = readFileSync(join(root, 'torn-attribute-tracker.user.js'), 'utf8');

  function extractBody(source, fnName) {
    const start = source.indexOf('function ' + fnName + '(');
    if (start === -1) throw new Error('could not find ' + fnName + ' in source');
    let i = source.indexOf('{', start);
    if (i === -1) throw new Error('no opening brace for ' + fnName);
    let depth = 1;
    i++;
    while (i < source.length && depth > 0) {
      const c = source[i];
      if (c === '{') depth++;
      else if (c === '}') depth--;
      i++;
    }
    return source.slice(start, i);
  }

  // Both src and bundle reference module-scope `SUFFIXES`, so inject it for both.
  const srcFn = eval('(function() { const SUFFIXES = { k: 1e3, m: 1e6, b: 1e9, t: 1e12 }; ' + extractBody(src, 'parseTarget') + ' ; return parseTarget; })()');
  const bundleFn = eval('(function() { const SUFFIXES = { k: 1e3, m: 1e6, b: 1e9, t: 1e12 }; ' + extractBody(bundle, 'parseTarget') + ' ; return parseTarget; })()');

  for (const input of [25, 25000000, '25M', '1.5B', '25,000,000', 'abc', null, undefined, 0, -1]) {
    assert.equal(bundleFn(input), srcFn(input), 'parseTarget drift on input: ' + JSON.stringify(input));
  }
});

test('bundle computeEstimate behavior matches src/pure.js', () => {
  const src = readFileSync(join(root, 'src/pure.js'), 'utf8');
  const bundle = readFileSync(join(root, 'torn-attribute-tracker.user.js'), 'utf8');

  function extractBody(source, fnName) {
    const start = source.indexOf('function ' + fnName + '(');
    if (start === -1) throw new Error('could not find ' + fnName + ' in source');
    let i = source.indexOf('{', start);
    if (i === -1) throw new Error('no opening brace for ' + fnName);
    let depth = 1;
    i++;
    while (i < source.length && depth > 0) {
      const c = source[i];
      if (c === '{') depth++;
      else if (c === '}') depth--;
      i++;
    }
    return source.slice(start, i);
  }

  // The bundle inlines the 86_400_000 constant; src/pure.js uses MS_PER_DAY.
  // Both versions call `Date.now()` inside the function for the `eta` Date, so
  // we strip `eta` from the comparison (it would differ by sub-millisecond
  // jitter between the two evals) and only compare the numeric fields.
  const srcFn = eval('(function() { const MS_PER_DAY = 86_400_000; ' + extractBody(src, 'computeEstimate') + ' ; return computeEstimate; })()');
  const bundleFn = eval('(function() { ' + extractBody(bundle, 'computeEstimate') + ' ; return computeEstimate; })()');

  function stripEta(r) {
    return { remaining: r.remaining, trainsToGo: r.trainsToGo, days: r.days, etaDays: r.days };
  }

  for (const args of [
    [14_328_501, 25_000_000, 247, 4520],
    [25_000_000, 25_000_000, 247, 4520],
    [30_000_000, 25_000_000, 247, 4520],
    [100, 200, 0, 50],
    [100, 200, 50, 0],
  ]) {
    const [c, t, pt, pd] = args;
    const srcResult = srcFn(c, t, pt, pd);
    const bundleResult = bundleFn(c, t, pt, pd);
    // Both eta fields should be null together, or both should be Date objects.
    assert.equal(bundleResult.eta === null, srcResult.eta === null, 'eta nullity drift on args: ' + JSON.stringify(args));
    assert.deepEqual(stripEta(bundleResult), stripEta(srcResult), 'computeEstimate drift on args: ' + JSON.stringify(args));
  }
});

test('bundle pruneHistory behavior matches src/pure.js (catches strict-boundary regressions)', () => {
  const src = readFileSync(join(root, 'src/pure.js'), 'utf8');
  const bundle = readFileSync(join(root, 'torn-attribute-tracker.user.js'), 'utf8');

  function extractBody(source, fnName) {
    const start = source.indexOf('function ' + fnName + '(');
    if (start === -1) throw new Error('could not find ' + fnName + ' in source');
    let i = source.indexOf('{', start);
    if (i === -1) throw new Error('no opening brace for ' + fnName);
    let depth = 1;
    i++;
    while (i < source.length && depth > 0) {
      const c = source[i];
      if (c === '{') depth++;
      else if (c === '}') depth--;
      i++;
    }
    return source.slice(start, i);
  }

  // The bundle inlines 30 * 86_400_000; src uses THIRTY_DAYS_MS = 30 * MS_PER_DAY.
  // Both must be visible to the extracted function body.
  const srcFn = eval('(function() { const MS_PER_DAY = 86_400_000; const THIRTY_DAYS_MS = 30 * MS_PER_DAY; ' + extractBody(src, 'pruneHistory') + ' ; return pruneHistory; })()');
  const bundleFn = eval('(function() { const THIRTY_DAYS_MS = 30 * 86_400_000; ' + extractBody(bundle, 'pruneHistory') + ' ; return pruneHistory; })()');

  const NOW = 1_700_000_000_000;
  const DAY = 86_400_000;

  // Critical case: entry at exactly 30 days. Source drops it (strict >), bundle should too.
  const boundaryEntries = [
    { ts: NOW, delta: 1 },
    { ts: NOW - 1 * DAY, delta: 1 },
    { ts: NOW - 29 * DAY, delta: 1 },
    { ts: NOW - 30 * DAY, delta: 1 },  // exactly 30 days — should be DROPPED
    { ts: NOW - 31 * DAY, delta: 1 },
  ];

  const srcResult = srcFn(boundaryEntries, NOW);
  const bundleResult = bundleFn(boundaryEntries, NOW);

  assert.deepEqual(bundleResult, srcResult, 'pruneHistory drift on 30-day boundary');
  assert.equal(srcResult.length, 3, 'source should keep 3 entries (drop the 30-day one)');
  assert.equal(bundleResult.length, 3, 'bundle should keep 3 entries (drop the 30-day one)');
});