import ReactDOM from 'react-dom'
import { useState, useEffect, useRef, useMemo, useCallback } from 'react'
import DOM from 'react-dom'
import { useTripStore } from '../../store/tripStore'
import { useCanDo } from '../../store/permissionsStore'
import { useTranslation } from '../../i18n'
import { Plus, Trash2, Calculator, Wallet, Pencil, Users, Check, Info, ChevronDown, ChevronRight, Download } from 'lucide-react'
import CustomSelect from '../shared/CustomSelect'
import { budgetApi } from '../../api/client'
import { CustomDatePicker } from '../shared/CustomDateTimePicker'
import type { BudgetItem, BudgetMember } from '../../types'
import { currencyDecimals } from '../../utils/formatters'

interface TripMember {
  id: number
  username: string
  avatar_url?: string | null
}

interface PieSegment {
  label: string
  value: number
  color: string
}

interface PerPersonSummaryEntry {
  user_id: number
  username: string
  avatar_url: string | null
  total_assigned: number
}

// ── Helpers ──────────────────────────────────────────────────────────────────
const CURRENCIES = [
  'EUR', 'USD', 'GBP', 'JPY', 'CHF', 'CZK', 'PLN', 'SEK', 'NOK', 'DKK',
  'TRY', 'THB', 'AUD', 'CAD', 'NZD', 'BRL', 'MXN', 'INR', 'IDR', 'MYR',
  'PHP', 'SGD', 'KRW', 'CNY', 'HKD', 'TWD', 'ZAR', 'AED', 'SAR', 'ILS',
  'EGP', 'MAD', 'HUF', 'RON', 'BGN', 'HRK', 'ISK', 'RUB', 'UAH', 'BDT',
  'LKR', 'VND', 'CLP', 'COP', 'PEN', 'ARS',
]
const SYMBOLS = {
  EUR: '€', USD: '$', GBP: '£', JPY: '¥', CHF: 'CHF', CZK: 'Kč', PLN: 'zł',
  SEK: 'kr', NOK: 'kr', DKK: 'kr', TRY: '₺', THB: '฿', AUD: 'A$', CAD: 'C$',
  NZD: 'NZ$', BRL: 'R$', MXN: 'MX$', INR: '₹', IDR: 'Rp', MYR: 'RM',
  PHP: '₱', SGD: 'S$', KRW: '₩', CNY: '¥', HKD: 'HK$', TWD: 'NT$',
  ZAR: 'R', AED: 'د.إ', SAR: '﷼', ILS: '₪', EGP: 'E£', MAD: 'MAD',
  HUF: 'Ft', RON: 'lei', BGN: 'лв', HRK: 'kn', ISK: 'kr', RUB: '₽',
  UAH: '₴', BDT: '৳', LKR: 'Rs', VND: '₫', CLP: 'CL$', COP: 'CO$',
  PEN: 'S/.', ARS: 'AR$',
}
const PIE_COLORS = ['#6366f1', '#ec4899', '#f59e0b', '#10b981', '#3b82f6', '#8b5cf6', '#ef4444', '#14b8a6', '#f97316', '#06b6d4', '#84cc16', '#a855f7']

const fmtNum = (v, locale, cur) => {
  if (v == null || isNaN(v)) return '-'
  const d = currencyDecimals(cur)
  return Number(v).toLocaleString(locale, { minimumFractionDigits: d, maximumFractionDigits: d }) + ' ' + (SYMBOLS[cur] || cur)
}

const calcPP = (p, n) => (n > 0 ? p / n : null)
const calcPD = (p, d) => (d > 0 ? p / d : null)
const calcPPD = (p, n, d) => (n > 0 && d > 0 ? p / (n * d) : null)

// ── Inline Edit Cell ─────────────────────────────────────────────────────────
function InlineEditCell({ value, onSave, type = 'text', style = {}, placeholder = '', decimals = 2, locale, editTooltip, readOnly = false }) {
  const [editing, setEditing] = useState(false)
  const [editValue, setEditValue] = useState(value ?? '')
  const inputRef = useRef(null)

  useEffect(() => { if (editing && inputRef.current) { inputRef.current.focus(); inputRef.current.select() } }, [editing])

  const save = () => {
    setEditing(false)
    let v = editValue
    if (type === 'number') { const p = parseFloat(String(editValue).replace(',', '.')); v = isNaN(p) ? null : p }
    if (v !== value) onSave(v)
  }

  if (editing) {
    return <input ref={inputRef} type="text" inputMode={type === 'number' ? 'decimal' : 'text'} value={editValue}
      onChange={e => setEditValue(e.target.value)} onBlur={save}
      onKeyDown={e => { if (e.key === 'Enter') save(); if (e.key === 'Escape') { setEditValue(value ?? ''); setEditing(false) } }}
      style={{ width: '100%', border: '1px solid var(--accent)', borderRadius: 4, padding: '4px 6px', fontSize: 13, outline: 'none', background: 'var(--bg-input)', color: 'var(--text-primary)', fontFamily: 'inherit', ...style }}
      placeholder={placeholder} />
  }

  const display = type === 'number' && value != null
    ? Number(value).toLocaleString(locale, { minimumFractionDigits: decimals, maximumFractionDigits: decimals })
    : (value || '')

  return (
    <div onClick={() => { if (readOnly) return; setEditValue(value ?? ''); setEditing(true) }} title={readOnly ? undefined : editTooltip}
      style={{ cursor: readOnly ? 'default' : 'pointer', padding: '2px 4px', borderRadius: 4, minHeight: 22, display: 'flex', alignItems: 'center',
        justifyContent: style?.textAlign === 'center' ? 'center' : 'flex-start', transition: 'background 0.15s',
        color: display ? 'var(--text-primary)' : 'var(--text-faint)', fontSize: 13, ...style }}
      onMouseEnter={e => { if (!readOnly) e.currentTarget.style.background = 'var(--bg-hover)' }}
      onMouseLeave={e => { if (!readOnly) e.currentTarget.style.background = 'transparent' }}>
      {display || placeholder || '-'}
    </div>
  )
}

