using System;
using System.Collections.Generic;
using System.Linq;
using UnityEditor.Animations;
using UnityEngine;

// ReSharper disable once CheckNamespace
namespace AnimatorAsCode.V1
{
    public class AacBackingAnimator
    {
        private readonly AacAnimatorGenerator _generator;

        public AacBackingAnimator(AacAnimatorGenerator animatorGenerator)
        {
            _generator = animatorGenerator;
        }

        public AacFlBoolParameter BoolParameter(string parameterName)
        {
            var result = AacFlBoolParameter.Internally(parameterName);
            _generator.CreateParamsAsNeeded(result);
            return result;
        }

        public AacFlBoolParameter TriggerParameter(string parameterName)
        {
            var result = AacFlBoolParameter.Internally(parameterName);
            _generator.CreateTriggerParamsAsNeeded(result);
            return result;
        }

        public AacFlFloatParameter FloatParameter(string parameterName)
        {
            var result = AacFlFloatParameter.Internally(parameterName);
            _generator.CreateParamsAsNeeded(result);
            return result;
        }

        public AacFlIntParameter IntParameter(string parameterName)
        {
            var result = AacFlIntParameter.Internally(parameterName);
            _generator.CreateParamsAsNeeded(result);
            return result;
        }

        public AacFlEnumIntParameter<TEnum> EnumParameter<TEnum>(string parameterName) where TEnum : Enum
        {
            var result = AacFlEnumIntParameter<TEnum>.Internally<TEnum>(parameterName);
            _generator.CreateParamsAsNeeded(result);
            return result;
        }

        public AacFlBoolParameterGroup BoolParameters(params string[] parameterNames)
        {
            var result = AacFlBoolParameterGroup.Internally(parameterNames);
            _generator.CreateParamsAsNeeded(result.ToList().ToArray());
            return result;
        }

        public AacFlBoolParameterGroup TriggerParameters(params string[] parameterNames)
        {
            var result = AacFlBoolParameterGroup.Internally(parameterNames);
            _generator.CreateTriggerParamsAsNeeded(result.ToList().ToArray());
            return result;
        }

        public AacFlFloatParameterGroup FloatParameters(params string[] parameterNames)
        {
            var result = AacFlFloatParameterGroup.Internally(parameterNames);
            _generator.CreateParamsAsNeeded(result.ToList().ToArray());
            return result;
        }

        public AacFlIntParameterGroup IntParameters(params string[] parameterNames)
        {
            var result = AacFlIntParameterGroup.Internally(parameterNames);
            _generator.CreateParamsAsNeeded(result.ToList().ToArray());
            return result;
        }

        public AacFlBoolParameterGroup BoolParameters(params AacFlBoolParameter[] parameters)
        {
            var result = AacFlBoolParameterGroup.Internally(parameters.Select(parameter => parameter.Name).ToArray());
            _generator.CreateParamsAsNeeded(parameters);
            return result;
        }

        public AacFlBoolParameterGroup TriggerParameters(params AacFlBoolParameter[] parameters)
        {
            var result = AacFlBoolParameterGroup.Internally(parameters.Select(parameter => parameter.Name).ToArray());
            _generator.CreateTriggerParamsAsNeeded(parameters);
            return result;
        }

        public AacFlFloatParameterGroup FloatParameters(params AacFlFloatParameter[] parameters)
        {
            var result = AacFlFloatParameterGroup.Internally(parameters.Select(parameter => parameter.Name).ToArray());
            _generator.CreateParamsAsNeeded(parameters);
            return result;
        }

        public AacFlIntParameterGroup IntParameters(params AacFlIntParameter[] parameters)
        {
            var result = AacFlIntParameterGroup.Internally(parameters.Select(parameter => parameter.Name).ToArray());
            _generator.CreateParamsAsNeeded(parameters);
            return result;
        }
    }

    public class AacFlStateMachine : AacAnimatorNode<AacFlStateMachine>
    {
        public readonly AnimatorStateMachine Machine;
        private readonly AnimationClip _emptyClip;
        private readonly AacBackingAnimator _backingAnimator;
        private readonly IAacDefaultsProvider _defaultsProvider;
        private readonly float _gridShiftX;
        private readonly float _gridShiftY;

        private readonly List<AacAnimatorNode> _childNodes;

        private readonly HashSet<string> _stateNames;

        internal AacFlStateMachine(AnimatorStateMachine machine, AnimationClip emptyClip, AacBackingAnimator backingAnimator, IAacDefaultsProvider defaultsProvider, AacFlStateMachine parent = null)
            : base(parent, defaultsProvider)
        {
            Machine = machine;
            _emptyClip = emptyClip;
            _backingAnimator = backingAnimator;
            _defaultsProvider = defaultsProvider;
            _stateNames = new HashSet<string>();

            var grid = defaultsProvider.Grid();
            _gridShiftX = grid.x;
            _gridShiftY = grid.y;

