From 045bf530a1798acddb8b74d836e2d6d7e153d787 Mon Sep 17 00:00:00 2001
From: James Ketrenos <james_git@ketrenos.com>
Date: Sun, 25 Nov 2018 16:19:34 -0800
Subject: [PATCH] Holiday selection working

Signed-off-by: James Ketrenos <james_git@ketrenos.com>
---
 frontend/src/ketr-photos/ketr-photos.html | 49 +++++++++++++++++------
 server/lib/pascha.js                      | 29 +++++++++++++-
 2 files changed, 64 insertions(+), 14 deletions(-)

diff --git a/frontend/src/ketr-photos/ketr-photos.html b/frontend/src/ketr-photos/ketr-photos.html
index c1aa428..c652f00 100755
--- a/frontend/src/ketr-photos/ketr-photos.html
+++ b/frontend/src/ketr-photos/ketr-photos.html
@@ -317,6 +317,11 @@
       #holiday [selected] {
         font-weight: bold;
       }
+
+      .isNext {
+        margin-left: 0.5em;
+        opacity: 0.5;
+      }
     </style>
 
     <app-location route="{{route}}"></app-location>
@@ -336,7 +341,7 @@
           <div id="holiday" class="flex layout vertical">
             <div>Holidays</div>
             <template is="dom-repeat" items="[[holidays]]">
-              <div tabindex="0" on-tap="loadHoliday">[[item]]</div>
+              <div tabindex="0" holiday on-tap="loadHoliday">[[item]]</div>
             </template>
           </div>
           <div id="time"><div>... time slider ...</div></div>
@@ -405,7 +410,10 @@
                   <div tabindex="0" on-tap="loadPath">[[item.name]] /</div>
                 </template>
               </div>
-              <div mode="holiday">[[holidayTitle]]</div>
+              <div mode="holiday" class="layout horizontal">
+                <div>[[holidayTitle]]</div>
+                <div class='isNext' hidden$="[[!isNextHoliday(holidayTitle, nextHoliday)]]">(next upcoming Holiday!!)</div>
+              </div>
               <div mode="time">time</div>
               <div mode="memories">Photos taken on <b on-tap="drawerToggle">[[memoryDate]]</b></div>
             </iron-pages>
@@ -585,9 +593,18 @@
           "userChanged(user)",
           "daysChanged(days)",
           "baseRouteChanged(route.path, basePath)",
-          "pathChanged(path, route.path, basePath)",
+          "pathChanged(path, route.path, basePath)"
         ],
 
+        listeners: {
+          "scroll": "onScroll",
+          "iron-resize" : "onResize"
+        },
+
+        isNextHoliday: function(holiday, nextHoliday) {
+          return (holiday == nextHoliday);
+        },
+
         pathChanged: function(path, routePath, basePath) {
           if (!basePath || !routePath || !path) {
             return;
@@ -864,19 +881,24 @@
           }
         },
 
-        listeners: {
-          "scroll": "onScroll",
-          "iron-resize" : "onResize"
-        },
-
-        loadHoliday: function(event) {
+        highlightHoliday: function(holiday) {
           Array.prototype.forEach.call(this.$.holiday.querySelectorAll("[selected]"), function(el) {
             el.removeAttribute("selected");
           });
-          event.currentTarget.setAttribute("selected", true);
+          Array.prototype.forEach.call(this.$.holiday.querySelectorAll("[holiday]"), function(el) {
+            if (el.textContent == holiday) {
+              el.setAttribute("selected", true);
+            }
+          });
+        },
+
+        loadHoliday: function(event) {
           this.holiday = event.model.item;
-          this.resetPhotos();
-          this._loadPhotos();
+          this.highlightHoliday(this.holiday);
+          if (this.mode == "holiday") {
+            this.resetPhotos();
+            this._loadPhotos();
+          }
         },
 
         loadPath: function(event) {
@@ -1959,7 +1981,10 @@
             }
 
             this.holiday = results.next;
+            this.nextHoliday = results.next;
             this.holidays = results.holidays;
+            Polymer.dom.flush();
+            this.highlightHoliday(this.holiday);
           }.bind(this));
         },
 
diff --git a/server/lib/pascha.js b/server/lib/pascha.js
index 4ded784..4a01f9f 100644
--- a/server/lib/pascha.js
+++ b/server/lib/pascha.js
@@ -52,14 +52,39 @@ function init(moment) {
   //};
   });
 
+/*
   const orthodoxDates = require("./pascha-dates.js");
 
   var pascha = function(year) {
-    /* Date lookup table.. */
     var date = orthodoxDates[year].split("-");
-    date[1] -= 1; /* month needs to be zero index */
+    date[1] -= 1; // month needs to be zero index
     return moment(date);
   }
+*/
+
+  /**
+  * Calculates Easter in the Gregorian/Western (Catholic and Protestant) calendar 
+  * based on the algorithm by Oudin (1940) from http://www.tondering.dk/claus/cal/easter.php
+  * @returns {array} [int month, int day]
+  */
+  var pascha = function(year) {
+    var f = Math.floor,
+      // Golden Number - 1
+      G = year % 19,
+      C = f(year / 100),
+      // related to Epact
+      H = (C - f(C / 4) - f((8 * C + 13)/25) + 19 * G + 15) % 30,
+      // number of days from 21 March to the Paschal full moon
+      I = H - f(H/28) * (1 - f(29/(H + 1)) * f((21-G)/11)),
+      // weekday for the Paschal full moon
+      J = (year + f(year / 4) + I + 2 - C + f(C / 4)) % 7,
+      // number of days from 21 March to the Sunday on or before the Paschal full moon
+      L = I - J,
+      month = 3 + f((L + 40)/44),
+      day = L + 28 - 31 * f(month / 4);
+
+    return moment([year, (month - 1),day]);
+  }
 
   moment.modifyHolidays.extendParser(function(m, date){
     if (~date.indexOf('pascha')) {