'use client'

import { useState, useCallback } from 'react'
import { motion, AnimatePresence } from 'motion/react'
import { Sparkles, X, CheckCircle2, FolderPlus, Folder, ChevronDown, ChevronUp, Loader2, AlertCircle, Check } from 'lucide-react'
import { cn } from '@/lib/utils'
import {
  analyzeNotebookForOrganization,
  executeNotebookOrganization,
  type OrganizationGroup,
  type OrganizationPlan,
} from '@/app/actions/organize-notebook'
import { toast } from 'sonner'
import { useLanguage } from '@/lib/i18n'

interface OrganizeNotebookDialogProps {
  open: boolean
  onOpenChange: (open: boolean) => void
  notebookId: string
  notebookName: string
  onDone?: () => void
}

type Step = 'idle' | 'analyzing' | 'preview' | 'executing' | 'done'

export function OrganizeNotebookDialog({
  open,
  onOpenChange,
  notebookId,
  notebookName,
  onDone,
}: OrganizeNotebookDialogProps) {
  const { t, language } = useLanguage()
  const organizePanelSlide = language === 'fa' || language === 'ar' ? -60 : 60
  const [step, setStep] = useState<Step>('idle')
  const [plan, setPlan] = useState<OrganizationPlan | null>(null)
  const [editableGroups, setEditableGroups] = useState<OrganizationGroup[]>([])
  const [expandedGroups, setExpandedGroups] = useState<Set<number>>(new Set())
  const [error, setError] = useState<string | null>(null)
  const [result, setResult] = useState<{ created: number; moved: number } | null>(null)

  const handleAnalyze = useCallback(async () => {
    setStep('analyzing')
    setError(null)
    setPlan(null)

    const res = await analyzeNotebookForOrganization(notebookId)

    if (!res.success || !res.plan) {
      setError(res.error ?? t('organizeNotebook.unknownError'))
      setStep('idle')
      return
    }

    setPlan(res.plan)
    setEditableGroups(res.plan.groups.map(g => ({ ...g, notes: [...g.notes] })))
    setExpandedGroups(new Set(res.plan.groups.map((_, i) => i)))
    setStep('preview')
  }, [notebookId])

  const handleRenameGroup = (idx: number, name: string) => {
    setEditableGroups(prev => prev.map((g, i) => i === idx ? { ...g, name } : g))
  }

  const handleToggleNote = (groupIdx: number, noteId: string) => {
    setEditableGroups(prev => prev.map((g, i) => {
      if (i !== groupIdx) return g
      const has = g.notes.some(n => n.id === noteId)
      return {
        ...g,
        notes: has ? g.notes.filter(n => n.id !== noteId) : g.notes,
      }
    }))
  }

  const handleRemoveGroup = (idx: number) => {
    setEditableGroups(prev => prev.filter((_, i) => i !== idx))
  }

  const toggleExpand = (idx: number) => {
    setExpandedGroups(prev => {
      const next = new Set(prev)
      next.has(idx) ? next.delete(idx) : next.add(idx)
      return next
    })
  }

  const handleExecute = useCallback(async () => {
    if (!plan) return
    setStep('executing')

    const finalPlan: OrganizationPlan = {
      notebookId: plan.notebookId,
      groups: editableGroups.filter(g => g.notes.length > 0 && g.name.trim()),
    }

    const res = await executeNotebookOrganization(finalPlan)

    if (!res.success) {
      setError(res.error ?? t('organizeNotebook.unknownError'))
      setStep('preview')
      return
    }

    setResult({ created: res.created, moved: res.moved })
    setStep('done')
    toast.success(t('organizeNotebook.toastSuccess', { created: res.created, moved: res.moved }))
    onDone?.()
  }, [plan, editableGroups, onDone])

  const handleClose = () => {
    if (step === 'analyzing' || step === 'executing') return
    onOpenChange(false)
    // Reset after close animation
    setTimeout(() => {
      setStep('idle')
      setPlan(null)
      setEditableGroups([])
      setError(null)
      setResult(null)
    }, 300)
  }

  if (!open) return null

  const totalNotes = editableGroups.reduce((acc, g) => acc + g.notes.length, 0)
  const newSubNbs = editableGroups.filter(g => g.isNew).length

  return (
    <AnimatePresence>
      {open && (
        <>
          {/* Backdrop */}
          <motion.div
            initial={{ opacity: 0 }}
            animate={{ opacity: 1 }}
            exit={{ opacity: 0 }}
            className="fixed inset-0 z-50 bg-ink/30 backdrop-blur-sm"
            onClick={handleClose}
          />