            _childNodes = new List<AacAnimatorNode>();
        }

        public AacBackingAnimator InternalBackingAnimator()
        {
            return _backingAnimator;
        }

        public AacFlStateMachine NewSubStateMachine(string name)
        {
            var lastState = LastNodePosition();
            return NewSubStateMachine(name, 0, 0).Shift(lastState, 0, 1);
        }

        public AacFlStateMachine NewSubStateMachine(string name, int x, int y)
        {
            var stateMachine = AacInternals.NoUndo(Machine, () => Machine.AddStateMachine(name, GridPosition(x, y)));
            var aacMachine = new AacFlStateMachine(stateMachine, _emptyClip, _backingAnimator, DefaultsProvider, this);
            _defaultsProvider.ConfigureStateMachine(stateMachine);
            _childNodes.Add(aacMachine);
            return aacMachine;
        }

        public AacFlStateMachine WithEntryPosition(int x, int y)
        {
            Machine.entryPosition = GridPosition(x, y);
            return this;
        }

        public AacFlStateMachine WithExitPosition(int x, int y)
        {
            Machine.exitPosition = GridPosition(x, y);
            return this;
        }

        public AacFlStateMachine WithAnyStatePosition(int x, int y)
        {
            Machine.anyStatePosition = GridPosition(x, y);
            return this;
        }

        public AacFlStateMachine WithParentStateMachinePosition(int x, int y)
        {
            Machine.parentStateMachinePosition = GridPosition(x, y);
            return this;
        }

        public AacFlState NewState(string name)
        {
            var lastState = LastNodePosition();
            return NewState(name, 0, 0).Shift(lastState, 0, 1);
        }

        public AacFlState NewState(string name, int x, int y)
        {
            var state = AacInternals.NoUndo(Machine, () => Machine.AddState(name, GridPosition(x, y)));
            DefaultsProvider.ConfigureState(state, _emptyClip);
            var aacState = new AacFlState(state, this, DefaultsProvider);
            _childNodes.Add(aacState);

            int suffix = 0;
            string stateName = name;
            while (_stateNames.Contains(stateName))
            {
                stateName = name + " " + (++suffix);
            }

            state.name = stateName;
            _stateNames.Add(state.name);
            
            return aacState;
        }

        public AacFlTransition AnyTransitionsTo(AacFlState destination)
        {
            return AnyTransition(destination, Machine);
        }

        public AacFlTransition AnyTransitionsTo(AacFlStateMachine destination)
        {
            return AnyTransition(destination, Machine);
        }

        public AacFlEntryTransition EntryTransitionsTo(AacFlState destination)
        {
            return EntryTransition(destination, Machine);
        }

        public AacFlEntryTransition EntryTransitionsTo(AacFlStateMachine destination)
        {
            return EntryTransition(destination, Machine);
        }

        public AacFlEntryTransition TransitionsFromEntry()
        {
            return EntryTransition(this, ParentMachine.Machine);
        }

        public AacFlNewTransitionContinuation TransitionsTo(AacFlState destination)
        {
            return new AacFlNewTransitionContinuation(AacInternals.NoUndo(ParentMachine.Machine, () => ParentMachine.Machine.AddStateMachineTransition(Machine, destination.State)), ParentMachine.Machine, Machine, destination.State);
        }

        public AacFlNewTransitionContinuation TransitionsTo(AacFlStateMachine destination)
        {
            return new AacFlNewTransitionContinuation(AacInternals.NoUndo(ParentMachine.Machine, () => ParentMachine.Machine.AddStateMachineTransition(Machine, destination.Machine)), ParentMachine.Machine, Machine, destination.Machine);
        }

        public AacFlNewTransitionContinuation Restarts()
        {
            return new AacFlNewTransitionContinuation(AacInternals.NoUndo(ParentMachine.Machine, () => ParentMachine.Machine.AddStateMachineTransition(Machine, Machine)), ParentMachine.Machine, Machine, Machine);
        }

