import { promises as fs } from 'fs'
import { getServerDataPath } from './paths.js'
import { readSpielplanData } from './spielplan-data.js'

const CLUB_ID = '43030'

function parseCsvRows(content) {
  const rows = []
  let row = []
  let value = ''
  let quoted = false

  for (let index = 0; index < content.length; index += 1) {
    const char = content[index]
    if (char === '"') {
      if (quoted && content[index + 1] === '"') {
        value += '"'
        index += 1
      } else {
        quoted = !quoted
      }
    } else if (char === ',' && !quoted) {
      row.push(value)
      value = ''
    } else if ((char === '\n' || char === '\r') && !quoted) {
      if (char === '\r' && content[index + 1] === '\n') index += 1
      row.push(value)
      if (row.some(cell => cell !== '')) rows.push(row)
      row = []
      value = ''
    } else {
      value += char
    }
  }
  row.push(value)
  if (row.some(cell => cell !== '')) rows.push(row)
  return rows
}

function csvCell(value) {
  const text = String(value ?? '')
  return /[",\n\r]/.test(text) ? `"${text.replace(/"/g, '""')}"` : text
}

function romanToNumber(value) {
  const roman = String(value || '').toUpperCase()
  const values = { I: 1, V: 5, X: 10 }
  let result = 0
  for (let index = 0; index < roman.length; index += 1) {
    const current = values[roman[index]] || 0
    const next = values[roman[index + 1]] || 0
    result += current < next ? -current : current
  }
  return result || null
}

function getCmsTeamCriteria(name, league) {
  const teamName = String(name || '').trim()
  const youth = teamName.match(/^jugend\s+j(\d{1,2})(?:\s+([ivx]+|\d+))?\b/i)
  if (youth) {
    const rawNumber = youth[2]
    return {
      ageClass: `Jugend ${youth[1]}`,
      teamNumber: rawNumber ? (Number(rawNumber) || romanToNumber(rawNumber)) : null
    }
  }

  // In bestehenden CMS-Daten steht die Altersklasse häufig nur in der Liga,
  // z. B. Mannschaft "Jugend I" mit Liga "Jugend 13 (J13)".
  const ageMatch = `${teamName} ${String(league || '')}`.match(/\b(?:jugend\s*|j\s*\(?)(\d{1,2})\b/i)
  if (ageMatch) {
    const ordinal = teamName.match(/^jugend\s+([ivx]+|\d+)\b/i)?.[1]
    return {
      ageClass: `Jugend ${ageMatch[1]}`,
      teamNumber: ordinal ? (Number(ordinal) || romanToNumber(ordinal)) : null
    }
  }

  const adult = teamName.match(/^erwachsene\s+(\d+)\b/i)
  if (adult) return { ageClass: 'Erwachsene', teamNumber: Number(adult[1]) }
  return null
}

function collectImportedTeams(rows) {
  const teams = new Map()
  for (const row of rows) {
    for (const side of ['Heim', 'Gast']) {
      if (String(row[`${side}VereinNr`] || '') !== CLUB_ID) continue
      const id = String(row[`${side}MannschaftId`] || '').trim()
      if (!id) continue
      teams.set(id, {
        id,
        ageClass: String(row[`${side}MannschaftAltersklasse`] || '').trim(),
        teamNumber: Number(row[`${side}MannschaftNr`]) || null
      })
    }
  }
  return [...teams.values()]
}

/**
 * Adds every league and cup team ID matching a CMS team to its CSV row.
 * A manually chosen ID is retained if no automatic match can be derived.
 */
export async function synchronizeMannschaftenSpielplanIds(seasonSlug) {
  const filePath = getServerDataPath('public-data', `mannschaften_${seasonSlug}.csv`)
  let content
  try {
    content = await fs.readFile(filePath, 'utf8')
  } catch (error) {
    if (error?.code === 'ENOENT') return { updatedTeams: 0, skipped: true }
    throw error
  }

  const parsed = parseCsvRows(content)
  if (parsed.length < 2) return { updatedTeams: 0 }
  const header = parsed[0]
  let idColumn = header.indexOf('Spielplan Mannschaft ID')
  if (idColumn < 0) {
    header.push('Spielplan Mannschaft ID')
    idColumn = header.length - 1
  }

  const spielplan = await readSpielplanData({ season: seasonSlug })
  const importedTeams = collectImportedTeams(spielplan.data)
  let updatedTeams = 0

  for (const row of parsed.slice(1)) {
    const criteria = getCmsTeamCriteria(row[0], row[1])
    if (!criteria) continue
    const ids = importedTeams
      .filter(team => team.ageClass === criteria.ageClass && (!criteria.teamNumber || team.teamNumber === criteria.teamNumber))
      .map(team => team.id)
      .sort((a, b) => Number(a) - Number(b))
    if (!ids.length) continue
    const nextValue = ids.join(',')
    if (row[idColumn] === nextValue) continue
    row[idColumn] = nextValue
    updatedTeams += 1
  }

  if (updatedTeams) {
    const output = `${parsed.map(row => header.map((_, index) => csvCell(row[index])).join(',')).join('\n')}\n`
    const temporaryPath = `${filePath}.tmp-${process.pid}-${Date.now()}`
    await fs.writeFile(temporaryPath, output, 'utf8')
    await fs.rename(temporaryPath, filePath)
  }

  return { updatedTeams, importedTeamCount: importedTeams.length }
}