'use client'

import React, { useState, useEffect, useCallback, useRef } from 'react'

// =============================================================================
// TOAST
// =============================================================================

export interface ToastMessage {
  id: number
  message: string
  type: 'success' | 'error'
}

let toastIdCounter = 0

export function useToast() {
  const [toasts, setToasts] = useState<ToastMessage[]>([])

  const addToast = useCallback((message: string, type: 'success' | 'error' = 'success') => {
    const id = ++toastIdCounter
    setToasts((prev) => [...prev, { id, message, type }])
    setTimeout(() => {
      setToasts((prev) => prev.filter((t) => t.id !== id))
    }, 3500)
  }, [])

  return { toasts, addToast }
}

export function ToastContainer({ toasts }: { toasts: ToastMessage[] }) {
  if (toasts.length === 0) return null
  return (
    <div className="fixed top-4 right-4 z-[100] flex flex-col gap-2">
      {toasts.map((t) => (
        <div
          key={t.id}
          className={`px-5 py-3 rounded-lg shadow-lg text-sm font-medium text-white transition-all animate-slide-in ${
            t.type === 'success' ? 'bg-green-600' : 'bg-red-600'
          }`}
        >
          {t.message}
        </div>
      ))}
    </div>
  )
}

// =============================================================================
// LOADING SKELETON
// =============================================================================

export function Skeleton({ className = '' }: { className?: string }) {
  return <div className={`animate-pulse bg-gray-200 rounded ${className}`} />
}

export function DashboardSkeleton() {
  return (
    <div className="space-y-6">
      <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-4 gap-4">
        {Array.from({ length: 4 }).map((_, i) => (
          <Skeleton key={i} className="h-28 rounded-xl" />
        ))}
      </div>
      <div className="grid grid-cols-1 md:grid-cols-2 xl:grid-cols-3 gap-6">
        {Array.from({ length: 3 }).map((_, i) => (
          <Skeleton key={i} className="h-64 rounded-xl" />
        ))}
      </div>
    </div>
  )
}

// =============================================================================
// MODAL
// =============================================================================

export function Modal({
  open, onClose, title, children, maxWidth = 'max-w-lg',
}: {
  open: boolean; onClose: () => void; title: string
  children: React.ReactNode; maxWidth?: string
}) {
  const overlayRef = useRef<HTMLDivElement>(null)

  useEffect(() => {
    if (!open) return
    const handleEsc = (e: KeyboardEvent) => { if (e.key === 'Escape') onClose() }
    document.addEventListener('keydown', handleEsc)
    return () => document.removeEventListener('keydown', handleEsc)
  }, [open, onClose])

  if (!open) return null

  return (
    <div ref={overlayRef}
      className="fixed inset-0 z-50 flex items-center justify-center bg-black/50 backdrop-blur-sm"
      onClick={(e) => { if (e.target === overlayRef.current) onClose() }}>
      <div className={`bg-white rounded-2xl shadow-2xl w-full ${maxWidth} mx-4 overflow-hidden`}>
        <div className="flex items-center justify-between px-6 py-4 border-b border-gray-200 bg-purple-50">
          <h3 className="text-lg font-semibold text-purple-900">{title}</h3>
          <button onClick={onClose} className="p-1 rounded-lg hover:bg-purple-100 transition-colors text-purple-600">
            <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
            </svg>
          </button>
        </div>
        <div className="px-6 py-4 max-h-[70vh] overflow-y-auto">{children}</div>
      </div>
    </div>
  )
}

// =============================================================================
// STAT CARD, PROGRESS BARS, BADGE
// =============================================================================

export function StatCard({
  title, value, icon, accent = false,
}: {
  title: string; value: string | number; icon: React.ReactNode; accent?: boolean
}) {
  return (
    <div className={`rounded-xl border p-5 transition-all ${
      accent ? 'bg-red-50 border-red-200' : 'bg-white border-gray-200 hover:border-purple-300'
    }`}>
      <div className="flex items-center gap-3">
        <div className={`w-10 h-10 rounded-lg flex items-center justify-center ${
          accent ? 'bg-red-100 text-red-600' : 'bg-purple-100 text-purple-600'
        }`}>{icon}</div>
        <div>
          <p className="text-sm text-gray-500">{title}</p>
          <p className={`text-2xl font-bold ${accent ? 'text-red-700' : 'text-gray-900'}`}>{value}</p>
        </div>
      </div>
    </div>
  )
}

export function ComplianceBar({ score }: { score: number }) {
  const color = score < 40 ? 'bg-red-500' : score < 70 ? 'bg-yellow-500' : 'bg-green-500'
  const textColor = score < 40 ? 'text-red-700' : score < 70 ? 'text-yellow-700' : 'text-green-700'
  return (
    <div className="flex items-center gap-2">
      <div className="flex-1 h-2.5 bg-gray-100 rounded-full overflow-hidden">
        <div className={`h-full rounded-full transition-all ${color}`} style={{ width: `${Math.min(score, 100)}%` }} />
      </div>
      <span className={`text-xs font-semibold min-w-[36px] text-right ${textColor}`}>{score}%</span>
    </div>
  )
}