        public AacFlNewTransitionContinuation Exits()
        {
            return new AacFlNewTransitionContinuation(AacInternals.NoUndo(ParentMachine.Machine, () => ParentMachine.Machine.AddStateMachineExitTransition(Machine)), ParentMachine.Machine, Machine, null);
        }

        private AacFlTransition AnyTransition(AacFlState destination, AnimatorStateMachine animatorStateMachine)
        {
            return new AacFlTransition(ConfigureTransition(AacInternals.NoUndo(animatorStateMachine, () => animatorStateMachine.AddAnyStateTransition(destination.State))), animatorStateMachine, null, destination.State);
        }

        private AacFlTransition AnyTransition(AacFlStateMachine destination, AnimatorStateMachine animatorStateMachine)
        {
            return new AacFlTransition(ConfigureTransition(AacInternals.NoUndo(animatorStateMachine, () => animatorStateMachine.AddAnyStateTransition(destination.Machine))), animatorStateMachine, null, destination.Machine);
        }

        private AnimatorStateTransition ConfigureTransition(AnimatorStateTransition transition)
        {
            DefaultsProvider.ConfigureTransition(transition);
            return transition;
        }

        private AacFlEntryTransition EntryTransition(AacFlState destination, AnimatorStateMachine animatorStateMachine)
        {
            return new AacFlEntryTransition(AacInternals.NoUndo(animatorStateMachine, () => animatorStateMachine.AddEntryTransition(destination.State)), animatorStateMachine, null, destination.State);
        }

        private AacFlEntryTransition EntryTransition(AacFlStateMachine destination, AnimatorStateMachine animatorStateMachine)
        {
            return new AacFlEntryTransition(AacInternals.NoUndo(animatorStateMachine, () => animatorStateMachine.AddEntryTransition(destination.Machine)), animatorStateMachine, null, destination.Machine);
        }

        internal Vector3 LastNodePosition()
        {
            return _childNodes.LastOrDefault()?.GetPosition() ?? Vector3.right * _gridShiftX * 2;
        }

        private Vector3 GridPosition(int x, int y)
        {
            return new Vector3(x * _gridShiftX, y * _gridShiftY, 0);
        }

        internal IReadOnlyList<AacAnimatorNode> GetChildNodes()
        {
            return _childNodes;
        }

        protected internal override Vector3 GetPosition()
        {
            return ParentMachine.Machine.stateMachines.First(x => x.stateMachine == Machine).position;
        }

        protected internal override void SetPosition(Vector3 position)
        {
            var stateMachines = ParentMachine.Machine.stateMachines;
            for (var i = 0; i < stateMachines.Length; i++)
            {
                var m = stateMachines[i];
                if (m.stateMachine == Machine)
                {
                    m.position = position;
                    stateMachines[i] = m;
                    break;
                }
            }
            ParentMachine.Machine.stateMachines = stateMachines;
        }

        public AacFlStateMachine WithDefaultState(AacFlState newDefaultState)
        {
            Machine.defaultState = newDefaultState.State;
            return this;
        }

        public override TBehaviour EnsureBehaviour<TBehaviour>()
        {
            foreach (var behaviour in Machine.behaviours)
                if (behaviour is TBehaviour myBehaviour)
                    return myBehaviour;

            return AacInternals.NoUndo(Machine, () => Machine.AddStateMachineBehaviour<TBehaviour>());
        }
    }

    public class AacFlState : AacAnimatorNode<AacFlState>
    {
        public readonly AnimatorState State;
        private readonly AnimatorStateMachine _machine;

        public AacFlState(AnimatorState state, AacFlStateMachine parentMachine, IAacDefaultsProvider defaultsProvider) : base(parentMachine, defaultsProvider)
        {
            State = state;
            _machine = parentMachine.Machine;
        }

        public AacFlState WithAnimation(Motion clip)
        {
            State.motion = clip;
            return this;
        }

        public AacFlState WithAnimation(AacFlClip clip)
        {
            State.motion = clip.Clip;
            return this;
        }

        public AacFlState WithAnimation(AacFlBlendTree blendTree)
        {
            State.motion = blendTree.BlendTree;
            return this;
        }

