import { useEffect, useMemo, useRef, useState } from 'react'
import { api } from '../utils/api'
import FoodSearchModal from './FoodSearchModal'
import FoodNutrientFields, { foodCreatePayload } from './FoodNutrientFields'
import FoodRecipeEditor, { RecipeForm } from './FoodRecipeEditor'

const PERIODS = [
  { days: 14, label: '14 Tage' },
  { days: 28, label: '4 Wochen' },
  { days: 90, label: '90 Tage' },
  { days: 0, label: 'Alle' },
]

function formatDay(iso) {
  const s = String(iso || '').slice(0, 10)
  if (s.length < 10) return ''
  const [y, m, d] = s.split('-')
  return `${d}.${m}.${String(y).slice(2)}`
}

function suggestQuery(raw) {
  let s = (raw || '').replace(/^\s*[!]?\s*\d+(?:[.,]\d+)?\s*(?:g|kg|ml|l|stück|stk)?\s*/i, '').trim()
  s = s.replace(/^!+/, '').trim()
  const comma = s.indexOf(',')
  if (comma > 2) s = s.slice(0, comma).trim()
  return s
}

function RecipePickModal({ recipes, sourceName, onPick, onClose }) {
  const [q, setQ] = useState(suggestQuery(sourceName))
  const filtered = recipes.filter((r) => {
    const hay = `${r.name_raw || ''} ${r.name_normalized || ''}`.toLowerCase()
    return !q.trim() || hay.includes(q.trim().toLowerCase())
  })
  return (
    <div
      style={{
        position: 'fixed', inset: 0, background: 'rgba(0,0,0,0.45)',
        display: 'flex', alignItems: 'center', justifyContent: 'center', zIndex: 20000, padding: 16,
      }}
      onClick={onClose}
    >
      <div
        role="dialog"
        aria-modal="true"
        onClick={(e) => e.stopPropagation()}
        style={{
          width: '100%', maxWidth: 480, maxHeight: 'min(88vh, 560px)',
          background: 'var(--surface)', borderRadius: 16,
          boxShadow: '0 8px 32px rgba(0,0,0,0.18)',
          display: 'flex', flexDirection: 'column',
        }}
      >
        <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', padding: '14px 16px', borderBottom: '1px solid var(--border)' }}>
          <h2 className="card-title" style={{ margin: 0, fontSize: 16 }}>Eigenes Rezept wählen</h2>
          <button type="button" className="btn btn-secondary" onClick={onClose}>Schließen</button>
        </div>
        <div style={{ padding: '12px 16px' }}>
          <input className="form-input" style={{ width: '100%', textAlign: 'left' }} autoFocus placeholder="Rezeptname filtern" value={q} onChange={(e) => setQ(e.target.value)} />
        </div>
        <div style={{ overflowY: 'auto', padding: '0 16px 16px', flex: 1 }}>
          {filtered.length === 0 && <p style={{ fontSize: 13, color: 'var(--text3)' }}>Kein passendes Rezept.</p>}
          {filtered.map((r) => (
            <button key={r.id} type="button" className="btn btn-secondary btn-full" style={{ marginTop: 8, justifyContent: 'flex-start', textAlign: 'left', height: 'auto', padding: '10px 12px' }} onClick={() => onPick(r.id)}>
              <span>
                <strong style={{ display: 'block' }}>{r.name_raw}</strong>
                <span style={{ fontSize: 12, color: 'var(--text3)' }}>{(r.ingredients || []).length} Zutaten</span>
              </span>
            </button>
          ))}
        </div>
      </div>
    </div>
  )
}

