import { h, Component, createRef } from 'https://unpkg.com/preact?module';
import htm from 'https://unpkg.com/htm?module';
const html = htm.bind(h);

import { EmojiButton } from 'https://cdn.skypack.dev/pin/@joeattardi/emoji-button@v4.1.0-v8psdkkxts3LNdpA0m5Q/min/@joeattardi/emoji-button.js';
import ContentEditable from './content-editable.js';
import { generatePlaceholderText, getCaretPosition, convertToText, convertOnPaste } from '../../utils/chat.js';
import { getLocalStorage, setLocalStorage } from '../../utils/helpers.js';
import { URL_CUSTOM_EMOJIS, KEY_CHAT_FIRST_MESSAGE_SENT } from '../../utils/constants.js';

export default class ChatInput extends Component {
  constructor(props, context) {
    super(props, context);
    this.formMessageInput = createRef();
    this.emojiPickerButton = createRef();

    this.messageCharCount = 0;
    this.maxMessageLength = 500;
    this.maxMessageBuffer = 20;

    this.emojiPicker = null;

    this.prepNewLine = false;

    this.state = {
      inputHTML: '',
      inputWarning: '',
      hasSentFirstChatMessage: getLocalStorage(KEY_CHAT_FIRST_MESSAGE_SENT),
    };

    this.handleEmojiButtonClick = this.handleEmojiButtonClick.bind(this);
    this.handleEmojiSelected = this.handleEmojiSelected.bind(this);
    this.getCustomEmojis = this.getCustomEmojis.bind(this);

    this.handleMessageInputKeydown = this.handleMessageInputKeydown.bind(this);
    this.handleMessageInputKeyup = this.handleMessageInputKeyup.bind(this);
    this.handleMessageInputBlur = this.handleMessageInputBlur.bind(this);
    this.handleSubmitChatButton = this.handleSubmitChatButton.bind(this);
    this.handlePaste = this.handlePaste.bind(this);

    this.handleContentEditableChange = this.handleContentEditableChange.bind(this);
  }

  componentDidMount() {
    this.getCustomEmojis();
  }

  getCustomEmojis() {
    fetch(URL_CUSTOM_EMOJIS)
      .then(response => {
        if (!response.ok) {
          throw new Error(`Network response was not ok ${response.ok}`);
        }
        return response.json();
      })
      .then(json => {
        this.emojiPicker = new EmojiButton({
          zIndex: 100,
          theme: 'dark',
          custom: json,
          initialCategory: 'custom',
          showPreview: false,
          emojiSize: '30px',
          position: 'right-start',
          strategy: 'absolute',
        });
        this.emojiPicker.on('emoji', emoji => {
          this.handleEmojiSelected(emoji);
        });
      })
      .catch(error => {
        // this.handleNetworkingError(`Emoji Fetch: ${error}`);
      });
  }

  handleEmojiButtonClick() {
    if (this.emojiPicker) {
      this.emojiPicker.togglePicker(this.emojiPickerButton.current);
    }
  }

  handleEmojiSelected(emoji) {
    const { inputHTML } = this.state;
    let content = '';
    if (emoji.url) {
      const url = location.protocol + "//" + location.host + "/" + emoji.url;
      const name = url.split('\\').pop().split('/').pop();
      content = "<img class=\"emoji\" alt=\"" + name + "\" src=\"" + url + "\"/>";
    } else {
      content = emoji.emoji;
    }

    this.setState({
      inputHTML: inputHTML + content,
    });
  }

  // autocomplete user names
  autoCompleteNames() {
    const { chatUserNames } = this.props;
    const { inputHTML } = this.state;
    const position = getCaretPosition(this.formMessageInput.current);
    const at = inputHTML.lastIndexOf('@', position - 1);
    if (at === -1) {
      return false;
    }

    let partial = inputHTML.substring(at + 1, position).trim();

    if (partial === this.suggestion) {
      partial = this.partial;
    } else {
      this.partial = partial;
    }

    const possibilities = chatUserNames.filter(function (username) {
      return username.toLowerCase().startsWith(partial.toLowerCase());
    });

    if (this.completionIndex === undefined || ++this.completionIndex >= possibilities.length) {
      this.completionIndex = 0;
    }

    if (possibilities.length > 0) {
      this.suggestion = possibilities[this.completionIndex];

      this.setState({
        inputHTML: inputHTML.substring(0, at + 1) + this.suggestion + ' ' + inputHTML.substring(position),
      })
    }