        public AacFlTransition TransitionsTo(AacFlState destination)
        {
            return new AacFlTransition(ConfigureTransition(AacInternals.NoUndo(State, () => State.AddTransition(destination.State))), _machine, State, destination.State);
        }

        public AacFlTransition TransitionsTo(AacFlStateMachine destination)
        {
            return new AacFlTransition(ConfigureTransition(AacInternals.NoUndo(State, () => State.AddTransition(destination.Machine))), _machine, State, destination.Machine);
        }

        public AacFlTransition TransitionsFromAny()
        {
            return new AacFlTransition(ConfigureTransition(AacInternals.NoUndo(State, () => _machine.AddAnyStateTransition(State))), _machine, null, State);
        }

        public AacFlEntryTransition TransitionsFromEntry()
        {
            return new AacFlEntryTransition(AacInternals.NoUndo(State, () => _machine.AddEntryTransition(State)), _machine, null, State);
        }

        public AacFlState AutomaticallyMovesTo(AacFlState destination)
        {
            var transition = ConfigureTransition(AacInternals.NoUndo(State, () => State.AddTransition(destination.State)));
            transition.hasExitTime = true;
            return this;
        }

        public AacFlState AutomaticallyMovesTo(AacFlStateMachine destination)
        {
            var transition = ConfigureTransition(AacInternals.NoUndo(State, () => State.AddTransition(destination.Machine)));
            transition.hasExitTime = true;
            return this;
        }

        public AacFlTransition Exits()
        {
            return new AacFlTransition(ConfigureTransition(AacInternals.NoUndo(State, () => State.AddExitTransition())), _machine, State, null);
        }

        private AnimatorStateTransition ConfigureTransition(AnimatorStateTransition transition)
        {
            DefaultsProvider.ConfigureTransition(transition);
            return transition;
        }

        public AacFlState WithWriteDefaultsSetTo(bool shouldWriteDefaults)
        {
            State.writeDefaultValues = shouldWriteDefaults;
            return this;
        }

        public AacFlState MotionTime(AacFlFloatParameter floatParam)
        {
            State.timeParameterActive = true;
            State.timeParameter = floatParam.Name;

            return this;
        }

        public AacFlState WithCycleOffset(AacFlFloatParameter floatParam)
        {
            State.cycleOffsetParameterActive = false;
            State.cycleOffsetParameter = floatParam.Name;

            return this;
        }

        public AacFlState WithCycleOffsetSetTo(float cycleOffset)
        {
            State.cycleOffsetParameterActive = false;
            State.cycleOffset = cycleOffset;

            return this;
        }

        public AacFlState WithSpeed(AacFlFloatParameter parameter)
        {
            State.speedParameterActive = true;
            State.speedParameter = parameter.Name;

            return this;
        }

        public AacFlState WithSpeedSetTo(float speed)
        {
            State.speedParameterActive = false;
            State.speed = speed;

            return this;
        }

        protected internal override Vector3 GetPosition()
        {
            return _machine.states.First(x => x.state == State).position;
        }

        protected internal override void SetPosition(Vector3 position)
        {
            var states = _machine.states;
            for (var i = 0; i < states.Length; i++)
            {
                var m = states[i];
                if (m.state == State)
                {
                    m.position = position;
                    states[i] = m;
                    break;
                }
            }
            _machine.states = states;
        }

        public override TBehaviour EnsureBehaviour<TBehaviour>()
        {
            foreach (var behaviour in State.behaviours)
                if (behaviour is TBehaviour myBehaviour)
                    return myBehaviour;

            return AacInternals.NoUndo(State, () => State.AddStateMachineBehaviour<TBehaviour>());
        }
    }

    public class AacFlTransition : AacFlNewTransitionContinuation
    {
        private readonly AnimatorStateTransition _transition;

        public AacFlTransition(AnimatorStateTransition transition, AnimatorStateMachine machine, AacTransitionEndpoint sourceNullableIfAny, AacTransitionEndpoint destinationNullableIfExits) : base(transition, machine, sourceNullableIfAny, destinationNullableIfExits)
        {
            _transition = transition;
        }

        public AacFlTransition WithSourceInterruption()
        {
            _transition.interruptionSource = TransitionInterruptionSource.Source;
            return this;
        }

        public AacFlTransition WithInterruption(TransitionInterruptionSource interruptionSource)
        {
            _transition.interruptionSource = interruptionSource;
            return this;
        }

