using System;

namespace Engine.Core;

/// <summary>
/// Represents a two-dimensional integer vector.
/// </summary>
/// <param name="x">X position of the <see cref="Vector2DInt"/>.</param>
/// <param name="y">Y position of the <see cref="Vector2DInt"/>.</param>
/// <remarks>
/// Initializes a new instance of the <see cref="Vector2DInt"/> struct with the specified positions.
/// </remarks>
[System.Diagnostics.DebuggerDisplay("{ToString(),nq}")]
public readonly struct Vector2DInt(int x, int y) : IEquatable<Vector2DInt>
{
    /// <summary>
    /// The X coordinate of the <see cref="Vector2DInt"/>.
    /// </summary>
    public readonly int X = x;

    /// <summary>
    /// The Y coordinate of the <see cref="Vector2DInt"/>.
    /// </summary>
    public readonly int Y = y;

    /// <summary>
    /// The magnitude (length) of the <see cref="Vector2DInt"/>.
    /// </summary>
    public float Magnitude => Length(this);

    /// <summary>
    /// The squared magnitude (length) of the <see cref="Vector2DInt"/>.
    /// </summary>
    public float MagnitudeSquared => LengthSquared(this);

    /// <summary>
    /// Gets a <see cref="Vector2DInt"/> with the direction reversed.
    /// </summary>
    public readonly Vector2DInt Reversed => -this;

    /// <summary>
    /// Represents the unit <see cref="Vector2DInt"/> pointing upwards.
    /// </summary>
    public readonly static Vector2DInt Up = new(0, 1);

    /// <summary>
    /// Represents the unit <see cref="Vector2DInt"/> pointing downwards.
    /// </summary>
    public readonly static Vector2DInt Down = new(0, -1);

    /// <summary>
    /// Represents the unit <see cref="Vector2DInt"/> pointing leftwards.
    /// </summary>
    public readonly static Vector2DInt Left = new(-1, 0);

    /// <summary>
    /// Represents the unit <see cref="Vector2DInt"/> pointing rightwards.
    /// </summary>
    public readonly static Vector2DInt Right = new(1, 0);

    /// <summary>
    /// Represents the zero <see cref="Vector2DInt"/>.
    /// </summary>
    public readonly static Vector2DInt Zero = new(0, 0);

    /// <summary>
    /// Represents the <see cref="Vector2DInt"/> with both components equal to 1.
    /// </summary>
    public readonly static Vector2DInt One = new(1, 1);

    public static Vector2DInt operator -(Vector2DInt vector) => new(0 - vector.X, 0 - vector.Y);
    public static Vector2DInt operator +(Vector2DInt left, Vector2DInt right) => new(left.X + right.X, left.Y + right.Y);
    public static Vector2DInt operator -(Vector2DInt left, Vector2DInt right) => new(left.X - right.X, left.Y - right.Y);
    public static bool operator ==(Vector2DInt left, Vector2DInt right) => left.X == right.X && left.Y == right.Y;
    public static bool operator !=(Vector2DInt left, Vector2DInt right) => left.X != right.X || left.Y != right.Y;

    public static implicit operator Vector2DInt(Vector2D vector) => new(vector.X.RoundToInt(), vector.Y.RoundToInt());
    public static implicit operator Vector2DInt(Vector3DInt vector) => new(vector.X, vector.Y);

    /// <summary>
    /// Calculates the length of the <see cref="Vector2DInt"/>.
    /// </summary>
    /// <param name="vector">The <see cref="Vector2DInt"/>.</param>
    /// <returns>The length of the <see cref="Vector2DInt"/>.</returns>
    public static float Length(Vector2DInt vector) => Engine.Core.Math.Sqrt(LengthSquared(vector));

    /// <summary>
    /// Calculates the squared length of the <see cref="Vector2DInt"/>.
    /// </summary>
    /// <param name="vector">The <see cref="Vector2DInt"/>.</param>
    /// <returns>The squared length of the <see cref="Vector2DInt"/>.</returns>
    public static float LengthSquared(Vector2DInt vector) => vector.X * vector.X + vector.Y * vector.Y;