function InlineCreate({ defaultName, disabled, learned, allowRecipe, onCreateFood, onCreateRecipe }) {
  const [kind, setKind] = useState(allowRecipe ? null : 'food')
  const [name, setName] = useState(defaultName || '')
  const [macros, setMacros] = useState({ kcal: '0', protein_g: '0', fat_g: '0', carbs_g: '0' })
  const [extras, setExtras] = useState([])
  const [servingG, setServingG] = useState('100')
  if (!kind) {
    return (
      <div style={{ marginTop: 8, padding: 10, background: 'var(--surface2)', borderRadius: 8 }}>
        <p style={{ fontSize: 12, margin: '0 0 8px', color: 'var(--text2)' }}>Lebensmittel (ein Eintrag im Katalog) oder Rezept (mehrere Zutaten)?</p>
        <div style={{ display: 'flex', flexWrap: 'wrap', gap: 8 }}>
          <button type="button" className="btn btn-primary" disabled={disabled} onClick={() => setKind('food')}>Lebensmittel</button>
          {allowRecipe && (
            <button type="button" className="btn btn-secondary" disabled={disabled} onClick={() => setKind('recipe')}>Rezept</button>
          )}
        </div>
      </div>
    )
  }
  if (kind === 'recipe') {
    return (
      <RecipeForm
        defaultName={defaultName}
        learned={learned}
        disabled={disabled}
        submitLabel="Rezept anlegen und zuordnen"
        onCancel={() => setKind(null)}
        onSave={onCreateRecipe}
      />
    )
  }
  return (
    <div style={{ marginTop: 8, padding: 10, background: 'var(--surface2)', borderRadius: 8 }}>
      <p style={{ fontSize: 12, margin: '0 0 8px', color: 'var(--text2)' }}>Neuer Katalogeintrag. Salz: Makros 0. Öl/Supplement: Stoffe wie EPA dazusuchen.</p>
      <input className="form-input" style={{ width: '100%', textAlign: 'left', marginBottom: 8 }} value={name} onChange={(e) => setName(e.target.value)} placeholder="Name" />
      <FoodNutrientFields
        macros={macros}
        setMacros={setMacros}
        extras={extras}
        setExtras={setExtras}
        servingG={servingG}
        setServingG={setServingG}
      />
      <div style={{ display: 'flex', gap: 8, marginTop: 8 }}>
        <button type="button" className="btn btn-secondary" disabled={disabled} onClick={() => setKind(null)}>Zurück</button>
        <button
          type="button"
          className="btn btn-primary"
          style={{ flex: 1 }}
          disabled={disabled || !name.trim()}
          onClick={() => onCreateFood(foodCreatePayload(name, macros, extras, servingG))}
        >
          Anlegen und zuordnen
        </button>
      </div>
    </div>
  )
}

export default function NutritionFoodMap({ onChanged, onMapped }) {
  const [unmapped, setUnmapped] = useState([])
  const [learned, setLearned] = useState([])
  const [recipes, setRecipes] = useState([])
  const [error, setError] = useState(null)
  const [notice, setNotice] = useState(null)
  const [saving, setSaving] = useState(null)
  const [searchFor, setSearchFor] = useState(null)
  const [recipeFor, setRecipeFor] = useState(null)
  const [createFor, setCreateFor] = useState(null)
  const [filter, setFilter] = useState('all')
  const [sinceDays, setSinceDays] = useState(28)
  const [totalOpen, setTotalOpen] = useState(0)
  const [q, setQ] = useState('')
  const [visible, setVisible] = useState(80)
  const [showLearned, setShowLearned] = useState(false)
  const [importing, setImporting] = useState(false)
  const [busy, setBusy] = useState(false)
  const listRef = useRef(null)
  const bundleRef = useRef(null)
  const loadGen = useRef(0)
  const askedSuggest = useRef(new Set())

  const load = async () => {
    const gen = ++loadGen.current
    try {
      const [u, m, r, counts] = await Promise.all([
        api.listUnmappedFoods(sinceDays),
        api.listMyFoodMappings(),
        api.listNutritionRecipes().catch(() => []),
        api.listUnmappedFoodCount(sinceDays).catch(() => null),
      ])
      if (gen !== loadGen.current) return
      askedSuggest.current = new Set()
      setUnmapped(Array.isArray(u) ? u : [])
      setTotalOpen(Number(counts?.total) || (Array.isArray(u) ? u.length : 0))
      setLearned(m)
      setRecipes(Array.isArray(r) ? r : [])
    } catch (e) {
      if (gen !== loadGen.current) return
      setError(e.message)
    }
  }

  useEffect(() => { load() }, [sinceDays])

