import { useRef, useState } from 'react'

function fmtPrice(v) {
  return Number(v).toFixed(2) + ' €'
}

// ── Icons ─────────────────────────────────────────────────────────────────────

function SectionIcon({ type }) {
  const icons = {
    prefs:   <svg width="13" height="13" viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="4" fill="#f59e0b"/><circle cx="12" cy="12" r="9" stroke="#f59e0b" strokeWidth="2"/></svg>,
    quick:   <svg width="13" height="13" viewBox="0 0 24 24" fill="none"><path d="M5 12h14M13 6l6 6-6 6" stroke="#a3e635" strokeWidth="2.2" strokeLinecap="round" strokeLinejoin="round"/></svg>,
    extras:  <svg width="13" height="13" viewBox="0 0 24 24" fill="none"><path d="M12 5v14M5 12h14" stroke="#60a5fa" strokeWidth="2.5" strokeLinecap="round"/></svg>,
    removed: <svg width="13" height="13" viewBox="0 0 24 24" fill="none"><path d="M5 12h14" stroke="#ef4444" strokeWidth="2.5" strokeLinecap="round"/></svg>,
    note:    <svg width="13" height="13" viewBox="0 0 24 24" fill="none"><circle cx="12" cy="12" r="1.5" fill="#94a3b8"/><path d="M12 7v1M12 16v1" stroke="#94a3b8" strokeWidth="2" strokeLinecap="round"/><circle cx="12" cy="12" r="9" stroke="#94a3b8" strokeWidth="1.5"/></svg>,
  }
  return <span style={{ display: 'inline-flex', alignItems: 'center', flexShrink: 0 }}>{icons[type] ?? null}</span>
}

// ── Parse selected_options into grouped sections (same logic as cart) ────────

function buildSections(item) {
  const sections = []
  const opts = (() => {
    try { return item.selected_options ? JSON.parse(item.selected_options) : [] } catch { return [] }
  })()
  const removed = (() => {
    try { return item.removed_ingredients ? JSON.parse(item.removed_ingredients) : [] } catch { return [] }
  })()

  // We don't have product metadata here, so we classify by heuristics:
  // - id != null → could be a pref choice or extra; we use the _type hint if present, else we group them
  // - id == null → sub-choice (follows its parent)
  // Strategy: walk through opts in order, attaching sub-choices to their parent,
  // then classify parent items: items with a real id that appear multiple times → extra (stacked),
  // but without product metadata we can't fully distinguish prefs from extras.
  // We use a simple rule: if an option with id appears only once in the stream → treat as pref
  // (since extras can be added multiple times). This matches how handleAdd() emits them.

  const prefGroups = []  // { setName: null (unknown), values: [...] }
  const extraGroups = [] // { id, name, subName, qty }
  const quickLines = []  // { name, _qty }

  // Count how many times each id appears (extras can be stacked → appear multiple times)
  const idCount = {}
  opts.forEach(o => { if (o.id != null) idCount[o.id] = (idCount[o.id] || 0) + 1 })

  // Single pass: consume each item and its optional following sub (id=null)
  const consumedAsSubAtIndex = new Set()
  let i = 0
  while (i < opts.length) {
    const o = opts[i]
    if (consumedAsSubAtIndex.has(i)) { i++; continue }

    if (o.id == null) {
      // Standalone id=null → quick option
      const existing = quickLines.find(x => x.name === o.name)
      if (existing) existing._qty = (existing._qty || 1) + 1
      else quickLines.push({ name: o.name, _qty: 1 })
      i++
      continue
    }

    // id != null — look ahead for immediate sub
    let subName = null
    if (i + 1 < opts.length && opts[i + 1].id == null) {
      subName = opts[i + 1].name
      consumedAsSubAtIndex.add(i + 1)
    }

    if (idCount[o.id] > 1) {
      // Extra — appears multiple times in the list
      const existing = extraGroups.find(g => g.id === o.id && g.subName === subName)
      if (existing) existing.qty++
      else extraGroups.push({ id: o.id, name: o.name, subName, qty: 1 })
    } else {
      // Single occurrence → preference choice
      const value = subName ? `${o.name} · ${subName}` : o.name
      prefGroups.push({ setName: null, values: [value] })
    }
    i++
  }

  if (prefGroups.length > 0) sections.push({ type: 'prefs', lines: prefGroups })
  if (quickLines.length > 0) sections.push({ type: 'quick', lines: quickLines })
  if (extraGroups.length > 0) sections.push({ type: 'extras', lines: extraGroups })
  if (removed.length > 0) sections.push({ type: 'removed', lines: removed.map(n => ({ name: n })) })
  if (item.notes) sections.push({ type: 'note', lines: [{ name: item.notes }] })

  return sections
}

// ── ItemRow ───────────────────────────────────────────────────────────────────

function ItemRow({ item, selectable, selected, onToggle, onLongPress, isLast }) {
  const isPaid = item.status === 'paid'
  const isCancelled = item.status === 'cancelled'

  const sections = buildSections(item)
  const hasDetails = sections.length > 0
  const [expanded, setExpanded] = useState(false)

