namespace Terraria
{
    using Microsoft.Xna.Framework;
    using System;
    using System.Runtime.InteropServices;

    public class Collision
    {
        public static Vector2 AnyCollision(Vector2 Position, Vector2 Velocity, int Width, int Height)
        {
            Vector2 vector = Velocity;
            Vector2 vector2 = Velocity;
            Vector2 vector4 = Position + Velocity;
            Vector2 vector5 = Position;
            int num = ((int) (Position.X / 16f)) - 1;
            int maxTilesX = ((int) ((Position.X + Width) / 16f)) + 2;
            int num3 = ((int) (Position.Y / 16f)) - 1;
            int maxTilesY = ((int) ((Position.Y + Height) / 16f)) + 2;
            int num5 = -1;
            int num6 = -1;
            int num7 = -1;
            int num8 = -1;
            if (num < 0)
            {
                num = 0;
            }
            if (maxTilesX > Main.maxTilesX)
            {
                maxTilesX = Main.maxTilesX;
            }
            if (num3 < 0)
            {
                num3 = 0;
            }
            if (maxTilesY > Main.maxTilesY)
            {
                maxTilesY = Main.maxTilesY;
            }
            for (int i = num; i < maxTilesX; i++)
            {
                for (int j = num3; j < maxTilesY; j++)
                {
                    if ((Main.tile[i, j] != null) && Main.tile[i, j].active)
                    {
                        Vector2 vector3;
                        vector3.X = i * 0x10;
                        vector3.Y = j * 0x10;
                        if ((((vector4.X + Width) > vector3.X) && (vector4.X < (vector3.X + 16f))) && (((vector4.Y + Height) > vector3.Y) && (vector4.Y < (vector3.Y + 16f))))
                        {
                            if ((vector5.Y + Height) <= vector3.Y)
                            {
                                num7 = i;
                                num8 = j;
                                if (num7 != num5)
                                {
                                    vector.Y = vector3.Y - (vector5.Y + Height);
                                }
                            }
                            else if (((vector5.X + Width) <= vector3.X) && !Main.tileSolidTop[Main.tile[i, j].type])
                            {
                                num5 = i;
                                num6 = j;
                                if (num6 != num8)
                                {
                                    vector.X = vector3.X - (vector5.X + Width);
                                }
                                if (num7 == num5)
                                {
                                    vector.Y = vector2.Y;
                                }
                            }
                            else if ((vector5.X >= (vector3.X + 16f)) && !Main.tileSolidTop[Main.tile[i, j].type])
                            {
                                num5 = i;
                                num6 = j;
                                if (num6 != num8)
                                {
                                    vector.X = (vector3.X + 16f) - vector5.X;
                                }
                                if (num7 == num5)
                                {
                                    vector.Y = vector2.Y;
                                }
                            }
                            else if ((vector5.Y >= (vector3.Y + 16f)) && !Main.tileSolidTop[Main.tile[i, j].type])
                            {
                                num7 = i;
                                num8 = j;
                                vector.Y = ((vector3.Y + 16f) - vector5.Y) + 0.01f;
                                if (num8 == num6)
                                {
                                    vector.X = vector2.X + 0.01f;
                                }
                            }
                        }
                    }
                }
            }
            return vector;
        }