// ── Add Item Row ─────────────────────────────────────────────────────────────
interface AddItemRowProps {
  onAdd: (data: { name: string; total_price: number; persons: number | null; days: number | null; note: string | null; expense_date: string | null }) => void
  t: (key: string) => string
}

function AddItemRow({ onAdd, t }: AddItemRowProps) {
  const [name, setName] = useState('')
  const [price, setPrice] = useState('')
  const [persons, setPersons] = useState('')
  const [days, setDays] = useState('')
  const [note, setNote] = useState('')
  const [expenseDate, setExpenseDate] = useState('')
  const nameRef = useRef(null)

  const handleAdd = () => {
    if (!name.trim()) return
    onAdd({ name: name.trim(), total_price: parseFloat(String(price).replace(',', '.')) || 0, persons: parseInt(persons) || null, days: parseInt(days) || null, note: note.trim() || null, expense_date: expenseDate || null })
    setName(''); setPrice(''); setPersons(''); setDays(''); setNote(''); setExpenseDate('')
    setTimeout(() => nameRef.current?.focus(), 50)
  }

  const inp = { border: '1px solid var(--border-primary)', borderRadius: 4, padding: '4px 6px', fontSize: 13, outline: 'none', fontFamily: 'inherit', width: '100%', background: 'var(--bg-input)', color: 'var(--text-primary)' }

  return (
    <tr style={{ background: 'var(--bg-secondary)' }}>
      <td style={{ padding: '4px 6px' }}>
        <input ref={nameRef} value={name} onChange={e => setName(e.target.value)} onKeyDown={e => e.key === 'Enter' && handleAdd()}
          placeholder={t('budget.newEntry')} style={inp} />
      </td>
      <td style={{ padding: '4px 6px' }}>
        <input value={price} onChange={e => setPrice(e.target.value)} onKeyDown={e => e.key === 'Enter' && handleAdd()}
          placeholder="0,00" inputMode="decimal" style={{ ...inp, textAlign: 'center' }} />
      </td>
      <td className="hidden sm:table-cell" style={{ padding: '4px 6px', textAlign: 'center' }}>
        <input value={persons} onChange={e => setPersons(e.target.value)} onKeyDown={e => e.key === 'Enter' && handleAdd()}
          placeholder="-" inputMode="numeric" style={{ ...inp, textAlign: 'center', maxWidth: 60, margin: '0 auto' }} />
      </td>
      <td className="hidden sm:table-cell" style={{ padding: '4px 6px', textAlign: 'center' }}>
        <input value={days} onChange={e => setDays(e.target.value)} onKeyDown={e => e.key === 'Enter' && handleAdd()}
          placeholder="-" inputMode="numeric" style={{ ...inp, textAlign: 'center', maxWidth: 60, margin: '0 auto' }} />
      </td>
      <td className="hidden md:table-cell" style={{ padding: '4px 6px', color: 'var(--text-faint)', fontSize: 12, textAlign: 'center' }}>-</td>
      <td className="hidden md:table-cell" style={{ padding: '4px 6px', color: 'var(--text-faint)', fontSize: 12, textAlign: 'center' }}>-</td>
      <td className="hidden lg:table-cell" style={{ padding: '4px 6px', color: 'var(--text-faint)', fontSize: 12, textAlign: 'center' }}>-</td>
      <td className="hidden sm:table-cell" style={{ padding: '4px 6px', textAlign: 'center' }}>
        <div style={{ maxWidth: 90, margin: '0 auto' }}>
          <CustomDatePicker value={expenseDate} onChange={setExpenseDate} placeholder="-" compact />
        </div>
      </td>
      <td className="hidden sm:table-cell" style={{ padding: '4px 6px' }}>
        <input value={note} onChange={e => setNote(e.target.value)} onKeyDown={e => e.key === 'Enter' && handleAdd()} placeholder={t('budget.table.note')} style={inp} />
      </td>
      <td style={{ padding: '4px 6px', textAlign: 'center' }}>
        <button onClick={handleAdd} disabled={!name.trim()} title={t('reservations.add')}
          style={{ background: name.trim() ? 'var(--text-primary)' : 'var(--border-primary)', border: 'none', borderRadius: 4, color: 'var(--bg-primary)',
            cursor: name.trim() ? 'pointer' : 'default', padding: '4px 8px', display: 'inline-flex', alignItems: 'center' }}>
          <Plus size={14} />
        </button>
      </td>
    </tr>
  )
}

// ── Chip with custom tooltip ─────────────────────────────────────────────────
interface ChipWithTooltipProps {
  label: string
  avatarUrl: string | null
  size?: number
  paid?: boolean
  onClick?: () => void
}

function ChipWithTooltip({ label, avatarUrl, size = 20, paid, onClick }: ChipWithTooltipProps) {
  const [hover, setHover] = useState(false)
  const [pos, setPos] = useState({ top: 0, left: 0 })
  const ref = useRef(null)

  const onEnter = () => {
    if (ref.current) {
      const rect = ref.current.getBoundingClientRect()
      setPos({ top: rect.top - 6, left: rect.left + rect.width / 2 })
    }
    setHover(true)
  }

  const borderColor = paid ? '#22c55e' : 'var(--border-primary)'
  const bg = paid ? 'rgba(34,197,94,0.15)' : 'var(--bg-tertiary)'

  return (
    <>
      <div ref={ref} onMouseEnter={onEnter} onMouseLeave={() => setHover(false)}
        onClick={onClick}
        style={{
          width: size, height: size, borderRadius: '50%', border: `2px solid ${borderColor}`,
          background: bg, display: 'flex', alignItems: 'center', justifyContent: 'center',
          fontSize: size * 0.4, fontWeight: 700, color: paid ? '#16a34a' : 'var(--text-muted)',
          overflow: 'hidden', flexShrink: 0, cursor: onClick ? 'pointer' : 'default',
          transition: 'border-color 0.15s, background 0.15s',
        }}>
        {avatarUrl
          ? <img src={avatarUrl} style={{ width: '100%', height: '100%', objectFit: 'cover' }} />
          : label?.[0]?.toUpperCase()
        }
      </div>
      {hover && ReactDOM.createPortal(
        <div style={{
          position: 'fixed', top: pos.top, left: pos.left, transform: 'translate(-50%, -100%)',
          pointerEvents: 'none', zIndex: 10000, whiteSpace: 'nowrap',
          display: 'flex', alignItems: 'center', gap: 5,
          background: 'var(--bg-card, white)', color: 'var(--text-primary, #111827)',
          fontSize: 11, fontWeight: 500, padding: '5px 10px', borderRadius: 8,
          boxShadow: '0 4px 12px rgba(0,0,0,0.15)', border: '1px solid var(--border-faint, #e5e7eb)',
        }}>
          {label}
          {paid && (
            <span style={{
              fontSize: 9, fontWeight: 700, padding: '1px 5px', borderRadius: 4,
              background: 'rgba(34,197,94,0.15)', color: '#16a34a',
              textTransform: 'uppercase', letterSpacing: '0.03em',
            }}>Paid</span>
          )}
        </div>,
        document.body
      )}
    </>
  )
}