  const filtered = useMemo(() => {
    const term = q.trim().toLowerCase()
    return unmapped.filter((u) => {
      if (filter === 'suggested' && !(u.suggestions || []).length) return false
      if (filter === 'none' && (u.suggestions || []).length) return false
      if (!term) return true
      const hay = `${u.source_name_raw || ''} ${u.source_name_normalized || ''}`.toLowerCase()
      return hay.includes(term)
    })
  }, [unmapped, filter, q])

  const shown = filtered.slice(0, visible)

  useEffect(() => {
    const need = []
    const seen = new Set()
    const take = (u) => {
      const key = u.source_name_normalized
      if (!key || askedSuggest.current.has(key) || seen.has(key)) return
      seen.add(key)
      need.push(u)
    }
    shown.forEach(take)
    if (need.length < 80) {
      for (const u of unmapped) {
        take(u)
        if (need.length >= 80) break
      }
    }
    if (!need.length) return
    need.forEach((u) => askedSuggest.current.add(u.source_name_normalized))
    const names = need.map((u) => u.source_name_raw).filter(Boolean)
    if (!names.length) return
    api.suggestFoodsBatch(names, 3).then((packed) => {
      if (!packed || typeof packed !== 'object') return
      setUnmapped((list) => list.map((u) => {
        const hit = packed[u.source_name_raw]
        return hit ? { ...u, ...hit } : u
      }))
    }).catch(() => {
      need.forEach((u) => askedSuggest.current.delete(u.source_name_normalized))
    })
  }, [visible, filter, q, unmapped.length])

  const assign = async (row, foodId, extras = {}, foodMeta = {}) => {
    const sourceName = row.source_name_raw
    setSaving(sourceName)
    setError(null)
    try {
      const res = await api.upsertMyFoodMapping({
        source_name: sourceName,
        food_id: foodId,
        grams_per_unit: extras.grams_per_unit || null,
        source_unit: extras.source_unit || null,
      })
      setSearchFor(null)
      setCreateFor(null)
      setUnmapped((list) => list.filter((x) => x.source_name_normalized !== row.source_name_normalized))
      setLearned((list) => [{
        id: res.mapping_id,
        source_name_raw: sourceName,
        food_name_de: res.food_name_de || foodMeta.name_de,
        bls_code: res.bls_code || foodMeta.bls_code,
        catalog_kind: res.catalog_kind || foodMeta.catalog_kind,
      }, ...list])
      setNotice(`Gespeichert: ${suggestQuery(sourceName) || sourceName}`)
      onMapped?.()
    } catch (e) {
      setError(e.message)
    } finally {
      setSaving(null)
    }
  }

  const createAndAssign = async (row, body) => {
    setSaving(row.source_name_raw)
    setError(null)
    try {
      const food = await api.createUserFood(body)
      await assign(row, food.id, {}, { name_de: food.name_de, catalog_kind: food.catalog_kind })
    } catch (e) {
      setError(e.message)
      setSaving(null)
    }
  }

  const createRecipeAndAssign = async (row, body) => {
    setSaving(row.source_name_raw)
    setError(null)
    try {
      const rec = await api.createNutritionRecipe({ ...body, source: 'manual' })
      await api.applyNutritionRecipe(rec.id, row.source_name_raw)
      setCreateFor(null)
      setSearchFor(null)
      setNotice(`Rezept angelegt. Offene Zutaten erscheinen in der Liste.`)
      await load()
      onMapped?.()
    } catch (e) {
      setError(e.message)
      throw e
    } finally {
      setSaving(null)
    }
  }

  const applyRecipe = async (sourceName, recipeId) => {
    setSaving(sourceName)
    setError(null)
    try {
      await api.applyNutritionRecipe(recipeId, sourceName)
      setRecipeFor(null)
      setNotice('Rezept verknüpft. Offene Zutaten erscheinen in der Liste.')
      await load()
      onMapped?.()
    } catch (e) {
      setError(e.message)
    } finally {
      setSaving(null)
    }
  }

  const remove = async (id) => {
    if (!confirm('Zuordnung wirklich löschen?')) return
    try {
      await api.deleteMyFoodMapping(id)
      setLearned((list) => list.filter((x) => x.id !== id))
      await load()
      onChanged?.()
    } catch (e) {
      setError(e.message)
    }
  }