        public AacFlTransition WithTransitionDurationSeconds(float transitionDuration)
        {
            _transition.duration = transitionDuration;
            return this;
        }

        public AacFlTransition WithOrderedInterruption()
        {
            _transition.orderedInterruption = true;
            return this;
        }

        public AacFlTransition WithNoOrderedInterruption()
        {
            _transition.orderedInterruption = false;
            return this;
        }

        public AacFlTransition WithTransitionToSelf()
        {
            _transition.canTransitionToSelf = true;
            return this;
        }

        public AacFlTransition WithNoTransitionToSelf()
        {
            _transition.canTransitionToSelf = false;
            return this;
        }

        public AacFlTransition AfterAnimationFinishes()
        {
            _transition.hasExitTime = true;
            _transition.exitTime = 1;

            return this;
        }

        public AacFlTransition Automatically()
        {
            _transition.hasExitTime = true;
            _transition.exitTime = 0;

            return this;
        }

        public AacFlTransition AfterAnimationIsAtLeastAtPercent(float exitTimeNormalized)
        {
            _transition.hasExitTime = true;
            _transition.exitTime = exitTimeNormalized;

            return this;
        }

        public AacFlTransition WithTransitionDurationPercent(float transitionDurationNormalized)
        {
            _transition.hasFixedDuration = false;
            _transition.duration = transitionDurationNormalized;

            return this;
        }
    }

    public class AacFlEntryTransition : AacFlNewTransitionContinuation
    {
        public AacFlEntryTransition(AnimatorTransition transition, AnimatorStateMachine machine, AnimatorState sourceNullableIfAny, AacTransitionEndpoint destinationNullableIfExits) : base(transition, machine, sourceNullableIfAny, destinationNullableIfExits)
        {
        }
    }

    public interface IAacFlCondition
    {
        void ApplyTo(AacFlCondition appender);
    }

    public interface IAacFlOrCondition
    {
        List<AacFlTransitionContinuation> ApplyTo(AacFlNewTransitionContinuation firstContinuation);
    }

    public class AacFlCondition
    {
        private readonly AnimatorTransitionBase _transition;

        public AacFlCondition(AnimatorTransitionBase transition)
        {
            _transition = transition;
        }

        public AacFlCondition Add(string parameter, AnimatorConditionMode mode, float threshold)
        {
            AacInternals.NoUndo(_transition, () => _transition.AddCondition(mode, threshold, parameter));
            return this;
        }
    }

    public class AacFlNewTransitionContinuation
    {
        public readonly AnimatorTransitionBase Transition;
        private readonly AnimatorStateMachine _machine;
        private readonly AacTransitionEndpoint _sourceNullableIfAny;
        private readonly AacTransitionEndpoint _destinationNullableIfExits;

        public AacFlNewTransitionContinuation(AnimatorTransitionBase transition, AnimatorStateMachine machine, AacTransitionEndpoint sourceNullableIfAny, AacTransitionEndpoint destinationNullableIfExits)
        {
            Transition = transition;
            _machine = machine;
            _sourceNullableIfAny = sourceNullableIfAny;
            _destinationNullableIfExits = destinationNullableIfExits;
        }

        /// Adds a condition to the transition.
        ///
        /// The settings of the transition can no longer be modified after this point.
        /// <example>
        /// <code>
        /// .When(_aac.BoolParameter(my.myBoolParameterName).IsTrue())
        /// .And(_aac.BoolParameter(my.myIntParameterName).IsGreaterThan(2))
        /// .And(AacAv3.ItIsLocal())
        /// .Or()
        /// .When(_aac.BoolParameters(
        ///     my.myBoolParameterName,
        ///     my.myOtherBoolParameterName
        /// ).AreTrue())
        /// .And(AacAv3.ItIsRemote());
        /// </code>
        /// </example>
        public AacFlTransitionContinuation When(IAacFlCondition action)
        {
            action.ApplyTo(new AacFlCondition(Transition));
            return AsContinuationWithOr();
        }

        /// <summary>
        /// Applies a series of conditions to this transition, but this series of conditions cannot include an Or operator.
        /// </summary>
        /// <param name="actionsWithoutOr"></param>
        /// <returns></returns>
        public AacFlTransitionContinuation When(Action<AacFlTransitionContinuationWithoutOr> actionsWithoutOr)
        {
            actionsWithoutOr(new AacFlTransitionContinuationWithoutOr(Transition));
            return AsContinuationWithOr();
        }

