using Godot;
using RogueTank.Combat;
using RogueTank.Util;

namespace RogueTank.Actors;

public partial class PlayerTank : CharacterBody2D, IDamageable
{
    [Signal] public delegate void StatsChangedEventHandler();
    [Signal] public delegate void DiedEventHandler();
    [Signal] public delegate void ShotFiredEventHandler();

    public Vector2 DebugLastMoveInput { get; private set; } = Vector2.Zero;

    // Stats
    public float MoveSpeed { get; set; } = 165f;
    public float FireRate { get; set; } = 4.0f; // shots/sec
    public float Damage { get; set; } = 12f;
    public float Armor { get; set; } = 0f; // flat reduction
    public float BulletSpeed { get; set; } = 520f;
    public int BulletPierce { get; set; } = 0;
    public float MagnetRadius { get; set; } = 42f;

    public float MaxHp { get; set; } = 100f;
    public float Hp { get; private set; } = 100f;

    public int Level { get; private set; } = 1;
    public int Xp { get; private set; }
    public int XpToNext { get; private set; } = 30;
    public int Coins { get; private set; }

    // References
    public Node2D? ProjectilesRoot { get; set; }
    public PackedScene? BulletScene { get; set; }
    public Node2D? PickupsRoot { get; set; }

    private Sprite2D _sprite = null!;
    private Sprite2D _turret = null!;
    private Area2D _magnet = null!;
    private CollisionShape2D _magnetShape = null!;

    private float _shootCd;

    public override void _Ready()
    {
        Hp = MaxHp;

        CollisionLayer = 1u << 3; // player
        CollisionMask = (1u << 0) | (1u << 1); // walls + enemies

        _sprite = new Sprite2D
        {
            Texture = PixelArt.MakeTankTexture(16, new Color(0.15f, 0.75f, 0.35f), new Color(0.1f, 0.9f, 0.35f)),
            Centered = true,
            TextureFilter = CanvasItem.TextureFilterEnum.Nearest
        };
        AddChild(_sprite);

        _turret = new Sprite2D
        {
            Texture = PixelArt.MakeTankTexture(16, new Color(0.0f, 0.0f, 0.0f, 0.0f), new Color(0.95f, 0.95f, 0.95f)),
            Centered = true,
            TextureFilter = CanvasItem.TextureFilterEnum.Nearest,
            Modulate = new Color(0.85f, 0.95f, 0.9f)
        };
        AddChild(_turret);

        var col = new CollisionShape2D
        {
            Shape = new CircleShape2D { Radius = 7f }
        };
        AddChild(col);

        _magnet = new Area2D();
        _magnet.CollisionLayer = 1u << 5; // magnet
        _magnet.CollisionMask = 0;
        _magnetShape = new CollisionShape2D { Shape = new CircleShape2D { Radius = MagnetRadius } };
        _magnet.AddChild(_magnetShape);
        AddChild(_magnet);
    }

    public override void _PhysicsProcess(double delta)
    {
        var d = (float)delta;
        var input = ReadMoveInput();
        DebugLastMoveInput = input;
        if (input.Length() > 1f)
            input = input.Normalized();

        Velocity = input * MoveSpeed;
        MoveAndSlide();

        AimTurret();
        HandleShooting(d);
        UpdateMagnet();
    }

    private static Vector2 ReadMoveInput()
    {
        // Prefer InputMap actions; if they're missing/broken, fallback to raw keys.
        if (InputMap.HasAction("move_left") && InputMap.HasAction("move_right") &&
            InputMap.HasAction("move_up") && InputMap.HasAction("move_down"))
        {
            return Input.GetVector("move_left", "move_right", "move_up", "move_down");
        }

        float x = 0f;
        float y = 0f;
        if (Input.IsKeyPressed(Key.A) || Input.IsKeyPressed(Key.Left)) x -= 1f;
        if (Input.IsKeyPressed(Key.D) || Input.IsKeyPressed(Key.Right)) x += 1f;
        if (Input.IsKeyPressed(Key.W) || Input.IsKeyPressed(Key.Up)) y -= 1f;
        if (Input.IsKeyPressed(Key.S) || Input.IsKeyPressed(Key.Down)) y += 1f;
        return new Vector2(x, y);
    }

    private void AimTurret()
    {
        var viewport = GetViewport();
        if (viewport == null) return;

        var worldMouse = GetGlobalMousePosition();
        _turret.Rotation = (worldMouse - GlobalPosition).Angle();
    }

    private void HandleShooting(float delta)
    {
        _shootCd -= delta;
        var wantShoot =
            (InputMap.HasAction("shoot") && Input.IsActionPressed("shoot")) ||
            Input.IsMouseButtonPressed(MouseButton.Left);
        if (!wantShoot || _shootCd > 0f) return;
        if (BulletScene == null || ProjectilesRoot == null) return;

        _shootCd = 1f / Mathf.Max(0.1f, FireRate);

        var bullet = BulletScene.Instantiate<Bullet>();
        var dir = new Vector2(Mathf.Cos(_turret.Rotation), Mathf.Sin(_turret.Rotation));
        bullet.GlobalPosition = GlobalPosition + dir * 10f;
        bullet.Speed = BulletSpeed;
        bullet.Damage = Damage;
        bullet.Pierce = BulletPierce;
        bullet.Init(dir);
        ProjectilesRoot.AddChild(bullet);

        EmitSignal(SignalName.ShotFired);
    }

    private void UpdateMagnet()
    {
        if (_magnetShape.Shape is CircleShape2D cs)
            cs.Radius = MagnetRadius;
    }

    public void AddCoins(int amount)
    {
        Coins += amount;
        EmitSignal(SignalName.StatsChanged);
    }

    public bool AddXp(int amount)
    {
        Xp += amount;
        var leveled = false;
        while (Xp >= XpToNext)
        {
            Xp -= XpToNext;
            Level++;
            XpToNext = Mathf.RoundToInt(XpToNext * 1.22f + 10);
            leveled = true;
        }
        EmitSignal(SignalName.StatsChanged);
        return leveled;
    }

    public void Heal(float amount)
    {
        Hp = Mathf.Min(MaxHp, Hp + amount);
        EmitSignal(SignalName.StatsChanged);
    }

    public void TakeDamage(float amount)
    {
        var final = Mathf.Max(1f, amount - Armor);
        Hp -= final;
        if (Hp <= 0f)
        {
            Hp = 0f;
            EmitSignal(SignalName.StatsChanged);
            EmitSignal(SignalName.Died);
            QueueFree();
            return;
        }
        EmitSignal(SignalName.StatsChanged);
    }

    public Area2D GetMagnetArea() => _magnet;
}