  // Long-press detection
  const pressTimer = useRef(null)
  const didLongPress = useRef(false)
  const touchStartPos = useRef({ x: 0, y: 0 })

  function handleTouchStart(e) {
    if (!selectable || isPaid || isCancelled || !onLongPress) return
    didLongPress.current = false
    touchStartPos.current = { x: e.touches[0].clientX, y: e.touches[0].clientY }
    pressTimer.current = setTimeout(() => {
      didLongPress.current = true
      onLongPress(item)
    }, 500)
  }

  function handleTouchMove(e) {
    const dx = Math.abs(e.touches[0].clientX - touchStartPos.current.x)
    const dy = Math.abs(e.touches[0].clientY - touchStartPos.current.y)
    if (dx > 8 || dy > 8) clearTimeout(pressTimer.current)
  }

  function handleTouchEnd() { clearTimeout(pressTimer.current) }

  function handleBodyClick() {
    if (didLongPress.current) { didLongPress.current = false; return }
    if (selectable && !isPaid && !isCancelled) onToggle(item.id)
  }

  return (
    <div
      className={`order-item ${isPaid ? 'order-item--paid' : ''} ${isCancelled ? 'order-item--cancelled' : ''} ${selectable && selected ? 'order-item--selected' : ''} ${isLast ? 'order-item--last' : ''}`}
      style={{ userSelect: 'none' }}
    >
      {/* Main row — click to select */}
      <div
        onClick={handleBodyClick}
        onTouchStart={handleTouchStart}
        onTouchMove={handleTouchMove}
        onTouchEnd={handleTouchEnd}
        onTouchCancel={handleTouchEnd}
        style={{
          display: 'flex', alignItems: 'center', gap: 8,
          padding: '10px 12px',
          cursor: selectable && !isPaid && !isCancelled ? 'pointer' : 'default',
        }}
      >
        {/* Selection checkbox */}
        {selectable && !isPaid && !isCancelled && (
          <span style={{ color: selected ? '#f59e0b' : '#475569', flexShrink: 0, fontSize: 16 }}>
            {selected ? '☑' : '☐'}
          </span>
        )}

        {/* Name + badges */}
        <div style={{ flex: 1, minWidth: 0 }}>
          <div style={{ display: 'flex', alignItems: 'center', gap: 6, flexWrap: 'wrap' }}>
            <span className="order-item__name">{item.product?.name || `#${item.product_id}`}</span>
            {isPaid && <span className="badge badge--paid">Paid</span>}
            {isCancelled && <span className="badge badge--cancelled">Cancelled</span>}
            {!isPaid && !isCancelled && !item.printed && (
              <span className="badge badge--draft" title="Δεν εκτυπώθηκε ακόμα">⏳</span>
            )}
          </div>
        </div>

        {/* Qty + price */}
        <span className="order-item__qty">×{item.quantity}</span>
        <span className="order-item__price">{fmtPrice(item.unit_price * item.quantity)}</span>

        {/* Expand arrow — only if there are details; stops propagation so it doesn't trigger select */}
        {hasDetails && (
          <button
            onClick={e => { e.stopPropagation(); setExpanded(v => !v) }}
            style={{
              background: 'none', border: 'none', padding: 4, cursor: 'pointer',
              color: 'var(--muted)', display: 'flex', alignItems: 'center', flexShrink: 0,
            }}
          >
            <svg width="14" height="14" viewBox="0 0 24 24" fill="none"
              style={{ transform: `rotate(${expanded ? 180 : 0}deg)`, transition: 'transform 180ms' }}>
              <path d="M6 9L12 15L18 9" stroke="currentColor" strokeWidth="2.2" strokeLinecap="round"/>
            </svg>
          </button>
        )}
      </div>

