From b574489950348bdff2813315653231b2de72b841 Mon Sep 17 00:00:00 2001
From: Javier Goizueta <jgoizueta@gmail.com>
Date: Thu, 12 May 2016 18:47:24 +0200
Subject: [PATCH] Refactor to reduce cyclomatic complexity

---
 lib/cartodb/utils/overviews_query_rewriter.js | 43 ++++++++++++-------
 1 file changed, 27 insertions(+), 16 deletions(-)

diff --git a/lib/cartodb/utils/overviews_query_rewriter.js b/lib/cartodb/utils/overviews_query_rewriter.js
index 4a23975c..bf20d6c9 100644
--- a/lib/cartodb/utils/overviews_query_rewriter.js
+++ b/lib/cartodb/utils/overviews_query_rewriter.js
@@ -206,6 +206,7 @@ function apply_filters_to_query(query, filters) {
 
 function zoom_level_for_bounding_box(query, bounding_box) {
     // TODO: implement
+    // jshint unused:false
     return '100'; // force use of base table
 }
 
@@ -227,6 +228,7 @@ function zoom_level_for_bounding_box(query, bounding_box) {
 // doesnn't prevent substitution inside literals).
 // But the transformation will currently only be applied to simple queries
 // of the form detected by the overviews_supported_query function.
+// TODO: document recent changes (options bounding_box, zoom_level, filters...)
 OverviewsQueryRewriter.prototype.query = function(query, data, options) {
     options = options || {};
 
@@ -245,23 +247,9 @@ OverviewsQueryRewriter.prototype.query = function(query, data, options) {
     var rewritten_query;
 
     var zoom_level_expression = this.options.zoom_level;
-    var zoom_level;
-    if ( _.has(options, 'bounding_box') ) {
-        // The presence of this key, even if it has a null value indicates the
-        // query cannot handle dynamic zoom expressinos (is not for the tiler)
-        zoom_level = zoom_level_for_bounding_box(unfiltered_query, options.bounding_box);
-    } else if ( options.zoom_level ) {
-        zoom_level = options.zoom_level;
-    }
-    if ( !zoom_level && !zoom_level_expression ) {
-        zoom_level = '0';
-    }
+    var zoom_level = zoom_level_for_query(unfiltered_query, zoom_level_expression, options);
 
-    if ( zoom_level || zoom_level === '0' || zoom_level === 0 ) {
-        rewritten_query = overviews_query_with_definite_zoom(unfiltered_query, overviews, zoom_level);
-    } else {
-        rewritten_query = overviews_query_with_zoom_expression(unfiltered_query, overviews, zoom_level_expression);
-    }
+    rewritten_query = overviews_query(unfiltered_query, overviews, zoom_level, zoom_level_expression);
 
     if ( rewritten_query === unfiltered_query ) {
         // could not or didn't need to alter the query
@@ -273,6 +261,29 @@ OverviewsQueryRewriter.prototype.query = function(query, data, options) {
     return rewritten_query;
 };
 
+function zoom_level_for_query(query, zoom_level_expression, options) {
+    var zoom_level = null;
+    if ( _.has(options, 'bounding_box') ) {
+        // The presence of this key, even if it has a null value indicates the
+        // query cannot handle dynamic zoom expressinos (is not for the tiler)
+        zoom_level = zoom_level_for_bounding_box(query, options.bounding_box);
+    } else if ( _.has(options, 'zoom_level') ) {
+        zoom_level = options.zoom_level;
+    }
+    if ( zoom_level === null && !zoom_level_expression ) {
+        zoom_level = '0';
+    }
+    return zoom_level;
+}
+
+function overviews_query(query, overviews, zoom_level, zoom_level_expression) {
+    if ( zoom_level || zoom_level === '0' || zoom_level === 0 ) {
+        return overviews_query_with_definite_zoom(query, overviews, zoom_level);
+    } else {
+        return overviews_query_with_zoom_expression(query, overviews, zoom_level_expression);
+    }
+}
+
 OverviewsQueryRewriter.prototype.is_supported_query = function(sql) {
     var basic_query =
         /\s*SELECT\s+[\*a-z0-9_,\s]+?\s+FROM\s+((\"[^"]+\"|[a-z0-9_]+)\.)?(\"[^"]+\"|[a-z0-9_]+)\s*;?\s*/i;