import React from 'react';
import { Transition } from '@headlessui/react'

export default class SiteSwitcher extends React.Component {
  constructor() {
    super()
    this.handleClick = this.handleClick.bind(this);
    this.handleKeydown = this.handleKeydown.bind(this);
    this.populateSites = this.populateSites.bind(this);
    this.toggle = this.toggle.bind(this);
    this.siteSwitcherButton = React.createRef();
    this.state = {
      open: false,
      sites: null,
      error: null,
      loading: true
    }
  }

  componentDidMount() {
    this.populateSites();
    this.siteSwitcherButton.current.addEventListener("click", this.toggle);
    document.addEventListener("keydown", this.handleKeydown);
    document.addEventListener('click', this.handleClick, false);
  }
  
  componentWillUnmount() {
    this.siteSwitcherButton.current.removeEventListener("click", this.toggle);
    document.removeEventListener("keydown", this.handleKeydown);
    document.removeEventListener('click', this.handleClick, false);
  }

  populateSites() {
    if (!this.props.loggedIn) return;

    fetch('/api/sites')
      .then( response => {
        if (!response.ok) { throw response }
        return response.json()
      })
      .then((sites) => this.setState({loading: false, sites: sites}))
      .catch((e) => this.setState({loading: false, error: e}))
  }

  handleClick(e) {
    // If this is an interaction with the dropdown menu itself, do nothing.
    if (this.dropDownNode && this.dropDownNode.contains(e.target)) return;

    // If the dropdown is not open, do nothing.
    if (!this.state.open) return;

    // In any other case, close it.
    this.setState({ open: false });
  }

  handleKeydown(e) {
    const { site } = this.props;
    const { sites } = this.state;

    if (e.target.tagName === 'INPUT') return true;
    if (e.ctrlKey || e.metaKey || e.altKey || e.isComposing || e.keyCode === 229 || !sites) return;

    const siteNum = parseInt(e.key)

    if (1 <= siteNum && siteNum <= 9 && siteNum <= sites.length && sites[siteNum-1] !== site.domain) {
      window.location = `/${encodeURIComponent(sites[siteNum-1])}`
    }

  }

  toggle(e) {
    /**
     * React doesn't seem to prioritise its own events when events are bubbling, and is unable to stop its events from propagating to the document's (root) event listeners which are attached on the DOM.
     * 
     * A simple trick is to hook up our own click event listener via a ref node, which allows React to manage events in this situation better between the two.
     */
    e.stopPropagation();
    e.preventDefault();
    if (!this.props.loggedIn) return;

    this.setState((prevState) => ({
      open: !prevState.open
    }))

    if (!this.state.sites) {
      this.populateSites();
    }
  }

  renderSiteLink(domain, index) {
    const extraClass = domain === this.props.site.domain ? 'font-medium text-gray-900 dark:text-gray-100 cursor-default font-bold' : 'hover:bg-gray-100 dark:hover:bg-gray-900 hover:text-gray-900 dark:hover:text-gray-100 focus:outline-none focus:bg-gray-100 dark:focus:bg-gray-900 focus:text-gray-900 dark:focus:text-gray-100'
    return (
      <a href={domain === this.props.site.domain ? null : `/${encodeURIComponent(domain)}`} key={domain} className={`flex items-center justify-between truncate px-4 py-2 md:text-sm leading-5 text-gray-700 dark:text-gray-300 ${extraClass}`}>
        <span>
          <img src={`/favicon/sources/${encodeURIComponent(domain)}`} className="inline w-4 mr-2 align-middle" />
          <span className="truncate inline-block align-middle max-w-3xs pr-2">{domain}</span>
        </span>
        {index < 9 && <span>{index+1}</span>}
      </a>
    )
  }

