From cc0eba7042aaad725a03f755ff076c9f4797957f Mon Sep 17 00:00:00 2001
From: Sijmen <me@vijf.life>
Date: Tue, 6 Jul 2021 00:04:24 +0200
Subject: [PATCH] Add event deletion

---
 BlazorApp/Data/Calendar.cs  | 22 +++++++++++++++++++++
 BlazorApp/Pages/Event.razor | 39 ++++++++++++++++++++++++++++++++++---
 2 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/BlazorApp/Data/Calendar.cs b/BlazorApp/Data/Calendar.cs
index 3d13e5f..93147b4 100644
--- a/BlazorApp/Data/Calendar.cs
+++ b/BlazorApp/Data/Calendar.cs
@@ -237,6 +237,9 @@ namespace BlazorApp.Data
 
             // Extract and parse the ICal data
             var dataNode = document.GetElementsByTagName("C:calendar-data")[0]?.InnerText;
+            if (dataNode == null)
+                return null;
+            
             var events = ParseICal(dataNode);
             if (events.Count == 0)
                 return null;
@@ -278,5 +281,24 @@ namespace BlazorApp.Data
             
             return newEvent;
         }
+
+        public async Task DeleteEvent(Event @event)
+        {
+            // Only delete when we have an E-Tag
+            if (@event.ETag == null)
+            {
+                Console.WriteLine($"Can not delete event '{@event.Uid}' because it has no ETag");
+                return;
+            }
+            
+            // TODO Can probably make `client` a member variable
+            var client = new HttpClient();
+            if (AuthorizationHeader != null)
+                client.DefaultRequestHeaders.Add("Authorization", AuthorizationHeader);
+
+            // Build a new URL based on the calendar's URL and the event's collection href.
+            var url = new Uri(new Uri(Url), @event.Href);
+            await client.DeleteAsync(url);
+        }
     }
 }
\ No newline at end of file
diff --git a/BlazorApp/Pages/Event.razor b/BlazorApp/Pages/Event.razor
index accf618..0d39f1c 100644
--- a/BlazorApp/Pages/Event.razor
+++ b/BlazorApp/Pages/Event.razor
@@ -1,5 +1,6 @@
 @page "/calendars/{calendarId:int}/events/{eventUid}"
 @inject Data.CalendarService _calendarService
+@inject NavigationManager _navigationManager
 
 <a href="/calendars/@CalendarId">
     <span class="oi oi-arrow-left"></span> Back
@@ -8,7 +9,7 @@
 @if (_event == null)
 {
     <p>
-        <em>Loading...</em>
+        <em>@(_notFound ? "Event not found" : "Loading...")</em>
     </p>
 }
 else
@@ -43,7 +44,19 @@ else
         </div>
     }
 
-    <p class="event-description">@_event.Description</p>
+    @if (_event.Description != null)
+    {
+        <p class="event-description">@_event.Description</p>
+    }
+
+    @if (!_confirmDelete)
+    {
+        <button class="btn btn-outline-danger" @onclick="DeleteEvent">Delete</button>
+    }
+    else
+    {
+        <button class="btn btn-danger" @onclick="DeleteEvent">Are you sure?</button>
+    }
 }
 
 @code
@@ -56,16 +69,36 @@ else
 
     private Data.Calendar _calendar;
     private Data.Event _event;
+
+    private bool _notFound;
     private bool _editTitle;
+    private bool _confirmDelete;
 
     protected override async Task OnInitializedAsync()
     {
         _calendar = await Data.CalendarService.GetCalendarById(CalendarId);
         _event = await _calendar.GetEventByUid(EventUid);
+        _notFound = _event == null;
     }
 
-    private async void UpdateEvent()
+    private async Task UpdateEvent()
     {
         _event = await _calendar.UpdateEvent(_event);
     }
+
+    private async Task DeleteEvent()
+    {
+        if (!_confirmDelete)
+        {
+            _confirmDelete = true;
+            await Task.Delay(2000);
+        }
+        else
+        {
+            await _calendar.DeleteEvent(_event);
+            _navigationManager.NavigateTo($"/calendars/{CalendarId}");
+        }
+
+        _confirmDelete = false;
+    }
 }
\ No newline at end of file