import React, { Component } from "react";
import ReactCSSTransitionGroup from "react-addons-css-transition-group";
import debug from "debug";
import PropTypes from "prop-types";
import SimpleModal from "./SimpleModal.jsx";

const log = debug("modal-slideshow:log");

export default class SimpleModalSlideshow extends Component {
  constructor(props) {
    super(props);

    // Initial state
    this.state = {
      open: false,
      currentSlide: 0,
      slideAnimationDirection: "left"
    };

    // Prepare keyboard event listener
    this._handleKeyboardInput = this._handleKeyboardInput.bind(this);

    // Bind API
    this.goTo = this.goTo.bind(this);
    this.goToNext = this.goToNext.bind(this);
    this.goToPrev = this.goToPrev.bind(this);
    this.open = this.open.bind(this);
    this.close = this.close.bind(this);
  }

  componentDidMount() {
    // Initially set current slide
    if (this.props.currentSlide) {
      this._goTo(this.props.currentSlide);
    }

    // Initially open the modal
    if (this.props.open) {
      this._open();
    }
  }

  componentWillReceiveProps(nextProps) {
    // Listen "open" / "currentSlide" props only if the API is disabled
    if (!nextProps.enableApi) {
      // Update current slide
      this._goTo(nextProps.currentSlide);

      // Make sure to open/close only when needed
      if (!this.props.open && nextProps.open) {
        this._open();
      } else if (this.props.open && !nextProps.open) {
        this._close();
      }
    }

    // If classNamePrefix is updated, make sure to update flag on html tag if set
    if (nextProps.classNamePrefix !== this.props.classNamePrefix) {
      document.documentElement.classList.remove(
        `${this.props.classNamePrefix}--opened`
      );
      document.documentElement.classList.add(
        `${nextProps.classNamePrefix}--opened`
      );
    }
  }

  /**
   * Keyboard event listener
   *
   * @param {Event} event Keyboard event
   */
  _handleKeyboardInput(event) {
    log(`Keyboard input captured (keyCode=${event.keyCode})`);

    // Left arrow
    if (event.keyCode === 37) {
      this._handlePrev();
      // Right arrow
    } else if (event.keyCode === 39) {
      this._handleNext();
      // Esc
    } else if (event.keyCode === 27) {
      this._handleClose();
    }
  }

  /**
   * Handle close event
   */
  _handleClose() {
    log("Handle Close");

    // If props.onClose is supplied, call it and stop here
    if (this.props.onClose) {
      this.props.onClose();
      return;
    }

    // If API is disabled only the parent can control the slideshow
    // through props.onClose
    if (this.props.enableApi) {
      this.close();
    }
  }

  /**
   * Handle prev event
   */
  _handlePrev() {
    const currentSlide = this.state.currentSlide;
    const prevSlide = currentSlide - 1;

    // Make sure there's a slide before the current one
    if (currentSlide <= 0) {
      return;
    }

    log("Handle Prev");

    // If props.onPrev is supplied, call it and stop here
    if (this.props.onPrev) {
      this.props.onPrev(prevSlide);
      return;
    }

    // If API is disabled only the parent can control the slideshow
    // through props.onPrev
    if (this.props.enableApi) {
      this._goTo(prevSlide);
    }
  }

  /**
   * Handle next event
   */
  _handleNext() {
    const currentSlide = this.state.currentSlide;
    const nextSlide = currentSlide + 1;

    // Make sure there's a slide after the current one
    if (nextSlide >= this.props.slides.length) {
      return;
    }

    log("Handle Next");

    // If props.onNext is supplied, call it and stop here
    if (this.props.onNext) {
      this.props.onNext(nextSlide);
      return;
    }

    // If API is disabled, only the parent component can control the slideshow
    // through props.onNext
    if (this.props.enableApi) {
      this._goTo(nextSlide);
    }
  }

  _goToPrev() {
    const currentSlide = this.state.currentSlide;
    const prevSlide = currentSlide - 1;

    if (currentSlide <= 0) {
      return;
    }

    this._goTo(prevSlide);
  }

  _goToNext() {
    const currentSlide = this.state.currentSlide;
    const nextSlide = currentSlide + 1;

    if (nextSlide >= this.props.slides.length) {
      return;
    }

    this._goTo(nextSlide);
  }

  _goTo(index) {
    if (this.props.slides.length === 0) {
      return;
    }

    // Make sure the slide exists
    if (index < 0 || index >= this.props.slides.length) {
      throw new Error(
        `Invalid index '${index}' supplied to SimpleModalSlideshow::goTo()`
      );
    }

    log(`Go to slide ${index}`);

    // Update state with the new index and animation direction
    this.setState({
      currentSlide: index,
      slideAnimationDirection:
        index < this.state.currentSlide ? "right" : "left"
    });
  }

