/** Replays selected public calendar outputs, not the private app's interpretation rules. */
import assert from 'node:assert/strict';
import { execFileSync } from 'node:child_process';
import { createHash } from 'node:crypto';
import { readFileSync, realpathSync } from 'node:fs';
import path from 'node:path';
import { fileURLToPath, pathToFileURL } from 'node:url';

export const SOURCE_REVISION = '694adfe64b5f17602c3f4e7359ae97d7232a6426';
export const DATASET_SHA256 = 'bc4d5afcc79dc0b2d5405199cddfae8bd4a203d73f4adc4e5f5a1b067485460d';

const formatTime = value => (
  `${value.year}-${String(value.month).padStart(2, '0')}-${String(value.day).padStart(2, '0')} `
  + `${String(value.hour).padStart(2, '0')}:${String(value.minute).padStart(2, '0')}:${String(value.second).padStart(2, '0')}`
);

/** Project only the fields promised by the frozen public v1 dataset. */
export function projectResult(chart) {
  const solar = chart.solarTimeInfo;
  return {
    pillars: Object.fromEntries(['year', 'month', 'day', 'hour'].map(key => [key, chart.pillars[key]?.ganZhi ?? null])),
    dayMaster: chart.dayMaster.char,
    calendar: {
      inputType: chart.calendar.inputType,
      civilSolar: formatTime(chart.calendar.civilSolar),
      calculationSolar: formatTime(chart.calendar.calculationSolar),
      lunar: formatTime(chart.calendar.lunar),
      lunarLeapMonth: chart.calendar.lunar.isLeapMonth,
    },
    metadata: {
      timezoneBasis: chart.metadata.timezoneBasis,
      dstOffset: chart.metadata.dstOffset,
      trueSolarTimeApplied: chart.metadata.trueSolarTimeApplied,
      dayBoundaryMode: chart.metadata.dayBoundaryMode,
    },
    solarTime: solar ? {
      trueSolarTime: solar.trueSolarTime,
      trueSolarDateTime: solar.trueSolarDateTime,
      standardMeridian: solar.standardMeridian,
      longitudeCorrectionMinutes: Number(solar.longitudeCorrectionMinutes.toFixed(6)),
      equationOfTimeMinutes: Number(solar.equationOfTimeMinutes.toFixed(6)),
      algorithm: solar.algorithm,
    } : null,
    daYun: {
      direction: chart.daYun.isForward ? 'forward' : 'backward',
      startDate: chart.daYun.startDate,
      startOffset: chart.daYun.startOffset,
      firstCycle: chart.daYun.cycles[0].ganZhi,
    },
  };
}

/** Require every selected public field to match the frozen dataset exactly. */
export function replayCases(calculate, dataset) {
  assert.equal(dataset.cases.length, 8);
  const results = dataset.cases.map(testCase => {
    const actual = projectResult(calculate(testCase.input));
    assert.deepEqual(actual, testCase.expected, `${testCase.id}: public-source difference`);
    return { id: testCase.id, status: 'full-match', differences: [] };
  });
  assert.equal(results.filter(result => result.status === 'full-match').length, 8);
  return { sourceRevision: SOURCE_REVISION, fullMatches: 8, casesWithKnownReceiptDifference: 0, results };
}

const invokedPath = process.argv[1] ? realpathSync(path.resolve(process.argv[1])) : null;
const modulePath = realpathSync(fileURLToPath(import.meta.url));
if (invokedPath && modulePath === invokedPath) {
  const [sourceDirectory, datasetFile] = process.argv.slice(2);
  assert.ok(sourceDirectory && datasetFile, 'Usage: node --import tsx replay.mjs <engine-directory> <dataset.json>');
  const sourceRoot = path.resolve(sourceDirectory);
  const revision = execFileSync('git', ['rev-parse', 'HEAD'], { cwd: sourceRoot, encoding: 'utf8' }).trim();
  assert.equal(revision, SOURCE_REVISION, 'Check out the documented public source revision');
  const trackedChanges = execFileSync('git', ['status', '--porcelain', '--untracked-files=no'], { cwd: sourceRoot, encoding: 'utf8' });
  assert.equal(trackedChanges.trim(), '', 'Replay requires unmodified tracked source files');
  const rawDataset = readFileSync(path.resolve(datasetFile));
  assert.equal(createHash('sha256').update(rawDataset).digest('hex'), DATASET_SHA256, 'Dataset hash mismatch');
  const { calculateBaziChart } = await import(pathToFileURL(path.join(sourceRoot, 'src/index.ts')).href);
  console.log(JSON.stringify(replayCases(calculateBaziChart, JSON.parse(rawDataset)), null, 2));
}