          {/* Panel */}
          <motion.div
            initial={{ opacity: 0, x: organizePanelSlide }}
            animate={{ opacity: 1, x: 0 }}
            exit={{ opacity: 0, x: organizePanelSlide }}
            transition={{ type: 'spring', stiffness: 280, damping: 30 }}
            className="fixed end-0 top-0 bottom-0 z-50 w-[460px] bg-card border-s border-border shadow-2xl flex flex-col"
            onClick={e => e.stopPropagation()}
          >
            {/* Header */}
            <div className="px-6 py-5 border-b border-border/60 flex items-center justify-between shrink-0">
              <div className="flex items-center gap-3">
                <div className="w-8 h-8 rounded-lg bg-brand-accent/10 flex items-center justify-center">
                  <Sparkles size={16} className="text-brand-accent" />
                </div>
                <div>
                  <h2 className="text-[13px] font-semibold text-ink">{t('organizeNotebook.title')}</h2>
                  <p className="text-[11px] text-muted-ink truncate max-w-[240px]">{notebookName}</p>
                </div>
              </div>
              <button
                onClick={handleClose}
                disabled={step === 'analyzing' || step === 'executing'}
                className="w-7 h-7 rounded-md flex items-center justify-center text-muted-ink hover:text-ink hover:bg-foreground/5 transition-colors disabled:opacity-30"
              >
                <X size={14} />
              </button>
            </div>

            {/* Content */}
            <div className="flex-1 overflow-y-auto">
              <AnimatePresence mode="wait">

                {/* IDLE */}
                {step === 'idle' && (
                  <motion.div
                    key="idle"
                    initial={{ opacity: 0, y: 12 }}
                    animate={{ opacity: 1, y: 0 }}
                    exit={{ opacity: 0, y: -12 }}
                    className="p-6 space-y-5"
                  >
                    {error && (
                      <div className="flex items-start gap-3 p-3 rounded-xl bg-rose-50 dark:bg-rose-950/30 border border-rose-200 dark:border-rose-800/50">
                        <AlertCircle size={14} className="text-rose-500 mt-0.5 shrink-0" />
                        <p className="text-[12px] text-rose-600 dark:text-rose-400">{error}</p>
                      </div>
                    )}
                    <div className="space-y-3">
                      <p className="text-[13px] text-ink leading-relaxed">
                        {t('organizeNotebook.intro')}
                      </p>
                      <ul className="space-y-2">
                        {[t('organizeNotebook.bulletThemes'), t('organizeNotebook.bulletSubfolders'), t('organizeNotebook.bulletPreview')].map(item => (
                          <li key={item} className="flex items-center gap-2 text-[12px] text-muted-ink">
                            <div className="w-1.5 h-1.5 rounded-full bg-brand-accent shrink-0" />
                            {item}
                          </li>
                        ))}
                      </ul>
                    </div>
                  </motion.div>
                )}

                {/* ANALYZING */}
                {step === 'analyzing' && (
                  <motion.div
                    key="analyzing"
                    initial={{ opacity: 0 }}
                    animate={{ opacity: 1 }}
                    exit={{ opacity: 0 }}
                    className="flex flex-col items-center justify-center p-12 gap-6 min-h-[300px]"
                  >
                    <div className="relative">
                      <div className="w-16 h-16 rounded-2xl bg-brand-accent/10 flex items-center justify-center">
                        <Sparkles size={28} className="text-brand-accent" />
                      </div>
                      <motion.div
                        animate={{ rotate: 360 }}
                        transition={{ duration: 2, repeat: Infinity, ease: 'linear' }}
                        className="absolute -inset-2 rounded-2xl border-2 border-transparent border-t-brand-accent/40"
                      />
                    </div>
                    <div className="text-center space-y-1.5">
                      <p className="text-[14px] font-medium text-ink">{t('organizeNotebook.analyzingTitle')}</p>
                      <p className="text-[12px] text-muted-ink">{t('organizeNotebook.analyzingSubtitle')}</p>
                    </div>
                    <div className="flex gap-1.5">
                      {[0, 1, 2].map(i => (
                        <motion.div
                          key={i}
                          animate={{ opacity: [0.3, 1, 0.3] }}
                          transition={{ duration: 1.2, repeat: Infinity, delay: i * 0.2 }}
                          className="w-1.5 h-1.5 rounded-full bg-brand-accent"
                        />
                      ))}
                    </div>
                  </motion.div>
                )}