  const exportBundle = async () => {
    setBusy(true)
    setError(null)
    try {
      await api.exportFoodKnowledge()
      setNotice('Zuordnungen und Listen als JSON heruntergeladen.')
    } catch (e) {
      setError(e.message)
    } finally {
      setBusy(false)
    }
  }

  const importBundle = async (file) => {
    if (!file) return
    setBusy(true)
    setError(null)
    try {
      const res = await api.importFoodKnowledge(file)
      await load()
      onChanged?.()
      const skip = res.mappings_skipped ? `, ${res.mappings_skipped} ohne Katalogtreffer` : ''
      setNotice(`${res.mappings || 0} Zuordnungen und ${(res.inserted || 0) + (res.updated || 0)} Listen übernommen${skip}.`)
    } catch (e) {
      setError(e.message)
    } finally {
      setBusy(false)
    }
  }

  const importLists = async (file) => {
    if (!file) return
    setImporting(true)
    setError(null)
    try {
      const res = await api.importFddbLists(file)
      await load()
      onChanged?.()
      setNotice(`${res.recipes} Listen importiert, ${res.items_linked || 0} Tagebuchzeilen verknüpft.`)
    } catch (e) {
      setError(e.message)
    } finally {
      setImporting(false)
    }
  }

  const withSuggest = unmapped.filter((u) => (u.suggestions || []).length).length

  return (
    <div className="card section-gap">
      <div className="card-title">Lebensmittel zuordnen</div>
      <p style={{ fontSize: 13, color: 'var(--text2)', lineHeight: 1.6, marginBottom: 12 }}>
        Zuerst die letzten Wochen zuordnen. Ältere Namen (z. B. Getreide, das du nicht mehr isst) bleiben unter „Alle“ liegen und müssen nicht gemappt werden.
      </p>
      {error && <div style={{ color: 'var(--danger)', fontSize: 13, marginBottom: 10 }}>{error}</div>}
      {notice && <div style={{ fontSize: 13, color: 'var(--accent-dark)', marginBottom: 10 }}>{notice}</div>}

      <input ref={listRef} type="file" accept=".csv,text/csv" style={{ display: 'none' }} onChange={(e) => { const f = e.target.files?.[0]; e.target.value = ''; if (f) importLists(f) }} />
      <button type="button" className="btn btn-secondary btn-full" disabled={importing} onClick={() => listRef.current?.click()}>
        {importing ? 'Importiere Listen…' : 'FDDB-Listen / Rezepte importieren'}
      </button>
      <FoodRecipeEditor recipes={recipes} learned={learned} onChanged={() => { load(); onChanged?.() }} />
      <input ref={bundleRef} type="file" accept=".json,application/json" style={{ display: 'none' }} onChange={(e) => { const f = e.target.files?.[0]; e.target.value = ''; if (f) importBundle(f) }} />
      <div style={{ display: 'flex', flexWrap: 'wrap', gap: 8, marginTop: 8 }}>
        <button type="button" className="btn btn-secondary" disabled={busy} onClick={exportBundle}>Zuordnungen & Listen exportieren</button>
        <button type="button" className="btn btn-secondary" disabled={busy} onClick={() => bundleRef.current?.click()}>Zuordnungen & Listen importieren</button>
      </div>

      <h3 style={{ fontSize: 14, margin: '16px 0 8px' }}>
        Offen ({filtered.length}{sinceDays && totalOpen > unmapped.length ? ` von ${totalOpen}` : filtered.length !== unmapped.length ? ` / ${unmapped.length}` : ''})
      </h3>
      <p style={{ fontSize: 12, color: 'var(--text3)', margin: '0 0 8px' }}>{withSuggest} mit Vorschlag</p>
      <div style={{ display: 'flex', flexWrap: 'wrap', gap: 6, marginBottom: 8 }}>
        {PERIODS.map((p) => (
          <button
            key={p.days}
            type="button"
            className={sinceDays === p.days ? 'btn btn-primary' : 'btn btn-secondary'}
            style={{ fontSize: 12 }}
            onClick={() => { setSinceDays(p.days); setVisible(80); setQ('') }}
          >
            {p.label}
          </button>
        ))}
      </div>
      <input className="form-input" style={{ width: '100%', textAlign: 'left', marginBottom: 8 }} placeholder="Offene Liste filtern…" value={q} onChange={(e) => { setQ(e.target.value); setVisible(80) }} />
      <div style={{ display: 'flex', flexWrap: 'wrap', gap: 6, marginBottom: 8 }}>
        {[['all', 'Alle Treffer'], ['suggested', 'Mit Vorschlag'], ['none', 'Ohne Vorschlag']].map(([id, label]) => (
          <button key={id} type="button" className={filter === id ? 'btn btn-primary' : 'btn btn-secondary'} style={{ fontSize: 12 }} onClick={() => { setFilter(id); setVisible(80) }}>{label}</button>
        ))}
      </div>