    return true;
  }

  handleMessageInputKeydown(event) {
    const okCodes = [
      'ArrowLeft',
      'ArrowUp',
      'ArrowRight',
      'ArrowDown',
      'Shift',
      'Meta',
      'Alt',
      'Delete',
      'Backspace',
    ];
    const formField = this.formMessageInput.current;

    let textValue = formField.innerText.trim(); // get this only to count chars

    let numCharsLeft = this.maxMessageLength - textValue.length;
    const key = event.key;

    if (key === 'Enter') {
      if (!this.prepNewLine) {
        this.sendMessage();
        event.preventDefault();
        this.prepNewLine = false;
        return;
      }
    }
    if (key === 'Control' || key === 'Shift') {
      this.prepNewLine = true;
    }
    if (key === 'Tab') {
      if (this.autoCompleteNames()) {
        event.preventDefault();

        // value could have been changed, update char count
        textValue = formField.innerText.trim();
        numCharsLeft = this.maxMessageLength - textValue.length;
      }
    }

    // text count
    if (numCharsLeft <= this.maxMessageBuffer) {
      this.setState({
        inputWarning: `${numCharsLeft} chars left`,
      });
      if (numCharsLeft <= 0 && !okCodes.includes(key)) {
        event.preventDefault(); // prevent typing more
        return;
      }
    } else {
      this.setState({
        inputWarning: '',
      });
    }
  }

  handleMessageInputKeyup(event) {
    if (event.key === 'Control' || event.key === 'Shift') {
     this.prepNewLine = false;
    }
  }

  handleMessageInputBlur(event) {
    this.prepNewLine = false;
  }

  handlePaste(event) {
    convertOnPaste(event);
  }

  handleSubmitChatButton(event) {
    event.preventDefault();
    this.sendMessage();
  }

  sendMessage() {
    const { handleSendMessage } = this.props;
    const { hasSentFirstChatMessage, inputHTML } = this.state;
    const message = convertToText(inputHTML);
    const newStates = {
      inputWarning: '',
      inputHTML: '',
    };

    handleSendMessage(message);

    if (!hasSentFirstChatMessage) {
      newStates.hasSentFirstChatMessage = true;
      setLocalStorage(KEY_CHAT_FIRST_MESSAGE_SENT, true);
    }

    // clear things out.
    this.setState(newStates);
  }

  handleContentEditableChange(event) {
    this.setState({ inputHTML: event.target.value });
  }

  render(props, state) {
    const { hasSentFirstChatMessage, inputWarning, inputHTML } = state;
    const { inputEnabled } = props;
    const emojiButtonStyle = {
      display: this.emojiPicker ? 'block' : 'none',
    };

    const placeholderText = generatePlaceholderText(inputEnabled, hasSentFirstChatMessage);
    return (
      html`
        <div id="message-input-container" class="fixed bottom-0 shadow-md bg-gray-900 border-t border-gray-700 border-solid p-4 z-20">

          <${ContentEditable}
            id="message-input"
            class="appearance-none block w-full bg-gray-200 text-sm	text-gray-700 border border-black-500 rounded py-2 px-2 my-2 focus:bg-white h-20 overflow-auto"

            placeholderText=${placeholderText}
            innerRef=${this.formMessageInput}
            html=${inputHTML}
            disabled=${!inputEnabled}
            onChange=${this.handleContentEditableChange}
            onKeyDown=${this.handleMessageInputKeydown}
            onKeyUp=${this.handleMessageInputKeyup}
            onBlur=${this.handleMessageInputBlur}

            onPaste=${this.handlePaste}
          />

          <div id="message-form-actions" class="flex flex-row justify-between items-center w-full">
            <span id="message-form-warning" class="text-red-600 text-xs">${inputWarning}</span>

            <div id="message-form-actions-buttons" class="flex flex-row justify-end items-center">
              <button
                ref=${this.emojiPickerButton}
                id="emoji-button"
                class="mr-2 text-2xl cursor-pointer"
                type="button"
                style=${emojiButtonStyle}
                onclick=${this.handleEmojiButtonClick}
                disabled=${!inputEnabled}
              >😏</button>

              <button
                onclick=${this.handleSubmitChatButton}
                disabled=${!inputEnabled}
                type="button"
                id="button-submit-message"
                class="bg-blue-500 hover:bg-blue-700 text-white font-bold py-1 px-2 rounded"
              > Chat
              </button>
            </div>
          </div>
      </div>
    `);
  }

  }