                {/* PREVIEW */}
                {step === 'preview' && (
                  <motion.div
                    key="preview"
                    initial={{ opacity: 0, y: 12 }}
                    animate={{ opacity: 1, y: 0 }}
                    exit={{ opacity: 0 }}
                    className="p-5 space-y-4"
                  >
                    {/* Summary bar */}
                    <div className="flex items-center gap-3 p-3 rounded-xl bg-brand-accent/5 border border-brand-accent/20">
                      <Sparkles size={12} className="text-brand-accent shrink-0" />
                      <p className="text-[11px] text-brand-accent font-medium">
                        {t('organizeNotebook.previewSummary', {
                          groups: editableGroups.length,
                          notes: totalNotes,
                          newSubs: newSubNbs,
                        })}
                      </p>
                    </div>

                    {error && (
                      <div className="flex items-start gap-3 p-3 rounded-xl bg-rose-50 dark:bg-rose-950/30 border border-rose-200 dark:border-rose-800/50">
                        <AlertCircle size={14} className="text-rose-500 mt-0.5 shrink-0" />
                        <p className="text-[12px] text-rose-600 dark:text-rose-400">{error}</p>
                      </div>
                    )}

                    {/* Groups */}
                    <div className="space-y-3">
                      {editableGroups.map((group, idx) => (
                        <motion.div
                          key={idx}
                          layout
                          initial={{ opacity: 0, y: 8 }}
                          animate={{ opacity: 1, y: 0 }}
                          transition={{ delay: idx * 0.05 }}
                          className="rounded-xl border border-border bg-background overflow-hidden"
                        >
                          {/* Group header */}
                          <div className="flex items-center gap-2 px-3 py-2.5">
                            <div className="w-6 h-6 rounded-md flex items-center justify-center shrink-0">
                              {group.isNew
                                ? <FolderPlus size={13} className="text-brand-accent" />
                                : <Folder size={13} className="text-muted-ink" />
                              }
                            </div>
                            <input
                              value={group.name}
                              onChange={e => handleRenameGroup(idx, e.target.value)}
                              className="flex-1 bg-transparent text-[12px] font-semibold text-ink outline-none focus:text-brand-accent transition-colors min-w-0"
                            />
                            {group.isNew && (
                              <span className="px-1.5 py-0.5 rounded text-[9px] font-bold uppercase tracking-wider bg-brand-accent/10 text-brand-accent shrink-0">
                                {t('organizeNotebook.badgeNew')}
                              </span>
                            )}
                            <div className="flex items-center gap-1 shrink-0">
                              <button
                                onClick={() => toggleExpand(idx)}
                                className="w-6 h-6 rounded flex items-center justify-center text-muted-ink hover:text-ink transition-colors"
                              >
                                {expandedGroups.has(idx) ? <ChevronUp size={12} /> : <ChevronDown size={12} />}
                              </button>
                              <button
                                onClick={() => handleRemoveGroup(idx)}
                                className="w-6 h-6 rounded flex items-center justify-center text-muted-ink hover:text-rose-500 transition-colors"
                              >
                                <X size={12} />
                              </button>
                            </div>
                          </div>

                          {/* Notes list */}
                          <AnimatePresence>
                            {expandedGroups.has(idx) && (
                              <motion.div
                                initial={{ height: 0 }}
                                animate={{ height: 'auto' }}
                                exit={{ height: 0 }}
                                className="overflow-hidden"
                              >
                                <div className="border-t border-border/40 px-3 pb-2 pt-1 space-y-0.5">
                                  {group.notes.map(note => (
                                    <div
                                      key={note.id}
                                      className="flex items-center gap-2 py-1.5 rounded-lg px-2 hover:bg-foreground/3 transition-colors group cursor-pointer"
                                      onClick={() => handleToggleNote(idx, note.id)}
                                    >
                                      <div className="w-4 h-4 rounded border border-border flex items-center justify-center shrink-0 group-hover:border-brand-accent/50 transition-colors">
                                        <Check size={10} className="text-brand-accent" />
                                      </div>
                                      <span className="text-[11px] text-muted-ink truncate group-hover:text-ink transition-colors">
                                        {note.title || t('organizeNotebook.untitledNote')}
                                      </span>
                                    </div>
                                  ))}
                                </div>
                              </motion.div>
                            )}
                          </AnimatePresence>

