import React from 'react';
import CharacterCounter from './character_counter';
import Button from '../../../components/button';
import ImmutablePropTypes from 'react-immutable-proptypes';
import PropTypes from 'prop-types';
import ReplyIndicatorContainer from '../containers/reply_indicator_container';
import AutosuggestTextarea from '../../../components/autosuggest_textarea';
import AutosuggestInput from '../../../components/autosuggest_input';
import PollButtonContainer from '../containers/poll_button_container';
import UploadButtonContainer from '../containers/upload_button_container';
import { defineMessages, injectIntl } from 'react-intl';
import SpoilerButtonContainer from '../containers/spoiler_button_container';
import PrivacyDropdownContainer from '../containers/privacy_dropdown_container';
import EmojiPickerDropdown from '../containers/emoji_picker_dropdown_container';
import PollFormContainer from '../containers/poll_form_container';
import UploadFormContainer from '../containers/upload_form_container';
import WarningContainer from '../containers/warning_container';
import LanguageDropdown from '../containers/language_dropdown_container';
import ImmutablePureComponent from 'react-immutable-pure-component';
import { length } from 'stringz';
import { countableText } from '../util/counter';
import Icon from 'mastodon/components/icon';

const allowedAroundShortCode = '><\u0085\u0020\u00a0\u1680\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u202f\u205f\u3000\u2028\u2029\u0009\u000a\u000b\u000c\u000d';

const messages = defineMessages({
  placeholder: { id: 'compose_form.placeholder', defaultMessage: 'What is on your mind?' },
  spoiler_placeholder: { id: 'compose_form.spoiler_placeholder', defaultMessage: 'Write your warning here' },
  publish: { id: 'compose_form.publish', defaultMessage: 'Publish' },
  publishLoud: { id: 'compose_form.publish_loud', defaultMessage: '{publish}!' },
  saveChanges: { id: 'compose_form.save_changes', defaultMessage: 'Save changes' },
});

export default @injectIntl
class ComposeForm extends ImmutablePureComponent {

  static contextTypes = {
    router: PropTypes.object,
  };

  static propTypes = {
    intl: PropTypes.object.isRequired,
    text: PropTypes.string.isRequired,
    suggestions: ImmutablePropTypes.list,
    spoiler: PropTypes.bool,
    privacy: PropTypes.string,
    spoilerText: PropTypes.string,
    focusDate: PropTypes.instanceOf(Date),
    caretPosition: PropTypes.number,
    preselectDate: PropTypes.instanceOf(Date),
    isSubmitting: PropTypes.bool,
    isChangingUpload: PropTypes.bool,
    isEditing: PropTypes.bool,
    isUploading: PropTypes.bool,
    onChange: PropTypes.func.isRequired,
    onSubmit: PropTypes.func.isRequired,
    onClearSuggestions: PropTypes.func.isRequired,
    onFetchSuggestions: PropTypes.func.isRequired,
    onSuggestionSelected: PropTypes.func.isRequired,
    onChangeSpoilerText: PropTypes.func.isRequired,
    onPaste: PropTypes.func.isRequired,
    onPickEmoji: PropTypes.func.isRequired,
    autoFocus: PropTypes.bool,
    anyMedia: PropTypes.bool,
    isInReply: PropTypes.bool,
    singleColumn: PropTypes.bool,
    lang: PropTypes.string,
  };

  static defaultProps = {
    autoFocus: false,
  };

  handleChange = (e) => {
    this.props.onChange(e.target.value);
  };

  handleKeyDown = (e) => {
    if (e.keyCode === 13 && (e.ctrlKey || e.metaKey)) {
      this.handleSubmit();
    }
  };

  getFulltextForCharacterCounting = () => {
    return [this.props.spoiler? this.props.spoilerText: '', countableText(this.props.text)].join('');
  };

  canSubmit = () => {
    const { isSubmitting, isChangingUpload, isUploading, anyMedia } = this.props;
    const fulltext = this.getFulltextForCharacterCounting();
    const isOnlyWhitespace = fulltext.length !== 0 && fulltext.trim().length === 0;

    return !(isSubmitting || isUploading || isChangingUpload || length(fulltext) > 500 || (isOnlyWhitespace && !anyMedia));
  };

  handleSubmit = (e) => {
    if (this.props.text !== this.autosuggestTextarea.textarea.value) {
      // Something changed the text inside the textarea (e.g. browser extensions like Grammarly)
      // Update the state to match the current text
      this.props.onChange(this.autosuggestTextarea.textarea.value);
    }

    if (!this.canSubmit()) {
      return;
    }

    this.props.onSubmit(this.context.router ? this.context.router.history : null);

    if (e) {
      e.preventDefault();
    }
  };

  onSuggestionsClearRequested = () => {
    this.props.onClearSuggestions();
  };

  onSuggestionsFetchRequested = (token) => {
    this.props.onFetchSuggestions(token);
  };

  onSuggestionSelected = (tokenStart, token, value) => {
    this.props.onSuggestionSelected(tokenStart, token, value, ['text']);
  };

  onSpoilerSuggestionSelected = (tokenStart, token, value) => {
    this.props.onSuggestionSelected(tokenStart, token, value, ['spoiler_text']);
  };

  handleChangeSpoilerText = (e) => {
    this.props.onChangeSpoilerText(e.target.value);
  };

  handleFocus = () => {
    if (this.composeForm && !this.props.singleColumn) {
      const { left, right } = this.composeForm.getBoundingClientRect();
      if (left < 0 || right > (window.innerWidth || document.documentElement.clientWidth)) {
        this.composeForm.scrollIntoView();
      }
    }
  };

  componentDidMount () {
    this._updateFocusAndSelection({ });
  }

  componentDidUpdate (prevProps) {
    this._updateFocusAndSelection(prevProps);
  }

