package io.github.bananapuncher714.operation.gunsmoke.api.entity.projectile;

import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
import java.util.UUID;

import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.block.Block;
import org.bukkit.entity.Entity;

import io.github.bananapuncher714.operation.gunsmoke.api.EnumTickResult;
import io.github.bananapuncher714.operation.gunsmoke.api.entity.GunsmokeEntity;
import io.github.bananapuncher714.operation.gunsmoke.api.entity.bukkit.GunsmokeEntityWrapper;
import io.github.bananapuncher714.operation.gunsmoke.api.util.ProjectileTarget;
import io.github.bananapuncher714.operation.gunsmoke.api.util.ProjectileTargetBlock;
import io.github.bananapuncher714.operation.gunsmoke.api.util.ProjectileTargetEntity;
import io.github.bananapuncher714.operation.gunsmoke.core.util.GunsmokeUtil;
import io.github.bananapuncher714.operation.gunsmoke.core.util.VectorUtil;

public abstract class GunsmokeProjectile extends GunsmokeEntity {
    private Set< UUID > hitEntities;
    private Set< Location > hitBlocks;

    public GunsmokeProjectile( Location location ) {
        super( location );

        hitEntities = new HashSet< UUID >();
        hitBlocks = new HashSet< Location >();
    }

    @Override
    public EnumTickResult tick() {
        // First get a set of all things hit, then call events in order from closest hit to farthest hit
        Set< ProjectileTarget > hitTargets = new TreeSet< ProjectileTarget >();

        // Detect if this hit any entities
        // TODO Add way to hit Gunsmoke entities too...
        List< Entity > nearbyEntities = GunsmokeUtil.getNearbyEntities( null, location, velocity );
        for ( Entity entity : nearbyEntities ) {
            if ( getHitEntities().contains( entity.getUniqueId() ) ) {
                continue;
            }
            Location intersection = VectorUtil.rayIntersect( entity, location, velocity );
            if ( intersection != null ) {
                // We know we hit something
                GunsmokeEntityWrapper wrappedEntity = new GunsmokeEntityWrapper( entity );

                hitTargets.add( new ProjectileTargetEntity( this, intersection, wrappedEntity ) );
                getHitEntities().add( entity.getUniqueId() );
            }
        }

        // Now start on block hit detection
        // Get the point where our projectile should be after this tick
        Location destination = location.clone().add( velocity );
        // Get the distance squared because getting the root is a scam
        double distance = location.distanceSquared( destination );

        // Don't want to detect the same block twice
        Set< Block > hitBlocks = new HashSet< Block >();
        // Don't hit the current block we're in
        hitBlocks.add( location.getBlock() );
        // Get the first iteration done
        Location hitBlock = GunsmokeUtil.rayTrace( location, velocity );
        // While we still haven't reached the full destination
        while ( distance >= location.distanceSquared( hitBlock ) ) {
            Block block = hitBlock.getBlock();

            // TODO Add GunsmokeStructure detection
            if ( !getHitBlocks().contains( block.getLocation() ) ) {
                if ( block.getType() != Material.AIR ) {
                    if ( !hitBlocks.contains( block ) ) {
                        hitTargets.add( new ProjectileTargetBlock( this, hitBlock, block ) );
                        hitBlocks.add( block );
                        getHitBlocks().add( block.getLocation() );
                    }
                }
            }

            hitBlock = GunsmokeUtil.rayTrace( hitBlock, velocity );
        }

        // Now that we have our targets we can start calling our other methods in order
        // Event calling should be handled by the implementation
        for ( ProjectileTarget target : hitTargets ) {
            hit( target );
        }
        location.add( velocity );

        // Erase this projectile from existence if it falls beyond the void
        return ( location.getY() > -64 ) ? EnumTickResult.CONTINUE : EnumTickResult.CANCEL;
    }

    protected Set< UUID > getHitEntities() {
        return hitEntities;
    }

    protected Set< Location > getHitBlocks() {
        return hitBlocks;
    }

    abstract public void hit( ProjectileTarget target );
}