        /// <summary>
        /// Applies a series of conditions, and this series may contain Or operators. However, the result can not be followed by an And operator. It can only be an Or operator.
        /// </summary>
        /// <param name="actionsWithOr"></param>
        /// <returns></returns>
        public AacFlTransitionContinuationOnlyOr When(Action<AacFlNewTransitionContinuation> actionsWithOr)
        {
            actionsWithOr(this);
            return AsContinuationOnlyOr();
        }

        /// <summary>
        /// Applies a series of conditions, and this series may contain Or operators. All And operators that follow will apply to all the conditions generated by this series, until the next Or operator.
        /// </summary>
        /// <param name="actionsWithOr"></param>
        /// <returns></returns>
        public AacFlMultiTransitionContinuation When(IAacFlOrCondition actionsWithOr)
        {
            var pendingContinuations = actionsWithOr.ApplyTo(this);
            return new AacFlMultiTransitionContinuation(Transition, _machine, _sourceNullableIfAny, _destinationNullableIfExits, pendingContinuations);
        }

        public AacFlTransitionContinuation WhenConditions()
        {
            return AsContinuationWithOr();
        }

        private AacFlTransitionContinuation AsContinuationWithOr()
        {
            return new AacFlTransitionContinuation(Transition, _machine, _sourceNullableIfAny, _destinationNullableIfExits);
        }

        private AacFlTransitionContinuationOnlyOr AsContinuationOnlyOr()
        {
            return new AacFlTransitionContinuationOnlyOr(Transition, _machine, _sourceNullableIfAny, _destinationNullableIfExits);
        }
    }

    public class AacFlTransitionContinuation : AacFlTransitionContinuationAbstractWithOr
    {
        public AacFlTransitionContinuation(AnimatorTransitionBase transition, AnimatorStateMachine machine, AacTransitionEndpoint sourceNullableIfAny, AacTransitionEndpoint destinationNullableIfExits) : base(transition, machine, sourceNullableIfAny, destinationNullableIfExits)
        {
        }

        /// Adds an additional condition to the transition that requires all preceding conditions to be true.
        /// <example>
        /// <code>
        /// .When(_aac.BoolParameter(my.myBoolParameterName).IsTrue())
        /// .And(_aac.BoolParameter(my.myIntParameterName).IsGreaterThan(2))
        /// .And(AacAv3.ItIsLocal())
        /// .Or()
        /// .When(_aac.BoolParameters(
        ///     my.myBoolParameterName,
        ///     my.myOtherBoolParameterName
        /// ).AreTrue())
        /// .And(AacAv3.ItIsRemote());
        /// </code>
        /// </example>
        public AacFlTransitionContinuation And(IAacFlCondition action)
        {
            action.ApplyTo(new AacFlCondition(Transition));
            return this;
        }

        /// <summary>
        /// Applies a series of conditions to this transition. The conditions cannot include an Or operator.
        /// </summary>
        /// <param name="actionsWithoutOr"></param>
        /// <returns></returns>
        public AacFlTransitionContinuation And(Action<AacFlTransitionContinuationWithoutOr> actionsWithoutOr)
        {
            actionsWithoutOr(new AacFlTransitionContinuationWithoutOr(Transition));
            return this;
        }
    }

    public class AacFlMultiTransitionContinuation : AacFlTransitionContinuationAbstractWithOr
    {
        private readonly List<AacFlTransitionContinuation> _pendingContinuations;

        public AacFlMultiTransitionContinuation(AnimatorTransitionBase transition, AnimatorStateMachine machine, AacTransitionEndpoint sourceNullableIfAny, AacTransitionEndpoint destinationNullableIfExits, List<AacFlTransitionContinuation> pendingContinuations) : base(transition, machine, sourceNullableIfAny, destinationNullableIfExits)
        {
            _pendingContinuations = pendingContinuations;
        }

