import { useEffect, useState } from 'react'
import { drive, message } from '@/api/client'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'
import { Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, DialogTitle } from '@/components/ui/dialog'
import QuotaField from '@/components/drive/QuotaField'
import {fromQuota,toQuota} from '@/lib/quota-utils'

export default function SpaceSettingsDialog({controller: c}) {
  const {spaceDialog, setSpaceDialog, spaces, activeSpaceId, loadSpaces, switchSpace, setError, setNote, setManagedSpaceId} = c
  const manage = spaceDialog?.mode === 'manage'
  const current = spaces.find(space => space.id === spaceDialog?.spaceId)
  const managed = spaces.filter(space => !space.is_private && space.permissions?.includes('create_spaces'))
  const [name,setName] = useState('')
  const [quota,setQuota] = useState('')
  const [parent,setParent] = useState('')
  const [busy,setBusy] = useState(false)
  const eligibleParents = spaces.filter(space => !space.is_private && space.id !== current?.id && space.permissions?.includes('create_spaces') && !isDescendant(space, current, spaces))
  const canMove = manage && !!current?.parent_id && eligibleParents.some(space => space.id !== current.parent_id)
  const [localError,setLocalError] = useState('')
  useEffect(() => {
    setName(manage ? current?.display_name || '' : '')
    setQuota(manage ? fromQuota(current?.quota_bytes) : fromQuota(managed.find(sp=>sp.id===(spaceDialog?.parentId || managed[0]?.id))?.quota_bytes))
    setParent(String(manage ? current?.parent_id || '' : spaceDialog?.parentId || managed[0]?.id || ''))
    setLocalError('')
  }, [spaceDialog?.mode,spaceDialog?.spaceId,spaceDialog?.parentId,current?.display_name,current?.quota_bytes,current?.parent_id,managed[0]?.id])

  async function save(event) {
    event.preventDefault()
    setBusy(true);setLocalError('')
    try {
      if (manage && !current) throw new Error('Sous-espace introuvable. Actualise la page.')
      const data={display_name:name.trim()}
      // Managing an assigned/shared space must never resubmit its quota.
      if (!manage || current?.can_edit_quota) data.quota_bytes=toQuota(quota)
      if (manage && canMove && parent && Number(parent) !== current.parent_id) data.parent_space = Number(parent)
      const result=manage ? await drive.editSpace(current.id,data) : await drive.createSpace({...data,parent_space:Number(parent)})
      await loadSpaces()
      if (!manage) switchSpace(result.id)
      if (manage && data.parent_space) await c.reloadStats()
      setNote(manage ? 'Espace modifié.' : 'Espace créé.')
      setSpaceDialog(null)
    } catch(exception) {setLocalError(exception?.response ? message(exception) : exception.message || message(exception))}
    finally {setBusy(false)}
  }
  function members() {
    if (!current) return
    setManagedSpaceId(current.id)
    setSpaceDialog(null)

  }
  return <Dialog open={!!spaceDialog && ['manage','create'].includes(spaceDialog.mode)} onOpenChange={open=>{if(!open&&!busy)setSpaceDialog(null)}}>
    <DialogContent className="sm:max-w-md">
      <DialogHeader>
        <DialogTitle>{manage ? `Gérer l’espace « ${current?.display_name || 'introuvable'} »` : 'Créer un espace partagé'}</DialogTitle>
        <DialogDescription className="sr-only">{manage ? 'Paramètres de cet espace' : 'Paramètres du nouvel espace'}</DialogDescription>
      </DialogHeader>
      <form onSubmit={save} className="space-y-4">
        {!manage && <div className="space-y-2"><Label htmlFor="space-parent">Espace parent</Label>
          <select id="space-parent" value={parent} onChange={e=>{setParent(e.target.value);setQuota(fromQuota(managed.find(sp=>sp.id===Number(e.target.value))?.quota_bytes))}} required
            className="h-10 w-full rounded-md border bg-background px-3 text-sm">
            {managed.map(space=><option key={space.id} value={space.id}>{space.display_name}</option>)}
          </select></div>}
        {canMove && <div className="space-y-2"><Label htmlFor="space-new-parent">Espace parent</Label>
          <select id="space-new-parent" value={parent} disabled={busy} onChange={e=>setParent(e.target.value)}
            className="h-10 w-full rounded-md border bg-background px-3 text-sm">
            {current?.parent_id && !eligibleParents.some(space => space.id === current.parent_id) &&
              <option value={current.parent_id}>{spaces.find(space => space.id === current.parent_id)?.display_name || 'Parent actuel'}</option>}
            {eligibleParents.map(space=><option key={space.id} value={space.id}>{space.display_name}</option>)}
          </select>
        </div>}
        <div className="space-y-2"><Label htmlFor="space-name">Nom affiché</Label>
          <Input id="space-name" value={name} onChange={e=>setName(e.target.value)} maxLength={120} required placeholder="Ex. Équipe projet" /></div>
        {(!manage || current?.can_edit_quota) &&
          <QuotaField id="space-quota" value={quota} onChange={setQuota} disabled={busy} />}
        {localError && <p role="alert" className="text-sm text-destructive">{localError}</p>}
        <DialogFooter className="gap-2 sm:justify-between">
          {manage && current?.can_invite && <Button type="button" variant="outline" onClick={members}>Gérer les accès</Button>}
          <Button disabled={busy||!name.trim()||(manage&&!current)||(!manage&&!parent)} type="submit">{busy ? 'Enregistrement…' : manage ? 'Enregistrer' : 'Créer l’espace'}</Button>
        </DialogFooter>
      </form>
    </DialogContent>
  </Dialog>
}

function isDescendant(candidate, ancestor, spaces) {
  if (!ancestor) return false
  let current = candidate
  const visited = new Set()
  while (current && !visited.has(current.id)) {
    if (current.id === ancestor.id) return true
    visited.add(current.id)
    current = spaces.find(space => space.id === current.parent_id)
  }
  return false
}