using System;
using System.Collections.Generic;
using System.Linq;
using Babushka.scripts.CSharp.Common.Camera;
using Babushka.scripts.CSharp.Common.Util;
using Godot;
namespace Babushka.scripts.CSharp.Common.Fight;

public partial class FightInstance : Node2D //TODO: remake
{
    [Export(PropertyHint.ArrayType)] private Node2D[] _friendlyFightSpots;
    [Export(PropertyHint.ArrayType)] private Node2D[] _enemyFightSpots;
    [Export] public Node2D camPositionNode;
    [Export] private FightStateManager _fightStateManager;
    [Export] private Label _fightEndText;


    [Signal]
    public delegate void FightStartedEventHandler();

    [Signal]
    public delegate void FightEndedEventHandler();

    private List<Fighter> _friendlyFighters = new();
    private List<Fighter> _enemyFighters = new();

    private FightAttack? _stagedAttack = null;

    public override void _Ready()
    {
        //_fightStateManager.CurrentFightState = FightStateManager.FightState.FightStartAnim;
        _fightStateManager.ExitingTransition += from =>
        {
            switch (from)
            {
                case FightStateManager.FightState.None:
                    CaptureCamera();
                    Show();
                    EmitSignalFightStarted();
                    break;
                case FightStateManager.FightState.Input:
                    HideAttackButtons();
                    break;
                case FightStateManager.FightState.InputTargetSelect:
                    HideTargetButtons();
                    break;
                case FightStateManager.FightState.FriendAttackAnim:
                    _stagedAttack = null;
                    break;
                case FightStateManager.FightState.PlayerWinAnim:
                case FightStateManager.FightState.EnemyWinAnim:
                    _fightEndText.Text = "";
                    break;
            }
        };

        _fightStateManager.EnteringTransition += to =>
        {
            switch (to)
            {
                case FightStateManager.FightState.None:
                    EmitSignalFightEnded();
                    CleanUp();
                    Hide();
                    ReleaseCamera();
                    break;
                case FightStateManager.FightState.Input:
                    if (CheckWinAndSetState())
                        break;
                    if (CheckFriendlyActionsLeftAndSetState())
                        break;
                    ShowAttackButtons();
                    break;
                case FightStateManager.FightState.InputTargetSelect:
                    ShowTargetButtons();
                    break;
                case FightStateManager.FightState.FriendAttackAnim:
                    ExecuteAttack();
                    GetTree().CreateTimer(1).Timeout += () => _fightStateManager.CurrentFightState = FightStateManager.FightState.Input;
                    break;
                case FightStateManager.FightState.Enemy:
                    if (CheckWinAndSetState())
                        break;
                    if (CheckEnemyActionsLeftAndSetState())
                        break;
                    DecideEnemyAttack();
                    _fightStateManager.CurrentFightState = FightStateManager.FightState.EnemyAttackAnim;
                    break;
                case FightStateManager.FightState.EnemyAttackAnim:
                    ExecuteAttack();
                    GetTree().CreateTimer(1).Timeout += () => _fightStateManager.CurrentFightState = FightStateManager.FightState.Enemy;
                    break;
                case FightStateManager.FightState.PlayerWinAnim:
                    _fightEndText.Text = "You Win!";
                    GetTree().CreateTimer(3).Timeout += () => _fightStateManager.CurrentFightState = FightStateManager.FightState.None;
                    break;
                case FightStateManager.FightState.EnemyWinAnim:
                    _fightEndText.Text = "You Died :(";
                    GetTree().CreateTimer(3).Timeout += () => _fightStateManager.CurrentFightState = FightStateManager.FightState.None;
                    break;
                case FightStateManager.FightState.ChangeSideToEnemy:
                    ResetEnemyActions();
                    _fightStateManager.CurrentFightState = FightStateManager.FightState.Enemy;
                    break;
                case FightStateManager.FightState.ChangeSideToFriendly:
                    ResetFriendlyActions();
                    _fightStateManager.CurrentFightState = FightStateManager.FightState.Input;
                    break;
                case FightStateManager.FightState.Heal:
                    Heal();
                    GetTree().CreateTimer(1).Timeout += () => _fightStateManager.CurrentFightState = FightStateManager.FightState.Input;
                    break;
            }
        };
    }
    private void Heal()
    {
        // TODO: make heal staging system
        _friendlyFighters.Where(f => !f.IsDead()).ForEach(f =>
        {
            f.Health += 50;
            f.HealAnimation();
            f.DecrementActions();
        });
        UpdateHealthVisual();
    }
    private void ResetEnemyActions()
    {
        _enemyFighters.ForEach(f => f.ResetActions());
    }

    private void ResetFriendlyActions()
    {
        _friendlyFighters.ForEach(f => f.ResetActions());
    }

    /**
     * <returns>
     * <c>true</c> if the state was changed
     * </returns>
     */
    private bool CheckFriendlyActionsLeftAndSetState()
    {
        var hasActionsLeft = _friendlyFighters.Where(f => !f.IsDead()).Any(f => f.HasActionsLeft());
        if (hasActionsLeft)
        {
            return false;
        } // else
        _fightStateManager.CurrentFightState = FightStateManager.FightState.ChangeSideToEnemy;
        return true;
    }

