function AnnotationPlugin(options) {

  const { onChange } = options

  return {

    onSelect(event, change) {

      event.preventDefault()

      const { value } = change

      const { selection } = value

      const { start, end} = selection

      if (selection.isCollapsed) {

        return;

      }

      let nodes = [];

      let hasStarted = false;

      let hasEnded = false;

      // Keep only the relevant nodes,

      // i.e. nodes which are contained within selection

      value.document.nodes.forEach((node) => {

        if (start.isInNode(node)) {

          hasStarted = true;

        }

        if (hasStarted && !hasEnded) {

          nodes.push(node);

        }

        if (end.isAtEndOfNode(node)) {

          hasEnded = true;

        }

      });

      let text = '';

      // Concatenate the nodes text

      if (nodes.length === 1) {

        text = nodes[0].text.substring(start.offset, end.offset);

      } else {

        text = nodes.map((node) => {

          if (start.isInNode(node)) return node.text.substring(start.offset);

          if (end.isAtEndOfNode(node)) return node.text.substring(0, end.offset);

          return node.text;

        }).join('\n');

      }

      if (onChange) {

        onChange(text, start.offset, end.offset);

      }

    }

  };

}

export default AnnotationPlugin;