import { autoBindMethodsForReact } from 'class-autobind-decorator';
import React, { PureComponent } from 'react';

import { AUTOBIND_CFG } from '../../../common/constants';
import KeydownBinder from '../keydown-binder';

export const shouldSave = (oldValue, newValue, preventBlank = false) => {
  // Should not save if length = 0 and we want to prevent blank
  if (preventBlank && !newValue.length) {
    return false;
  }

  // Should not save if old value and new value is the same
  if (oldValue === newValue) {
    return false;
  }

  // Should save
  return true;
};

interface Props {
  onSubmit: (value?: string) => void,
  value: string,
  fallbackValue?: string,
  blankValue?: string,
  renderReadView?: Function,
  singleClick?: boolean,
  onEditStart?: Function,
  className?: string,
  preventBlank?: boolean,
}

interface State {
  editing: boolean;
}

@autoBindMethodsForReact(AUTOBIND_CFG)
class Editable extends PureComponent<Props, State> {
  state: State = {
    editing: false,
  }

  _input: HTMLInputElement | null = null;

  _handleSetInputRef(n: HTMLInputElement) {
    this._input = n;
  }

  _handleSingleClickEditStart() {
    if (this.props.singleClick) {
      this._handleEditStart();
    }
  }

  _handleEditStart() {
    this.setState({
      editing: true,
    });
    setTimeout(() => {
      this._input?.focus();
      this._input?.select();
    });

    if (this.props.onEditStart) {
      this.props.onEditStart();
    }
  }

  _handleEditEnd() {
    const originalValue = this.props.value;

    const newValue = this._input?.value.trim();

    if (shouldSave(originalValue, newValue, this.props.preventBlank)) {
      // Don't run onSubmit for values that haven't been changed
      this.props.onSubmit(newValue);
    }

    // This timeout prevents the UI from showing the old value after submit.
    // It should give the UI enough time to redraw the new value.
    setTimeout(
      async () =>
        this.setState({
          editing: false,
        }),
      100,
    );
  }

  _handleEditKeyDown(e) {
    if (e.keyCode === 13) {
      // Pressed Enter
      this._handleEditEnd();
    } else if (e.keyCode === 27) {
      // Pressed Escape
      // Prevent bubbling to modals and other escape listeners.
      e.stopPropagation();

      if (this._input) {
        // Set the input to the original value
        this._input.value = this.props.value;

        this._handleEditEnd();
      }
    }
  }

  render() {
    const {
      value,
      fallbackValue,
      blankValue,
      singleClick,
      onEditStart,
      preventBlank,
      className,
      onSubmit,
      renderReadView,
      ...extra
    } = this.props;
    const { editing } = this.state;
    const initialValue = value || fallbackValue;

    if (editing) {
      return (
        // KeydownBinder must be used here to properly stop propagation
        // from reaching other scoped KeydownBinders
        <KeydownBinder onKeydown={this._handleEditKeyDown} scoped>
          <input
            {...extra}
            className={`editable ${className || ''}`}
            type="text"
            ref={this._handleSetInputRef}
            defaultValue={initialValue}
            onBlur={this._handleEditEnd}
          />
        </KeydownBinder>
      );
    } else {
      const readViewProps = {
        className: `editable ${className} ${!initialValue && 'empty'}`,
        title: singleClick ? 'Click to edit' : 'Double click to edit',
        onClick: this._handleSingleClickEditStart,
        onDoubleClick: this._handleEditStart,
        ...extra,
      };

      if (renderReadView) {
        return renderReadView(initialValue, readViewProps);
      } else {
        return <span {...readViewProps}>{initialValue || blankValue}</span>;
      }
    }
  }
}

export default Editable;