    /**
     * <returns>
     * <c>true</c> if the state was changed
     * </returns>
     */
    private bool CheckEnemyActionsLeftAndSetState()
    {
        var hasActionsLeft = _enemyFighters.Where(f => !f.IsDead()).Any(f => f.HasActionsLeft());
        if (hasActionsLeft)
        {
            return false;
        } // else
        _fightStateManager.CurrentFightState = FightStateManager.FightState.ChangeSideToFriendly;
        return true;
    }

    private void CleanUp()
    {
        _enemyFighters.ForEach(f => f.QueueFree());
        _friendlyFighters.ForEach(f => f.QueueFree());
        _enemyFighters = new();
        _friendlyFighters = new();
    }
    private void DecideEnemyAttack()
    {
        var availableEnemyFighters = 
            _enemyFighters
                .Where(f => !f.IsDead())
                .Where(f=>f.HasActionsLeft())
                .ToList();
        var aliveFriendlyFighters = 
            _friendlyFighters
                .Where(f => !f.IsDead())
                .ToList();

        if (availableEnemyFighters.Count <= 0)
            throw new InvalidOperationException("No enemy fighters available for attack.");

        if (aliveFriendlyFighters.Count <= 0)
            throw new InvalidOperationException("No friendly fighters available to target.");

        var fighter = availableEnemyFighters.Random();
        var target = aliveFriendlyFighters.Random();

        _stagedAttack = new FightAttack
        {
            attacker = fighter!,
            needsSelectedTarget = true,
            damage = fighter!.attackStrength,
            target = target!
        };
    }

    private void ExecuteAttack()
    {
        if (_stagedAttack == null)
            throw new InvalidOperationException("No staged attack to execute.");

        if (!_stagedAttack.needsSelectedTarget)
            throw new NotImplementedException("Non-targeted attacks are not implemented yet.");

        if (_stagedAttack.needsSelectedTarget && _stagedAttack.target == null)
            throw new InvalidOperationException("No target selected for the staged attack.");

        _stagedAttack.target!.Health -= _stagedAttack.damage;
        _stagedAttack.attacker.DecrementActions();
        _stagedAttack.attacker.AttackAnimation(_stagedAttack);

        UpdateHealthVisual();
    }

    private void UpdateHealthVisual()
    {
        _friendlyFighters
            .Concat(_enemyFighters)
            .ForEach(f => f.UpdateHealthVisual());
    }

    private void ReleaseCamera()
    {
        CameraController.Instance.fightToShow = null;
    }

    private void CaptureCamera()
    {
        CameraController.Instance.fightToShow = this;
    }

    public void Start(FightParty fightParty, PackedScene?[] enemies)
    {
        if (_fightStateManager.IsRunning())
        {
            GD.PushWarning("Can not start a running fight");
            return;
        }

        if (fightParty.vesna)
        {
            InstantiateFighter(_friendlyFightSpots[1], FightManager.Instance.fightingVesnaScene);
        }

        for (var i = 0; i < Math.Min(_enemyFightSpots.Length, enemies.Length); i++)
        {
            var enemy = enemies[i];
            if (enemy == null)
                continue;

            InstantiateFighter(_enemyFightSpots[i], enemy, true);
        }

        _fightStateManager.ToStartAnim();
    }

    private void InstantiateFighter(Node2D parent, PackedScene fighterScene, bool isEnemy = false)
    {
        var fighter = fighterScene.Instantiate<Fighter>();
        fighter.fightInstance = this;
        parent.AddChild(fighter);

        if (isEnemy)
        {
            _enemyFighters.Add(fighter);
        }
        else
        {
            _friendlyFighters.Add(fighter);
        }
    }

    public void SelectAttack(Fighter fighter)
    {
        _stagedAttack = new FightAttack
        {
            attacker = fighter,
            damage = fighter.attackStrength,
            needsSelectedTarget = true
        };

        if (_stagedAttack.needsSelectedTarget)
        {
            _fightStateManager.CurrentFightState = FightStateManager.FightState.InputTargetSelect;
        }
        else
        {
            _fightStateManager.CurrentFightState = FightStateManager.FightState.FriendAttackAnim;
        }
    }

    private void HideAttackButtons()
    {
        _friendlyFighters.ForEach(f => f.HideAttackButton());
    }

    private void ShowAttackButtons()
    {
        _friendlyFighters.ForEach(f => f.ShowAttackButton());
    }

    private void HideTargetButtons()
    {
        _enemyFighters.ForEach(f => f.HideTargetButtons());
    }

    private void ShowTargetButtons()
    {
        _enemyFighters.Where(f => !f.IsDead()).ForEach(f => f.ShowTargetButtons());
    }

    public void SelectTargetAndAttack(Fighter fighter)
    {
        if (_stagedAttack == null)
            throw new InvalidOperationException("No staged attack to select target for.");

        _stagedAttack.target = fighter;

        _fightStateManager.CurrentFightState = FightStateManager.FightState.FriendAttackAnim;
    }
    
    public void SelectHeal(Fighter fighter)
    {
        _fightStateManager.CurrentFightState = FightStateManager.FightState.Heal;
    }

    public bool CheckWinAndSetState()
    {
        if (_enemyFighters.All(f => f.IsDead()))
        {
            _fightStateManager.CurrentFightState = FightStateManager.FightState.PlayerWinAnim;
            return true;
        }
        if (_friendlyFighters.All(f => f.IsDead()))
        {
            _fightStateManager.CurrentFightState = FightStateManager.FightState.EnemyWinAnim;
            return true;
        }
        return false;
    }
}
public class FightAttack
{
    public int damage;
    public bool needsSelectedTarget;
    public Fighter? target;
    public Fighter attacker;
}