        /// Adds an additional condition to these transitions that requires all preceding conditions to be true.
        /// <example>
        /// <code>
        /// .When(_aac.BoolParameter(my.myBoolParameterName).IsTrue())
        /// .And(_aac.BoolParameter(my.myIntParameterName).IsGreaterThan(2))
        /// .And(AacAv3.ItIsLocal())
        /// .Or()
        /// .When(_aac.BoolParameters(
        ///     my.myBoolParameterName,
        ///     my.myOtherBoolParameterName
        /// ).AreTrue())
        /// .And(AacAv3.ItIsRemote());
        /// </code>
        /// </example>
        public AacFlMultiTransitionContinuation And(IAacFlCondition action)
        {
            foreach (var pendingContinuation in _pendingContinuations)
            {
                pendingContinuation.And(action);
            }

            return this;
        }

        /// <summary>
        /// Applies a series of conditions to these transitions. The conditions cannot include an Or operator.
        /// </summary>
        /// <param name="actionsWithoutOr"></param>
        /// <returns></returns>
        public AacFlMultiTransitionContinuation And(Action<AacFlTransitionContinuationWithoutOr> actionsWithoutOr)
        {
            foreach (var pendingContinuation in _pendingContinuations)
            {
                pendingContinuation.And(actionsWithoutOr);
            }

            return this;
        }
    }

    public class AacFlTransitionContinuationOnlyOr : AacFlTransitionContinuationAbstractWithOr
    {
        public AacFlTransitionContinuationOnlyOr(AnimatorTransitionBase transition, AnimatorStateMachine machine, AacTransitionEndpoint sourceNullableIfAny, AacTransitionEndpoint destinationNullableIfExits) : base(transition, machine, sourceNullableIfAny, destinationNullableIfExits)
        {
        }
    }

    public abstract class AacFlTransitionContinuationAbstractWithOr
    {
        protected readonly AnimatorTransitionBase Transition;
        private readonly AnimatorStateMachine _machine;
        private readonly AacTransitionEndpoint _sourceNullableIfAny;
        private readonly AacTransitionEndpoint _destinationNullableIfExits;

        public AacFlTransitionContinuationAbstractWithOr(AnimatorTransitionBase transition, AnimatorStateMachine machine, AacTransitionEndpoint sourceNullableIfAny, AacTransitionEndpoint destinationNullableIfExits)
        {
            Transition = transition;
            _machine = machine;
            _sourceNullableIfAny = sourceNullableIfAny;
            _destinationNullableIfExits = destinationNullableIfExits;
        }

        /// <summary>
        /// Creates a new transition with identical settings but having no conditions defined yet.
        /// </summary>
        /// <example>
        /// <code>
        /// .When(_aac.BoolParameter(my.myBoolParameterName).IsTrue())
        /// .And(_aac.BoolParameter(my.myIntParameterName).IsGreaterThan(2))
        /// .And(AacAv3.ItIsLocal())
        /// .Or()
        /// .When(_aac.BoolParameters(
        ///     my.myBoolParameterName,
        ///     my.myOtherBoolParameterName
        /// ).AreTrue())
        /// .And(AacAv3.ItIsRemote());
        /// </code>
        /// </example>
        public AacFlNewTransitionContinuation Or()
        {
            return new AacFlNewTransitionContinuation(NewTransitionFromTemplate(), _machine, _sourceNullableIfAny, _destinationNullableIfExits);
        }

        private AnimatorTransitionBase NewTransitionFromTemplate()
        {
            AnimatorTransitionBase newTransition;
            if (Transition is AnimatorStateTransition templateStateTransition)
            {
                var stateTransition = NewTransition();
                stateTransition.duration = templateStateTransition.duration;
                stateTransition.offset = templateStateTransition.offset;
                stateTransition.interruptionSource = templateStateTransition.interruptionSource;
                stateTransition.orderedInterruption = templateStateTransition.orderedInterruption;
                stateTransition.exitTime = templateStateTransition.exitTime;
                stateTransition.hasExitTime = templateStateTransition.hasExitTime;
                stateTransition.hasFixedDuration = templateStateTransition.hasFixedDuration;
                stateTransition.canTransitionToSelf = templateStateTransition.canTransitionToSelf;
                newTransition = stateTransition;
            }
            else
            {
                if (_sourceNullableIfAny == null)
                {
                    if (_destinationNullableIfExits.TryGetState(out var state))
                        newTransition = AacInternals.NoUndo(_machine, () => _machine.AddEntryTransition(state));
                    else if (_destinationNullableIfExits.TryGetStateMachine(out var stateMachine))
                        newTransition = AacInternals.NoUndo(_machine, () => _machine.AddEntryTransition(stateMachine));
                    else
                        throw new InvalidOperationException("_destinationNullableIfExits is not null but does not contain an AnimatorState or AnimatorStateMachine");
                }
                // source will never be a state if we're cloning an AnimatorTransition
                else if (_sourceNullableIfAny.TryGetStateMachine(out var stateMachine))
                {
                    if (_destinationNullableIfExits == null)
                        newTransition = AacInternals.NoUndo(_machine, () => _machine.AddStateMachineExitTransition(stateMachine));
                    else if (_destinationNullableIfExits.TryGetState(out var destinationState))
                        newTransition = AacInternals.NoUndo(_machine, () => _machine.AddStateMachineTransition(stateMachine, destinationState));
                    else if (_destinationNullableIfExits.TryGetStateMachine(out var destinationStateMachine))
                        newTransition = AacInternals.NoUndo(_machine, () => _machine.AddStateMachineTransition(stateMachine, destinationStateMachine));
                    else
                        throw new InvalidOperationException("_destinationNullableIfExits is not null but does not contain an AnimatorState or AnimatorStateMachine");
                }
                else
                    throw new InvalidOperationException("_sourceNullableIfAny is not null but does not contain an AnimatorStateMachine");
            }
            return newTransition;
        }