    /// <summary>
    /// Calculates the distance between two <see cref="Vector2DInt"/>s.
    /// </summary>
    /// <param name="from">The start <see cref="Vector2DInt"/>.</param>
    /// <param name="to">The end <see cref="Vector2DInt"/>.</param>
    /// <returns>The distance between the two <see cref="Vector2DInt"/>s.</returns>
    public static float Distance(Vector2DInt from, Vector2DInt to) => Length(FromTo(from, to));

    /// <summary>
    /// Inverts the direction of the <see cref="Vector2DInt"/>.
    /// </summary>
    /// <param name="vector">The <see cref="Vector2DInt"/>.</param>
    /// <returns>The inverted <see cref="Vector2DInt"/>.</returns>
    public static Vector2DInt Invert(Vector2DInt vector) => -vector;

    /// <summary>
    /// Adds two <see cref="Vector2DInt"/>s.
    /// </summary>
    /// <param name="left">The first <see cref="Vector2DInt"/>.</param>
    /// <param name="right">The second <see cref="Vector2DInt"/>.</param>
    /// <returns>The sum of the two <see cref="Vector2DInt"/>s.</returns>
    public static Vector2DInt Add(Vector2DInt left, Vector2DInt right) => left + right;

    /// <summary>
    /// Subtracts one <see cref="Vector2DInt"/> from another.
    /// </summary>
    /// <param name="left">The <see cref="Vector2DInt"/> to subtract from.</param>
    /// <param name="right">The <see cref="Vector2DInt"/> to subtract.</param>
    /// <returns>The result of subtracting the second <see cref="Vector2DInt"/> from the first.</returns>
    public static Vector2DInt Subtract(Vector2DInt left, Vector2DInt right) => left - right;

    /// <summary>
    /// Calculates the absolute value of each component of the vector.
    /// </summary>
    /// <param name="vector">The <see cref="Vector2DInt"/>.</param>
    /// <returns>The <see cref="Vector2DInt"/> with each component's absolute value.</returns>
    public static Vector2DInt Abs(Vector2DInt vector) => new(Engine.Core.Math.Abs(vector.X), Engine.Core.Math.Abs(vector.Y));

    /// <summary>
    /// Calculates the <see cref="Vector2DInt"/> from one point to another.
    /// </summary>
    /// <param name="from">The starting point.</param>
    /// <param name="to">The ending point.</param>
    /// <returns>The <see cref="Vector2DInt"/> from the starting point to the ending point.</returns>
    public static Vector2DInt FromTo(Vector2DInt from, Vector2DInt to) => to - from;

    /// <summary>
    /// Scales a <see cref="Vector2DInt"/> by another <see cref="Vector2DInt"/> component-wise.
    /// </summary>
    /// <param name="vector">The <see cref="Vector2DInt"/> to scale.</param>
    /// <param name="scale">The <see cref="Vector2DInt"/> containing the scaling factors for each component.</param>
    /// <returns>The scaled <see cref="Vector2DInt"/>.</returns>
    public static Vector2DInt Scale(Vector2DInt vector, Vector2DInt scale) => new(vector.X * scale.X, vector.Y * scale.Y);

    /// <summary>
    /// Calculates a perpendicular <see cref="Vector2DInt"/> to the given <see cref="Vector2DInt"/>.
    /// </summary>
    /// <param name="vector">The input <see cref="Vector2DInt"/>.</param>
    /// <returns>A <see cref="Vector2DInt"/> perpendicular to the input <see cref="Vector2DInt"/>.</returns>
    public static Vector2DInt Perpendicular(Vector2DInt vector) => new(-vector.Y, vector.X);

