'use client'

import { useState, useRef, useEffect, useCallback } from 'react'
import { useRouter } from 'next/navigation'
import { toast } from 'sonner'
import { Input } from '@/components/ui/input'
import { Textarea } from '@/components/ui/textarea'
import { Button } from '@/components/ui/button'
import { cn } from '@/lib/utils'
import { Plus, Loader2, Sparkles, X, Text, ChevronDown } from 'lucide-react'
import { inferNoteType, formatContentForType } from '@/lib/type-inference'
import { NoteType } from '@/types/note'

interface TypeSuggestion {
  type: NoteType
  confidence: 'high' | 'medium' | 'low'
  reason: string
  formattedContent: string
}

const TYPE_LABELS: Record<NoteType, string> = {
  command: 'Comando',
  snippet: 'Snippet',
  procedure: 'Procedimiento',
  recipe: 'Receta',
  decision: 'Decisión',
  inventory: 'Inventario',
  note: 'Nota',
}

export function QuickAdd() {
  const [value, setValue] = useState('')
  const [isLoading, setIsLoading] = useState(false)
  const [isOpen, setIsOpen] = useState(false)
  const [isMultiline, setIsMultiline] = useState(false)
  const [typeSuggestion, setTypeSuggestion] = useState<TypeSuggestion | null>(null)
  const [dismissedSuggestion, setDismissedSuggestion] = useState(false)
  const inputRef = useRef<HTMLInputElement>(null)
  const textareaRef = useRef<HTMLTextAreaElement>(null)
  const popupRef = useRef<HTMLDivElement>(null)
  const router = useRouter()

  const detectContentType = useCallback((text: string) => {
    if (!text.trim() || text.length < 10) {
      setTypeSuggestion(null)
      return
    }
    if (dismissedSuggestion) return

    const suggestion = inferNoteType(text)
    if (suggestion && suggestion.confidence === 'high') {
      const formatted = formatContentForType(text, suggestion.type)
      setTypeSuggestion({
        ...suggestion,
        formattedContent: formatted,
      })
    } else {
      setTypeSuggestion(null)
    }
  }, [dismissedSuggestion])

  const handlePaste = (e: React.ClipboardEvent) => {
    setDismissedSuggestion(false)
    setTimeout(() => {
      detectContentType(value)
    }, 0)
  }

  const acceptSuggestion = () => {
    if (typeSuggestion) {
      setValue(typeSuggestion.formattedContent)
      setTypeSuggestion(null)
      setIsMultiline(true)
      setIsOpen(true)
    }
  }

  const dismissSuggestion = () => {
    setTypeSuggestion(null)
    setDismissedSuggestion(true)
  }

  const handleSubmit = async (e?: React.FormEvent) => {
    e?.preventDefault()
    if (!value.trim() || isLoading) return

    setIsLoading(true)
    try {
      const response = await fetch('/api/notes/quick', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ text: value }),
      })

      if (!response.ok) {
        const error = await response.json()
        throw new Error(error.error || 'Error creating note')
      }

      const note = await response.json()
      toast.success('Nota creada', {
        description: note.title,
      })
      setValue('')
      setIsOpen(false)
      setIsMultiline(false)
      router.refresh()
    } catch (error) {
      toast.error('Error', {
        description: error instanceof Error ? error.message : 'No se pudo crear la nota',
      })
    } finally {
      setIsLoading(false)
    }
  }

  const handleKeyDown = (e: React.KeyboardEvent) => {
    if (e.key === 'Enter' && !e.shiftKey && !isMultiline) {
      e.preventDefault()
      handleSubmit()
    }
    if (e.key === 'Escape') {
      setValue('')
      setIsOpen(false)
      setIsMultiline(false)
      inputRef.current?.blur()
      textareaRef.current?.blur()
    }
  }

  const toggleMultiline = () => {
    setIsMultiline(!isMultiline)
    if (!isMultiline) {
      setTimeout(() => textareaRef.current?.focus(), 0)
    }
  }

  const handleInputFocus = () => {
    setIsOpen(true)
  }

  // Close popup when clicking outside
  useEffect(() => {
    const handleClickOutside = (e: MouseEvent) => {
      if (popupRef.current && !popupRef.current.contains(e.target as Node)) {
        setIsOpen(false)
      }
    }
    if (isOpen) {
      document.addEventListener('mousedown', handleClickOutside)
    }
    return () => document.removeEventListener('mousedown', handleClickOutside)
  }, [isOpen])

