import sortBy from "lodash/collection/sortBy";

export var metadata = {
  group: "builtin-trailing"
};

/**
 * [Please add a description.]
 *
 * Priority:
 *
 *  - 0 We want this to be at the **very** bottom
 *  - 1 Default node position
 *  - 2 Priority over normal nodes
 *  - 3 We want this to be at the **very** top
 */

export var visitor = {

  /**
   * [Please add a description.]
   */

  Block: {
    exit(node) {
      var hasChange = false;
      for (var i = 0; i < node.body.length; i++) {
        var bodyNode = node.body[i];
        if (bodyNode && bodyNode._blockHoist != null) hasChange = true;
      }
      if (!hasChange) return;

      node.body = sortBy(node.body, function(bodyNode){
        var priority = bodyNode && bodyNode._blockHoist;
        if (priority == null) priority = 1;
        if (priority === true) priority = 2;

        // Higher priorities should move toward the top.
        return -1 * priority;
      });
    }
  }
};