// ── Budget Member Chips (for Persons column) ────────────────────────────────
interface BudgetMemberChipsProps {
  members?: BudgetMember[]
  tripMembers?: TripMember[]
  onSetMembers: (memberIds: number[]) => void
  onTogglePaid?: (userId: number, paid: boolean) => void
  compact?: boolean
  readOnly?: boolean
}

function BudgetMemberChips({ members = [], tripMembers = [], onSetMembers, onTogglePaid, compact = true, readOnly = false }: BudgetMemberChipsProps) {
  const chipSize = compact ? 20 : 30
  const btnSize = compact ? 18 : 28
  const iconSize = compact ? (members.length > 0 ? 8 : 9) : (members.length > 0 ? 12 : 14)
  const [showDropdown, setShowDropdown] = useState(false)
  const [dropPos, setDropPos] = useState({ top: 0, left: 0 })
  const btnRef = useRef(null)
  const dropRef = useRef(null)

  const openDropdown = useCallback(() => {
    if (btnRef.current) {
      const rect = btnRef.current.getBoundingClientRect()
      setDropPos({ top: rect.bottom + 4, left: rect.left + rect.width / 2 })
    }
    setShowDropdown(v => !v)
  }, [])

  useEffect(() => {
    if (!showDropdown) return
    const close = (e) => {
      if (dropRef.current && dropRef.current.contains(e.target)) return
      if (btnRef.current && btnRef.current.contains(e.target)) return
      setShowDropdown(false)
    }
    document.addEventListener('mousedown', close)
    return () => document.removeEventListener('mousedown', close)
  }, [showDropdown])

  const memberIds = members.map(m => m.user_id)

  const toggleMember = (userId) => {
    const newIds = memberIds.includes(userId)
      ? memberIds.filter(id => id !== userId)
      : [...memberIds, userId]
    onSetMembers(newIds)
  }

  return (
    <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'center', gap: 2, flexWrap: 'wrap' }}>
      {members.map(m => (
        <ChipWithTooltip key={m.user_id} label={m.username} avatarUrl={m.avatar_url} size={chipSize}
          paid={!!m.paid}
          onClick={!readOnly && onTogglePaid ? () => onTogglePaid(m.user_id, !m.paid) : undefined}
        />
      ))}
      {!readOnly && (
        <button ref={btnRef} onClick={openDropdown}
          style={{
            width: btnSize, height: btnSize, borderRadius: '50%', border: '1.5px dashed var(--border-primary)',
            background: 'none', cursor: 'pointer', display: 'flex', alignItems: 'center', justifyContent: 'center',
            color: 'var(--text-faint)', padding: 0, flexShrink: 0,
          }}>
          {members.length > 0 ? <Pencil size={iconSize} /> : <Users size={iconSize} />}
        </button>
      )}
      {showDropdown && ReactDOM.createPortal(
        <div ref={dropRef} style={{
          position: 'fixed', top: dropPos.top, left: dropPos.left, transform: 'translateX(-50%)', zIndex: 10000,
          background: 'var(--bg-card)', border: '1px solid var(--border-primary)', borderRadius: 10,
          boxShadow: '0 4px 16px rgba(0,0,0,0.12)', padding: 4, minWidth: 150,
        }}>
          {tripMembers.map(tm => {
            const isActive = memberIds.includes(tm.id)
            return (
              <button key={tm.id} onClick={() => toggleMember(tm.id)} style={{
                display: 'flex', alignItems: 'center', gap: 6, width: '100%', padding: '5px 8px',
                borderRadius: 6, border: 'none', background: isActive ? 'var(--bg-hover)' : 'none', cursor: 'pointer',
                fontFamily: 'inherit', fontSize: 11, color: 'var(--text-primary)', textAlign: 'left',
              }}
                onMouseEnter={e => { if (!isActive) e.currentTarget.style.background = 'var(--bg-hover)' }}
                onMouseLeave={e => { if (!isActive) e.currentTarget.style.background = 'none' }}
              >
                <div style={{
                  width: 18, height: 18, borderRadius: '50%', background: 'var(--bg-tertiary)',
                  display: 'flex', alignItems: 'center', justifyContent: 'center', fontSize: 8, fontWeight: 700,
                  color: 'var(--text-muted)', overflow: 'hidden', flexShrink: 0,
                }}>
                  {tm.avatar_url
                    ? <img src={tm.avatar_url} style={{ width: '100%', height: '100%', objectFit: 'cover' }} />
                    : tm.username?.[0]?.toUpperCase()
                  }
                </div>
                <span style={{ flex: 1 }}>{tm.username}</span>
                {isActive && <Check size={12} color="var(--text-primary)" />}
              </button>
            )
          })}
        </div>,
        document.body
      )}
    </div>
  )
}