        public static bool CanHit(Vector2 Position1, int Width1, int Height1, Vector2 Position2, int Width2, int Height2)
        {
            int num = (int) ((Position1.X + (Width1 / 2)) / 16f);
            int num2 = (int) ((Position1.Y + (Height1 / 2)) / 16f);
            int num3 = (int) ((Position2.X + (Width2 / 2)) / 16f);
            int num4 = (int) ((Position2.Y + (Height2 / 2)) / 16f);
            do
            {
                int num5 = Math.Abs((int) (num - num3));
                int num6 = Math.Abs((int) (num2 - num4));
                if ((num == num3) && (num2 == num4))
                {
                    return true;
                }
                if (num5 > num6)
                {
                    if (num < num3)
                    {
                        num++;
                    }
                    else
                    {
                        num--;
                    }
                    if (Main.tile[num, num2 - 1] == null)
                    {
                        Main.tile[num, num2 - 1] = new Tile();
                    }
                    if (Main.tile[num, num2 + 1] == null)
                    {
                        Main.tile[num, num2 + 1] = new Tile();
                    }
                    if (((Main.tile[num, num2 - 1].active && Main.tileSolid[Main.tile[num, num2 - 1].type]) && (!Main.tileSolidTop[Main.tile[num, num2 - 1].type] && Main.tile[num, num2 + 1].active)) && (Main.tileSolid[Main.tile[num, num2 + 1].type] && !Main.tileSolidTop[Main.tile[num, num2 + 1].type]))
                    {
                        return false;
                    }
                }
                else
                {
                    if (num2 < num4)
                    {
                        num2++;
                    }
                    else
                    {
                        num2--;
                    }
                    if (Main.tile[num - 1, num2] == null)
                    {
                        Main.tile[num - 1, num2] = new Tile();
                    }
                    if (Main.tile[num + 1, num2] == null)
                    {
                        Main.tile[num + 1, num2] = new Tile();
                    }
                    if (((Main.tile[num - 1, num2].active && Main.tileSolid[Main.tile[num - 1, num2].type]) && (!Main.tileSolidTop[Main.tile[num - 1, num2].type] && Main.tile[num + 1, num2].active)) && (Main.tileSolid[Main.tile[num + 1, num2].type] && !Main.tileSolidTop[Main.tile[num + 1, num2].type]))
                    {
                        return false;
                    }
                }
                if (Main.tile[num, num2] == null)
                {
                    Main.tile[num, num2] = new Tile();
                }
            }
            while ((!Main.tile[num, num2].active || !Main.tileSolid[Main.tile[num, num2].type]) || Main.tileSolidTop[Main.tile[num, num2].type]);
            return false;
        }

        public static bool DrownCollision(Vector2 Position, int Width, int Height)
        {
            Vector2 vector2 = new Vector2(Position.X + (Width / 2), Position.Y + (Height / 2));
            int num = 10;
            int num2 = 12;
            if (num > Width)
            {
                num = Width;
            }
            if (num2 > Height)
            {
                num2 = Height;
            }
            vector2 = new Vector2(vector2.X - (num / 2), Position.Y + 2f);
            int num3 = ((int) (Position.X / 16f)) - 1;
            int maxTilesX = ((int) ((Position.X + Width) / 16f)) + 2;
            int num5 = ((int) (Position.Y / 16f)) - 1;
            int maxTilesY = ((int) ((Position.Y + Height) / 16f)) + 2;
            if (num3 < 0)
            {
                num3 = 0;
            }
            if (maxTilesX > Main.maxTilesX)
            {
                maxTilesX = Main.maxTilesX;
            }
            if (num5 < 0)
            {
                num5 = 0;
            }
            if (maxTilesY > Main.maxTilesY)
            {
                maxTilesY = Main.maxTilesY;
            }
            for (int i = num3; i < maxTilesX; i++)
            {
                for (int j = num5; j < maxTilesY; j++)
                {
                    if ((Main.tile[i, j] != null) && (Main.tile[i, j].liquid > 0))
                    {
                        Vector2 vector;
                        vector.X = i * 0x10;
                        vector.Y = j * 0x10;
                        int num9 = 0x10;
                        float num10 = 0x100 - Main.tile[i, j].liquid;
                        num10 /= 32f;
                        vector.Y += num10 * 2f;
                        num9 -= (int) (num10 * 2f);
                        if ((((vector2.X + num) > vector.X) && (vector2.X < (vector.X + 16f))) && (((vector2.Y + num2) > vector.Y) && (vector2.Y < (vector.Y + num9))))
                        {
                            return true;
                        }
                    }
                }
            }
            return false;
        }

