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

function attachReferenceBaselines(criteria, input = {}) {
  const baselines = loadReferenceBaselines(input);
  const providerStatus = input.referenceProviderStatus || {};
  if (!baselines.length) {
    return {
      ...criteria,
      referenceBaselines: [],
      referenceEvidenceStatus: buildEvidenceStatus(criteria, [], providerStatus)
    };
  }

  return {
    ...criteria,
    referenceBaselines: baselines,
    referenceBaselineSignals: [...new Set(baselines.flatMap(item => item.topSignals || []))],
    referenceEvidenceStatus: buildEvidenceStatus(criteria, baselines, providerStatus)
  };
}

function loadReferenceBaselines(input = {}) {
  const fromInput = Array.isArray(input.referenceBaselines) ? input.referenceBaselines : [];
  const baselinePath = input.referenceBaselinePath || input.referenceBaselinesPath || '';
  const fromPath = readBaselineFile(baselinePath);
  return dedupe([...fromInput, ...fromPath].map(normalizeBaseline).filter(Boolean));
}

function readBaselineFile(file) {
  if (!file) return [];
  const resolved = path.resolve(file);
  if (!fs.existsSync(resolved)) return [];
  try {
    const parsed = JSON.parse(fs.readFileSync(resolved, 'utf8'));
    if (Array.isArray(parsed)) return parsed;
    if (Array.isArray(parsed.referenceBaselines)) return parsed.referenceBaselines;
    if (Array.isArray(parsed.data)) return parsed.data;
    return [];
  } catch {
    return [];
  }
}

function normalizeBaseline(item) {
  if (!item || typeof item !== 'object') return null;
  const topSignals = normalizeSignals(item.topSignals || item.signals || item.referenceSignals || []);
  return {
    bucket: String(item.bucket || item.referenceBucket || '参考账号'),
    platform: item.platform || 'xiaohongshu',
    name: String(item.name || item.nickname || item.displayName || '').trim(),
    redId: String(item.redId || item.red_id || '').trim(),
    userId: String(item.userId || item.user_id || '').trim(),
    fans: Number(item.fans || item.fansCount || item.fansNum || 0),
    location: String(item.location || item.ipLocation || ''),
    profileDesc: String(item.profileDesc || item.desc || ''),
    sampleCount: Number(item.sampleCount || item.notesCount || 0),
    typeMix: String(item.typeMix || ''),
    collectMedian: toNullableNumber(item.collectMedian),
    commentMedian: toNullableNumber(item.commentMedian),
    topSignals,
    sampleTitles: normalizeTextList(item.sampleTitles || item.titles || []),
    source: item.source || 'reference-baseline-cache'
  };
}

function normalizeSignals(values) {
  return normalizeTextList(values)
    .map(item => item.replace(/\(\d+\)\s*$/, '').trim())
    .filter(Boolean);
}

function normalizeTextList(values) {
  return (Array.isArray(values) ? values : [values])
    .flatMap(item => String(item || '').split(/[、,；;]/))
    .map(item => item.trim())
    .filter(Boolean);
}

function buildEvidenceStatus(criteria, baselines, providerStatus = {}) {
  const linkCount = (criteria.referenceLinks || []).length;
  const status = baselines.length ? 'baseline_loaded' : linkCount ? 'needs_social_analysis_enrichment' : 'no_reference_links';
  return {
    referenceLinkCount: linkCount,
    baselineCount: baselines.length,
    status,
    providerRequested: Boolean(providerStatus.requested),
    providerStatus: providerStatus.status || 'not_requested',
    providerHttpStatus: providerStatus.httpStatus || 0,
    providerWarning: providerStatus.warning || '',
    note: providerStatus.warning || (baselines.length
      ? '已加载参考账号基线，可用于相似度与报告复核。'
      : linkCount
        ? '已识别参考链接，但尚未通过社媒分析服务加载账号详情。'
        : 'Brief 未提供明确参考链接。')
  };
}

function dedupe(items) {
  const seen = new Set();
  const result = [];
  for (const item of items) {
    const key = `${item.platform}:${item.userId || item.redId || item.name}:${item.bucket}`;
    if (seen.has(key)) continue;
    seen.add(key);
    result.push(item);
  }
  return result;
}

function toNullableNumber(value) {
  const number = Number(value);
  return Number.isFinite(number) ? number : null;
}

module.exports = {
  attachReferenceBaselines,
  loadReferenceBaselines,
  normalizeBaseline
};