using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using UnityEngine;

namespace Game {
    public class SpriteCollider {
        public List<Vector2> LeftColliderPoints { get; set; }
        public List<Vector2> RightColliderPoints { get; set; }

        private Texture2D texture2D;

        private float x;
        private float y;

        public SpriteCollider(Sprite s, float x, float y) {
            texture2D = RotateImage(TextureFromSprite(s), 90);
            LeftColliderPoints = new List<Vector2>();
            RightColliderPoints = new List<Vector2>();
            this.x = x;
            this.y = y;
            GenerateCollider();
        }


        public static Texture2D TextureFromSprite(Sprite sprite) {
            if (sprite.rect.width != sprite.texture.width) {
                Texture2D newText = new Texture2D((int)sprite.rect.width, (int)sprite.rect.height);
                Color[] newColors = sprite.texture.GetPixels((int)sprite.textureRect.x,
                                                             (int)sprite.textureRect.y,
                                                             (int)sprite.textureRect.width,
                                                             (int)sprite.textureRect.height);
                newText.SetPixels(newColors);
                newText.Apply();
                return newText;
            } else return sprite.texture;
        }

        private void GenerateCollider() {
            for (float i = 0; i <= texture2D.height; i++) {
                for (float j = 0; j <= texture2D.width; j++)
                    if (texture2D.GetPixel((int)i, (int)j).a != 0) {
                        float x = j - texture2D.width / 2f;
                        float y = -i + texture2D.width / 2f;

                        x = x / 300f;
                        y = y / 300f;
                        LeftColliderPoints.Add(new Vector2(this.x + x, this.y + y));
                        break;
                    }
            }

            for (float i = 0; i <= texture2D.height; i++) {
                for (float j = texture2D.width; j >=0; j--)
                    if (texture2D.GetPixel((int)i, (int)j).a != 0) {
                        float x = j - texture2D.width / 2f;
                        float y = -i + texture2D.width / 2f;
                        x = x / 300f;
                        y = y / 300f;

                        RightColliderPoints.Add(new Vector2(this.x + x, this.y + y));
                        break;
                    }
            }
        }

        public void DrawCollider() {
            for (int i = 0; i < LeftColliderPoints.Count - 1; i++) {
                Debug.DrawLine(LeftColliderPoints[i], LeftColliderPoints[i + 1], Color.blue);
            }

            for (int i = 0; i < RightColliderPoints.Count - 1; i++) {
                Debug.DrawLine(RightColliderPoints[i], RightColliderPoints[i + 1], Color.red);
            }
        }

        private static Texture2D RotateImage(Texture2D originTexture, int angle) {
            Texture2D result;
            result = new Texture2D(originTexture.width, originTexture.height);
            Color32[] pix1 = result.GetPixels32();
            Color32[] pix2 = originTexture.GetPixels32();
            int W = originTexture.width;
            int H = originTexture.height;
            int x = 0;
            int y = 0;
            Color32[] pix3 = rotateSquare(pix2, (Math.PI / 180 * (double)angle), originTexture);
            for (int j = 0; j < H; j++) {
                for (var i = 0; i < W; i++) {
                    //pix1[result.width/2 - originTexture.width/2 + x + i + result.width*(result.height/2-originTexture.height/2+j+y)] = pix2[i + j*originTexture.width];
                    pix1[result.width / 2 - W / 2 + x + i + result.width * (result.height / 2 - H / 2 + j + y)] = pix3[i + j * W];
                }
            }
            result.SetPixels32(pix1);
            result.Apply();
            return result;
        }

        private static Color32[] rotateSquare(Color32[] arr, double phi, Texture2D originTexture) {
            int x;
            int y;
            int i;
            int j;
            double sn = Math.Sin(phi);
            double cs = Math.Cos(phi);
            Color32[] arr2 = originTexture.GetPixels32();
            int W = originTexture.width;
            int H = originTexture.height;
            int xc = W / 2;
            int yc = H / 2;
            for (j = 0; j < H; j++) {
                for (i = 0; i < W; i++) {
                    arr2[j * W + i] = new Color32(0, 0, 0, 0);
                    x = (int)(cs * (i - xc) + sn * (j - yc) + xc);
                    y = (int)(-sn * (i - xc) + cs * (j - yc) + yc);
                    if ((x > -1) && (x < W) && (y > -1) && (y < H)) {
                        arr2[j * W + i] = arr[y * W + x];
                    }
                }
            }
            return arr2;
        }
    }
}