        public static bool EmptyTile(int i, int j, bool ignoreTiles = false)
        {
            Rectangle rectangle = new Rectangle(i * 0x10, j * 0x10, 0x10, 0x10);
            if (Main.tile[i, j].active && !ignoreTiles)
            {
                return false;
            }
            for (int k = 0; k < 8; k++)
            {
                if (Main.player[k].active && rectangle.Intersects(new Rectangle((int) Main.player[k].position.X, (int) Main.player[k].position.Y, Main.player[k].width, Main.player[k].height)))
                {
                    return false;
                }
            }
            for (int m = 0; m < 200; m++)
            {
                if (Main.item[m].active && rectangle.Intersects(new Rectangle((int) Main.item[m].position.X, (int) Main.item[m].position.Y, Main.item[m].width, Main.item[m].height)))
                {
                    return false;
                }
            }
            for (int n = 0; n < 0x3e8; n++)
            {
                if (Main.npc[n].active && rectangle.Intersects(new Rectangle((int) Main.npc[n].position.X, (int) Main.npc[n].position.Y, Main.npc[n].width, Main.npc[n].height)))
                {
                    return false;
                }
            }
            return true;
        }

        public static void HitTiles(Vector2 Position, Vector2 Velocity, int Width, int Height)
        {
            Vector2 vector2 = Position + Velocity;
            int num = ((int) (Position.X / 16f)) - 1;
            int maxTilesX = ((int) ((Position.X + Width) / 16f)) + 2;
            int num3 = ((int) (Position.Y / 16f)) - 1;
            int maxTilesY = ((int) ((Position.Y + Height) / 16f)) + 2;
            if (num < 0)
            {
                num = 0;
            }
            if (maxTilesX > Main.maxTilesX)
            {
                maxTilesX = Main.maxTilesX;
            }
            if (num3 < 0)
            {
                num3 = 0;
            }
            if (maxTilesY > Main.maxTilesY)
            {
                maxTilesY = Main.maxTilesY;
            }
            for (int i = num; i < maxTilesX; i++)
            {
                for (int j = num3; j < maxTilesY; j++)
                {
                    if (((Main.tile[i, j] != null) && Main.tile[i, j].active) && (Main.tileSolid[Main.tile[i, j].type] || (Main.tileSolidTop[Main.tile[i, j].type] && (Main.tile[i, j].frameY == 0))))
                    {
                        Vector2 vector;
                        vector.X = i * 0x10;
                        vector.Y = j * 0x10;
                        if ((((vector2.X + Width) >= vector.X) && (vector2.X <= (vector.X + 16f))) && (((vector2.Y + Height) >= vector.Y) && (vector2.Y <= (vector.Y + 16f))))
                        {
                            WorldGen.KillTile(i, j, true, true, false);
                        }
                    }
                }
            }
        }

        public static Vector2 HurtTiles(Vector2 Position, Vector2 Velocity, int Width, int Height, bool fireImmune = false)
        {
            Vector2 vector2 = Position;
            int num = ((int) (Position.X / 16f)) - 1;
            int maxTilesX = ((int) ((Position.X + Width) / 16f)) + 2;
            int num3 = ((int) (Position.Y / 16f)) - 1;
            int maxTilesY = ((int) ((Position.Y + Height) / 16f)) + 2;
            if (num < 0)
            {
                num = 0;
            }
            if (maxTilesX > Main.maxTilesX)
            {
                maxTilesX = Main.maxTilesX;
            }
            if (num3 < 0)
            {
                num3 = 0;
            }
            if (maxTilesY > Main.maxTilesY)
            {
                maxTilesY = Main.maxTilesY;
            }
            for (int i = num; i < maxTilesX; i++)
            {
                for (int j = num3; j < maxTilesY; j++)
                {
                    if (((Main.tile[i, j] != null) && Main.tile[i, j].active) && ((((Main.tile[i, j].type == 0x20) || (Main.tile[i, j].type == 0x25)) || ((Main.tile[i, j].type == 0x30) || (Main.tile[i, j].type == 0x35))) || (((Main.tile[i, j].type == 0x3a) || (Main.tile[i, j].type == 0x45)) || (Main.tile[i, j].type == 0x4c))))
                    {
                        Vector2 vector;
                        vector.X = i * 0x10;
                        vector.Y = j * 0x10;
                        int num7 = 0;
                        int type = Main.tile[i, j].type;
                        switch (type)
                        {
                            case 0x20:
                            case 0x45:
                                if ((((vector2.X + Width) > vector.X) && (vector2.X < (vector.X + 16f))) && (((vector2.Y + Height) > vector.Y) && (vector2.Y < (vector.Y + 16.01))))
                                {
                                    int num9 = 1;
                                    if ((vector2.X + (Width / 2)) < (vector.X + 8f))
                                    {
                                        num9 = -1;
                                    }
                                    num7 = 10;
                                    if (type == 0x45)
                                    {
                                        num7 = 0x19;
                                    }
                                    return new Vector2((float) num9, (float) num7);
                                }
                                break;

