'use strict';

const crypto = require('crypto');
const fs = require('fs');
const path = require('path');

const root = path.resolve(__dirname, '..');

function fixtureInputs() {
  return ['fengshu-er-road', 'nantaizi-lake-innovation-valley'].map((areaId) => {
    const isFengshu = areaId === 'fengshu-er-road';
    const outputRoot = path.join(root, 'outputs', areaId);
    return {
      areaId,
      osmFile: path.join(root, 'inputs', 'osm', isFengshu ? '枫树二路.osm' : '南台子湖创新谷OSM.osm'),
      outDir: path.join(outputRoot, 'native-road'),
      stagingDir: path.join(outputRoot, '_pipeline'),
      overridesFile: path.join(outputRoot, 'native-road-overrides.json'),
      trafficSignalsFile: path.join(outputRoot, 'native-traffic-signals.json'),
      comparisonDir: path.join(outputRoot, 'osm2streets_web_out'),
      options: { edgeLines: false, junctionTemplates: { enabled: false, references: [] } },
    };
  });
}

function digest(value) {
  return crypto.createHash('sha256').update(value).digest('hex');
}

function canonicalContent(file) {
  const raw = fs.readFileSync(file, 'utf8');
  if (!file.endsWith('.json') && !file.endsWith('.geojson')) return raw;
  return `${JSON.stringify(normalize(JSON.parse(raw)))}\n`;
}

function normalize(value) {
  if (Array.isArray(value)) return value.map(normalize);
  if (value && typeof value === 'object')
    return Object.fromEntries(Object.entries(value).map(([key, item]) => [key, normalize(item)]));
  return typeof value === 'string' ? value.split(root).join('<repo>') : value;
}

function snapshot(input) {
  const files = {};
  const candidates = [
    ['../native-traffic-signals.json', input.trafficSignalsFile],
    ...walk(input.outDir).filter(([relative]) => relative !== 'manifest.json'),
  ];
  for (const [relative, file] of candidates) {
    const content = canonicalContent(file);
    files[relative] = { contentHash: digest(content), bytes: Buffer.byteLength(content) };
  }
  return { contract: 'native-road-package/v1.1', areaId: input.areaId, files };
}

function walk(directory, prefix = '') {
  return fs
    .readdirSync(directory, { withFileTypes: true })
    .sort((first, second) => first.name.localeCompare(second.name))
    .flatMap((entry) => {
      const relative = path.join(prefix, entry.name);
      const file = path.join(directory, entry.name);
      return entry.isDirectory() ? walk(file, relative) : [[relative, file]];
    });
}

function baselineFile(areaId) {
  return path.join(root, 'test', 'baseline', `${areaId}.json`);
}

module.exports = { root, fixtureInputs, snapshot, baselineFile };