  renderSettingsLink() {
    if (['owner', 'admin'].includes(this.props.currentUserRole)) {
      return (
        <React.Fragment>
          <div className="py-1">
            <a href={`/${encodeURIComponent(this.props.site.domain)}/settings`} className="group flex items-center px-4 py-2 md:text-sm leading-5 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-900 hover:text-gray-900 dark:hover:text-gray-100 focus:outline-none focus:bg-gray-100 dark:focus:bg-gray-900 focus:text-gray-900 dark:focus:text-gray-100" role="menuitem">
              <svg className="mr-2 h-4 w-4 text-gray-500 dark:text-gray-200 group-hover:text-gray-600 dark:group-hover:text-gray-400 group-focus:text-gray-500 dark:group-focus:text-gray-200" fill="currentColor" viewBox="0 0 20 20" xmlns="http://www.w3.org/2000/svg"><path fillRule="evenodd" d="M11.49 3.17c-.38-1.56-2.6-1.56-2.98 0a1.532 1.532 0 01-2.286.948c-1.372-.836-2.942.734-2.106 2.106.54.886.061 2.042-.947 2.287-1.561.379-1.561 2.6 0 2.978a1.532 1.532 0 01.947 2.287c-.836 1.372.734 2.942 2.106 2.106a1.532 1.532 0 012.287.947c.379 1.561 2.6 1.561 2.978 0a1.533 1.533 0 012.287-.947c1.372.836 2.942-.734 2.106-2.106a1.533 1.533 0 01.947-2.287c1.561-.379 1.561-2.6 0-2.978a1.532 1.532 0 01-.947-2.287c.836-1.372-.734-2.942-2.106-2.106a1.532 1.532 0 01-2.287-.947zM10 13a3 3 0 100-6 3 3 0 000 6z" clipRule="evenodd"></path></svg>
              Site settings
            </a>
          </div>
          <div className="border-t border-gray-200 dark:border-gray-500"></div>
        </React.Fragment>
      )
    }
  }

  renderDropdown() {
    if (this.state.loading) {
      return <div className="px-4 py-6"><div className="loading sm mx-auto"><div></div></div></div>
    } else if (this.state.error) {
      return <div className="mx-auto px-4 py-6 dark:text-gray-100">Something went wrong, try again</div>
    } else {
      return (
        <React.Fragment>
          { this.renderSettingsLink() }
          <div className="py-1">
            { this.state.sites.map(this.renderSiteLink.bind(this)) }
          </div>
          <div className="border-t border-gray-200 dark:border-gray-500"></div>
          <div className="py-1">
            <a href='/sites/new' className="group flex items-center px-4 py-2 md:text-sm leading-5 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-900 hover:text-gray-900 dark:hover:text-gray-100 focus:outline-none focus:bg-gray-100 dark:focus:bg-gray-900 focus:text-gray-900 dark:focus:text-gray-100" role="menuitem">
            <svg className="mr-2 h-4 w-4 text-gray-500 dark:text-gray-200 group-hover:text-gray-600 dark:group-hover:text-gray-400 group-focus:text-gray-500 dark:group-focus:text-gray-200" fill="none" stroke="currentColor" viewBox="0 0 20 20" xmlns="http://www.w3.org/2000/svg"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth="2" d="M12 6v6m0 0v6m0-6h6m-6 0H6"></path></svg>
              Add Site
            </a>
          </div>
        </React.Fragment>
      )
    }
  }

  renderArrow() {
    if (this.props.loggedIn) {
      return (
        <svg className="-mr-1 ml-1 md:ml-2 h-5 w-5" viewBox="0 0 20 20" fill="currentColor">
          <path fillRule="evenodd" d="M5.293 7.293a1 1 0 011.414 0L10 10.586l3.293-3.293a1 1 0 111.414 1.414l-4 4a1 1 0 01-1.414 0l-4-4a1 1 0 010-1.414z" clipRule="evenodd" />
        </svg>
      )
    }
  }

  render() {
    const hoverClass = this.props.loggedIn ? 'hover:text-gray-500 dark:hover:text-gray-200 focus:border-blue-300 focus:ring ' : 'cursor-default'

    return (
      <div className="relative inline-block text-left mr-2 sm:mr-4">
        <button ref={this.siteSwitcherButton} className={`inline-flex items-center md:text-lg w-full rounded-md py-2 leading-5 font-bold text-gray-700 dark:text-gray-300 focus:outline-none transition ease-in-out duration-150 ${hoverClass}`}>

          <img src={`https://icons.duckduckgo.com/ip3/${this.props.site.domain}.ico`} onError={(e)=>{e.target.onerror = null; e.target.src="https://icons.duckduckgo.com/ip3/placeholder.ico"}} referrerPolicy="no-referrer" className="inline w-4 mr-1 md:mr-2 align-middle" />
          <span className="hidden sm:inline-block">{this.props.site.domain}</span>
          {this.renderArrow()}
        </button>

        <Transition
          show={this.state.open}
          enter="transition ease-out duration-100 transform"
          enterFrom="opacity-0 scale-95"
          enterTo="opacity-100 scale-100"
          leave="transition ease-in duration-75 transform"
          leaveFrom="opacity-100 scale-100"
          leaveTo="opacity-0 scale-95"
        >
        <div className="origin-top-left absolute left-0 mt-2 w-64 rounded-md shadow-lg" ref={node => this.dropDownNode = node} >
          <div className="rounded-md bg-white dark:bg-gray-800 ring-1 ring-black ring-opacity-5">
            { this.renderDropdown() }
          </div>
        </div>
        </Transition>
      </div>
    )
  }
}