export function HoursBar({ used, budget }: { used: number; budget: number }) {
  const pct = budget > 0 ? Math.min((used / budget) * 100, 100) : 0
  const over = used > budget
  return (
    <div className="flex items-center gap-2">
      <div className="flex-1 h-2.5 bg-gray-100 rounded-full overflow-hidden">
        <div className={`h-full rounded-full transition-all ${over ? 'bg-red-500' : 'bg-purple-500'}`} style={{ width: `${pct}%` }} />
      </div>
      <span className={`text-xs font-medium min-w-[60px] text-right ${over ? 'text-red-600' : 'text-gray-600'}`}>
        {used}h / {budget}h
      </span>
    </div>
  )
}

export function Badge({ label, className = '' }: { label: string; className?: string }) {
  return (
    <span className={`inline-flex items-center px-2 py-0.5 text-xs font-medium rounded-full border ${className}`}>
      {label}
    </span>
  )
}

// =============================================================================
// FORM COMPONENTS
// =============================================================================

export function FormLabel({ children, htmlFor }: { children: React.ReactNode; htmlFor?: string }) {
  return <label htmlFor={htmlFor} className="block text-sm font-medium text-gray-700 mb-1">{children}</label>
}

export function FormInput({
  id, type = 'text', value, onChange, placeholder, required, min, max, step,
}: {
  id?: string; type?: string; value: string | number; onChange: (val: string) => void
  placeholder?: string; required?: boolean; min?: string | number; max?: string | number; step?: string | number
}) {
  return (
    <input id={id} type={type} value={value} onChange={(e) => onChange(e.target.value)}
      placeholder={placeholder} required={required} min={min} max={max} step={step}
      className="w-full rounded-lg border border-gray-300 px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-purple-500 focus:border-purple-500" />
  )
}

export function FormTextarea({
  id, value, onChange, placeholder, rows = 3,
}: { id?: string; value: string; onChange: (val: string) => void; placeholder?: string; rows?: number }) {
  return (
    <textarea id={id} value={value} onChange={(e) => onChange(e.target.value)}
      placeholder={placeholder} rows={rows}
      className="w-full rounded-lg border border-gray-300 px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-purple-500 focus:border-purple-500 resize-none" />
  )
}

export function FormSelect({
  id, value, onChange, options, placeholder,
}: {
  id?: string; value: string; onChange: (val: string) => void
  options: { value: string; label: string }[]; placeholder?: string
}) {
  return (
    <select id={id} value={value} onChange={(e) => onChange(e.target.value)}
      className="w-full rounded-lg border border-gray-300 px-3 py-2 text-sm focus:outline-none focus:ring-2 focus:ring-purple-500 focus:border-purple-500 bg-white">
      {placeholder && <option value="" disabled>{placeholder}</option>}
      {options.map((o) => <option key={o.value} value={o.value}>{o.label}</option>)}
    </select>
  )
}

export function PrimaryButton({
  onClick, disabled, children, type = 'button', className = '',
}: {
  onClick?: () => void; disabled?: boolean; children: React.ReactNode
  type?: 'button' | 'submit'; className?: string
}) {
  return (
    <button type={type} onClick={onClick} disabled={disabled}
      className={`px-4 py-2 rounded-lg bg-purple-600 text-white text-sm font-medium hover:bg-purple-700 focus:ring-2 focus:ring-purple-500 focus:ring-offset-2 disabled:opacity-50 disabled:cursor-not-allowed transition-colors ${className}`}>
      {children}
    </button>
  )
}

export function SecondaryButton({
  onClick, disabled, children, type = 'button', className = '',
}: {
  onClick?: () => void; disabled?: boolean; children: React.ReactNode
  type?: 'button' | 'submit'; className?: string
}) {
  return (
    <button type={type} onClick={onClick} disabled={disabled}
      className={`px-4 py-2 rounded-lg border border-gray-300 text-gray-700 text-sm font-medium hover:bg-gray-50 focus:ring-2 focus:ring-purple-500 focus:ring-offset-2 disabled:opacity-50 disabled:cursor-not-allowed transition-colors ${className}`}>
      {children}
    </button>
  )
}

