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

function loadCsvNames(filePath) {
  try {
    const raw = fs.readFileSync(filePath, 'utf8')
    const lines = raw.split(/\r?\n/).map((l) => l.trim()).filter(Boolean)
    const names = []
    for (const line of lines) {
      const parts = line.split(/[;,\t]/).map((p) => p.trim()).filter(Boolean)
      for (const p of parts) {
        if (/^[A-Za-zÀ-ÖØ-öø-ÿ'\-\s]{2,}$/.test(p)) names.push(p)
      }
    }
    return names
  } catch {
    return []
  }
}

function buildNameSets() {
  const baseDir = path.join(__dirname, 'data', 'names')
  const firstNames = new Set()
  const lastNames = new Set()
  try {
    if (!fs.existsSync(baseDir)) return { firstNames, lastNames }
    // Prioriser les fichiers unifiés légers (références finales)
    const preferredOrder = [
      'firstnames_all.csv',
      'lastnames_all.csv',
    ]
    const files = fs
      .readdirSync(baseDir)
      .sort((a, b) => preferredOrder.indexOf(a) - preferredOrder.indexOf(b))
    for (const f of files) {
      const fp = path.join(baseDir, f)
      if (!fs.statSync(fp).isFile()) continue
      // N'utiliser que les deux références finales si présentes
      const isFirst = /^(firstnames_all\.|first|prenom|given)/i.test(f)
      const isLast = /^(lastnames_all\.|last|nom|surname|family)/i.test(f)
      if (!isFirst && !isLast) continue
      const list = loadCsvNames(fp)
      for (const n of list) {
        const norm = n.normalize('NFD').replace(/[\u0300-\u036f]/g, '').toLowerCase()
        if (isFirst) firstNames.add(norm)
        if (isLast) lastNames.add(norm)
      }
    }
  } catch {}
  return { firstNames, lastNames }
}

let cache = null
function getNameDirectory() {
  if (!cache) cache = buildNameSets()
  return cache
}

function nameConfidenceBoost(firstName, lastName) {
  try {
    const dir = getNameDirectory()
    const f = (firstName || '').normalize('NFD').replace(/[\u0300-\u036f]/g, '').toLowerCase()
    const l = (lastName || '').normalize('NFD').replace(/[\u0300-\u036f]/g, '').toLowerCase()
    let boost = 0
    if (f && dir.firstNames.has(f)) boost += 0.05
    if (l && dir.lastNames.has(l)) boost += 0.05
    return boost
  } catch {
    return 0
  }
}

module.exports = { getNameDirectory, nameConfidenceBoost }