// ── Per-Person Inline (inside total card) ────────────────────────────────────
interface PerPersonInlineProps {
  tripId: number
  budgetItems: BudgetItem[]
  currency: string
  locale: string
}

function PerPersonInline({ tripId, budgetItems, currency, locale }: PerPersonInlineProps) {
  const [data, setData] = useState(null)
  const fmt = (v) => fmtNum(v, locale, currency)

  useEffect(() => {
    budgetApi.perPersonSummary(tripId).then(d => setData(d.summary)).catch(() => {})
  }, [tripId, budgetItems])

  if (!data || data.length === 0) return null

  return (
    <div style={{ marginTop: 16, borderTop: '1px solid rgba(255,255,255,0.1)', paddingTop: 14, display: 'flex', flexDirection: 'column', gap: 8 }}>
      {data.map(person => (
        <div key={person.user_id} style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
          <div style={{
            width: 22, height: 22, borderRadius: '50%', background: 'rgba(255,255,255,0.1)',
            display: 'flex', alignItems: 'center', justifyContent: 'center', fontSize: 9, fontWeight: 700,
            color: 'rgba(255,255,255,0.7)', overflow: 'hidden', flexShrink: 0,
          }}>
            {person.avatar_url
              ? <img src={person.avatar_url} style={{ width: '100%', height: '100%', objectFit: 'cover' }} />
              : person.username?.[0]?.toUpperCase()
            }
          </div>
          <span style={{ flex: 1, fontSize: 12, fontWeight: 500, color: 'rgba(255,255,255,0.7)' }}>{person.username}</span>
          <span style={{ fontSize: 12, fontWeight: 600, color: '#fff' }}>{fmt(person.total_assigned)}</span>
        </div>
      ))}
    </div>
  )
}

// ── Pie Chart (pure CSS conic-gradient) ──────────────────────────────────────
interface PieChartProps {
  segments: PieSegment[]
  size?: number
  totalLabel: string
}

function PieChart({ segments, size = 200, totalLabel }: PieChartProps) {
  if (!segments.length) return null

  const total = segments.reduce((s, x) => s + x.value, 0)
  if (total === 0) return null

  let cumDeg = 0
  const stops = segments.map(seg => {
    const start = cumDeg
    const deg = (seg.value / total) * 360
    cumDeg += deg
    return `${seg.color} ${start}deg ${start + deg}deg`
  }).join(', ')

  return (
    <div style={{ position: 'relative', width: size, height: size, margin: '0 auto' }}>
      <div style={{
        width: size, height: size, borderRadius: '50%',
        background: `conic-gradient(${stops})`,
        boxShadow: '0 4px 24px rgba(0,0,0,0.08)',
      }} />
      <div style={{
        position: 'absolute', top: '50%', left: '50%',
        transform: 'translate(-50%, -50%)',
        width: size * 0.55, height: size * 0.55,
        borderRadius: '50%', background: 'var(--bg-card)',
        display: 'flex', flexDirection: 'column', alignItems: 'center', justifyContent: 'center',
        boxShadow: 'inset 0 0 12px rgba(0,0,0,0.04)',
      }}>
        <Wallet size={18} color="var(--text-faint)" style={{ marginBottom: 2 }} />
        <span style={{ fontSize: 10, color: 'var(--text-faint)', fontWeight: 500 }}>{totalLabel}</span>
      </div>
    </div>
  )
}

// ── Main Component ───────────────────────────────────────────────────────────
interface BudgetPanelProps {
  tripId: number
  tripMembers?: TripMember[]
}

export default function BudgetPanel({ tripId, tripMembers = [] }: BudgetPanelProps) {
  const { trip, budgetItems, addBudgetItem, updateBudgetItem, deleteBudgetItem, loadBudgetItems, updateTrip, setBudgetItemMembers, toggleBudgetMemberPaid } = useTripStore()
  const can = useCanDo()
  const { t, locale } = useTranslation()
  const [newCategoryName, setNewCategoryName] = useState('')
  const [editingCat, setEditingCat] = useState(null) // { name, value }
  const [settlement, setSettlement] = useState<{ balances: any[]; flows: any[] } | null>(null)
  const [settlementOpen, setSettlementOpen] = useState(false)
  const currency = trip?.currency || 'EUR'
  const canEdit = can('budget_edit', trip)

  const fmt = (v, cur) => fmtNum(v, locale, cur)
  const hasMultipleMembers = tripMembers.length > 1

  // Load settlement data whenever budget items change
  useEffect(() => {
    if (!hasMultipleMembers) return
    budgetApi.settlement(tripId).then(setSettlement).catch(() => {})
  }, [tripId, budgetItems, hasMultipleMembers])

  const setCurrency = (cur) => {
    if (tripId) updateTrip(tripId, { currency: cur })
  }

  useEffect(() => { if (tripId) loadBudgetItems(tripId) }, [tripId])

  const grouped = useMemo(() => (budgetItems || []).reduce((acc, item) => {
    const cat = item.category || 'Other'
    if (!acc[cat]) acc[cat] = []
    acc[cat].push(item)
    return acc
  }, {}), [budgetItems])

  const categoryNames = Object.keys(grouped)
  const grandTotal = (budgetItems || []).reduce((s, i) => s + (i.total_price || 0), 0)

  const pieSegments = useMemo(() =>
    categoryNames.map((cat, i) => ({
      name: cat,
      value: grouped[cat].reduce((s, x) => s + (x.total_price || 0), 0),
      color: PIE_COLORS[i % PIE_COLORS.length],
    })).filter(s => s.value > 0)
  , [grouped, categoryNames])

  const handleAddItem = async (category, data) => { try { await addBudgetItem(tripId, { ...data, category }) } catch {} }
  const handleUpdateField = async (id, field, value) => { try { await updateBudgetItem(tripId, id, { [field]: value }) } catch {} }
  const handleDeleteItem = async (id) => { try { await deleteBudgetItem(tripId, id) } catch {} }
  const handleDeleteCategory = async (cat) => {
    const items = grouped[cat] || []
    for (const item of Array.from(items)) await deleteBudgetItem(tripId, item.id)
  }
  const handleRenameCategory = async (oldName, newName) => {
    if (!newName.trim() || newName.trim() === oldName) return
    const items = grouped[oldName] || []
    for (const item of Array.from(items)) await updateBudgetItem(tripId, item.id, { category: newName.trim() })
  }
  const handleAddCategory = () => {
    if (!newCategoryName.trim()) return
    addBudgetItem(tripId, { name: t('budget.defaultEntry'), category: newCategoryName.trim(), total_price: 0 })
    setNewCategoryName('')
  }

  const handleExportCsv = () => {
    const sep = ';'
    const esc = (v: any) => { const s = String(v ?? ''); return s.includes(sep) || s.includes('"') || s.includes('\n') ? '"' + s.replace(/"/g, '""') + '"' : s }
    const d = currencyDecimals(currency)
    const fmtPrice = (v: number | null | undefined) => v != null ? v.toFixed(d) : ''

