using System.Collections.Generic;
using Microsoft.Xna.Framework;

using DWGame.Globals;

namespace DWGame.Player
{
    public class Collision
    {
        //player ship
        public static Human.playerShip human;

        //enviroment rectangles used for collision decection
        public static Rectangle[] frgrnd;
        
        //lists of player missles, enemy missles, and enemies fighters
        public static List<Human.missle> hMissles;
        public static List<AI.enemyFighter> enemies;
        public static List<AI.missle> eMissles;

        //constructor
        public Collision()
        {
            human = Human.getShip();
            hMissles = Human.getMissles();
            frgrnd = Background.getFrgrnd();
            enemies = AI.getFighters();
            eMissles = AI.getMissles();
        }

        //method used to detect collisions between player and world, player and enemies,
        //enemies and player missles, player and enemy missles, and missle to missle.
        //  Upon detection, this method removes enemies and missles from their lists, as well
        //as changing player state to dead if player collides with other objects
        public static void Update()
        {
            human = Human.getShip();
            hMissles = Human.getMissles();
            frgrnd = Background.getFrgrnd();
            enemies = AI.getFighters();
            eMissles = AI.getMissles();

            for (int i = 0; i < frgrnd.Length; i++)
            {
                for (int j = 0; j < hMissles.Count; j++)
                {
                    if (frgrnd[i].Intersects(hMissles[j].mBox))
                        hMissles.RemoveAt(j);                    
                }

                for (int j = 0; j < eMissles.Count; j++)
                {
                    if (frgrnd[i].Intersects(eMissles[j].mBox))
                        eMissles.RemoveAt(j);
                }

                for (int k = 0; k < enemies.Count; k++)
                {
                    for (int l = 0; l < hMissles.Count; l++)
                    {
                        if ( k < enemies.Count && (hMissles[l].mBox.Intersects(enemies[k].enemyBox)) )
                        {
                            enemies.RemoveAt(k);
                            hMissles.RemoveAt(l);
                            human.score = human.score + 100;
                        }
                    }

                    if (k < enemies.Count && (enemies[k].enemyBox.Intersects(human.playerBox)))
                    {
                        enemies.RemoveAt(k);
                        Statics.playerState = Enums_Engine.PlayerState.DEAD;
                    }
                }

                if (frgrnd[i].Intersects(human.playerBox))
                { Statics.playerState = Enums_Engine.PlayerState.DEAD; }
            }



            for (int i = 0; i < eMissles.Count; i++)
            {
                if (eMissles[i].mBox.Intersects(human.playerBox))
                {
                    eMissles.RemoveAt(i);
                    Statics.playerState = Enums_Engine.PlayerState.DEAD;
                }
                for (int j = 0; j < hMissles.Count; j++)
                {
                    if (i < eMissles.Count && eMissles[i].mBox.Intersects(hMissles[j].mBox))
                    {
                        eMissles.RemoveAt(i);
                        hMissles.RemoveAt(j);
                        human.score = human.score + 1;
                    }
                }
            }

        }

        //method to pass missle list back to Human
        public static List<Human.missle> getHMissles()
        { return hMissles; }

        //method to pass enemy missle list back to AI
        public static List<AI.missle> getEMissles()
        { return eMissles; }

        //method used to pass player score back to Human
        public static int getScore()
        { return human.score; }
    }
}