      {shown.length === 0 && (
        <p className="muted">
          {sinceDays && unmapped.length === 0 && totalOpen > 0
            ? `In diesem Zeitraum ist nichts Offen. ${totalOpen} ältere Namen liegen unter „Alle“ — die brauchst du nicht, wenn du sie nicht mehr isst.`
            : 'Keine offenen Bezeichner in diesem Filter.'}
        </p>
      )}
      {shown.map((u) => {
        const key = u.source_name_normalized
        const suggestions = u.suggestions || []
        const best = suggestions[0]
        const busyRow = saving === u.source_name_raw
        return (
          <div key={key} style={{ borderTop: '1px solid var(--border)', padding: '10px 0' }}>
            <div style={{ display: 'flex', justifyContent: 'space-between', gap: 8, alignItems: 'flex-start' }}>
              <div>
                <div style={{ fontWeight: 600 }}>{suggestQuery(u.source_name_raw) || u.source_name_raw}</div>
                <div style={{ fontSize: 12, color: 'var(--text3)' }}>
                  {u.kind === 'recipe_ingredient' ? 'Rezeptzutat' : `${u.count}×`}
                  {u.variant_count > 1 ? ` · ${u.variant_count} Mengen` : ''}
                  {u.last_date ? ` · zuletzt ${formatDay(u.last_date)}` : ''}
                </div>
              </div>
              {(u.ambiguous || suggestions.length > 1) && (
                <span style={{ fontSize: 11, padding: '2px 8px', borderRadius: 999, background: 'var(--surface2)', color: 'var(--danger)', whiteSpace: 'nowrap' }}>
                  mehrere möglich
                </span>
              )}
            </div>

            {best && (
              <div style={{ marginTop: 8, display: 'flex', flexWrap: 'wrap', gap: 8, alignItems: 'center' }}>
                <span style={{ fontSize: 13 }}>
                  → <strong>{best.name_de}</strong>
                  <span style={{ color: 'var(--text3)' }}>{best.bls_code ? ` · ${best.bls_code}` : ' · manuell'}</span>
                </span>
                <button type="button" className="btn btn-primary" disabled={busyRow} onClick={() => assign(u, best.id, {}, best)}>
                  Bestätigen
                </button>
              </div>
            )}
            {suggestions.slice(1).map((s) => (
              <div key={s.id} style={{ marginTop: 6, display: 'flex', flexWrap: 'wrap', gap: 8, alignItems: 'center' }}>
                <span style={{ fontSize: 12, color: 'var(--text2)' }}>oder {s.name_de}{s.bls_code ? ` · ${s.bls_code}` : ''}</span>
                <button type="button" className="btn btn-secondary" disabled={busyRow} onClick={() => assign(u, s.id, {}, s)}>Übernehmen</button>
              </div>
            ))}
            {!best && <p style={{ fontSize: 12, color: 'var(--text3)', margin: '8px 0 0' }}>Kein Katalogvorschlag — selbst anlegen.</p>}

