/**
   * @fileoverview require default case in switch statements
   * @author Aliaksei Shytkin
   */
  "use strict";
  
  const DEFAULT_COMMENT_PATTERN = /^no default$/i;
  
  //------------------------------------------------------------------------------
  // Rule Definition
  //------------------------------------------------------------------------------
  
  module.exports = {
      meta: {
          docs: {
              description: "require `default` cases in `switch` statements",
              category: "Best Practices",
              recommended: false
          },
  
          schema: [{
              type: "object",
              properties: {
                  commentPattern: {
                      type: "string"
                  }
              },
              additionalProperties: false
          }]
      },
  
      create(context) {
          const options = context.options[0] || {};
          const commentPattern = options.commentPattern
              ? new RegExp(options.commentPattern)
              : DEFAULT_COMMENT_PATTERN;
  
          const sourceCode = context.getSourceCode();
  
          //--------------------------------------------------------------------------
          // Helpers
          //--------------------------------------------------------------------------
  
          /**
           * Shortcut to get last element of array
           * @param  {*[]} collection Array
           * @returns {*} Last element
           */
          function last(collection) {
              return collection[collection.length - 1];
          }
  
          //--------------------------------------------------------------------------
          // Public
          //--------------------------------------------------------------------------
  
          return {
  
              SwitchStatement(node) {
  
                  if (!node.cases.length) {
  
                      /*
                       * skip check of empty switch because there is no easy way
                       * to extract comments inside it now
                       */
                      return;
                  }
  
                  const hasDefault = node.cases.some(v => v.test === null);
  
                  if (!hasDefault) {
  
                      let comment;
  
                      const lastCase = last(node.cases);
                      const comments = sourceCode.getComments(lastCase).trailing;
  
                      if (comments.length) {
                          comment = last(comments);
                      }
  
                      if (!comment || !commentPattern.test(comment.value.trim())) {
                          context.report({ node, message: "Expected a default case." });
                      }
                  }
              }
          };
      }
  };