import type { Exam, WeatherKind } from '@meteo-exam/shared'
import { WEATHER, WEATHER_KINDS, WEIGHT_PRESETS, kindFromWeight } from '@meteo-exam/shared'
import { h } from '../dom'
import { isoDayInput } from '../dates'
import { saveExam, setError } from '../store'
import { showToast } from '../toast'

interface Draft {
  subject: string
  teacher: string
  room: string
  chapter: string
  day: string
  time: string
  durationMin: number
  weight: number
  kind: WeatherKind
  note: string
}

const inputClass =
  'w-full bg-slate-900/80 border border-slate-700/80 rounded-xl px-3.5 py-2.5 text-sm text-slate-100 placeholder-slate-500 focus:outline-none focus:border-sky-500 transition-colors'

const labelClass = 'block text-[10px] font-black uppercase tracking-wider text-slate-500 mb-1.5'

function field(label: string, control: HTMLElement, hint?: string): HTMLElement {
  return h(
    'label',
    { class: 'block' },
    h('span', { class: labelClass }, label),
    control,
    hint ? h('span', { class: 'block text-[10px] text-slate-600 font-semibold mt-1' }, hint) : null,
  )
}

function draftFrom(exam: Exam | undefined): Draft {
  if (exam) {
    const date = new Date(exam.startsAt)
    return {
      subject: exam.subject,
      teacher: exam.teacher ?? '',
      room: exam.room ?? '',
      chapter: exam.chapter ?? '',
      day: isoDayInput(date),
      time: `${String(date.getHours()).padStart(2, '0')}:${String(date.getMinutes()).padStart(2, '0')}`,
      durationMin: exam.durationMin,
      weight: exam.weight,
      kind: exam.kind,
      note: exam.note ?? '',
    }
  }
  const now = new Date()
  now.setMinutes(0, 0, 0)
  now.setHours(Math.max(8, now.getHours() + 1))
  return {
    subject: '',
    teacher: '',
    room: '',
    chapter: '',
    day: isoDayInput(now),
    time: `${String(now.getHours()).padStart(2, '0')}:00`,
    durationMin: 60,
    weight: 2,
    kind: 'orage',
    note: '',
  }
}

function closeOverlay(overlay: HTMLElement): void {
  overlay.remove()
}

/** Modale d'ajout / modification. `exam` absent = création. */
export function openExamForm(exam: Exam | undefined, onSaved: () => void): void {
  const draft = draftFrom(exam)
  const editing = exam !== undefined

  const overlay = h('div', {
    class: 'fixed inset-0 z-[95] bg-slate-950/80 backdrop-blur-sm flex items-end sm:items-center justify-center',
  })

  const errorBox = h('p', { class: 'hidden text-xs font-bold text-rose-300 bg-rose-500/10 border border-rose-500/25 rounded-xl px-3 py-2' })

  const showError = (message: string): void => {
    errorBox.textContent = message
    errorBox.classList.remove('hidden')
  }

  // --- Champs ---------------------------------------------------------------
  const subject = h('input', { class: inputClass, value: draft.subject, placeholder: 'Mathématiques' })
  const teacher = h('input', { class: inputClass, value: draft.teacher, placeholder: 'M. Roussel' })
  const room = h('input', { class: inputClass, value: draft.room, placeholder: 'B204' })
  const chapter = h('input', { class: inputClass, value: draft.chapter, placeholder: 'Chapitre ou thème' })
  const day = h('input', { type: 'date', class: inputClass, value: draft.day })
  const time = h('input', { type: 'time', class: inputClass, value: draft.time })
  const note = h('textarea', { class: `${inputClass} min-h-[70px] resize-none`, placeholder: 'Circonscription, calculatrice autorisée…' })
  note.value = draft.note

  const duration = h('input', { type: 'number', class: inputClass, value: String(draft.durationMin), min: '5', max: '480', step: '5' })
  const weight = h('input', { type: 'number', class: inputClass, value: String(draft.weight), min: '0', max: '20', step: '0.5' })

