'use client'
import { useState, useEffect, useCallback } from 'react'
import { Plus, X, Trash2, ShoppingCart, FileText, Check, Circle, Calendar as CalendarIcon } from 'lucide-react'

interface NoteItem {
  id: string
  text: string
  done: boolean
}

interface Note {
  id: string
  type: 'note' | 'shopping'
  title: string
  items?: NoteItem[]
  text?: string
  color: string
  pinDate: string | null
  createdAt: string
  updatedAt: string
}

const NOTE_COLORS = ['#6366f1', '#ec4899', '#10b981', '#f59e0b', '#3b82f6', '#8b5cf6']

export default function NotesTab() {
  const [notes, setNotes] = useState<Note[]>([])
  const [loading, setLoading] = useState(true)
  const [activeNote, setActiveNote] = useState<Note | null>(null)
  const [showCreate, setShowCreate] = useState(false)
  const [newItemText, setNewItemText] = useState('')

  const load = useCallback(async () => {
    try {
      const r = await fetch('/api/notes')
      const d = await r.json()
      setNotes(d.notes || [])
    } catch {}
    finally { setLoading(false) }
  }, [])

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

  const createNote = async (type: 'note' | 'shopping') => {
    const title = type === 'shopping' ? 'Список покупок' : 'Новая заметка'
    const color = NOTE_COLORS[notes.length % NOTE_COLORS.length]
    try {
      const r = await fetch('/api/notes', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ type, title, color }),
      })
      const d = await r.json()
      setNotes(prev => [d.note, ...prev])
      setActiveNote(d.note)
      setShowCreate(false)
    } catch {}
  }

  const updateNote = async (id: string, updates: Partial<Note>) => {
    try {
      const r = await fetch('/api/notes', {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ id, ...updates }),
      })
      const d = await r.json()
      setNotes(prev => prev.map(n => n.id === id ? d.note : n))
      if (activeNote?.id === id) setActiveNote(d.note)
    } catch {}
  }

  const deleteNote = async (id: string) => {
    try {
      await fetch(`/api/notes?id=${id}`, { method: 'DELETE' })
      setNotes(prev => prev.filter(n => n.id !== id))
      if (activeNote?.id === id) setActiveNote(null)
    } catch {}
  }

  const addItem = async () => {
    if (!newItemText.trim() || !activeNote) return
    const items = [...(activeNote.items || []), { id: Date.now().toString(36), text: newItemText.trim(), done: false }]
    await updateNote(activeNote.id, { items })
    setNewItemText('')
  }

  const toggleItem = async (itemId: string) => {
    if (!activeNote) return
    const items = (activeNote.items || []).map(i => i.id === itemId ? { ...i, done: !i.done } : i)
    await updateNote(activeNote.id, { items })
  }

  const removeItem = async (itemId: string) => {
    if (!activeNote) return
    const items = (activeNote.items || []).filter(i => i.id !== itemId)
    await updateNote(activeNote.id, { items })
  }

  return (
    <div style={{ flex: 1, display: 'flex', overflow: 'hidden', padding: '16px 24px 24px', gap: 16 }}>
      {/* Left: notes list */}
      <div style={{ width: 260, flexShrink: 0, display: 'flex', flexDirection: 'column', gap: 10, overflowY: 'auto' }}>
        <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', marginBottom: 4 }}>
          <h2 style={{ fontSize: 20, fontWeight: 700, color: 'var(--text-primary)', margin: 0 }}>Заметки</h2>
          <button onClick={() => setShowCreate(v => !v)} style={{
            width: 36, height: 36, borderRadius: 12,
            background: showCreate ? 'rgba(255,255,255,0.06)' : 'linear-gradient(135deg, rgba(99,102,241,0.2), rgba(139,92,246,0.15))',
            border: showCreate ? '1px solid rgba(255,255,255,0.08)' : '1px solid rgba(129,140,248,0.25)',
            display: 'flex', alignItems: 'center', justifyContent: 'center',
            color: showCreate ? 'var(--text-secondary)' : '#a5b4fc',
          }}>
            {showCreate ? <X size={16} /> : <Plus size={16} />}
          </button>
        </div>

