import { load } from 'cheerio'
import type { CheerioAPI, Cheerio } from 'cheerio'
import type { Element } from 'domhandler'

// ── Types ──────────────────────────────────────────────────────────────────

export type Goal = {
  name: string
  minute?: number
  offset?: number
  penalty?: boolean
  owngoal?: boolean
}

export type ScoreObj = {
  ft?: [number, number]
  et?: [number, number]
  p?: [number, number]
}

export type Match = {
  round: string
  group?: string
  date?: string
  time?: string
  team1: string
  team2: string
  score?: ScoreObj
  goals1?: Goal[]
  goals2?: Goal[]
  ground?: string
}

export type Stadium = { name: string; city: string }
export type Group = { name: string; teams: string[] }
export type Meta = {
  host: string
  teams_count: number | null
  winner: string | null
  runner_up: string | null
  third_place: string | null
  fourth_place: string | null
}

export type Player = { name: string; number?: number; pos?: string; date_of_birth?: string }
export type Squad  = { name: string; players: Player[] }

export type YearResult = {
  matches: Match[]
  stadiums: Map<string, Stadium>
  groups: Map<string, Set<string>>
  meta: Meta
}

type State = { active: boolean; round: string; group: string | null }

// ── Fetch ──────────────────────────────────────────────────────────────────

const delay = (ms: number) => new Promise(r => setTimeout(r, ms))

export async function fetchWikiHtml(page: string, retries = 5): Promise<string | null> {
  const url = `https://en.wikipedia.org/w/api.php?action=parse&page=${encodeURIComponent(page)}&format=json&prop=text&disabletoc=1`
  for (let attempt = 0; attempt < retries; attempt++) {
    try {
      if (attempt > 0) await delay(3000 * attempt)
      const res = await fetch(url, { headers: { 'User-Agent': 'WorldCupScraper/1.0' } })
      if (!res.ok) continue
      const data = await res.json() as { parse?: { text?: { '*': string } } }
      const html = data?.parse?.text?.['*']
      if (html) return html
    } catch {
      // retry
    }
  }
  return null
}

// ── Parsing helpers ────────────────────────────────────────────────────────

function parseScoreText(text: string): [number, number] | null {
  const m = text.match(/(\d+)\s*[–\-]\s*(\d+)/)
  if (!m) return null
  return [parseInt(m[1]), parseInt(m[2])]
}

function extractTeam($: CheerioAPI, $cell: Cheerio<Element>): string {
  let name = ''
  $cell.find('a').each((_, a) => {
    const $a = $(a)
    if (!$a.find('img').length && $a.text().trim()) {
      name = $a.text().trim()
      return false
    }
  })
  return name
}

function parseGoals($: CheerioAPI, $td: Cheerio<Element>): Goal[] {
  const goals: Goal[] = []
  $td.find('li').each((_, li) => {
    const $li = $(li)
    let playerName = ''
    $li.find('a').each((_, a) => {
      if (!$(a).closest('.fb-goal').length) {
        const t = $(a).text().trim()
        if (t) { playerName = t; return false }
      }
    })
    if (!playerName) return
    const $fbGoal = $li.find('.fb-goal')
    if (!$fbGoal.length) return
    $fbGoal.children('span').each((_, span) => {
      const $span = $(span)
      if ($span.attr('typeof')) return
      const text = $span.text()
      const minMatch = text.match(/(\d+)(?:\+(\d+))?['′]/)
      if (!minMatch) return
      const minute = parseInt(minMatch[1])
      const offset = minMatch[2] ? parseInt(minMatch[2]) : 0
      const goal: Goal = { name: playerName }
      if (!isNaN(minute)) goal.minute = minute
      if (offset) goal.offset = offset
      if (text.includes('pen.')) goal.penalty = true
      if (text.includes('o.g.')) goal.owngoal = true
      goals.push(goal)
    })
  })
  return goals
}

function extractGround($: CheerioAPI, $box: Cheerio<Element>): string {
  const $loc = $box.find('[itemprop="name address"]').first()
  if ($loc.length) return $loc.text().trim()
  return $box.find('.fright').first().text().split('\n')[0].trim()
}

function parseGroundParts(ground: string): { name: string; city: string } {
  const commaIdx = ground.indexOf(',')
  if (commaIdx !== -1) return { name: ground.slice(0, commaIdx).trim(), city: ground.slice(commaIdx + 1).trim() }
  return { name: ground, city: '' }
}

