From e298e76e0f132398c7640b6c6e0b789070edac08 Mon Sep 17 00:00:00 2001
From: Rutherther <fandabohacek@gmail.com>
Date: Fri, 18 Feb 2022 23:32:40 +0100
Subject: [PATCH] feat(combat): add simple attack combat technique

---
 .../Techniques/ICombatTechnique.cs            |  26 ++++
 .../Techniques/SimpleAttackTechnique.cs       | 147 ++++++++++++++++++
 2 files changed, 173 insertions(+)
 create mode 100644 Extensions/NosSmooth.Extensions.Combat/Techniques/ICombatTechnique.cs
 create mode 100644 Extensions/NosSmooth.Extensions.Combat/Techniques/SimpleAttackTechnique.cs

diff --git a/Extensions/NosSmooth.Extensions.Combat/Techniques/ICombatTechnique.cs b/Extensions/NosSmooth.Extensions.Combat/Techniques/ICombatTechnique.cs
new file mode 100644
index 0000000..a7732de
--- /dev/null
+++ b/Extensions/NosSmooth.Extensions.Combat/Techniques/ICombatTechnique.cs
@@ -0,0 +1,26 @@
+//
+//  ICombatTechnique.cs
+//
+//  Copyright (c) František Boháček. All rights reserved.
+//  Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using NosSmooth.Extensions.Combat.Operations;
+using OneOf.Types;
+using Remora.Results;
+
+namespace NosSmooth.Extensions.Combat.Techniques;
+
+/// <summary>
+/// A combat technique that allows to handle the whole combat situations using step callbacks.
+/// </summary>
+/// <remarks>
+/// The callback methods decide the next steps, used in <see cref="CombatManager"/>.
+/// </remarks>
+public interface ICombatTechnique
+{
+    public bool ShouldContinue(ICombatState state);
+
+    public Result HandleCombatStep(ICombatState state);
+
+    public Result HandleError(ICombatState state, ICombatOperation operation, Result result);
+}
\ No newline at end of file
diff --git a/Extensions/NosSmooth.Extensions.Combat/Techniques/SimpleAttackTechnique.cs b/Extensions/NosSmooth.Extensions.Combat/Techniques/SimpleAttackTechnique.cs
new file mode 100644
index 0000000..c0b273f
--- /dev/null
+++ b/Extensions/NosSmooth.Extensions.Combat/Techniques/SimpleAttackTechnique.cs
@@ -0,0 +1,147 @@
+//
+//  SimpleAttackTechnique.cs
+//
+//  Copyright (c) František Boháček. All rights reserved.
+//  Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using NosSmooth.Extensions.Combat.Errors;
+using NosSmooth.Extensions.Combat.Extensions;
+using NosSmooth.Extensions.Combat.Operations;
+using NosSmooth.Extensions.Combat.Selectors;
+using NosSmooth.Extensions.Pathfinding;
+using NosSmooth.Game.Data.Characters;
+using NosSmooth.Game.Data.Entities;
+using Remora.Results;
+
+namespace NosSmooth.Extensions.Combat.Techniques;
+
+/// <summary>
+/// A combat technique that will attack on the specified enemy.
+/// </summary>
+public class SimpleAttackTechnique : ICombatTechnique
+{
+    private readonly int _targetId;
+    private readonly WalkManager _walkManager;
+    private readonly ISkillSelector _skillSelector;
+    private readonly IItemSelector _itemSelector;
+
+    private Skill? _currentSkill;
+    private ILivingEntity? _target;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="targetId"></param>
+    /// <param name="walkManager"></param>
+    /// <param name="skillSelector"></param>
+    /// <param name="itemSelector"></param>
+    public SimpleAttackTechnique
+    (
+        int targetId,
+        WalkManager walkManager,
+        ISkillSelector skillSelector,
+        IItemSelector itemSelector
+    )
+    {
+        _targetId = targetId;
+        _walkManager = walkManager;
+        _skillSelector = skillSelector;
+        _itemSelector = itemSelector;
+    }
+
+    /// <inheritdoc />
+    public bool ShouldContinue(ICombatState state)
+    {
+        var map = state.Game.CurrentMap;
+        if (map is null)
+        {
+            return false;
+        }
+
+        var entity = map.Entities.GetEntity<ILivingEntity>(_targetId);
+        return !(entity is null || entity.Hp is not null && (entity.Hp.Amount <= 0 || entity.Hp.Percentage <= 0));
+    }
+
+    /// <inheritdoc />
+    public Result HandleCombatStep(ICombatState state)
+    {
+        var map = state.Game.CurrentMap;
+        if (map is null)
+        {
+            return new MapNotInitializedError();
+        }
+
+        if (_target is null)
+        {
+            var entity = map.Entities.GetEntity<ILivingEntity>(_targetId);
+            if (entity is null)
+            {
+                return new EntityNotFoundError();
+            }
+
+            _target = entity;
+        }
+
+        var character = state.Game.Character;
+        if (character is null)
+        {
+            return new CharacterNotInitializedError();
+        }
+
+        if (_currentSkill is null)
+        {
+            var skills = character.Skills;
+            if (skills is null)
+            {
+                return new CharacterNotInitializedError("Skills");
+            }
+
+            var characterMp = character.Mp?.Amount ?? 0;
+            var usableSkills = new[] { skills.PrimarySkill, skills.SecondarySkill }
+                .Concat(skills.OtherSkills)
+                .Where(x => !x.IsOnCooldown && characterMp >= (x.Info?.MpCost ?? long.MaxValue));
+
+            var skillResult = _skillSelector.GetSelectedSkill(usableSkills);
+            if (!skillResult.IsSuccess)
+            {
+                if (skillResult.Error is SkillNotFoundError)
+                {
+                    return Result.FromSuccess();
+                }
+
+                return Result.FromError(skillResult);
+            }
+
+            _currentSkill = skillResult.Entity;
+        }
+
+        if (_currentSkill.Info is null)
+        {
+            var currentSkill = _currentSkill;
+            _currentSkill = null;
+            return new MissingInfoError("skill", currentSkill.SkillVNum);
+        }
+
+        if (character.Position is null || _target.Position is null)
+        {
+            return new;
+        }
+
+        if (!character.Position.Value.IsInRange(_target.Position.Value, _currentSkill.Info.Range))
+        {
+            state.WalkInRange(_walkManager, _target, _currentSkill.Info.Range);
+        }
+        else
+        {
+            state.UseSkill(_currentSkill, _target);
+        }
+
+        return Result.FromSuccess();
+    }
+
+    /// <inheritdoc />
+    public Result HandleError(ICombatState state, ICombatOperation operation, Result result)
+    {
+        return result;
+    }
+}
\ No newline at end of file
-- 
2.49.0