    const fmtDate = (iso: string) => { if (!iso) return ''; const d = new Date(iso + 'T00:00:00Z'); return d.toLocaleDateString(locale, { day: '2-digit', month: '2-digit', year: 'numeric', timeZone: 'UTC' }) }
    const header = ['Category', 'Name', 'Date', 'Total (' + currency + ')', 'Persons', 'Days', 'Per Person', 'Per Day', 'Per Person/Day', 'Note']
    const rows = [header.join(sep)]

    for (const cat of categoryNames) {
      for (const item of (grouped[cat] || [])) {
        const pp = calcPP(item.total_price, item.persons)
        const pd = calcPD(item.total_price, item.days)
        const ppd = calcPPD(item.total_price, item.persons, item.days)
        rows.push([
          esc(item.category), esc(item.name), esc(fmtDate(item.expense_date || '')),
          fmtPrice(item.total_price), item.persons ?? '', item.days ?? '',
          fmtPrice(pp), fmtPrice(pd), fmtPrice(ppd),
          esc(item.note || ''),
        ].join(sep))
      }
    }

    const bom = '\uFEFF'
    const blob = new Blob([bom + rows.join('\r\n')], { type: 'text/csv;charset=utf-8;' })
    const url = URL.createObjectURL(blob)
    const a = document.createElement('a')
    a.href = url
    const safeName = (trip?.title || 'trip').replace(/[^a-zA-Z0-9\u00C0-\u024F _-]/g, '').trim()
    a.download = `budget-${safeName}.csv`
    a.click()
    URL.revokeObjectURL(url)
  }

  const th = { padding: '6px 8px', textAlign: 'center', fontSize: 11, fontWeight: 600, color: 'var(--text-muted)', textTransform: 'uppercase', letterSpacing: '0.05em', borderBottom: '2px solid var(--border-primary)', whiteSpace: 'nowrap', background: 'var(--bg-secondary)' }
  const td = { padding: '2px 6px', borderBottom: '1px solid var(--border-secondary)', fontSize: 13, verticalAlign: 'middle', color: 'var(--text-primary)' }

  // ── Empty State ──────────────────────────────────────────────────────────
  if (!budgetItems || budgetItems.length === 0) {
    return (
      <div style={{ padding: 24, maxWidth: 600, margin: '60px auto', textAlign: 'center' }}>
        <div style={{ width: 64, height: 64, borderRadius: 16, background: 'var(--bg-tertiary)', display: 'flex', alignItems: 'center', justifyContent: 'center', margin: '0 auto 20px' }}>
          <Calculator size={28} color="#6b7280" />
        </div>
        <h2 style={{ fontSize: 20, fontWeight: 700, color: 'var(--text-primary)', margin: '0 0 8px' }}>{t('budget.emptyTitle')}</h2>
        <p style={{ fontSize: 14, color: 'var(--text-muted)', margin: '0 0 24px', lineHeight: 1.5 }}>{t('budget.emptyText')}</p>
        {canEdit && (
          <div style={{ display: 'flex', gap: 6, justifyContent: 'center', alignItems: 'stretch', maxWidth: 320, margin: '0 auto' }}>
            <input value={newCategoryName} onChange={e => setNewCategoryName(e.target.value)}
              onKeyDown={e => e.key === 'Enter' && handleAddCategory()}
              placeholder={t('budget.emptyPlaceholder')}
              style={{ flex: 1, padding: '9px 14px', borderRadius: 10, border: '1px solid var(--border-primary)', fontSize: 13, fontFamily: 'inherit', outline: 'none', background: 'var(--bg-input)', color: 'var(--text-primary)', minWidth: 0 }} />
            <button onClick={handleAddCategory} disabled={!newCategoryName.trim()}
              style={{ background: 'var(--accent)', color: 'var(--accent-text)', border: 'none', borderRadius: 10, padding: '0 12px', cursor: 'pointer', display: 'flex', alignItems: 'center', opacity: newCategoryName.trim() ? 1 : 0.5, flexShrink: 0 }}>
              <Plus size={16} />
            </button>
          </div>
        )}
      </div>
    )
  }

  // ── Main Layout ──────────────────────────────────────────────────────────
  return (
    <div style={{ fontFamily: "'Poppins', -apple-system, BlinkMacSystemFont, system-ui, sans-serif" }}>
      <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', padding: '16px 16px 12px', flexWrap: 'wrap', gap: 8 }}>
        <div style={{ display: 'flex', alignItems: 'center', gap: 10 }}>
          <Calculator size={20} color="var(--text-primary)" />
          <h2 style={{ fontSize: 18, fontWeight: 700, color: 'var(--text-primary)', margin: 0 }}>{t('budget.title')}</h2>
        </div>
        <button onClick={handleExportCsv} title={t('budget.exportCsv')}
          style={{ display: 'flex', alignItems: 'center', gap: 6, padding: '6px 12px', borderRadius: 8, border: '1px solid var(--border-primary)', background: 'none', color: 'var(--text-muted)', fontSize: 12, fontWeight: 500, cursor: 'pointer', fontFamily: 'inherit' }}>
          <Download size={13} /> CSV
        </button>
      </div>

      <div style={{ display: 'flex', gap: 20, padding: '0 16px 40px', alignItems: 'flex-start', flexWrap: 'wrap' }}>
        <div style={{ flex: 1, minWidth: 0 }}>
          {categoryNames.map((cat, ci) => {
            const items = grouped[cat]
            const subtotal = items.reduce((s, x) => s + (x.total_price || 0), 0)
            const color = PIE_COLORS[ci % PIE_COLORS.length]