function parseBox($: CheerioAPI, $box: Cheerio<Element>, round: string, group: string | null): Match | null {
  const team1 = extractTeam($, $box.find('.fhome'))
  const team2 = extractTeam($, $box.find('.faway'))
  if (!team1 || !team2) return null

  const dateStr = $box.find('.bday, .dtstart').first().text().trim() || undefined
  const timeText = $box.find('.ftime').first().text().trim()
  const timeStr = timeText.match(/(\d{2}:\d{2})/)?.[1]
  const scoreText = $box.find('.fscore').first().text().trim()
  const hasAET = scoreText.toLowerCase().includes('a.e.t.')
  const scoreArr = parseScoreText(scoreText)

  const $regularRow = $box.find('tr.fgoals').first()
  const goals1 = parseGoals($, $regularRow.find('.fhgoal'))
  const goals2 = parseGoals($, $regularRow.find('.fagoal'))

  let penScore: [number, number] | undefined
  $box.find('tr').each((_, tr) => {
    const $tr = $(tr)
    if ($tr.find('th[colspan]').text().toLowerCase().includes('penalt')) {
      const ps = parseScoreText($tr.next('tr').find('th').not('.fhome,.faway').first().text().trim())
      if (ps) penScore = ps
      return false
    }
  })

  let score: ScoreObj | undefined
  if (scoreArr) {
    if (hasAET) {
      const ftGoals = (gs: Goal[], includeOG = false) =>
        gs.filter(g => {
          const w90 = g.minute === undefined || g.minute <= 90
          return includeOG ? g.owngoal === true && w90 : !g.owngoal && w90
        }).length
      score = { ft: [ftGoals(goals1) + ftGoals(goals2, true), ftGoals(goals2) + ftGoals(goals1, true)], et: scoreArr }
    } else {
      score = { ft: scoreArr }
    }
    if (penScore) score.p = penScore
  }

  const ground = extractGround($, $box) || undefined
  return {
    round,
    ...(group ? { group } : {}),
    ...(dateStr ? { date: dateStr } : {}),
    ...(timeStr ? { time: timeStr } : {}),
    team1, team2,
    ...(score ? { score } : {}),
    ...(goals1.length ? { goals1 } : {}),
    ...(goals2.length ? { goals2 } : {}),
    ...(ground ? { ground } : {}),
  }
}

function collectBoxes($: CheerioAPI, round: string, group: string | null): Match[] {
  const matches: Match[] = []
  $('.footballbox').each((_, el) => {
    const m = parseBox($, $(el), round, group)
    if (m) matches.push(m)
  })
  return matches
}

function processHeading(text: string, level: number, state: State): void {
  const t = text.toLowerCase().trim()
  if (level === 2) {
    if (/group stage/i.test(t) && !/second/i.test(t)) {
      state.active = true; state.round = 'Group stage'; state.group = null
    } else if (/first group stage/i.test(t)) {
      state.active = true; state.round = 'Group stage'; state.group = null
    } else if (/second group stage/i.test(t)) {
      state.active = true; state.round = 'Second group stage'; state.group = null
    } else if (t === 'final round') {
      state.active = true; state.round = 'Final round'; state.group = null
    } else if (/final tournament/i.test(t)) {
      state.active = true; state.round = ''; state.group = null
    } else if (/knock.?out stage/i.test(t)) {
      state.active = true; state.round = ''; state.group = null
    } else if (/round of 16/i.test(t)) {
      state.active = true; state.round = 'Round of 16'; state.group = null
    } else if (/quarter.final/i.test(t)) {
      state.active = true; state.round = 'Quarter-finals'; state.group = null
    } else if (/semi.final/i.test(t)) {
      state.active = true; state.round = 'Semi-finals'; state.group = null
    } else if (/third.place|match for third|play.off for third/i.test(t)) {
      state.active = true; state.round = 'Third-place match'; state.group = null
    } else if (t === 'final') {
      state.active = true; state.round = 'Final'; state.group = null
    } else {
      state.active = false
    }
    return
  }
  if (!state.active) return
  if (level === 3 || level === 4) {
    if (/^group [a-h1-9]+$/i.test(t)) {
      state.group = text.trim()
    } else if (/round of 32/i.test(t)) {
      state.round = 'Round of 32'; state.group = null
    } else if (/round of 16/i.test(t)) {
      state.round = 'Round of 16'; state.group = null
    } else if (/quarter.final/i.test(t)) {
      state.round = 'Quarter-finals'; state.group = null
    } else if (/semi.final/i.test(t)) {
      state.round = 'Semi-finals'; state.group = null
    } else if (/third.place|match for third|play.off for third/i.test(t)) {
      state.round = 'Third-place match'; state.group = null
    } else if (t === 'final') {
      state.round = 'Final'; state.group = null
    }
  }
}

