From c9b3075d19372e9c2f221c5c59f737876fc76b9f Mon Sep 17 00:00:00 2001
From: FReenen <git@finnvanreenen.nl>
Date: Wed, 15 May 2024 22:56:38 +0200
Subject: [PATCH] handel concurrency clash on an already clashed event (#6)

---
 main.js | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/main.js b/main.js
index ed0881e..8d864db 100644
--- a/main.js
+++ b/main.js
@@ -643,6 +643,7 @@ class CalendarView extends ItemView
 
 		// check for concurrent events
 		let classes = "frcal__event";
+		let concurrentClash = "";
 		for (let i in container.children)
 		{
 			let child = container.children[i];
@@ -653,15 +654,35 @@ class CalendarView extends ItemView
 					&& (time[0] < parseInt(child.dataset.end))
 				)
 				{
-					if (time[0] < parseInt(child.dataset.start))
+					if (child.dataset.concurrentClash != "")
 					{
-						classes += " frcal__event_concurrent1";
-						child.addClass("frcal__event_concurrent2");
+						let third = document.getElementById("fr_event_" + child.dataset.concurrentClash);
+						if (
+							   (time[1] > parseInt(third.dataset.start))
+							&& (time[0] < parseInt(third.dataset.end))
+						)
+						{
+							console.warn("triple concurrent clashes are not suported with " + event.id + ", " + child.dataset.id + " and " + child.dataset.concurrentClash);
+						}
+						else
+						{
+							classes += (child.hasClass("frcal__event_concurrent2")) ? " frcal__event_concurrent1" : " frcal__event_concurrent2";
+						}
 					}
 					else
 					{
-						child.addClass("frcal__event_concurrent1");
-						classes += " frcal__event_concurrent2";
+						if (time[0] < parseInt(child.dataset.start))
+						{
+							classes += " frcal__event_concurrent1";
+							child.addClass("frcal__event_concurrent2");
+						}
+						else
+						{
+							child.addClass("frcal__event_concurrent1");
+							classes += " frcal__event_concurrent2";
+						}
+						child.dataset.concurrentClash = event.id;
+						concurrentClash = child.dataset.id;
 					}
 				}
 			}
@@ -671,11 +692,13 @@ class CalendarView extends ItemView
 			cls: classes,
 			attr: {
 				'id': "fr_event_" + event.id,
+				'data-id': event.id,
 				'data-group': event.group,
 				'data-state': event.state,
 				'data-type': event.type,
 				'data-start': time[0].toString(),
 				'data-end': time[1].toString(),
+				'data-concurrent-clash': concurrentClash,
 				'style': ((allDay) ? '' : 'top:' + (time[0]*this.zoom).toString() + 'px')
 			},
 		});