// =============================================================================
// ERROR / EMPTY STATES
// =============================================================================

export function ErrorState({ message, onRetry }: { message: string; onRetry: () => void }) {
  return (
    <div className="flex flex-col items-center justify-center py-16 text-center">
      <div className="w-16 h-16 rounded-full bg-red-100 flex items-center justify-center mb-4">
        <svg className="w-8 h-8 text-red-500" fill="none" stroke="currentColor" viewBox="0 0 24 24">
          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2}
            d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4c-.77-.833-1.964-.833-2.732 0L4.082 16.5c-.77.833.192 2.5 1.732 2.5z" />
        </svg>
      </div>
      <p className="text-gray-700 font-medium mb-1">Fehler beim Laden</p>
      <p className="text-sm text-gray-500 mb-4 max-w-md">{message}</p>
      <PrimaryButton onClick={onRetry}>Erneut versuchen</PrimaryButton>
    </div>
  )
}

export function EmptyState({ icon, title, description }: { icon: React.ReactNode; title: string; description: string }) {
  return (
    <div className="flex flex-col items-center justify-center py-12 text-center">
      <div className="w-14 h-14 rounded-full bg-purple-50 flex items-center justify-center mb-3 text-purple-400">{icon}</div>
      <p className="text-gray-700 font-medium">{title}</p>
      <p className="text-sm text-gray-400 mt-1">{description}</p>
    </div>
  )
}

// =============================================================================
// ICONS
// =============================================================================

export function IconUsers({ className = 'w-5 h-5' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M17 20h5v-2a3 3 0 00-5.356-1.857M17 20H7m10 0v-2c0-.656-.126-1.283-.356-1.857M7 20H2v-2a3 3 0 015.356-1.857M7 20v-2c0-.656.126-1.283.356-1.857m0 0a5.002 5.002 0 019.288 0M15 7a3 3 0 11-6 0 3 3 0 016 0zm6 3a2 2 0 11-4 0 2 2 0 014 0zM7 10a2 2 0 11-4 0 2 2 0 014 0z" />
  </svg>)
}

export function IconClock({ className = 'w-5 h-5' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 8v4l3 3m6-3a9 9 0 11-18 0 9 9 0 0118 0z" />
  </svg>)
}

export function IconTask({ className = 'w-5 h-5' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4" />
  </svg>)
}

export function IconAlert({ className = 'w-5 h-5' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4c-.77-.833-1.964-.833-2.732 0L4.082 16.5c-.77.833.192 2.5 1.732 2.5z" />
  </svg>)
}

export function IconBack({ className = 'w-5 h-5' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M10 19l-7-7m0 0l7-7m-7 7h18" />
  </svg>)
}

export function IconPlus({ className = 'w-4 h-4' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
  </svg>)
}

export function IconCheck({ className = 'w-4 h-4' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 13l4 4L19 7" />
  </svg>)
}

export function IconMail({ className = 'w-5 h-5' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 8l7.89 5.26a2 2 0 002.22 0L21 8M5 19h14a2 2 0 002-2V7a2 2 0 00-2-2H5a2 2 0 00-2 2v10a2 2 0 002 2z" />
  </svg>)
}

export function IconSettings({ className = 'w-5 h-5' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M10.325 4.317c.426-1.756 2.924-1.756 3.35 0a1.724 1.724 0 002.573 1.066c1.543-.94 3.31.826 2.37 2.37a1.724 1.724 0 001.066 2.573c1.756.426 1.756 2.924 0 3.35a1.724 1.724 0 00-1.066 2.573c.94 1.543-.826 3.31-2.37 2.37a1.724 1.724 0 00-2.573 1.066c-.426 1.756-2.924 1.756-3.35 0a1.724 1.724 0 00-2.573-1.066c-1.543.94-3.31-.826-2.37-2.37a1.724 1.724 0 00-1.066-2.573c-1.756-.426-1.756-2.924 0-3.35a1.724 1.724 0 001.066-2.573c-.94-1.543.826-3.31 2.37-2.37.996.608 2.296.07 2.572-1.065z" />
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" />
  </svg>)
}

export function IconRefresh({ className = 'w-4 h-4' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15" />
  </svg>)
}

export function IconInbound({ className = 'w-4 h-4' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M11 19l-7-7 7-7m8 14l-7-7 7-7" />
  </svg>)
}

export function IconOutbound({ className = 'w-4 h-4' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M13 5l7 7-7 7M5 5l7 7-7 7" />
  </svg>)
}

export function IconShield({ className = 'w-6 h-6' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12l2 2 4-4m5.618-4.016A11.955 11.955 0 0112 2.944a11.955 11.955 0 01-8.618 3.04A12.02 12.02 0 003 9c0 5.591 3.824 10.29 9 11.622 5.176-1.332 9-6.03 9-11.622 0-1.042-.133-2.052-.382-3.016z" />
  </svg>)
}

export function IconCalendar({ className = 'w-4 h-4' }: { className?: string }) {
  return (<svg className={className} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M8 7V3m8 4V3m-9 8h10M5 21h14a2 2 0 002-2V7a2 2 0 00-2-2H5a2 2 0 00-2 2v12a2 2 0 002 2z" />
  </svg>)
}