    /// <summary>
    /// Returns the component-wise minimum of two <see cref="Vector2DInt"/>s.
    /// </summary>
    /// <param name="left">The first <see cref="Vector2DInt"/>.</param>
    /// <param name="right">The second <see cref="Vector2DInt"/>.</param>
    /// <returns>The <see cref="Vector2DInt"/> containing the minimum components from both input <see cref="Vector2DInt"/>s.</returns>
    public static Vector2DInt Min(Vector2DInt left, Vector2DInt right) => new((left.X < right.X) ? left.X : right.X, (left.Y < right.Y) ? left.Y : right.Y);

    /// <summary>
    /// Returns the component-wise maximum of two <see cref="Vector2DInt"/>s.
    /// </summary>
    /// <param name="left">The first <see cref="Vector2DInt"/>.</param>
    /// <param name="right">The second <see cref="Vector2DInt"/>.</param>
    /// <returns>The <see cref="Vector2DInt"/> containing the maximum components from both input <see cref="Vector2DInt"/>s.</returns>
    public static Vector2DInt Max(Vector2DInt left, Vector2DInt right) => new((left.X > right.X) ? left.X : right.X, (left.Y > right.Y) ? left.Y : right.Y);

    /// <summary>
    /// Clamps each component of a <see cref="Vector2DInt"/> between the corresponding component of two other <see cref="Vector2DInt"/>s.
    /// </summary>
    /// <param name="vector">The <see cref="Vector2DInt"/> to clamp.</param>
    /// <param name="min">The <see cref="Vector2DInt"/> representing the minimum values for each component.</param>
    /// <param name="max">The <see cref="Vector2DInt"/> representing the maximum values for each component.</param>
    /// <returns>A <see cref="Vector2DInt"/> with each component clamped between the corresponding components of the min and max <see cref="Vector2DInt"/>s.</returns>
    public static Vector2DInt Clamp(Vector2DInt vector, Vector2DInt min, Vector2DInt max) => new(Engine.Core.Math.Clamp(vector.X, min.X, max.X), Engine.Core.Math.Clamp(vector.Y, min.Y, max.Y));

    /// <summary>
    /// Calculates the cross product of two <see cref="Vector2DInt"/>s.
    /// </summary>
    /// <param name="left">The first <see cref="Vector2DInt"/>.</param>
    /// <param name="right">The second <see cref="Vector2DInt"/>.</param>
    /// <returns>The cross product of the two <see cref="Vector2DInt"/>s.</returns>
    public static int Cross(Vector2DInt left, Vector2DInt right) => left.X * right.Y - left.Y * right.X;

    /// <summary>
    /// Calculates the dot product of two <see cref="Vector2DInt"/>s.
    /// </summary>
    /// <param name="left">The first <see cref="Vector2DInt"/>.</param>
    /// <param name="right">The second <see cref="Vector2DInt"/>.</param>
    /// <returns>The dot product of the two <see cref="Vector2DInt"/>s.</returns>
    public static int Dot(Vector2DInt left, Vector2DInt right) => left.X * right.X + left.Y * right.Y;

    /// <summary>
    /// Determines whether the specified object is equal to the current <see cref="Vector2DInt"/>.
    /// </summary>
    /// <param name="obj">The object to compare with the current <see cref="Vector2DInt"/>.</param>
    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Vector2DInt"/>; otherwise, <see cref="false"/>.</returns>
    public override bool Equals(object? obj) => obj is Vector2DInt vector2DInt && this == vector2DInt;
    public bool Equals(Vector2DInt other) => this == other;

    /// <summary>
    /// Generates a hash code for the <see cref="Vector2DInt"/>.
    /// </summary>
    /// <returns>A hash code for the <see cref="Vector2DInt"/>.</returns>
    public override int GetHashCode() => System.HashCode.Combine(X, Y);

    /// <summary>
    /// Converts the <see cref="Vector2DInt"/> to its string representation.
    /// </summary>
    /// <returns>A string representation of the <see cref="Vector2DInt"/>.</returns>
    public override string ToString() => $"{nameof(Vector2DInt)}({X}, {Y})";
}