            return (
              <div key={cat} style={{ marginBottom: 16 }}>
                <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', background: '#000000', color: '#fff', borderRadius: '10px 10px 0 0', padding: '9px 14px' }}>
                  <div style={{ display: 'flex', alignItems: 'center', gap: 8, flex: 1, minWidth: 0 }}>
                    <div style={{ width: 10, height: 10, borderRadius: 3, background: color, flexShrink: 0 }} />
                    {canEdit && editingCat?.name === cat ? (
                      <input
                        autoFocus
                        value={editingCat.value}
                        onChange={e => setEditingCat({ ...editingCat, value: e.target.value })}
                        onBlur={() => { handleRenameCategory(cat, editingCat.value); setEditingCat(null) }}
                        onKeyDown={e => { if (e.key === 'Enter') { handleRenameCategory(cat, editingCat.value); setEditingCat(null) } if (e.key === 'Escape') setEditingCat(null) }}
                        style={{ fontWeight: 600, fontSize: 13, background: 'rgba(255,255,255,0.15)', border: 'none', borderRadius: 4, color: '#fff', padding: '1px 6px', outline: 'none', fontFamily: 'inherit', width: '100%' }}
                      />
                    ) : (
                      <>
                        <span style={{ fontWeight: 600, fontSize: 13 }}>{cat}</span>
                        {canEdit && (
                          <button onClick={() => setEditingCat({ name: cat, value: cat })}
                            style={{ background: 'none', border: 'none', cursor: 'pointer', color: 'rgba(255,255,255,0.4)', display: 'flex', padding: 1 }}
                            onMouseEnter={e => e.currentTarget.style.color = '#fff'} onMouseLeave={e => e.currentTarget.style.color = 'rgba(255,255,255,0.4)'}>
                            <Pencil size={10} />
                          </button>
                        )}
                      </>
                    )}
                  </div>
                  <div style={{ display: 'flex', alignItems: 'center', gap: 10 }}>
                    <span style={{ fontSize: 13, fontWeight: 500, opacity: 0.9 }}>{fmt(subtotal, currency)}</span>
                    {canEdit && (
                      <button onClick={() => handleDeleteCategory(cat)} title={t('budget.deleteCategory')}
                        style={{ background: 'rgba(255,255,255,0.1)', border: 'none', borderRadius: 4, color: '#fff', cursor: 'pointer', padding: '3px 6px', display: 'flex', alignItems: 'center', opacity: 0.6 }}
                        onMouseEnter={e => e.currentTarget.style.opacity = '1'} onMouseLeave={e => e.currentTarget.style.opacity = '0.6'}>
                        <Trash2 size={13} />
                      </button>
                    )}
                  </div>
                </div>

                <div style={{ overflowX: 'auto', border: '1px solid var(--border-primary)', borderTop: 'none', borderRadius: '0 0 10px 10px' }}>
                  <table style={{ width: '100%', borderCollapse: 'collapse' }}>
                    <thead>
                      <tr>
                        <th style={{ ...th, textAlign: 'left', minWidth: 120 }}>{t('budget.table.name')}</th>
                        <th style={{ ...th, minWidth: 75 }}>{t('budget.table.total')}</th>
                        <th className="hidden sm:table-cell" style={{ ...th, minWidth: 160 }}>{t('budget.table.persons')}</th>
                        <th className="hidden sm:table-cell" style={{ ...th, minWidth: 55 }}>{t('budget.table.days')}</th>
                        <th className="hidden md:table-cell" style={{ ...th, minWidth: 100 }}>{t('budget.table.perPerson')}</th>
                        <th className="hidden md:table-cell" style={{ ...th, minWidth: 90 }}>{t('budget.table.perDay')}</th>
                        <th className="hidden lg:table-cell" style={{ ...th, minWidth: 95 }}>{t('budget.table.perPersonDay')}</th>
                        <th className="hidden sm:table-cell" style={{ ...th, width: 90, maxWidth: 90 }}>{t('budget.table.date')}</th>
                        <th className="hidden sm:table-cell" style={{ ...th, minWidth: 150 }}>{t('budget.table.note')}</th>
                        <th style={{ ...th, width: 36 }}></th>
                      </tr>
                    </thead>
                    <tbody>
                      {items.map(item => {
                        const pp = calcPP(item.total_price, item.persons)
                        const pd = calcPD(item.total_price, item.days)
                        const ppd = calcPPD(item.total_price, item.persons, item.days)
                        const hasMembers = item.members?.length > 0
                        return (
                          <tr key={item.id} style={{ transition: 'background 0.1s' }}
                            onMouseEnter={e => e.currentTarget.style.background = 'var(--bg-hover)'}
                            onMouseLeave={e => e.currentTarget.style.background = 'transparent'}>
                            <td style={td}>
                              <InlineEditCell value={item.name} onSave={v => handleUpdateField(item.id, 'name', v)} placeholder={t('budget.table.name')} locale={locale} editTooltip={t('budget.editTooltip')} readOnly={!canEdit} />
                              {/* Mobile: larger chips under name since Persons column is hidden */}
                              {hasMultipleMembers && (
                                <div className="sm:hidden" style={{ marginTop: 4 }}>
                                  <BudgetMemberChips
                                    members={item.members || []}
                                    tripMembers={tripMembers}
                                    onSetMembers={(userIds) => setBudgetItemMembers(tripId, item.id, userIds)}
                                    onTogglePaid={(userId, paid) => toggleBudgetMemberPaid(tripId, item.id, userId, paid)}
                                    compact={false}
                                    readOnly={!canEdit}
                                  />
                                </div>
                              )}
                            </td>
                            <td style={{ ...td, textAlign: 'center' }}>
                              <InlineEditCell value={item.total_price} type="number" decimals={currencyDecimals(currency)} onSave={v => handleUpdateField(item.id, 'total_price', v)} style={{ textAlign: 'center' }} placeholder={currencyDecimals(currency) === 0 ? '0' : '0,00'} locale={locale} editTooltip={t('budget.editTooltip')} readOnly={!canEdit} />
                            </td>
                            <td className="hidden sm:table-cell" style={{ ...td, textAlign: 'center', position: 'relative' }}>
                              {hasMultipleMembers ? (
                                <BudgetMemberChips
                                  members={item.members || []}
                                  tripMembers={tripMembers}
                                  onSetMembers={(userIds) => setBudgetItemMembers(tripId, item.id, userIds)}
                                  onTogglePaid={(userId, paid) => toggleBudgetMemberPaid(tripId, item.id, userId, paid)}
                                  readOnly={!canEdit}
                                />
                              ) : (
                                <InlineEditCell value={item.persons} type="number" decimals={0} onSave={v => handleUpdateField(item.id, 'persons', v != null ? parseInt(v) || null : null)} style={{ textAlign: 'center' }} placeholder="-" locale={locale} editTooltip={t('budget.editTooltip')} readOnly={!canEdit} />
                              )}
                            </td>
                            <td className="hidden sm:table-cell" style={{ ...td, textAlign: 'center' }}>
                              <InlineEditCell value={item.days} type="number" decimals={0} onSave={v => handleUpdateField(item.id, 'days', v != null ? parseInt(v) || null : null)} style={{ textAlign: 'center' }} placeholder="-" locale={locale} editTooltip={t('budget.editTooltip')} readOnly={!canEdit} />
                            </td>
                            <td className="hidden md:table-cell" style={{ ...td, textAlign: 'center', color: pp != null ? 'var(--text-secondary)' : 'var(--text-faint)' }}>{pp != null ? fmt(pp, currency) : '-'}</td>
                            <td className="hidden md:table-cell" style={{ ...td, textAlign: 'center', color: pd != null ? 'var(--text-secondary)' : 'var(--text-faint)' }}>{pd != null ? fmt(pd, currency) : '-'}</td>
                            <td className="hidden lg:table-cell" style={{ ...td, textAlign: 'center', color: ppd != null ? 'var(--text-secondary)' : 'var(--text-faint)' }}>{ppd != null ? fmt(ppd, currency) : '-'}</td>
                            <td className="hidden sm:table-cell" style={{ ...td, padding: '2px 6px', width: 90, maxWidth: 90, textAlign: 'center' }}>
                              {canEdit ? (
                                <div style={{ maxWidth: 90, margin: '0 auto' }}>
                                  <CustomDatePicker value={item.expense_date || ''} onChange={v => handleUpdateField(item.id, 'expense_date', v || null)} placeholder="—" compact borderless />
                                </div>
                              ) : (
                                <span style={{ fontSize: 11, color: item.expense_date ? 'var(--text-secondary)' : 'var(--text-faint)' }}>{item.expense_date || '—'}</span>
                              )}
                            </td>
                            <td className="hidden sm:table-cell" style={td}><InlineEditCell value={item.note} onSave={v => handleUpdateField(item.id, 'note', v)} placeholder={t('budget.table.note')} locale={locale} editTooltip={t('budget.editTooltip')} readOnly={!canEdit} /></td>
                            <td style={{ ...td, textAlign: 'center' }}>
                              {canEdit && (
                              <button onClick={() => handleDeleteItem(item.id)} title={t('common.delete')}
                                style={{ background: 'none', border: 'none', cursor: 'pointer', padding: 4, color: 'var(--text-faint)', borderRadius: 4, display: 'inline-flex', transition: 'color 0.15s' }}
                                onMouseEnter={e => e.currentTarget.style.color = '#ef4444'} onMouseLeave={e => e.currentTarget.style.color = '#d1d5db'}>
                                <Trash2 size={14} />
                              </button>
                              )}
                            </td>
                          </tr>
                        )
                      })}
                      {canEdit && <AddItemRow onAdd={data => handleAddItem(cat, data)} t={t} />}
                    </tbody>
                  </table>
                </div>
              </div>
            )
          })}
        </div>

