app.jsx

import React from 'react'

class App extends React.Component {
  constructor(props) {
    super(props)
    // Initialize the state on mount
    this.state = {
      items: props.items,
    }
  }
  
  // Keep the state in sync with props in further updates
  componentDidUpdate = (prevProps) => {
    const items = []
    // after  calculations comparing prevProps with this.props
    if (...) {
      this.setState({ items })
    }
  }
}