  // Le statut découle du coefficient tant qu'on ne le surcharge pas à la main.
  let kindOverride = false
  const kindPreview = h('div', { class: 'flex flex-wrap gap-1.5' })

  const renderKinds = (): void => {
    kindPreview.replaceChildren(
      ...WEATHER_KINDS.map((kind) => {
        const active = draft.kind === kind
        return h(
          'button',
          {
            type: 'button',
            class: `px-2.5 py-1.5 rounded-xl text-[11px] font-extrabold border transition-colors ${
              active ? WEATHER[kind].badge : 'bg-slate-800/60 border-slate-700 text-slate-400'
            }`,
            onclick: () => {
              draft.kind = kind
              kindOverride = true
              renderKinds()
            },
          },
          `${WEATHER[kind].icon} ${WEATHER[kind].label}`,
        )
      }),
    )
  }

  weight.addEventListener('input', () => {
    const value = Number(weight.value)
    if (!Number.isFinite(value)) return
    draft.weight = value
    if (!kindOverride) {
      draft.kind = kindFromWeight(value)
      renderKinds()
    }
  })
  renderKinds()

  // --- Actions --------------------------------------------------------------
  const submit = async (): Promise<void> => {
    if (!subject.value.trim()) {
      showError('La matière est obligatoire.')
      return
    }
    const startsAt = new Date(`${day.value}T${time.value || '08:00'}:00`)
    if (Number.isNaN(startsAt.getTime())) {
      showError('Date ou heure invalide.')
      return
    }
    const durationMin = Number(duration.value)
    if (!Number.isFinite(durationMin) || durationMin < 5) {
      showError('Durée minimum : 5 minutes.')
      return
    }

    submitBtn.disabled = true
    submitBtn.classList.add('opacity-60')
    try {
      await saveExam(
        {
          subject: subject.value.trim(),
          teacher: teacher.value.trim() || null,
          room: room.value.trim() || null,
          chapter: chapter.value.trim() || null,
          startsAt: startsAt.toISOString(),
          durationMin,
          weight: Number(weight.value) || 0,
          kind: draft.kind,
          note: note.value.trim() || null,
        },
        exam?.id,
      )
      showToast(editing ? 'Évaluation mise à jour' : 'Évaluation ajoutée', 'success')
      closeOverlay(overlay)
      onSaved()
    } catch (error) {
      setError(error instanceof Error ? error.message : 'Enregistrement impossible')
      showError(error instanceof Error ? error.message : 'Enregistrement impossible')
      submitBtn.disabled = false
      submitBtn.classList.remove('opacity-60')
    }
  }

  const submitBtn = h(
    'button',
    { class: 'flex-1 bg-sky-500 text-slate-950 text-sm font-extrabold py-3 rounded-xl active:scale-95 transition-transform', onclick: submit },
    editing ? 'Enregistrer' : 'Ajouter au bulletin',
  )

  const panel = h(
    'div',
    { class: 'w-full sm:max-w-md bg-slate-900 border border-slate-700 rounded-t-[2rem] sm:rounded-[2rem] p-5 max-h-[90vh] overflow-y-auto no-scrollbar shadow-2xl' },
    h(
      'div',
      { class: 'flex items-start justify-between gap-3 mb-4' },
      h(
        'div',
        {},
        h('h2', { class: 'text-lg font-black text-slate-100' }, editing ? 'Modifier l’évaluation' : 'Nouvelle évaluation'),
        h('p', { class: 'text-xs text-slate-400 font-semibold mt-0.5' }, 'Le statut météo découle du coefficient.'),
      ),
      h('button', { class: 'text-slate-400 hover:text-slate-200 text-lg', onclick: () => closeOverlay(overlay) },
        h('i', { class: 'fa-solid fa-xmark' })),
    ),
    h(
      'div',
      { class: 'space-y-3.5' },
      field('Matière', subject),
      h('div', { class: 'grid grid-cols-2 gap-3' }, field('Enseignant', teacher), field('Salle', room)),
      field('Chapitre', chapter),
      h('div', { class: 'grid grid-cols-2 gap-3' }, field('Date', day), field('Heure', time)),
      h('div', { class: 'grid grid-cols-2 gap-3' }, field('Durée (min)', duration), field('Coefficient', weight)),
      field(
        'Statut météo',
        kindPreview,
        kindOverride ? 'Statut forcé manuellement.' : WEIGHT_PRESETS.find((p) => p.value === draft.weight)?.label,
      ),
      field('Note', note),
      errorBox,
      h('div', { class: 'flex gap-2 pt-1' },
        h('button', { class: 'bg-slate-800 border border-slate-700 text-slate-300 text-sm font-extrabold px-4 py-3 rounded-xl active:scale-95 transition-transform', onclick: () => closeOverlay(overlay) },
          'Annuler'),
        submitBtn,
      ),
    ),
  )

  overlay.append(panel)
  overlay.addEventListener('click', (event) => {
    if (event.target === overlay) closeOverlay(overlay)
  })
  document.body.append(overlay)
  subject.focus()
}