From 6856ff725439f8680d14c23f96e2d7d896de748e Mon Sep 17 00:00:00 2001
From: Ritchie Martori <skawful@gmail.com>
Date: Mon, 24 Jun 2013 15:21:59 -0700
Subject: [PATCH] Add geo filtering for memory adapter

---
 lib/adapters/memory.js | 33 +++++++++++++++++++++++++-
 lib/geo.js             | 53 ++++++++++++++++++++++++++++++++++++++++++
 lib/model-builder.js   |  3 +++
 3 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 lib/geo.js

diff --git a/lib/adapters/memory.js b/lib/adapters/memory.js
index 7982ad0f..17b614bd 100644
--- a/lib/adapters/memory.js
+++ b/lib/adapters/memory.js
@@ -1,3 +1,5 @@
+var geo = require('../geo');
+
 exports.initialize = function initializeSchema(schema, callback) {
     schema.adapter = new Memory();
     schema.adapter.connect(callback);
@@ -108,9 +110,10 @@ Memory.prototype.all = function all(model, filter, callback) {
     var nodes = Object.keys(this.cache[model]).map(function (key) {
         return this.fromDb(model, this.cache[model][key]);
     }.bind(this));
+    var isGeo = false;
+
 
     if (filter) {
-
         // do we need some sorting?
         if (filter.order) {
             var props = this._models[model].properties;
@@ -129,6 +132,13 @@ Memory.prototype.all = function all(model, filter, callback) {
             });
             nodes = nodes.sort(sorting.bind(orders));
         }
+        
+        var nearFilter = nearFilter(filter.where);
+        
+        // geo sorting
+        if(nearFilter) {
+          nodes = geo.filter(nodes, nearFilter);
+        }
 
         // do we need some filtration?
         if (filter.where) {
@@ -160,6 +170,26 @@ Memory.prototype.all = function all(model, filter, callback) {
         }
         return 0;
     }
+    
+    function nearFilter(where) {
+      var result = false;
+      
+      if(where && typeof where === 'object') {
+        Object.keys(where).forEach(function (key) {
+          var ex = where[key];
+          
+          if(ex && ex.near) {
+            result = {
+              near: ex.near,
+              maxDistance: ex.maxDistance,
+              key: key
+            };
+          }
+        });
+      }
+      
+      return result;
+    }
 };
 
 function applyFilter(filter) {
@@ -191,6 +221,7 @@ function applyFilter(filter) {
                 }
                 return false;
             }
+            
             if(isNum(example.gt) && example.gt < value) return true;
             if(isNum(example.gte) && example.gte <= value) return true;
             if(isNum(example.lt) && example.lt > value) return true;
diff --git a/lib/geo.js b/lib/geo.js
new file mode 100644
index 00000000..6ef18d09
--- /dev/null
+++ b/lib/geo.js
@@ -0,0 +1,53 @@
+exports.filter = function (arr, filter) {
+  var origin = filter.near;
+  var max = filter.maxDistance > 0 ? filter.maxDistance : false;
+  var key = filter.key;
+  
+  // create distance index
+  var distances = {};
+  var result = [];
+  
+  arr.forEach(function (obj) {
+    var loc = obj[key];
+    
+    // filter out objects without locations
+    if(!loc) return;
+    if(typeof loc.lat !== 'number') return;
+    if(typeof loc.long !== 'number') return;
+    
+    var d = distanceBetween(origin, loc);
+    
+    if(max && d > max) {
+      // dont add
+    } else {
+      distances[obj.id] = d;
+      result.push(obj);
+    }
+  });
+  
+  return result.sort(function (objA, objB) {
+    var a = objB[key];
+    var b = objB[key];
+    
+    if(a && b) {
+      var da = distances[objA.id];
+      var db = distances[objB.id];
+      
+      if(db === da) return 0;
+      return da > db ? -1 : 1;
+    } else {
+      return 0;
+    }
+  });
+}
+
+var distanceBetween = exports.distanceBetween = function distanceBetween(a, b) {
+  var xs = 0;
+  var ys = 0;
+  xs = a.lat - b.lat;
+  xs = xs * xs;
+  ys = a.long - b.long;
+  ys = ys * ys;
+  
+  return Math.sqrt( xs + ys );
+}
\ No newline at end of file
diff --git a/lib/model-builder.js b/lib/model-builder.js
index 940f99ca..51b8e534 100644
--- a/lib/model-builder.js
+++ b/lib/model-builder.js
@@ -215,6 +215,9 @@ ModelBuilder.prototype.define = function defineClass(className, properties, sett
                     if (value === null || value === undefined) {
                         this.__data[attr] = value;
                     } else {
+                        if(attr === 'geo') {
+                          debugger;
+                        }
                         this.__data[attr] = DataType(value);
                     }
                 }