        {/* Create new */}
        {showCreate && (
          <div style={{ display: 'flex', gap: 8, marginBottom: 4 }}>
            <button onClick={() => createNote('note')} style={{
              flex: 1, padding: '14px 12px', borderRadius: 14,
              background: 'rgba(99,102,241,0.08)', border: '1px solid rgba(129,140,248,0.15)',
              display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 6,
              color: '#a5b4fc', fontSize: 12, fontWeight: 600,
            }}>
              <FileText size={20} />
              Заметка
            </button>
            <button onClick={() => createNote('shopping')} style={{
              flex: 1, padding: '14px 12px', borderRadius: 14,
              background: 'rgba(16,185,129,0.08)', border: '1px solid rgba(16,185,129,0.15)',
              display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 6,
              color: '#34d399', fontSize: 12, fontWeight: 600,
            }}>
              <ShoppingCart size={20} />
              Список
            </button>
          </div>
        )}

        {/* Notes list */}
        {notes.map(note => {
          const isActive = activeNote?.id === note.id
          const doneCount = note.items?.filter(i => i.done).length || 0
          const totalCount = note.items?.length || 0
          return (
            <button key={note.id} onClick={() => setActiveNote(note)} style={{
              padding: '14px 16px', borderRadius: 16, textAlign: 'left', width: '100%',
              background: isActive ? `${note.color}15` : 'rgba(255,255,255,0.025)',
              border: `1px solid ${isActive ? note.color + '30' : 'rgba(255,255,255,0.05)'}`,
              transition: 'all 0.2s ease',
            }}>
              <div style={{ display: 'flex', alignItems: 'center', gap: 8, marginBottom: 6 }}>
                {note.type === 'shopping'
                  ? <ShoppingCart size={14} color={note.color} />
                  : <FileText size={14} color={note.color} />
                }
                <span style={{ fontSize: 14, fontWeight: 600, color: 'var(--text-primary)', overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap', flex: 1 }}>
                  {note.title}
                </span>
              </div>
              {note.pinDate && (
                <div style={{ fontSize: 11, color: note.color, fontWeight: 600, marginBottom: 4, display: 'flex', alignItems: 'center', gap: 4 }}>
                  <CalendarIcon size={11} />
                  {new Date(note.pinDate).toLocaleDateString('ru-RU', { day: 'numeric', month: 'short' })}
                </div>
              )}
              {note.type === 'shopping' && totalCount > 0 && (
                <div style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
                  <div style={{
                    flex: 1, height: 3, borderRadius: 2, background: 'rgba(255,255,255,0.08)',
                    overflow: 'hidden',
                  }}>
                    <div style={{
                      width: `${totalCount > 0 ? (doneCount / totalCount) * 100 : 0}%`,
                      height: '100%', borderRadius: 2, background: note.color,
                      transition: 'width 0.3s ease',
                    }} />
                  </div>
                  <span style={{ fontSize: 11, color: 'var(--text-secondary)', flexShrink: 0 }}>{doneCount}/{totalCount}</span>
                </div>
              )}
              {note.type === 'note' && note.text && (
                <div style={{ fontSize: 12, color: 'var(--text-secondary)', overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>
                  {note.text}
                </div>
              )}
            </button>
          )
        })}

        {!loading && notes.length === 0 && (
          <div style={{ textAlign: 'center', padding: '40px 0', color: 'var(--text-secondary)' }}>
            <FileText size={32} style={{ margin: '0 auto 12px', opacity: 0.3 }} />
            <div style={{ fontSize: 14 }}>Нет заметок</div>
            <div style={{ fontSize: 12, marginTop: 4 }}>Нажмите + чтобы создать</div>
          </div>
        )}
      </div>