        private AnimatorStateTransition NewTransition()
        {
            AnimatorState state;
            AnimatorStateMachine stateMachine;

            if (_sourceNullableIfAny == null)
            {
                if (_destinationNullableIfExits.TryGetState(out state))
                    return AacInternals.NoUndo(_machine, () => _machine.AddAnyStateTransition(state));
                if (_destinationNullableIfExits.TryGetStateMachine(out stateMachine))
                    return AacInternals.NoUndo(_machine, () => _machine.AddAnyStateTransition(stateMachine));
                throw new InvalidOperationException("Transition has no source nor destination.");
            }

            // source will never be a state machine if we're cloning an AnimatorStateTransition
            if (_sourceNullableIfAny.TryGetState(out var sourceState))
            {
                if (_destinationNullableIfExits == null)
                {
                    return AacInternals.NoUndo(sourceState, () => sourceState.AddExitTransition());
                }

                if (_destinationNullableIfExits.TryGetState(out state))
                {
                    return AacInternals.NoUndo(sourceState, () => sourceState.AddTransition(state));
                }

                if (_destinationNullableIfExits.TryGetStateMachine(out stateMachine))
                {
                    return AacInternals.NoUndo(sourceState, () => sourceState.AddTransition(stateMachine));
                }

                throw new InvalidOperationException("_destinationNullableIfExits is not null but does not contain an AnimatorState or AnimatorStateMachine");
            }
            throw new InvalidOperationException("_sourceNullableIfAny is not null but does not contain an AnimatorState");
        }
    }

    public class AacFlTransitionContinuationWithoutOr
    {
        private readonly AnimatorTransitionBase _transition;

        public AacFlTransitionContinuationWithoutOr(AnimatorTransitionBase transition)
        {
            _transition = transition;
        }

        public AacFlTransitionContinuationWithoutOr And(IAacFlCondition action)
        {
            action.ApplyTo(new AacFlCondition(_transition));
            return this;
        }

        /// <summary>
        /// Applies a series of conditions to this transition. The conditions cannot include an Or operator.
        /// </summary>
        /// <param name="action"></param>
        /// <returns></returns>
        public AacFlTransitionContinuationWithoutOr AndWhenever(Action<AacFlTransitionContinuationWithoutOr> action)
        {
            action(this);
            return this;
        }
    }

    public class AacTransitionEndpoint
    {
        private readonly AnimatorState _state;
        private readonly AnimatorStateMachine _stateMachine;

        public AacTransitionEndpoint(AnimatorState state)
        {
            _state = state;
        }

        public AacTransitionEndpoint(AnimatorStateMachine stateMachine)
        {
            _stateMachine = stateMachine;
        }

        public static implicit operator AacTransitionEndpoint(AnimatorState state)
        {
            return new AacTransitionEndpoint(state);
        }

        public static implicit operator AacTransitionEndpoint(AnimatorStateMachine stateMachine)
        {
            return new AacTransitionEndpoint(stateMachine);
        }

        public bool TryGetState(out AnimatorState state)
        {
            state = _state;
            return _state != null;
        }

        public bool TryGetStateMachine(out AnimatorStateMachine stateMachine)
        {
            stateMachine = _stateMachine;
            return _stateMachine != null;
        }
    }
}