                          {/* Collapsed count */}
                          {!expandedGroups.has(idx) && (
                            <div className="px-4 pb-2.5 text-[11px] text-muted-ink/60">
                              {t('organizeNotebook.notesInGroup', { count: group.notes.length })}
                            </div>
                          )}
                        </motion.div>
                      ))}
                    </div>
                  </motion.div>
                )}

                {/* EXECUTING */}
                {step === 'executing' && (
                  <motion.div
                    key="executing"
                    initial={{ opacity: 0 }}
                    animate={{ opacity: 1 }}
                    className="flex flex-col items-center justify-center p-12 gap-5 min-h-[300px]"
                  >
                    <Loader2 size={32} className="text-brand-accent animate-spin" />
                    <div className="text-center space-y-1">
                      <p className="text-[14px] font-medium text-ink">{t('organizeNotebook.executingTitle')}</p>
                      <p className="text-[12px] text-muted-ink">{t('organizeNotebook.executingSubtitle')}</p>
                    </div>
                  </motion.div>
                )}

                {/* DONE */}
                {step === 'done' && (
                  <motion.div
                    key="done"
                    initial={{ opacity: 0, scale: 0.95 }}
                    animate={{ opacity: 1, scale: 1 }}
                    className="flex flex-col items-center justify-center p-12 gap-5 min-h-[300px]"
                  >
                    <div className="w-16 h-16 rounded-2xl bg-emerald-50 dark:bg-emerald-950/30 flex items-center justify-center">
                      <CheckCircle2 size={32} className="text-emerald-500" />
                    </div>
                    <div className="text-center space-y-1.5">
                      <p className="text-[15px] font-semibold text-ink">{t('organizeNotebook.doneTitle')}</p>
                      {result && (
                        <p className="text-[12px] text-muted-ink">
                          {t('organizeNotebook.doneStats', { created: result.created, moved: result.moved })}
                        </p>
                      )}
                    </div>
                  </motion.div>
                )}

              </AnimatePresence>
            </div>

            {/* Footer actions */}
            <div className="px-5 py-4 border-t border-border/60 shrink-0">
              {step === 'idle' && (
                <button
                  onClick={handleAnalyze}
                  className="w-full flex items-center justify-center gap-2 px-4 py-2.5 rounded-xl bg-ink text-paper text-[13px] font-semibold hover:opacity-85 transition-opacity"
                >
                  <Sparkles size={14} />
                  {t('organizeNotebook.analyzeButton')}
                </button>
              )}

              {step === 'preview' && (
                <div className="flex gap-2">
                  <button
                    onClick={() => { setStep('idle'); setError(null) }}
                    className="flex-1 px-4 py-2.5 rounded-xl border border-border text-[13px] font-medium text-muted-ink hover:text-ink transition-colors"
                  >
                    {t('organizeNotebook.restart')}
                  </button>
                  <button
                    onClick={handleExecute}
                    disabled={editableGroups.filter(g => g.notes.length > 0).length === 0}
                    className={cn(
                      'flex-1 flex items-center justify-center gap-2 px-4 py-2.5 rounded-xl text-[13px] font-semibold transition-all',
                      editableGroups.filter(g => g.notes.length > 0).length > 0
                        ? 'bg-ink text-paper hover:opacity-85'
                        : 'bg-foreground/10 text-muted-ink cursor-not-allowed'
                    )}
                  >
                    <Check size={14} />
                    {t('organizeNotebook.confirm')}
                  </button>
                </div>
              )}

              {step === 'done' && (
                <button
                  onClick={handleClose}
                  className="w-full px-4 py-2.5 rounded-xl border border-border text-[13px] font-medium text-muted-ink hover:text-ink transition-colors"
                >
                  {t('organizeNotebook.closeButton')}
                </button>
              )}
            </div>
          </motion.div>
        </>
      )}
    </AnimatePresence>
  )
}