/**
   * @fileoverview Define the cursor which iterates tokens and comments in reverse.
   * @author Toru Nagashima
   */
  "use strict";
  
  //------------------------------------------------------------------------------
  // Requirements
  //------------------------------------------------------------------------------
  
  const Cursor = require("./cursor");
  const utils = require("./utils");
  
  //------------------------------------------------------------------------------
  // Exports
  //------------------------------------------------------------------------------
  
  /**
   * The cursor which iterates tokens and comments in reverse.
   */
  module.exports = class BackwardTokenCommentCursor extends Cursor {
  
      /**
       * Initializes this cursor.
       * @param {Token[]} tokens - The array of tokens.
       * @param {Comment[]} comments - The array of comments.
       * @param {Object} indexMap - The map from locations to indices in `tokens`.
       * @param {number} startLoc - The start location of the iteration range.
       * @param {number} endLoc - The end location of the iteration range.
       */
      constructor(tokens, comments, indexMap, startLoc, endLoc) {
          super();
          this.tokens = tokens;
          this.comments = comments;
          this.tokenIndex = utils.getLastIndex(tokens, indexMap, endLoc);
          this.commentIndex = utils.search(comments, endLoc) - 1;
          this.border = startLoc;
      }
  
      /** @inheritdoc */
      moveNext() {
          const token = (this.tokenIndex >= 0) ? this.tokens[this.tokenIndex] : null;
          const comment = (this.commentIndex >= 0) ? this.comments[this.commentIndex] : null;
  
          if (token && (!comment || token.range[1] > comment.range[1])) {
              this.current = token;
              this.tokenIndex -= 1;
          } else if (comment) {
              this.current = comment;
              this.commentIndex -= 1;
          } else {
              this.current = null;
          }
  
          return Boolean(this.current) && (this.border === -1 || this.current.range[0] >= this.border);
      }
  };