                            case 0x35:
                                if (((((vector2.X + Width) - 2f) >= vector.X) && ((vector2.X + 2f) <= (vector.X + 16f))) && ((((vector2.Y + Height) - 2f) >= vector.Y) && ((vector2.Y + 2f) <= (vector.Y + 16f))))
                                {
                                    int num10 = 1;
                                    if ((vector2.X + (Width / 2)) < (vector.X + 8f))
                                    {
                                        num10 = -1;
                                    }
                                    if (type == 0x35)
                                    {
                                        num7 = 20;
                                    }
                                    return new Vector2((float) num10, (float) num7);
                                }
                                break;

                            default:
                                if ((((vector2.X + Width) >= vector.X) && (vector2.X <= (vector.X + 16f))) && (((vector2.Y + Height) >= vector.Y) && (vector2.Y <= (vector.Y + 16.01))))
                                {
                                    int num11 = 1;
                                    if ((vector2.X + (Width / 2)) < (vector.X + 8f))
                                    {
                                        num11 = -1;
                                    }
                                    if (!fireImmune && (((type == 0x25) || (type == 0x3a)) || (type == 0x4c)))
                                    {
                                        num7 = 20;
                                    }
                                    if (type == 0x30)
                                    {
                                        num7 = 40;
                                    }
                                    return new Vector2((float) num11, (float) num7);
                                }
                                break;
                        }
                    }
                }
            }
            return new Vector2();
        }

        public static bool LavaCollision(Vector2 Position, int Width, int Height)
        {
            int num = ((int) (Position.X / 16f)) - 1;
            int maxTilesX = ((int) ((Position.X + Width) / 16f)) + 2;
            int num3 = ((int) (Position.Y / 16f)) - 1;
            int maxTilesY = ((int) ((Position.Y + Height) / 16f)) + 2;
            if (num < 0)
            {
                num = 0;
            }
            if (maxTilesX > Main.maxTilesX)
            {
                maxTilesX = Main.maxTilesX;
            }
            if (num3 < 0)
            {
                num3 = 0;
            }
            if (maxTilesY > Main.maxTilesY)
            {
                maxTilesY = Main.maxTilesY;
            }
            for (int i = num; i < maxTilesX; i++)
            {
                for (int j = num3; j < maxTilesY; j++)
                {
                    if (((Main.tile[i, j] != null) && (Main.tile[i, j].liquid > 0)) && Main.tile[i, j].lava)
                    {
                        Vector2 vector;
                        vector.X = i * 0x10;
                        vector.Y = j * 0x10;
                        int num7 = 0x10;
                        float num8 = 0x100 - Main.tile[i, j].liquid;
                        num8 /= 32f;
                        vector.Y += num8 * 2f;
                        num7 -= (int) (num8 * 2f);
                        if ((((Position.X + Width) > vector.X) && (Position.X < (vector.X + 16f))) && (((Position.Y + Height) > vector.Y) && (Position.Y < (vector.Y + num7))))
                        {
                            return true;
                        }
                    }
                }
            }
            return false;
        }