        <div className="w-full md:w-[240px]" style={{ flexShrink: 0, position: 'sticky', top: 16, alignSelf: 'flex-start' }}>
          <div style={{ marginBottom: 12 }}>
            <CustomSelect
              value={currency}
              onChange={setCurrency}
              disabled={!canEdit}
              options={CURRENCIES.map(c => ({ value: c, label: `${c} (${SYMBOLS[c] || c})` }))}
              searchable
            />
          </div>

          {canEdit && (
            <div style={{ display: 'flex', gap: 6, marginBottom: 12 }}>
              <input
                value={newCategoryName}
                onChange={e => setNewCategoryName(e.target.value)}
                onKeyDown={e => { if (e.key === 'Enter') handleAddCategory() }}
                placeholder={t('budget.categoryName')}
                style={{ flex: 1, border: '1px solid var(--border-primary)', borderRadius: 10, padding: '9px 14px', fontSize: 13, outline: 'none', fontFamily: 'inherit', background: 'var(--bg-input)', color: 'var(--text-primary)' }}
              />
              <button onClick={handleAddCategory} disabled={!newCategoryName.trim()}
                style={{ background: 'var(--accent)', color: 'var(--accent-text)', border: 'none', borderRadius: 10, padding: '9px 12px', cursor: 'pointer', display: 'flex', alignItems: 'center', opacity: newCategoryName.trim() ? 1 : 0.4, flexShrink: 0 }}>
                <Plus size={16} />
              </button>
            </div>
          )}

          <div style={{
            background: 'linear-gradient(135deg, #000000 0%, #18181b 100%)',
            borderRadius: 16, padding: '24px 20px', color: '#fff', marginBottom: 16,
            boxShadow: '0 8px 32px rgba(15,23,42,0.18)',
          }}>
            <div style={{ display: 'flex', alignItems: 'center', gap: 8, marginBottom: 16 }}>
              <div style={{ width: 36, height: 36, borderRadius: 10, background: 'rgba(255,255,255,0.1)', display: 'flex', alignItems: 'center', justifyContent: 'center' }}>
                <Wallet size={18} color="rgba(255,255,255,0.8)" />
              </div>
              <div>
                <div style={{ fontSize: 11, color: 'rgba(255,255,255,0.5)', fontWeight: 500, letterSpacing: 0.5 }}>{t('budget.totalBudget')}</div>
              </div>
            </div>
            <div style={{ fontSize: 22, fontWeight: 700, lineHeight: 1, marginBottom: 4 }}>
              {Number(grandTotal).toLocaleString(locale, { minimumFractionDigits: currencyDecimals(currency), maximumFractionDigits: currencyDecimals(currency) })}
            </div>
            <div style={{ fontSize: 14, color: 'rgba(255,255,255,0.5)', fontWeight: 500 }}>{SYMBOLS[currency] || currency} {currency}</div>
            {hasMultipleMembers && (budgetItems || []).some(i => i.members?.length > 0) && (
              <PerPersonInline tripId={tripId} budgetItems={budgetItems} currency={currency} locale={locale} />
            )}