  _updateFocusAndSelection = (prevProps) => {
    // This statement does several things:
    // - If we're beginning a reply, and,
    //     - Replying to zero or one users, places the cursor at the end of the textbox.
    //     - Replying to more than one user, selects any usernames past the first;
    //       this provides a convenient shortcut to drop everyone else from the conversation.
    if (this.props.focusDate && this.props.focusDate !== prevProps.focusDate) {
      let selectionEnd, selectionStart;

      if (this.props.preselectDate !== prevProps.preselectDate && this.props.isInReply) {
        selectionEnd   = this.props.text.length;
        selectionStart = this.props.text.search(/\s/) + 1;
      } else if (typeof this.props.caretPosition === 'number') {
        selectionStart = this.props.caretPosition;
        selectionEnd   = this.props.caretPosition;
      } else {
        selectionEnd   = this.props.text.length;
        selectionStart = selectionEnd;
      }

      // Because of the wicg-inert polyfill, the activeElement may not be
      // immediately selectable, we have to wait for observers to run, as
      // described in https://github.com/WICG/inert#performance-and-gotchas
      Promise.resolve().then(() => {
        this.autosuggestTextarea.textarea.setSelectionRange(selectionStart, selectionEnd);
        this.autosuggestTextarea.textarea.focus();
      }).catch(console.error);
    } else if(prevProps.isSubmitting && !this.props.isSubmitting) {
      this.autosuggestTextarea.textarea.focus();
    } else if (this.props.spoiler !== prevProps.spoiler) {
      if (this.props.spoiler) {
        this.spoilerText.input.focus();
      } else if (prevProps.spoiler) {
        this.autosuggestTextarea.textarea.focus();
      }
    }
  };

  setAutosuggestTextarea = (c) => {
    this.autosuggestTextarea = c;
  };

  setSpoilerText = (c) => {
    this.spoilerText = c;
  };

  setRef = c => {
    this.composeForm = c;
  };

  handleEmojiPick = (data) => {
    const { text }     = this.props;
    const position     = this.autosuggestTextarea.textarea.selectionStart;
    const needsSpace   = data.custom && position > 0 && !allowedAroundShortCode.includes(text[position - 1]);

    this.props.onPickEmoji(position, data, needsSpace);
  };

  render () {
    const { intl, onPaste, autoFocus } = this.props;
    const disabled = this.props.isSubmitting;

    let publishText = '';

    if (this.props.isEditing) {
      publishText = intl.formatMessage(messages.saveChanges);
    } else if (this.props.privacy === 'private' || this.props.privacy === 'direct') {
      publishText = <span className='compose-form__publish-private'><Icon id='lock' /> {intl.formatMessage(messages.publish)}</span>;
    } else {
      publishText = this.props.privacy !== 'unlisted' ? intl.formatMessage(messages.publishLoud, { publish: intl.formatMessage(messages.publish) }) : intl.formatMessage(messages.publish);
    }

    return (
      <form className='compose-form' onSubmit={this.handleSubmit}>
        <WarningContainer />

        <ReplyIndicatorContainer />

        <div className={`spoiler-input ${this.props.spoiler ? 'spoiler-input--visible' : ''}`} ref={this.setRef} aria-hidden={!this.props.spoiler}>
          <AutosuggestInput
            placeholder={intl.formatMessage(messages.spoiler_placeholder)}
            value={this.props.spoilerText}
            onChange={this.handleChangeSpoilerText}
            onKeyDown={this.handleKeyDown}
            disabled={!this.props.spoiler}
            ref={this.setSpoilerText}
            suggestions={this.props.suggestions}
            onSuggestionsFetchRequested={this.onSuggestionsFetchRequested}
            onSuggestionsClearRequested={this.onSuggestionsClearRequested}
            onSuggestionSelected={this.onSpoilerSuggestionSelected}
            searchTokens={[':']}
            id='cw-spoiler-input'
            className='spoiler-input__input'
            lang={this.props.lang}
            spellCheck
          />
        </div>

        <AutosuggestTextarea
          ref={this.setAutosuggestTextarea}
          placeholder={intl.formatMessage(messages.placeholder)}
          disabled={disabled}
          value={this.props.text}
          onChange={this.handleChange}
          suggestions={this.props.suggestions}
          onFocus={this.handleFocus}
          onKeyDown={this.handleKeyDown}
          onSuggestionsFetchRequested={this.onSuggestionsFetchRequested}
          onSuggestionsClearRequested={this.onSuggestionsClearRequested}
          onSuggestionSelected={this.onSuggestionSelected}
          onPaste={onPaste}
          autoFocus={autoFocus}
          lang={this.props.lang}
        >
          <EmojiPickerDropdown onPickEmoji={this.handleEmojiPick} />

          <div className='compose-form__modifiers'>
            <UploadFormContainer />
            <PollFormContainer />
          </div>
        </AutosuggestTextarea>

        <div className='compose-form__buttons-wrapper'>
          <div className='compose-form__buttons'>
            <UploadButtonContainer />
            <PollButtonContainer />
            <PrivacyDropdownContainer disabled={this.props.isEditing} />
            <SpoilerButtonContainer />
            <LanguageDropdown />
          </div>

          <div className='character-counter__wrapper'>
            <CharacterCounter max={500} text={this.getFulltextForCharacterCounting()} />
          </div>
        </div>

        <div className='compose-form__publish'>
          <div className='compose-form__publish-button-wrapper'>
            <Button
              type='submit'
              text={publishText}
              disabled={!this.canSubmit()}
              block
            />
          </div>
        </div>
      </form>
    );
  }

}