      {/* Right: note editor */}
      <div style={{
        flex: 1, display: 'flex', flexDirection: 'column',
        background: 'rgba(255,255,255,0.02)', borderRadius: 22,
        border: '1px solid rgba(255,255,255,0.04)', overflow: 'hidden',
      }}>
        {!activeNote ? (
          <div style={{ flex: 1, display: 'flex', alignItems: 'center', justifyContent: 'center', color: 'var(--text-secondary)' }}>
            <div style={{ textAlign: 'center' }}>
              <FileText size={40} style={{ margin: '0 auto 12px', opacity: 0.2 }} />
              <div style={{ fontSize: 15 }}>Выберите заметку</div>
            </div>
          </div>
        ) : (
          <>
            {/* Header */}
            <div style={{
              padding: '18px 24px', borderBottom: '1px solid rgba(255,255,255,0.05)',
              display: 'flex', flexDirection: 'column', gap: 10,
              background: `${activeNote.color}08`,
            }}>
              <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', gap: 12 }}>
                <input
                  value={activeNote.title}
                  onChange={e => {
                    const newTitle = e.target.value
                    setActiveNote(prev => prev ? { ...prev, title: newTitle } : null)
                  }}
                  onBlur={() => updateNote(activeNote.id, { title: activeNote.title })}
                  style={{
                    background: 'transparent', border: 'none', outline: 'none',
                    fontSize: 18, fontWeight: 700, color: 'var(--text-primary)',
                    fontFamily: 'inherit', flex: 1, minWidth: 0,
                  }}
                />
                <button onClick={() => { if (confirm('Удалить заметку?')) deleteNote(activeNote.id) }} style={{
                  width: 32, height: 32, borderRadius: 10,
                  background: 'rgba(239,68,68,0.08)',
                  display: 'flex', alignItems: 'center', justifyContent: 'center',
                  color: '#f87171', flexShrink: 0,
                }}>
                  <Trash2 size={15} />
                </button>
              </div>
              <div style={{ display: 'flex', alignItems: 'center', gap: 10 }}>
                <CalendarIcon size={14} color={activeNote.color} />
                <input
                  type="date"
                  value={activeNote.pinDate || ''}
                  onChange={e => {
                    const v = e.target.value || null
                    setActiveNote(prev => prev ? { ...prev, pinDate: v } : null)
                    updateNote(activeNote.id, { pinDate: v })
                  }}
                  style={{
                    background: 'rgba(255,255,255,0.04)',
                    border: '1px solid rgba(255,255,255,0.07)',
                    borderRadius: 10, padding: '6px 10px',
                    color: 'var(--text-primary)', fontSize: 13,
                    outline: 'none', fontFamily: 'inherit',
                    colorScheme: 'dark' as any,
                  }}
                />
                {activeNote.pinDate && (
                  <button
                    onClick={() => {
                      setActiveNote(prev => prev ? { ...prev, pinDate: null } : null)
                      updateNote(activeNote.id, { pinDate: null })
                    }}
                    style={{
                      background: 'transparent', border: 'none',
                      color: 'var(--text-tertiary)', fontSize: 12,
                      padding: '4px 8px', cursor: 'pointer',
                    }}
                  >
                    Очистить
                  </button>
                )}
              </div>
            </div>

            {/* Content */}
            <div style={{ flex: 1, overflowY: 'auto', padding: '16px 24px 24px' }}>
              {activeNote.type === 'shopping' ? (
                <>
                  {/* Add item */}
                  <div style={{ display: 'flex', gap: 8, marginBottom: 16 }}>
                    <input
                      value={newItemText}
                      onChange={e => setNewItemText(e.target.value)}
                      onKeyDown={e => e.key === 'Enter' && addItem()}
                      placeholder="Добавить..."
                      style={{
                        flex: 1, padding: '12px 16px', borderRadius: 12,
                        background: 'rgba(255,255,255,0.04)', border: '1px solid rgba(255,255,255,0.07)',
                        color: 'var(--text-primary)', fontSize: 15, outline: 'none', fontFamily: 'inherit',
                        boxSizing: 'border-box' as any,
                      }}
                    />
                    <button onClick={addItem} style={{
                      width: 44, borderRadius: 12,
                      background: `${activeNote.color}20`, border: `1px solid ${activeNote.color}30`,
                      display: 'flex', alignItems: 'center', justifyContent: 'center',
                      color: activeNote.color,
                    }}>
                      <Plus size={18} />
                    </button>
                  </div>