      {/* Expanded details */}
      {expanded && hasDetails && (
        <div style={{ paddingBottom: 8 }}>
          {sections.map((sec, si) => (
            <div key={si}>
              <div style={{ margin: '0 12px', height: 1, background: 'var(--border)' }} />
              <div style={{ padding: '5px 12px 2px', display: 'flex', flexDirection: 'column', gap: 4 }}>
                {sec.type === 'prefs' && sec.lines.map((line, li) => (
                  <div key={li} style={{ display: 'flex', alignItems: 'flex-start', gap: 7 }}>
                    <SectionIcon type="prefs" />
                    <span style={{ fontSize: 12, lineHeight: 1.4, flex: 1 }}>
                      {line.setName && (
                        <span style={{ color: 'var(--muted)', display: 'block', fontSize: 11 }}>{line.setName}</span>
                      )}
                      <span style={{ color: 'var(--text)' }}>{line.values.join(' · ')}</span>
                    </span>
                  </div>
                ))}
                {sec.type === 'quick' && sec.lines.map((line, li) => (
                  <div key={li} style={{ display: 'flex', alignItems: 'center', gap: 7 }}>
                    <SectionIcon type="quick" />
                    <span style={{ fontSize: 12, color: 'var(--text)', flex: 1 }}>
                      {line.name}
                      {line._qty > 1 && <span style={{ color: '#f59e0b', marginLeft: 4, fontWeight: 700 }}>×{line._qty}</span>}
                    </span>
                  </div>
                ))}
                {sec.type === 'extras' && sec.lines.map((line, li) => (
                  <div key={li} style={{ display: 'flex', alignItems: 'center', gap: 7 }}>
                    <SectionIcon type="extras" />
                    <span style={{ fontSize: 12, color: 'var(--text)', flex: 1 }}>
                      {line.name}
                      {line.subName && <span> · {line.subName}</span>}
                      {line.qty > 1 && <span style={{ color: '#f59e0b', marginLeft: 4, fontWeight: 700 }}>×{line.qty}</span>}
                    </span>
                  </div>
                ))}
                {sec.type === 'removed' && sec.lines.map((line, li) => (
                  <div key={li} style={{ display: 'flex', alignItems: 'center', gap: 7 }}>
                    <SectionIcon type="removed" />
                    <span style={{ fontSize: 12, color: 'var(--text)', flex: 1 }}>Χωρίς {line.name}</span>
                  </div>
                ))}
                {sec.type === 'note' && sec.lines.map((line, li) => (
                  <div key={li} style={{ display: 'flex', alignItems: 'flex-start', gap: 7 }}>
                    <SectionIcon type="note" />
                    <span style={{ fontSize: 12, color: 'var(--text)', lineHeight: 1.4, flex: 1, whiteSpace: 'pre-wrap' }}>{line.name}</span>
                  </div>
                ))}
              </div>
            </div>
          ))}
        </div>
      )}
    </div>
  )
}

export default function OrderSummary({ order, selectable = false, selectedIds = [], onToggle, onLongPressItem }) {
  const activeItems = order.items?.filter(i => i.status !== 'cancelled') || []
  const total = activeItems
    .filter(i => i.status !== 'cancelled')
    .reduce((s, i) => s + i.unit_price * i.quantity, 0)
  const paidTotal = activeItems
    .filter(i => i.status === 'paid')
    .reduce((s, i) => s + i.unit_price * i.quantity, 0)

  return (
    <div className="order-summary">
      {activeItems.length === 0 && <p style={{ color: '#64748b', textAlign: 'center' }}>Δεν υπάρχουν αντικείμενα</p>}
      {activeItems.map((item, idx) => (
        <ItemRow
          key={item.id}
          item={item}
          selectable={selectable}
          selected={selectedIds.includes(item.id)}
          onToggle={onToggle}
          onLongPress={onLongPressItem}
          isLast={idx === activeItems.length - 1}
        />
      ))}
      <div className="order-summary__total">
        <span>Σύνολο</span>
        <span>{fmtPrice(total)}</span>
      </div>
      {paidTotal > 0 && paidTotal < total && (
        <div style={{ display: 'flex', justifyContent: 'space-between', paddingBottom: 8, fontSize: 13, color: '#64748b' }}>
          <span>Πληρωμένο</span>
          <span style={{ color: '#22c55e' }}>{fmtPrice(paidTotal)}</span>
        </div>
      )}
      {paidTotal > 0 && paidTotal < total && (
        <div style={{ display: 'flex', justifyContent: 'space-between', paddingBottom: 8, fontSize: 13, color: '#94a3b8' }}>
          <span>Εκκρεμεί</span>
          <span style={{ color: '#f59e0b', fontWeight: 700 }}>{fmtPrice(total - paidTotal)}</span>
        </div>
      )}
    </div>
  )
}