/// <summary>
/// Provides extension methods for <see cref="Vector2DInt"/> type.
/// </summary>
public static class Vector2DIntExtensions
{
    /// <inheritdoc cref="Vector2DInt.Length(Vector2DInt)" />
    public static float Length(this Vector2DInt vector) => Vector2DInt.Length(vector);

    /// <inheritdoc cref="Vector2DInt.LengthSquared(this vector) => Vector2DInt/>
    public static float LengthSquared(this Vector2DInt vector) => Vector2DInt.LengthSquared(vector);

    /// <inheritdoc cref="Vector2DInt.Distance(Vector2DInt, Vector2DInt)" />
    public static float Distance(this Vector2DInt from, Vector2DInt to) => Vector2DInt.Distance(from, to);

    /// <inheritdoc cref="Vector2DInt.Invert(this vector) => Vector2DInt/>
    public static Vector2DInt Invert(this Vector2DInt vector) => Vector2DInt.Invert(vector);

    /// <inheritdoc cref="Vector2DInt.Add(Vector2DInt, Vector2DInt)" />
    public static Vector2DInt Add(this Vector2DInt vector, Vector2DInt vectorToAdd) => Vector2DInt.Add(vector, vectorToAdd);

    /// <inheritdoc cref="Vector2DInt.Subtract(Vector2DInt, Vector2DInt)" />
    public static Vector2DInt Subtract(this Vector2DInt vector, Vector2DInt vectorToSubtract) => Vector2DInt.Subtract(vector, vectorToSubtract);

    /// <inheritdoc cref="Vector2DInt.Abs(Vector2DInt)" />
    public static Vector2DInt Abs(this Vector2DInt vector) => Vector2DInt.Abs(vector);

    /// <inheritdoc cref="Vector2DInt.FromTo(Vector2DInt, Vector2DInt)" />
    public static Vector2DInt FromTo(this Vector2DInt from, Vector2DInt to) => Vector2DInt.FromTo(from, to);

    /// <inheritdoc cref="Vector2DInt.Scale(Vector2DInt, Vector2DInt)" />
    public static Vector2DInt Scale(this Vector2DInt vector, Vector2DInt scale) => Vector2DInt.Scale(vector, scale);

    /// <inheritdoc cref="Vector2DInt.Perpendicular(Vector2DInt)" />
    public static Vector2DInt Perpendicular(this Vector2DInt vector) => Vector2DInt.Perpendicular(vector);

    /// <inheritdoc cref="Vector2DInt.Min(Vector2DInt, Vector2DInt)" />
    public static Vector2DInt Min(this Vector2DInt left, Vector2DInt right) => Vector2DInt.Min(left, right);

    /// <inheritdoc cref="Vector2DInt.Max(Vector2DInt, Vector2DInt)" />
    public static Vector2DInt Max(this Vector2DInt left, Vector2DInt right) => Vector2DInt.Max(left, right);

    /// <inheritdoc cref="Vector2DInt.Clamp(Vector2DInt, Vector2DInt,Vector2DInt)" />
    public static Vector2DInt Clamp(this Vector2DInt vector, Vector2DInt min, Vector2DInt max) => Vector2DInt.Clamp(vector, min, max);

    /// <inheritdoc cref="Vector2DInt.Cross(Vector2DInt, Vector2DInt)" />
    public static int Cross(this Vector2DInt left, Vector2DInt right) => Vector2DInt.Cross(left, right);

    /// <inheritdoc cref="Vector2D.Angle(Vector2D, Vector2D)" />
    public static float AngleBetween(this Vector2D left, Vector2D right) => Vector2D.Angle(left, right);

    /// <inheritdoc cref="Vector2DInt.Dot(Vector2DInt, Vector2DInt)" />
    public static int Dot(this Vector2DInt left, Vector2DInt right) => Vector2DInt.Dot(left, right);
}