  _close() {
    log("Close");

    // Remove class from html tag
    document.documentElement.classList.remove(
      `${this.props.classNamePrefix}--opened`
    );

    // Remove keyboard event listener
    document.removeEventListener("keydown", this._handleKeyboardInput);

    // Update state
    this.setState({
      open: false
    });
  }

  _open(index) {
    log("Open");

    // Add a class to the body (to disable background scroll)
    document.documentElement.classList.add(
      `${this.props.classNamePrefix}--opened`
    );

    // Enable keyboard event listener
    document.addEventListener("keydown", this._handleKeyboardInput);

    // If an index is given, jump to the slide before opening
    if (index !== undefined) {
      this._goTo(index);
    }

    // Update state
    this.setState({
      open: true
    });
  }

  /**
   * Go to previous slide
   */
  goToPrev() {
    if (!this.props.enableApi) {
      throw new Error("SimpleModalSlideshow API is disabled");
    }

    this._goToPrev();
  }

  /**
   * Go to next slide
   */
  goToNext() {
    if (!this.props.enableApi) {
      throw new Error("SimpleModalSlideshow API is disabled");
    }

    this._goToNext();
  }

  /**
   * Go to a specific slide
   *
   * @param {Int} index Slide index to go to
   */
  goTo(index) {
    if (!this.props.enableApi) {
      throw new Error("SimpleModalSlideshow API is disabled");
    }

    this._goTo(index);
  }

  /**
   * Open the slideshow
   *
   * @param {Int} index If specified, the given slide will be opened
   */
  open(index) {
    if (!this.props.enableApi) {
      throw new Error("SimpleModalSlideshow API is disabled");
    }

    this._open(index);
  }

  /**
   * Close the slideshow
   */
  close() {
    if (!this.props.enableApi) {
      throw new Error("SimpleModalSlideshow API is disabled");
    }

    this._close();
  }

  render() {
    let modal = null;

    // Modal is added to the DOM only if it has a slide to display
    if (this.props.slides.length > 0 && this.state.open) {
      modal = (
        <SimpleModal
          key="modal-slideshow"
          slide={this.props.slides[this.state.currentSlide]}
          slideIndex={this.state.currentSlide}
          slideAnimations={this.props.slideAnimations}
          slideAnimationDirection={this.state.slideAnimationDirection}
          slideTransitionEnterTimeout={this.props.slideTransitionEnterTimeout}
          slideTransitionLeaveTimeout={this.props.slideTransitionLeaveTimeout}
          showPrev={this.state.currentSlide > 0}
          showNext={this.state.currentSlide < this.props.slides.length - 1}
          onPrev={this._handlePrev.bind(this)}
          onNext={this._handleNext.bind(this)}
          onClose={this._handleClose.bind(this)}
          classNamePrefix={this.props.classNamePrefix}
        />
      );
    }

    return (
      <ReactCSSTransitionGroup
        component="div"
        transitionName={`${this.props.classNamePrefix}__modal`}
        transitionEnter={this.props.modalAnimations}
        transitionLeave={this.props.modalAnimations}
        transitionEnterTimeout={this.props.modalTransitionEnterTimeout}
        transitionLeaveTimeout={this.props.modalTransitionLeaveTimeout}
      >
        {modal}
      </ReactCSSTransitionGroup>
    );
  }
}

SimpleModalSlideshow.propTypes = {
  // Slides
  slides: PropTypes.arrayOf(
    PropTypes.shape({
      media: PropTypes.node.isRequired,
      content: PropTypes.node,
      title: PropTypes.node
    })
  ).isRequired,

  // Controls
  open: PropTypes.bool,
  currentSlide: PropTypes.number,

  // Options
  enableApi: PropTypes.bool,
  classNamePrefix: PropTypes.string,

  // Animations
  modalAnimations: PropTypes.bool,
  slideAnimations: PropTypes.bool,
  modalTransitionEnterTimeout: PropTypes.number,
  modalTransitionLeaveTimeout: PropTypes.number,
  slideTransitionEnterTimeout: PropTypes.number,
  slideTransitionLeaveTimeout: PropTypes.number,

  // Event listeners
  onClose: PropTypes.func,
  onPrev: PropTypes.func,
  onNext: PropTypes.func
};

SimpleModalSlideshow.defaultProps = {
  open: false,
  currentSlide: 0,
  enableApi: false,
  classNamePrefix: "modal-slideshow",
  modalAnimations: true,
  slideAnimations: true,
  modalTransitionEnterTimeout: 300,
  modalTransitionLeaveTimeout: 300,
  slideTransitionEnterTimeout: 300,
  slideTransitionLeaveTimeout: 300
};