// ── Infobox ────────────────────────────────────────────────────────────────

function parseInfobox($: CheerioAPI): Partial<Meta> {
  const result: Partial<Meta> = {}

  function tdText($td: Cheerio<Element>): string {
    const $clone = $td.clone()
    $clone.find('br').replaceWith(' / ')
    $clone.find('sup, img').remove()
    return $clone.text().replace(/\[\d+\]/g, '').replace(/\s+/g, ' ').trim()
  }
  function tdFirstLink($td: Cheerio<Element>): string | null {
    let name: string | null = null
    $td.find('a').each((_, a) => {
      const t = $(a).clone().find('img').remove().end().text().trim()
      if (t && !/\[\d+\]/.test(t)) { name = t; return false }
    })
    return name ?? (tdText($td) || null)
  }
  function tdAllLinks($td: Cheerio<Element>): string {
    const names: string[] = []
    $td.find('a').each((_, a) => {
      const t = $(a).clone().find('img').remove().end().text().trim()
      if (t && !/\[\d+\]/.test(t)) names.push(t)
    })
    return names.length ? names.join(' / ') : tdText($td)
  }

  $('table.infobox').first().find('tr').each((_, tr) => {
    const $tr = $(tr)
    const label = $tr.find('th').text().trim().toLowerCase()
    const $td = $tr.find('td').first()
    if (!$td.length) return
    if (/host countr/i.test(label))       result.host        = tdAllLinks($td)
    else if (/^teams$/i.test(label))      { const m = $td.text().match(/\d+/); if (m) result.teams_count = parseInt(m[0]) }
    else if (/champion/i.test(label))     result.winner      = tdFirstLink($td)
    else if (/runners?.up/i.test(label))  result.runner_up   = tdFirstLink($td)
    else if (/third.place/i.test(label))  result.third_place = tdFirstLink($td)
    else if (/fourth.place/i.test(label)) result.fourth_place = tdFirstLink($td)
  })

  return result
}

function derivePlacements(matches: Match[]): Pick<Meta, 'winner' | 'runner_up' | 'third_place' | 'fourth_place'> {
  function matchWinner(m: Match): [string, string] | null {
    if (!m.score) return null
    const [h, a] = m.score.et ?? m.score.ft ?? [0, 0]
    if (h > a) return [m.team1, m.team2]
    if (a > h) return [m.team2, m.team1]
    if (m.score.p) {
      const [ph, pa] = m.score.p
      if (ph > pa) return [m.team1, m.team2]
      if (pa > ph) return [m.team2, m.team1]
    }
    return null
  }
  let winner: string | null = null, runner_up: string | null = null
  let third_place: string | null = null, fourth_place: string | null = null
  for (const m of matches) {
    if (m.round === 'Final') {
      const r = matchWinner(m); if (r) [winner, runner_up] = r
    } else if (m.round === 'Third-place match') {
      const r = matchWinner(m); if (r) [third_place, fourth_place] = r
    }
  }
  return { winner, runner_up, third_place, fourth_place }
}

// ── Main year scraper ──────────────────────────────────────────────────────

export async function scrapeYear(
  year: number,
  mainHtml: string,
  opts?: { skipGroups?: Set<string> },
): Promise<YearResult> {
  const $ = load(mainHtml)
  const matches: Match[] = []
  const stadiums = new Map<string, Stadium>()
  const groups = new Map<string, Set<string>>()
  const state: State = { active: false, round: '', group: null }
  const groupSubpages = new Map<string, string>()
  const groupsOnMainPage = new Set<string>()

  function recordMatch(m: Match) {
    matches.push(m)
    if (m.group) groupsOnMainPage.add(m.group)
    if (m.ground) {
      const { name, city } = parseGroundParts(m.ground)
      if (name && !stadiums.has(name)) stadiums.set(name, { name, city })
    }
    if (m.group) {
      if (!groups.has(m.group)) groups.set(m.group, new Set())
      groups.get(m.group)!.add(m.team1)
      groups.get(m.group)!.add(m.team2)
    }
  }