  // Focus on keyboard shortcut
  useEffect(() => {
    const handleGlobalKeyDown = (e: KeyboardEvent) => {
      if ((e.key === 'n' && (e.metaKey || e.ctrlKey)) || (e.key === 'n' && e.altKey)) {
        e.preventDefault()
        inputRef.current?.focus()
        inputRef.current?.select()
        setIsOpen(true)
      }
      if (e.key === 'Escape' && document.activeElement === inputRef.current) {
        inputRef.current?.blur()
        setIsOpen(false)
      }
    }
    window.addEventListener('keydown', handleGlobalKeyDown)
    return () => window.removeEventListener('keydown', handleGlobalKeyDown)
  }, [])

  return (
    <div className="relative" ref={popupRef}>
      {/* Compact input row */}
      <form onSubmit={handleSubmit} className="flex items-center gap-1.5">
        <div className="relative">
          <Input
            ref={inputRef}
            type="text"
            placeholder="cmd: título..."
            value={value}
            onChange={(e) => {
              setValue(e.target.value)
              detectContentType(e.target.value)
              if (e.target.value) setIsOpen(true)
            }}
            onKeyDown={handleKeyDown}
            onFocus={handleInputFocus}
            onPaste={handlePaste}
            className="w-full sm:w-80 h-9 pr-16"
            disabled={isLoading}
          />
          {isLoading && (
            <Loader2 className="absolute right-2 top-1/2 -translate-y-1/2 h-4 w-4 animate-spin text-muted-foreground" />
          )}
          {/* Action buttons inside input */}
          <div className="absolute right-1 top-1/2 -translate-y-1/2 flex items-center gap-0.5">
            <button
              type="button"
              onClick={toggleMultiline}
              className={cn(
                'p-1 rounded hover:bg-accent transition-colors',
                isMultiline && 'bg-accent text-accent-foreground'
              )}
              title={isMultiline ? 'Modo línea' : 'Modo multilínea'}
            >
              {isMultiline ? (
                <ChevronDown className="h-3.5 w-3.5" />
              ) : (
                <Text className="h-3.5 w-3.5" />
              )}
            </button>
            <button
              type="submit"
              disabled={!value.trim() || isLoading}
              className={cn(
                'p-1 rounded hover:bg-accent transition-colors',
                'disabled:pointer-events-none disabled:opacity-30'
              )}
            >
              {isLoading ? (
                <Loader2 className="h-3.5 w-3.5 animate-spin" />
              ) : (
                <Plus className="h-3.5 w-3.5" />
              )}
            </button>
          </div>
        </div>
      </form>

      {/* Expanded popup */}
      {isOpen && (
        <div className="absolute top-full left-0 right-0 mt-2 p-3 bg-popover border rounded-lg shadow-lg z-50">
          {/* Multiline textarea (shown when multiline mode) */}
          {isMultiline && (
            <Textarea
              ref={textareaRef}
              placeholder="Contenido multilínea..."
              value={value}
              onChange={(e) => {
                setValue(e.target.value)
                detectContentType(e.target.value)
              }}
              onKeyDown={handleKeyDown}
              onPaste={handlePaste}
              className="min-h-[100px] max-h-[200px] resize-none w-full"
              disabled={isLoading}
            />
          )}

          {/* Smart paste suggestion */}
          {typeSuggestion && (
            <div className="mt-2 p-2 bg-muted/50 rounded-lg border">
              <div className="flex items-start gap-2">
                <Sparkles className="h-4 w-4 text-primary mt-0.5 flex-shrink-0" />
                <div className="flex-1 min-w-0">
                  <p className="text-sm font-medium">
                    Detectado: <span className="text-primary">{TYPE_LABELS[typeSuggestion.type]}</span>
                  </p>
                  <p className="text-xs text-muted-foreground mt-0.5">{typeSuggestion.reason}</p>
                </div>
                <button
                  type="button"
                  onClick={dismissSuggestion}
                  className="p-1 hover:bg-accent rounded"
                >
                  <X className="h-3 w-3" />
                </button>
              </div>
              <div className="mt-2 flex gap-2">
                <button
                  type="button"
                  onClick={acceptSuggestion}
                  className="text-xs px-2 py-1 bg-primary text-primary-foreground rounded hover:bg-primary/90"
                >
                  Usar plantilla
                </button>
                <button
                  type="button"
                  onClick={dismissSuggestion}
                  className="text-xs px-2 py-1 text-muted-foreground hover:bg-accent rounded"
                >
                  Descartar
                </button>
              </div>
            </div>
          )}

          {/* Help text */}
          {!value && !typeSuggestion && (
            <div className="text-xs text-muted-foreground">
              Usa prefijos como <span className="font-mono bg-muted px-1 rounded">cmd:</span>, <span className="font-mono bg-muted px-1 rounded">snip:</span> para тип notes
            </div>
          )}
        </div>
      )}
    </div>
  )
}