'use client'

import { useState, useEffect } from 'react'
import { validatePassword } from '@/lib/validation'
import { updatePassword } from '@/lib/auth-actions'
import { useToast } from './ToastContainer'

interface PasswordChangeFormProps {
  userId: string
}

export default function PasswordChangeForm({ userId }: PasswordChangeFormProps) {
  const { showToast } = useToast()
  const [currentPassword, setCurrentPassword] = useState('')
  const [newPassword, setNewPassword] = useState('')
  const [confirmPassword, setConfirmPassword] = useState('')
  const [isSubmitting, setIsSubmitting] = useState(false)
  const [errors, setErrors] = useState<{
    currentPassword?: string
    newPassword?: string
    confirmPassword?: string
  }>({})
  const [touched, setTouched] = useState<{
    currentPassword: boolean
    newPassword: boolean
    confirmPassword: boolean
  }>({
    currentPassword: false,
    newPassword: false,
    confirmPassword: false,
  })

  // Inline validation when fields change
  useEffect(() => {
    if (touched.currentPassword) {
      if (!currentPassword) {
        setErrors((prev) => ({ ...prev, currentPassword: 'Current password is required' }))
      } else {
        setErrors((prev) => ({ ...prev, currentPassword: undefined }))
      }
    }
  }, [currentPassword, touched.currentPassword])

  useEffect(() => {
    if (touched.newPassword) {
      const result = validatePassword(newPassword)
      setErrors((prev) => ({
        ...prev,
        newPassword: result.isValid ? undefined : result.error,
      }))
    }
  }, [newPassword, touched.newPassword])

  useEffect(() => {
    if (touched.confirmPassword) {
      if (!confirmPassword) {
        setErrors((prev) => ({ ...prev, confirmPassword: 'Please confirm your new password' }))
      } else if (newPassword !== confirmPassword) {
        setErrors((prev) => ({ ...prev, confirmPassword: 'Passwords do not match' }))
      } else {
        setErrors((prev) => ({ ...prev, confirmPassword: undefined }))
      }
    }
  }, [confirmPassword, newPassword, touched.confirmPassword])

  const handleCurrentPasswordBlur = () => {
    setTouched((prev) => ({ ...prev, currentPassword: true }))
  }

  const handleNewPasswordBlur = () => {
    setTouched((prev) => ({ ...prev, newPassword: true }))
  }

  const handleConfirmPasswordBlur = () => {
    setTouched((prev) => ({ ...prev, confirmPassword: true }))
  }

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()

    // Validate all fields before submission
    const newPasswordResult = validatePassword(newPassword)

    const newErrors: {
      currentPassword?: string
      newPassword?: string
      confirmPassword?: string
    } = {}

    if (!currentPassword) {
      newErrors.currentPassword = 'Current password is required'
    }

    if (!newPasswordResult.isValid) {
      newErrors.newPassword = newPasswordResult.error
    }

    if (!confirmPassword) {
      newErrors.confirmPassword = 'Please confirm your new password'
    } else if (newPassword !== confirmPassword) {
      newErrors.confirmPassword = 'Passwords do not match'
    }

    if (currentPassword === newPassword) {
      newErrors.newPassword = 'New password must be different from current password'
    }

    if (Object.keys(newErrors).length > 0) {
      setErrors(newErrors)
      setTouched({ currentPassword: true, newPassword: true, confirmPassword: true })
      return
    }

    setIsSubmitting(true)
    setErrors({})

    try {
      const result = await updatePassword(userId, currentPassword, newPassword)

      if (!result.success) {
        if (result.error === 'Current password is incorrect') {
          setErrors({ currentPassword: 'Current password is incorrect' })
          showToast('Current password is incorrect', 'error')
        } else {
          showToast(result.error || 'Password update failed', 'error')
        }
      } else {
        showToast('Password updated successfully', 'success')
        // Reset form
        setCurrentPassword('')
        setNewPassword('')
        setConfirmPassword('')
        setTouched({ currentPassword: false, newPassword: false, confirmPassword: false })
      }
    } catch (err) {
      console.error('Password update error:', err)
      showToast('An error occurred. Please try again.', 'error')
    } finally {
      setIsSubmitting(false)
    }
  }