                  {/* Items */}
                  <div style={{ display: 'flex', flexDirection: 'column', gap: 6 }}>
                    {(activeNote.items || []).filter(i => !i.done).map(item => (
                      <div key={item.id} style={{
                        display: 'flex', alignItems: 'center', gap: 12,
                        padding: '12px 14px', borderRadius: 12,
                        background: 'rgba(255,255,255,0.02)', border: '1px solid rgba(255,255,255,0.04)',
                      }}>
                        <button onClick={() => toggleItem(item.id)} style={{
                          width: 22, height: 22, borderRadius: 6,
                          border: `2px solid ${activeNote.color}50`,
                          background: 'transparent',
                          display: 'flex', alignItems: 'center', justifyContent: 'center',
                          flexShrink: 0,
                        }} />
                        <span style={{ flex: 1, fontSize: 15, color: 'var(--text-primary)' }}>{item.text}</span>
                        <button onClick={() => removeItem(item.id)} style={{ color: 'var(--text-tertiary)', padding: 4, flexShrink: 0 }}>
                          <X size={14} />
                        </button>
                      </div>
                    ))}

                    {/* Done items */}
                    {(activeNote.items || []).filter(i => i.done).length > 0 && (
                      <>
                        <div style={{ fontSize: 11, color: 'var(--text-secondary)', fontWeight: 600, textTransform: 'uppercase', letterSpacing: '0.08em', marginTop: 12, marginBottom: 4 }}>
                          Выполнено
                        </div>
                        {(activeNote.items || []).filter(i => i.done).map(item => (
                          <div key={item.id} style={{
                            display: 'flex', alignItems: 'center', gap: 12,
                            padding: '10px 14px', borderRadius: 12,
                            background: 'rgba(255,255,255,0.01)',
                            opacity: 0.5,
                          }}>
                            <button onClick={() => toggleItem(item.id)} style={{
                              width: 22, height: 22, borderRadius: 6,
                              border: 'none', background: activeNote.color,
                              display: 'flex', alignItems: 'center', justifyContent: 'center',
                              flexShrink: 0,
                            }}>
                              <Check size={14} color="#fff" />
                            </button>
                            <span style={{ flex: 1, fontSize: 15, color: 'var(--text-secondary)', textDecoration: 'line-through' }}>{item.text}</span>
                            <button onClick={() => removeItem(item.id)} style={{ color: 'var(--text-tertiary)', padding: 4, flexShrink: 0 }}>
                              <X size={14} />
                            </button>
                          </div>
                        ))}
                      </>
                    )}
                  </div>
                </>
              ) : (
                /* Text note */
                <textarea
                  value={activeNote.text || ''}
                  onChange={e => {
                    const newText = e.target.value
                    setActiveNote(prev => prev ? { ...prev, text: newText } : null)
                  }}
                  onBlur={() => updateNote(activeNote.id, { text: activeNote.text })}
                  placeholder="Начните писать..."
                  style={{
                    width: '100%', height: '100%', resize: 'none',
                    background: 'transparent', border: 'none', outline: 'none',
                    color: 'var(--text-primary)', fontSize: 15, lineHeight: 1.7,
                    fontFamily: 'inherit', boxSizing: 'border-box' as any,
                  }}
                />
              )}
            </div>
          </>
        )}
      </div>
    </div>
  )
}