From 038416bbaf0874bc6b7949171d045fa4217ebe53 Mon Sep 17 00:00:00 2001
From: Max Grossman <m.grossman1813@gmail.com>
Date: Sun, 13 May 2018 15:09:50 -0500
Subject: [PATCH] implement haversine; test dan's images

ref #10
---
 adapters/sequence/helpers.js   | 15 +++++++++++----
 adapters/sequence/index.js     |  6 +++---
 adapters/sequence/split.js     |  3 +--
 helpers/index.js               | 17 +++++++++++------
 test/adapters/sequencerSpec.js | 11 +++++++++--
 5 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/adapters/sequence/helpers.js b/adapters/sequence/helpers.js
index e6c0022..18995f0 100644
--- a/adapters/sequence/helpers.js
+++ b/adapters/sequence/helpers.js
@@ -13,10 +13,17 @@ const uuidv4 = require('uuid/v4');
  * @return {number} euclidean distance between two points
  */
 exports.calcDistance = (metaLoc, nextMetaLoc) => {
-    return Math.sqrt(
-        Math.pow(nextMetaLoc.lon - metaLoc.lon, 2) + 
-        Math.pow(nextMetaLoc.lat - metaLoc.lat, 2)
-    )
+    var R = 6371e3,
+        latRadians = [metaLoc.lat, nextMetaLoc.lat].map(lat => lat * (Math.PI / 180)),
+        latDiffs = (latRadians[0] - latRadians[1]) * (Math.PI / 180),
+        lonDiffs = (metaLoc.lon - nextMetaLoc.lon) * (Math.PI / 180),
+
+        a = Math.pow(Math.sin(lonDiffs / 2), 2) +
+           (Math.cos(latRadians[0]) * Math.cos(latRadians[1]) * Math.pow(lonDiffs/2, 2)),
+            
+        c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
+
+        return R * c;
 }
 
 /**
diff --git a/adapters/sequence/index.js b/adapters/sequence/index.js
index f0f7c0b..960cd79 100644
--- a/adapters/sequence/index.js
+++ b/adapters/sequence/index.js
@@ -3,7 +3,7 @@
 const fs = require('fs-extra');
 const path = require('path');
 const buildSequences = require('./build');
-const { flatten } = require('../../helpers');
+const flatten = require('../../helpers').flatten;
 
 Promise = require('bluebird')
 
@@ -25,8 +25,8 @@ module.exports = (paths, cutDist, cutTime, cutSize) => {
         .then(async (images) => {
             try {
                 const params = { 
-                          maxDist: cutDist || 0.2,
-                          minDist: 0.1,
+                          maxDist: cutDist || 300,
+                          minDist: 1,
                           maxDetla: cutTime || 120, 
                           size: cutSize || 0 
                       },
diff --git a/adapters/sequence/split.js b/adapters/sequence/split.js
index 64e1837..be08456 100644
--- a/adapters/sequence/split.js
+++ b/adapters/sequence/split.js
@@ -30,8 +30,7 @@ module.exports = (metas, params) => {
     sortedMetas.slice(0, pelIndex).forEach((meta, i) => {
         const partnerMeta = sortedMetas[i + 1],
               distance = calcDistance(meta.loc, partnerMeta.loc),
-              tooClose = false;
-            //   tooClose = distance < minDist;
+              tooClose = distance < minDist;
         
         // ... if image is not too close to its partner, add it to a sequence.
         if (!tooClose) {
diff --git a/helpers/index.js b/helpers/index.js
index 1d5ad5e..49d7a96 100644
--- a/helpers/index.js
+++ b/helpers/index.js
@@ -1,14 +1,19 @@
 'use strict';
 
+// total wizard! thanks!
+// https://stackoverflow.com/questions/10865025/merge-flatten-an-array-of-arrays-in-javascripts
+const isArray = (elementInQuestion) => Array.isArray(elementInQuestion);
+const flattener = (elementsToFlatten) => {
+    return elementsToFlatten.reduce((flatElements, element) => {
+        return flatElements.concat(isArray(element) ? flattener(element) : element);
+    }, []);
+}
+
+
 /**
  * flattens array of nested elements
  * 
  * @param {array} nested array of (potentially nested array) elements
  * @return {array} flattened array of elements in nested
  */
-exports.flatten = (nested) => {
-    return nested.reduce((flatt, el) => {
-        return flatt.concat(Array.isArray(el) ? flatten(el) : el)
-
-    });
-}
\ No newline at end of file
+exports.flatten = (nestedElements) => flattener(nestedElements)
\ No newline at end of file
diff --git a/test/adapters/sequencerSpec.js b/test/adapters/sequencerSpec.js
index c1abbe9..ba88d67 100644
--- a/test/adapters/sequencerSpec.js
+++ b/test/adapters/sequencerSpec.js
@@ -33,10 +33,16 @@ describe('sequence', () => {
     })
     it ('given a path of images, generates a list of sequence objects', async () => {
         try {
-            const paths = ['/testData/exif-gps-samples'].map(p => process.cwd() + p),
+            const paths = [
+                '/testData/exif-gps-samples', 
+                '/testData/danbjoseph'
+            ].map(p => process.cwd() + p),
                   sequences = await sequenceAdapter(paths),
                   validation = Joi.validate(sequences, sequencesSchema);
-
+            Object.keys(sequences).forEach(s => {
+                console.log(s);
+                console.log(sequences[s].length)
+            })
             expect(validation.value).to.be.eql(sequences)
             expect(validation.error).to.be.null;
 
@@ -45,4 +51,5 @@ describe('sequence', () => {
 
         }
     })
+    .timeout(10000000)
 })
\ No newline at end of file