            <div style={{ display: 'flex', flexWrap: 'wrap', gap: 8, marginTop: 8 }}>
              <button type="button" className="btn btn-secondary" disabled={busyRow} onClick={() => setCreateFor(createFor === key ? null : key)}>
                {createFor === key ? 'Anlegen schließen' : (u.kind === 'recipe_ingredient' ? 'Neu anlegen' : 'Lebensmittel oder Rezept')}
              </button>
              <button type="button" className="btn btn-secondary" disabled={busyRow} onClick={() => setSearchFor(u)}>Mehr suchen</button>
              {u.kind !== 'recipe_ingredient' && u.matching_recipe_id && (
                <button type="button" className="btn btn-secondary" disabled={busyRow} onClick={() => applyRecipe(u.source_name_raw, u.matching_recipe_id)}>Als Rezept</button>
              )}
              {u.kind !== 'recipe_ingredient' && recipes.length > 0 && (
                <button type="button" className="btn btn-secondary" disabled={busyRow} onClick={() => setRecipeFor(u)}>Rezept wählen</button>
              )}
            </div>
            {createFor === key && (
              <InlineCreate
                defaultName={suggestQuery(u.source_name_raw) || u.source_name_raw}
                disabled={busyRow}
                learned={learned}
                allowRecipe={u.kind !== 'recipe_ingredient'}
                onCreateFood={(body) => createAndAssign(u, body)}
                onCreateRecipe={(body) => createRecipeAndAssign(u, body)}
              />
            )}
          </div>
        )
      })}
      {visible < filtered.length && (
        <button type="button" className="btn btn-secondary btn-full" style={{ marginTop: 8 }} onClick={() => setVisible((n) => n + 80)}>
          Weitere {Math.min(80, filtered.length - visible)} zeigen
        </button>
      )}

      <h3 style={{ fontSize: 14, margin: '20px 0 8px' }}>
        Gelernt ({learned.length}){' '}
        <button type="button" className="btn btn-secondary" style={{ fontSize: 11, padding: '2px 8px' }} onClick={() => setShowLearned((v) => !v)}>
          {showLearned ? 'Einklappen' : 'Anzeigen'}
        </button>
      </h3>
      {showLearned && learned.map((m) => (
        <div key={m.id} style={{ display: 'flex', justifyContent: 'space-between', gap: 8, padding: '8px 0', borderTop: '1px solid var(--border)' }}>
          <div>
            <div style={{ fontWeight: 500 }}>{m.source_name_raw}</div>
            <div style={{ fontSize: 12, color: 'var(--text3)' }}>
              → {m.food_name_de}{m.bls_code ? ` · ${m.bls_code}` : ''}
              {m.catalog_kind !== 'official_bls' ? ' (manuell)' : ''}
            </div>
          </div>
          <button type="button" className="btn btn-secondary" onClick={() => remove(m.id)}>Löschen</button>
        </div>
      ))}

      {searchFor && (
        <FoodSearchModal
          title={`Suchen: ${searchFor.source_name_raw}`}
          initialQuery={suggestQuery(searchFor.source_name_raw)}
          quantityHint={searchFor.sample_quantity_raw || searchFor.source_name_raw}
          allowRecipe={searchFor.kind !== 'recipe_ingredient'}
          learned={learned}
          onClose={() => setSearchFor(null)}
          onSelect={(food, extras) => assign(searchFor, food.id, extras, food)}
          onCreateRecipe={searchFor.kind === 'recipe_ingredient' ? undefined : (body) => createRecipeAndAssign(searchFor, body)}
        />
      )}
      {recipeFor && (
        <RecipePickModal recipes={recipes} sourceName={recipeFor.source_name_raw} onClose={() => setRecipeFor(null)} onPick={(id) => applyRecipe(recipeFor.source_name_raw, id)} />
      )}
    </div>
  )
}

export function DayMarkButtons({ date, markType, onChanged }) {
  const setMark = async (type) => {
    try {
      if (markType === type) await api.deleteNutritionDayMark(date)
      else await api.putNutritionDayMark(date, { mark_type: type })
      onChanged?.()
    } catch (e) {
      alert(e.message)
    }
  }
  return (
    <span style={{ display: 'inline-flex', gap: 8 }}>
      <button type="button" className="btn btn-secondary" style={{ fontSize: 11, padding: '4px 8px' }} onClick={() => setMark('fasting')}>
        {markType === 'fasting' ? '✓ Fasten' : 'Fasten'}
      </button>
      <button type="button" className="btn btn-secondary" style={{ fontSize: 11, padding: '4px 8px' }} onClick={() => setMark('incomplete')}>
        {markType === 'incomplete' ? '✓ Lücke' : 'Lücke'}
      </button>
    </span>
  )
}