using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
using Microsoft.Xna.Framework.Net;
using Microsoft.Xna.Framework.Storage;

namespace President_Evil
{
    class Line
    {
        public Vector2 Start, End;
        public float Length;
        public float KValue;
        public float MValue;
        public float Angle = 0;

        public Sprite line;

        public Rectangle Box;

        public Line()
        {
            Length = 0;
        }

        public Line(Vector2 start, Vector2 end)
        {
            if (end.X < start.X)
            {
                End = start;
                Start = end;
            }
            else
            {
                Start = start;
                End = end;
            }

            if (Start.X == End.X)
                End.X += 0.001f;

            Length = Vector2.Distance(Start, End);
            KValue = (End.Y - Start.Y) / (End.X - Start.X);
            MValue = Start.Y - Start.X * KValue;

            float XDistance = Start.X - End.X;
            float YDistance = Start.Y - End.Y;

            Angle = (float)Math.Atan2(YDistance, XDistance);

            //Top = new Vector2(Start.X, (int)Math.Min(Start.Y, End.Y));
            //Bottom = new Vector2(End.X, (int)Math.Max(Start.Y, End.Y));
            Box = new Rectangle((int)Start.X, (int)Math.Min(Start.Y, End.Y), (int)(End.X - Start.X), (int)(Math.Max(Start.Y, End.Y) - Math.Min(Start.Y, End.Y)));
        }

        public void recalculateKAndM()
        {
            KValue = (End.Y - Start.Y) / (End.X - Start.X);
            MValue = Start.Y - Start.X * KValue;

            Box.X = (int)Start.X;
            Box.Y = (int)Math.Min(Start.Y, End.Y);

            //Top = new Vector2(Start.X, (int)Math.Min(Start.Y, End.Y));
            //Bottom = new Vector2(End.X, (int)Math.Max(Start.Y, End.Y));
        }

        public void recalculateLength()
        {
            Length = Vector2.Distance(Start, End);
        }

        public static Vector2 MoveLineIfColliding(Line MoveLine, Line LineOne, Vector2 MoveSpeed)
        {
            Vector2 Move = Vector2.Zero;

            MoveLine.Start += MoveSpeed;
            MoveLine.End += MoveSpeed;
            MoveLine.recalculateKAndM();
            while (Line.LineToLineCollision(LineOne, MoveLine) != new Vector2(-1, -1))
            {
                Move += MoveSpeed;
                MoveLine.Start += MoveSpeed;
                MoveLine.End += MoveSpeed;
                MoveLine.recalculateKAndM();
                if (Move.X > 50 || Move.X < -50 || Move.Y > 50 || Move.Y < -50)
                    break;
            }

            return Move;
        }

        public static Vector2 LineToLineCollision(Line LineOne, Line LineTwo)
        {
            //if (LineTwo.Top.X > LineOne.Bottom.X)
            //    return new Vector2(-1, -1);
            //if (LineTwo.Top.Y > LineOne.Bottom.Y)
            //    return new Vector2(-1, -1);
            //if (LineTwo.Bottom.X < LineOne.Top.X)
            //    return new Vector2(-1, -1);
            //if (LineTwo.Bottom.Y < LineOne.Top.Y)
            //    return new Vector2(-1, -1);

            if (!LineOne.Box.Intersects(LineTwo.Box))
                return new Vector2(-1, -1);

            Vector2 Collision = new Vector2();

            Collision.X = (LineTwo.MValue - LineOne.MValue) / (LineOne.KValue - LineTwo.KValue);
            Collision.Y = LineOne.KValue * Collision.X + LineOne.MValue;

            bool lineOneCollision = Vector2.Distance(LineOne.Start, Collision) <= LineOne.Length && Vector2.Distance(LineOne.End, Collision) <= LineOne.Length;
            bool lineTwoCollision = Vector2.Distance(LineTwo.Start, Collision) <= LineTwo.Length && Vector2.Distance(LineTwo.End, Collision) <= LineTwo.Length;
            if (lineOneCollision && lineTwoCollision)
                return Collision;
            else
                return new Vector2(-1, -1);
        }

        public void LoadContent(ContentManager content)
        {
            line = new Sprite(content, "Sprites//Pixel", Start);
            line._Color = Color.Red;
            line._Scale.X = Length;
            line._Rotation = (float)Math.Atan2((double)(End.Y - Start.Y),(double)(End.X - Start.X));
        }

        public void Draw(SpriteBatch spritebatch, Vector2 CamerPosition)
        {
            if (line != null)
            {
                line._Position = Start;
                line._CameraPosition = CamerPosition;
                line.Draw(spritebatch, CamerPosition);
            }
        }

    }
}