            {/* Settlement dropdown inside the total card */}
            {hasMultipleMembers && settlement && settlement.flows.length > 0 && (
              <div style={{ marginTop: 16, borderTop: '1px solid rgba(255,255,255,0.1)', paddingTop: 12 }}>
                <button onClick={() => setSettlementOpen(v => !v)} style={{
                  display: 'flex', alignItems: 'center', gap: 6, width: '100%',
                  background: 'none', border: 'none', cursor: 'pointer', padding: 0, fontFamily: 'inherit',
                  color: 'rgba(255,255,255,0.6)', fontSize: 11, fontWeight: 600, letterSpacing: 0.5,
                }}>
                  {settlementOpen ? <ChevronDown size={13} /> : <ChevronRight size={13} />}
                  {t('budget.settlement')}
                  <span style={{ position: 'relative', display: 'inline-flex', marginLeft: 2 }}>
                    <span style={{ display: 'flex', cursor: 'help' }}
                      onMouseEnter={e => { const tip = e.currentTarget.nextElementSibling as HTMLElement; if (tip) tip.style.display = 'block' }}
                      onMouseLeave={e => { const tip = e.currentTarget.nextElementSibling as HTMLElement; if (tip) tip.style.display = 'none' }}
                      onClick={e => e.stopPropagation()}
                    >
                      <Info size={11} strokeWidth={2} />
                    </span>
                    <div style={{
                      display: 'none', position: 'absolute', top: '100%', left: '50%', transform: 'translateX(-50%)',
                      marginTop: 6, width: 220, padding: '10px 12px', borderRadius: 10, zIndex: 100,
                      background: 'var(--bg-card)', border: '1px solid var(--border-faint)',
                      boxShadow: '0 4px 16px rgba(0,0,0,0.12)',
                      fontSize: 11, fontWeight: 400, color: 'var(--text-secondary)', lineHeight: 1.5, textAlign: 'left',
                    }}>
                      {t('budget.settlementInfo')}
                    </div>
                  </span>
                </button>

                {settlementOpen && (
                  <div style={{ marginTop: 10, display: 'flex', flexDirection: 'column', gap: 8 }}>
                    {settlement.flows.map((flow, i) => (
                      <div key={i} style={{
                        display: 'flex', alignItems: 'center', justifyContent: 'center', gap: 10,
                        padding: '8px 10px', borderRadius: 10,
                        background: 'rgba(255,255,255,0.06)',
                      }}>
                        <ChipWithTooltip label={flow.from.username} avatarUrl={flow.from.avatar_url} size={28} />
                        <div style={{ display: 'flex', alignItems: 'center', gap: 4 }}>
                          <span style={{ fontSize: 11, color: 'rgba(255,255,255,0.3)' }}>→</span>
                          <span style={{ fontSize: 12, fontWeight: 700, color: '#f87171', whiteSpace: 'nowrap' }}>
                            {fmt(flow.amount, currency)}
                          </span>
                          <span style={{ fontSize: 11, color: 'rgba(255,255,255,0.3)' }}>→</span>
                        </div>
                        <ChipWithTooltip label={flow.to.username} avatarUrl={flow.to.avatar_url} size={28} />
                      </div>
                    ))}

                    {settlement.balances.filter(b => Math.abs(b.balance) > 0.01).length > 0 && (
                      <div style={{ marginTop: 4, borderTop: '1px solid rgba(255,255,255,0.08)', paddingTop: 8 }}>
                        <div style={{ fontSize: 9, fontWeight: 600, color: 'rgba(255,255,255,0.35)', textTransform: 'uppercase', letterSpacing: '0.05em', marginBottom: 6 }}>
                          {t('budget.netBalances')}
                        </div>
                        {settlement.balances.filter(b => Math.abs(b.balance) > 0.01).map(b => (
                          <div key={b.user_id} style={{ display: 'flex', alignItems: 'center', gap: 6, padding: '2px 0' }}>
                            <div style={{
                              width: 20, height: 20, borderRadius: '50%', flexShrink: 0,
                              background: 'rgba(255,255,255,0.1)', display: 'flex', alignItems: 'center', justifyContent: 'center',
                              fontSize: 8, fontWeight: 700, color: 'rgba(255,255,255,0.6)', overflow: 'hidden',
                            }}>
                              {b.avatar_url
                                ? <img src={b.avatar_url} style={{ width: '100%', height: '100%', objectFit: 'cover' }} />
                                : b.username?.[0]?.toUpperCase()
                              }
                            </div>
                            <span style={{ flex: 1, fontSize: 11, color: 'rgba(255,255,255,0.6)', fontWeight: 500, overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>
                              {b.username}
                            </span>
                            <span style={{
                              fontSize: 11, fontWeight: 600, flexShrink: 0,
                              color: b.balance > 0 ? '#4ade80' : '#f87171',
                            }}>
                              {b.balance > 0 ? '+' : ''}{fmt(b.balance, currency)}
                            </span>
                          </div>
                        ))}
                      </div>
                    )}
                  </div>
                )}
              </div>
            )}
          </div>

          {pieSegments.length > 0 && (
            <div style={{
              background: 'var(--bg-card)', borderRadius: 16, padding: '20px 16px',
              border: '1px solid var(--border-primary)',
              boxShadow: '0 2px 12px rgba(0,0,0,0.04)',
              marginBottom: 16,
            }}>
              <div style={{ fontSize: 13, fontWeight: 600, color: 'var(--text-primary)', marginBottom: 16, textAlign: 'center' }}>{t('budget.byCategory')}</div>

              <PieChart segments={pieSegments} size={180} totalLabel={t('budget.total')} />

              <div style={{ marginTop: 20, display: 'flex', flexDirection: 'column', gap: 6 }}>
                {pieSegments.map(seg => {
                  const pct = grandTotal > 0 ? ((seg.value / grandTotal) * 100).toFixed(1) : '0.0'
                  return (
                    <div key={seg.name} style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
                      <div style={{ width: 10, height: 10, borderRadius: 3, background: seg.color, flexShrink: 0 }} />
                      <span style={{ flex: 1, fontSize: 12, color: 'var(--text-secondary)', fontWeight: 500 }}>{seg.name}</span>
                      <span style={{ fontSize: 11, color: 'var(--text-faint)', fontWeight: 600, whiteSpace: 'nowrap' }}>{fmt(seg.value, currency)}</span>
                      <span style={{ fontSize: 11, color: 'var(--text-muted)', fontWeight: 600, whiteSpace: 'nowrap', minWidth: 38, textAlign: 'right' }}>{pct}%</span>
                    </div>
                  )
                })}
              </div>
            </div>
          )}

        </div>
      </div>
    </div>
  )
}