        public static bool SolidTiles(int startX, int endX, int startY, int endY)
        {
            if (startX < 0)
            {
                return true;
            }
            if (endX >= Main.maxTilesX)
            {
                return true;
            }
            if (startY < 0)
            {
                return true;
            }
            if (endY >= Main.maxTilesY)
            {
                return true;
            }
            for (int i = startX; i < (endX + 1); i++)
            {
                for (int j = startY; j < (endY + 1); j++)
                {
                    if (Main.tile[i, j] == null)
                    {
                        return false;
                    }
                    if ((Main.tile[i, j].active && Main.tileSolid[Main.tile[i, j].type]) && !Main.tileSolidTop[Main.tile[i, j].type])
                    {
                        return true;
                    }
                }
            }
            return false;
        }

        public static bool StickyTiles(Vector2 Position, Vector2 Velocity, int Width, int Height)
        {
            Vector2 vector2 = Position;
            bool flag = false;
            int num = ((int) (Position.X / 16f)) - 1;
            int maxTilesX = ((int) ((Position.X + Width) / 16f)) + 2;
            int num3 = ((int) (Position.Y / 16f)) - 1;
            int maxTilesY = ((int) ((Position.Y + Height) / 16f)) + 2;
            if (num < 0)
            {
                num = 0;
            }
            if (maxTilesX > Main.maxTilesX)
            {
                maxTilesX = Main.maxTilesX;
            }
            if (num3 < 0)
            {
                num3 = 0;
            }
            if (maxTilesY > Main.maxTilesY)
            {
                maxTilesY = Main.maxTilesY;
            }
            for (int i = num; i < maxTilesX; i++)
            {
                for (int j = num3; j < maxTilesY; j++)
                {
                    if (((Main.tile[i, j] != null) && Main.tile[i, j].active) && (Main.tile[i, j].type == 0x33))
                    {
                        Vector2 vector;
                        vector.X = i * 0x10;
                        vector.Y = j * 0x10;
                        if ((((vector2.X + Width) > vector.X) && (vector2.X < (vector.X + 16f))) && (((vector2.Y + Height) > vector.Y) && (vector2.Y < (vector.Y + 16.01))))
                        {
                            if (((Math.Abs(Velocity.X) + Math.Abs(Velocity.Y)) > 0.7) && (Main.rand.Next(30) == 0))
                            {
                                Color newColor = new Color();
                                Dust.NewDust(new Vector2((float) (i * 0x10), (float) (j * 0x10)), 0x10, 0x10, 30, 0f, 0f, 0, newColor, 1f);
                            }
                            flag = true;
                        }
                    }
                }
            }
            return flag;
        }