  return (
    <form onSubmit={handleSubmit} className="space-y-4 sm:space-y-5">
      <div>
        <label htmlFor="currentPassword" className="block text-sm font-medium text-gray-700 mb-2">
          Current Password *
        </label>
        <input
          type="password"
          id="currentPassword"
          value={currentPassword}
          onChange={(e) => setCurrentPassword(e.target.value)}
          onBlur={handleCurrentPasswordBlur}
          className={`w-full px-3 sm:px-4 py-3 border rounded-lg focus:outline-none focus:ring-2 text-sm sm:text-base ${
            errors.currentPassword && touched.currentPassword
              ? 'border-red-500 focus:ring-red-500'
              : 'border-gray-300 focus:ring-blue-500'
          }`}
          placeholder="Enter your current password"
          disabled={isSubmitting}
          autoComplete="current-password"
          aria-invalid={errors.currentPassword && touched.currentPassword ? 'true' : 'false'}
          aria-describedby={errors.currentPassword && touched.currentPassword ? 'current-password-error' : undefined}
        />
        {errors.currentPassword && touched.currentPassword && (
          <p id="current-password-error" className="mt-1.5 text-xs sm:text-sm text-red-600">
            {errors.currentPassword}
          </p>
        )}
      </div>

      <div>
        <label htmlFor="newPassword" className="block text-sm font-medium text-gray-700 mb-2">
          New Password *
        </label>
        <input
          type="password"
          id="newPassword"
          value={newPassword}
          onChange={(e) => setNewPassword(e.target.value)}
          onBlur={handleNewPasswordBlur}
          className={`w-full px-3 sm:px-4 py-3 border rounded-lg focus:outline-none focus:ring-2 text-sm sm:text-base ${
            errors.newPassword && touched.newPassword
              ? 'border-red-500 focus:ring-red-500'
              : 'border-gray-300 focus:ring-blue-500'
          }`}
          placeholder="At least 8 characters"
          disabled={isSubmitting}
          autoComplete="new-password"
          aria-invalid={errors.newPassword && touched.newPassword ? 'true' : 'false'}
          aria-describedby={errors.newPassword && touched.newPassword ? 'new-password-error' : undefined}
        />
        {errors.newPassword && touched.newPassword && (
          <p id="new-password-error" className="mt-1.5 text-xs sm:text-sm text-red-600">
            {errors.newPassword}
          </p>
        )}
        {!errors.newPassword && touched.newPassword && (
          <p className="mt-1.5 text-xs sm:text-sm text-gray-500">
            Password must be at least 8 characters
          </p>
        )}
      </div>

      <div>
        <label htmlFor="confirmPassword" className="block text-sm font-medium text-gray-700 mb-2">
          Confirm New Password *
        </label>
        <input
          type="password"
          id="confirmPassword"
          value={confirmPassword}
          onChange={(e) => setConfirmPassword(e.target.value)}
          onBlur={handleConfirmPasswordBlur}
          className={`w-full px-3 sm:px-4 py-3 border rounded-lg focus:outline-none focus:ring-2 text-sm sm:text-base ${
            errors.confirmPassword && touched.confirmPassword
              ? 'border-red-500 focus:ring-red-500'
              : 'border-gray-300 focus:ring-blue-500'
          }`}
          placeholder="Re-enter your new password"
          disabled={isSubmitting}
          autoComplete="new-password"
          aria-invalid={errors.confirmPassword && touched.confirmPassword ? 'true' : 'false'}
          aria-describedby={
            errors.confirmPassword && touched.confirmPassword ? 'confirm-password-error' : undefined
          }
        />
        {errors.confirmPassword && touched.confirmPassword && (
          <p id="confirm-password-error" className="mt-1.5 text-xs sm:text-sm text-red-600">
            {errors.confirmPassword}
          </p>
        )}
      </div>

      <button
        type="submit"
        disabled={isSubmitting}
        className="w-full px-4 sm:px-5 py-3 bg-blue-500 hover:bg-blue-600 active:bg-blue-700 text-white rounded-lg transition-colors disabled:opacity-50 disabled:cursor-not-allowed tap-target font-medium text-sm sm:text-base"
      >
        {isSubmitting ? 'Updating...' : 'Update Password'}
      </button>
    </form>
  )
}