From d0ad5e7aec5084b56486f6dec7d8490e5ab42e04 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franti=C5=A1ek=20Boh=C3=A1=C4=8Dek?=
 <fandabohacek@gmail.com>
Date: Thu, 23 Dec 2021 16:11:51 +0100
Subject: [PATCH] feat: implement walk command handler

---
 .../Walk/WalkCommandHandler.cs                | 69 +++++++++++++++++--
 1 file changed, 64 insertions(+), 5 deletions(-)

diff --git a/Local/NosSmooth.LocalClient/CommandHandlers/Walk/WalkCommandHandler.cs b/Local/NosSmooth.LocalClient/CommandHandlers/Walk/WalkCommandHandler.cs
index ca13c27e4b6fcf20d4386850c128a01498cf50ab..7fd2a6a4abb89401016893ec6e4e12badbccb6f9 100644
--- a/Local/NosSmooth.LocalClient/CommandHandlers/Walk/WalkCommandHandler.cs
+++ b/Local/NosSmooth.LocalClient/CommandHandlers/Walk/WalkCommandHandler.cs
@@ -4,11 +4,13 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using Microsoft.Extensions.Options;
 using NosSmooth.Core.Commands;
+using NosSmooth.LocalClient.CommandHandlers.Walk.Errors;
 using NosSmoothCore;
 using Remora.Results;
 
-namespace NosSmooth.LocalClient.CommandHandlers;
+namespace NosSmooth.LocalClient.CommandHandlers.Walk;
 
 /// <summary>
 /// Handles <see cref="WalkCommand"/>.
@@ -16,20 +18,77 @@ namespace NosSmooth.LocalClient.CommandHandlers;
 public class WalkCommandHandler : ICommandHandler<WalkCommand>
 {
     private readonly NosClient _nosClient;
+    private readonly WalkStatus _walkStatus;
+    private readonly WalkCommandHandlerOptions _options;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="WalkCommandHandler"/> class.
     /// </summary>
     /// <param name="nosClient">The local client.</param>
-    public WalkCommandHandler(NosClient nosClient)
+    /// <param name="walkStatus">The walk status.</param>
+    /// <param name="options">The options.</param>
+    public WalkCommandHandler(NosClient nosClient, WalkStatus walkStatus, IOptions<WalkCommandHandlerOptions> options)
     {
+        _options = options.Value;
         _nosClient = nosClient;
+        _walkStatus = walkStatus;
     }
 
     /// <inheritdoc/>
-    public Task<Result> HandleCommand(WalkCommand command, CancellationToken ct = default)
+    /// 1) If client called walk, cancel.
+    /// 2) If another walk command requested, cancel.
+    /// 3) If at the correct spot, cancel.
+    /// 4) If not walking for over x ms, cancel.
+    public async Task<Result> HandleCommand(WalkCommand command, CancellationToken ct = default)
     {
-        _nosClient.GetCharacter().Walk(command.TargetX, command.TargetY);
-        return Task.Delay(1000).ContinueWith(_ => Result.FromSuccess()); // TODO: Wait for the move to finish
+        CancellationTokenSource linked = CancellationTokenSource.CreateLinkedTokenSource(ct);
+        ct = linked.Token;
+        await _walkStatus.SetWalking(linked, command.TargetX, command.TargetY, command.CancelOnUserMove);
+        while (!ct.IsCancellationRequested)
+        {
+            try
+            {
+                _nosClient.GetCharacter().Walk(command.TargetX, command.TargetY);
+            }
+            catch (Exception e)
+            {
+                try
+                {
+                    await _walkStatus.CancelWalkingAsync(ct: ct);
+                }
+                catch
+                {
+                    // ignored, just for cancellation
+                }
+
+                return e;
+            }
+
+            try
+            {
+                await Task.Delay(_options.CheckDelay, ct);
+            }
+            catch
+            {
+                // ignored
+            }
+
+            if (_walkStatus.IsFinished)
+            {
+                return Result.FromSuccess();
+            }
+
+            if (_walkStatus.Error is not null)
+            {
+                return new WalkNotFinishedError(_walkStatus.CurrentX, _walkStatus.CurrentY, (WalkCancelReason)_walkStatus.Error);
+            }
+
+            if ((DateTimeOffset.Now - _walkStatus.LastWalkTime).TotalMilliseconds > _options.NotWalkingTooLongTrigger)
+            {
+                return new WalkNotFinishedError(_walkStatus.CurrentX, _walkStatus.CurrentY, WalkCancelReason.NotWalkingTooLong);
+            }
+        }
+
+        return new WalkNotFinishedError(_walkStatus.CurrentX, _walkStatus.CurrentY, WalkCancelReason.Unknown);
     }
 }
\ No newline at end of file