  $('.mw-parser-output').find('div.mw-heading, .footballbox, .hatnote').each((_, el) => {
    const $el = $(el)
    if ($el.hasClass('mw-heading')) {
      const $h = $el.find('h2, h3, h4').first()
      const level = parseInt($h.prop('tagName')?.slice(1) ?? '9')
      processHeading($h.text().replace(/\[edit\]/g, '').trim(), level, state)
    } else if ($el.hasClass('hatnote') && $el.text().includes('Main article')) {
      if (state.active && state.group) {
        const link = $el.find('a[href^="/wiki/"]').first().attr('href')
        if (link) {
          const page = link.replace('/wiki/', '').split('#')[0]
          if (/World_Cup_Group/i.test(page) && !groupSubpages.has(state.group))
            groupSubpages.set(state.group, page)
        }
      }
    } else if ($el.hasClass('footballbox')) {
      if (!state.active) return
      const m = parseBox($, $el, state.round || state.group || 'Unknown', state.group)
      if (m) recordMatch(m)
    }
  })

  for (const [group, page] of groupSubpages) {
    if (groupsOnMainPage.has(group)) continue
    if (opts?.skipGroups?.has(group)) {
      process.stdout.write(`[skip ${group}] `)
      continue
    }
    await delay(1200)
    const subHtml = await fetchWikiHtml(page)
    if (!subHtml) { process.stdout.write(`(failed: ${page}) `); continue }

    const stateTemp: State = { active: false, round: '', group: null }
    let round = 'Group stage'
    $('.mw-parser-output').find('div.mw-heading').each((_, el) => {
      const $h = $(el).find('h2, h3, h4').first()
      const level = parseInt($h.prop('tagName')?.slice(1) ?? '9')
      processHeading($h.text().replace(/\[edit\]/g, '').trim(), level, stateTemp)
      if (stateTemp.group === group) { round = stateTemp.round || 'Group stage'; return false }
    })

    const $sub = load(subHtml)
    for (const m of collectBoxes($sub, round, group)) recordMatch(m)
    process.stdout.write(`[+${page.slice(-8)}] `)
  }

  const infobox = parseInfobox($)
  const placements = derivePlacements(matches)
  const meta: Meta = {
    host:         infobox.host         ?? '',
    teams_count:  infobox.teams_count  ?? null,
    winner:       placements.winner      ?? infobox.winner      ?? null,
    runner_up:    placements.runner_up   ?? infobox.runner_up   ?? null,
    third_place:  placements.third_place ?? infobox.third_place ?? null,
    fourth_place: placements.fourth_place?? infobox.fourth_place?? null,
  }

  return { matches, stadiums, groups, meta }
}

// ── Squad page scraper ─────────────────────────────────────────────────────

export function scrapeSquads(html: string): Squad[] {
  const $ = load(html)
  const squads: Squad[] = []
  let currentTeam: Squad | null = null

  $('.mw-parser-output').find('div.mw-heading, tr.nat-fs-player').each((_, el) => {
    const $el = $(el)

    if ($el.hasClass('mw-heading')) {
      const $h = $el.find('h3, h4').first()
      if (!$h.length) return
      if (parseInt($h.prop('tagName')?.slice(1) ?? '9') !== 3) return
      const name = $h.text().replace(/\[edit\]/g, '').trim()
      if (/^group /i.test(name)) return
      currentTeam = { name, players: [] }
      squads.push(currentTeam)
      return
    }

    if (!currentTeam) return

    let number: number | undefined
    let pos: string | undefined
    let playerName = ''
    let dob: string | undefined

    $el.find('td, th[scope="row"]').each((i, td) => {
      const $td = $(td)
      const text = $td.text().trim()
      if ($td.is('th[scope="row"]')) {
        playerName = $td.find('a').first().text().trim() || text
      } else if (i === 0 && !playerName) {
        const n = parseInt(text); if (!isNaN(n)) number = n
      } else if (i === 1 && !playerName && !pos) {
        const p = $td.find('a').first().text().trim()
        if (['GK', 'DF', 'MF', 'FW'].includes(p)) pos = p
      }
      const $bday = $td.find('.bday')
      if ($bday.length) dob = $bday.text().trim()
    })

    if (!playerName) return
    const player: Player = { name: playerName }
    if (number !== undefined) player.number = number
    if (pos) player.pos = pos
    if (dob) player.date_of_birth = dob
    currentTeam.players.push(player)
  })

  return squads.filter(s => s.players.length > 0)
}