        public static Vector2 TileCollision(Vector2 Position, Vector2 Velocity, int Width, int Height, bool fallThrough = false, bool fall2 = false)
        {
            Vector2 vector = Velocity;
            Vector2 vector2 = Velocity;
            Vector2 vector4 = Position + Velocity;
            Vector2 vector5 = Position;
            int num = ((int) (Position.X / 16f)) - 1;
            int maxTilesX = ((int) ((Position.X + Width) / 16f)) + 2;
            int num3 = ((int) (Position.Y / 16f)) - 1;
            int maxTilesY = ((int) ((Position.Y + Height) / 16f)) + 2;
            int num5 = -1;
            int num6 = -1;
            int num7 = -1;
            int num8 = -1;
            if (num < 0)
            {
                num = 0;
            }
            if (maxTilesX > Main.maxTilesX)
            {
                maxTilesX = Main.maxTilesX;
            }
            if (num3 < 0)
            {
                num3 = 0;
            }
            if (maxTilesY > Main.maxTilesY)
            {
                maxTilesY = Main.maxTilesY;
            }
            for (int i = num; i < maxTilesX; i++)
            {
                for (int j = num3; j < maxTilesY; j++)
                {
                    if (((Main.tile[i, j] != null) && Main.tile[i, j].active) && (Main.tileSolid[Main.tile[i, j].type] || (Main.tileSolidTop[Main.tile[i, j].type] && (Main.tile[i, j].frameY == 0))))
                    {
                        Vector2 vector3;
                        vector3.X = i * 0x10;
                        vector3.Y = j * 0x10;
                        if ((((vector4.X + Width) > vector3.X) && (vector4.X < (vector3.X + 16f))) && (((vector4.Y + Height) > vector3.Y) && (vector4.Y < (vector3.Y + 16f))))
                        {
                            if ((vector5.Y + Height) <= vector3.Y)
                            {
                                if ((!Main.tileSolidTop[Main.tile[i, j].type] || !fallThrough) || ((Velocity.Y > 1f) && !fall2))
                                {
                                    num7 = i;
                                    num8 = j;
                                    if (num7 != num5)
                                    {
                                        vector.Y = vector3.Y - (vector5.Y + Height);
                                    }
                                }
                            }
                            else if (((vector5.X + Width) <= vector3.X) && !Main.tileSolidTop[Main.tile[i, j].type])
                            {
                                num5 = i;
                                num6 = j;
                                if (num6 != num8)
                                {
                                    vector.X = vector3.X - (vector5.X + Width);
                                }
                                if (num7 == num5)
                                {
                                    vector.Y = vector2.Y;
                                }
                            }
                            else if ((vector5.X >= (vector3.X + 16f)) && !Main.tileSolidTop[Main.tile[i, j].type])
                            {
                                num5 = i;
                                num6 = j;
                                if (num6 != num8)
                                {
                                    vector.X = (vector3.X + 16f) - vector5.X;
                                }
                                if (num7 == num5)
                                {
                                    vector.Y = vector2.Y;
                                }
                            }
                            else if ((vector5.Y >= (vector3.Y + 16f)) && !Main.tileSolidTop[Main.tile[i, j].type])
                            {
                                num7 = i;
                                num8 = j;
                                vector.Y = ((vector3.Y + 16f) - vector5.Y) + 0.01f;
                                if (num8 == num6)
                                {
                                    vector.X = vector2.X + 0.01f;
                                }
                            }
                        }
                    }
                }
            }
            return vector;
        }

        public static bool WetCollision(Vector2 Position, int Width, int Height)
        {
            Vector2 vector2 = new Vector2(Position.X + (Width / 2), Position.Y + (Height / 2));
            int num = 10;
            int num2 = Height / 2;
            if (num > Width)
            {
                num = Width;
            }
            if (num2 > Height)
            {
                num2 = Height;
            }
            vector2 = new Vector2(vector2.X - (num / 2), vector2.Y - (num2 / 2));
            int num3 = ((int) (Position.X / 16f)) - 1;
            int maxTilesX = ((int) ((Position.X + Width) / 16f)) + 2;
            int num5 = ((int) (Position.Y / 16f)) - 1;
            int maxTilesY = ((int) ((Position.Y + Height) / 16f)) + 2;
            if (num3 < 0)
            {
                num3 = 0;
            }
            if (maxTilesX > Main.maxTilesX)
            {
                maxTilesX = Main.maxTilesX;
            }
            if (num5 < 0)
            {
                num5 = 0;
            }
            if (maxTilesY > Main.maxTilesY)
            {
                maxTilesY = Main.maxTilesY;
            }
            for (int i = num3; i < maxTilesX; i++)
            {
                for (int j = num5; j < maxTilesY; j++)
                {
                    if ((Main.tile[i, j] != null) && (Main.tile[i, j].liquid > 0))
                    {
                        Vector2 vector;
                        vector.X = i * 0x10;
                        vector.Y = j * 0x10;
                        int num9 = 0x10;
                        float num10 = 0x100 - Main.tile[i, j].liquid;
                        num10 /= 32f;
                        vector.Y += num10 * 2f;
                        num9 -= (int) (num10 * 2f);
                        if ((((vector2.X + num) > vector.X) && (vector2.X < (vector.X + 16f))) && (((vector2.Y + num2) > vector.Y) && (vector2.Y < (vector.Y + num9))))
                        {
                            return true;
                        }
                    }
                }
            }
            return false;
        }
    }
}