// You can find the Turtle API reference here: https://turtletoy.net/syntax
Canvas.setpenopacity(1);
console.clear()

// Global code will be evaluated once.
const turtle = new Turtle();
let seed = 1000; // min=1 max=1000000 step=1
const bits = 20; 
const samples = 150000; 
const mod = 1<<bits;
const ticks = 80; // min = 1 max = 200 step = 1
const num_hunters = 1; // min = 1 max = 20 step = 1
const num_hiders = 150; // min = 1 max = 300 step = 1
const bounds = 100; // min = 1 max = 100 step = 1
const hunter_spawn_bounds = 80; // min = 0 max = 100 step = 1
const hider_spawn_bounds = 25; // min = 0 max = 100 step = 1
const draw_hunters = 0; //min=0 max=1 step=1 (No, Yes)
const draw_hiders = 1; //min=0 max=1 step=1 (No, Yes)

////////////////////////////////////////////////////////////////
// Pseudorandom number generator. Created by Reinder Nijhoff 2024
// https://turtletoy.net/turtle/a2274fd1fe
////////////////////////////////////////////////////////////////
function random() { // returns a number [0, 1[
    let r = 1103515245 * (((seed+=12345) >> 1) ^ seed);
    r = 1103515245 * (r ^ (r >> 3));
    r = r ^ (r >> 16);
    return (r % mod) / mod;
}

class Hunter {
    constructor(radius, speed, x_pos, y_pos) {
        this.radius = radius;
        this.speed = speed;
        this.x_pos = x_pos;
        this.y_pos = y_pos;
        this.turtle = new Turtle();
    }
    
    move(list_hunters, list_hiders) {
        if(list_hiders.length <= 0) {
            return [];
        }
        let x_closest = list_hiders[0].x_pos;
        let y_closest = list_hiders[0].y_pos;
        for(let i in list_hiders) {
            if(this.distance(x_closest,y_closest,this.x_pos,this.y_pos) 
            > this.distance(list_hiders[i].x_pos,list_hiders[i].y_pos,this.x_pos,this.y_pos)){
                x_closest = list_hiders[i].x_pos;
                y_closest = list_hiders[i].y_pos;
            }
        }
        
        let x_dir = (x_closest - this.x_pos) / this.distance(x_closest,y_closest,this.x_pos,this.y_pos);
        let y_dir = (y_closest - this.y_pos) / this.distance(x_closest,y_closest,this.x_pos,this.y_pos);
        
        this.x_pos += x_dir * this.speed;
        this.y_pos += y_dir * this.speed;
        
        for(let i = list_hiders.length-1; i >= 0; i--) {
            if(this.distance(list_hiders[i].x_pos,list_hiders[i].y_pos,this.x_pos,this.y_pos) < this.radius / 1.5) {
                list_hiders.splice(i,1);
            }
        }
        
        // if(this.x_pos > bounds) {
        //     this.x_pos = bounds
        // }
        // if(this.x_pos < -bounds) {
        //     this.x_pos = -bounds
        // }
        // if(this.y_pos > bounds) {
        //     this.y_pos = bounds
        // }
        // if(this.y_pos < -bounds) {
        //     this.y_pos = -bounds
        // }
        let pos_mag = this.distance(0,0,this.x_pos,this.y_pos);
        if(pos_mag > bounds) {
            this.x_pos *= bounds / pos_mag;
            this.y_pos *= bounds / pos_mag;
        }
        
        return list_hiders;
    }
    
    draw() {
        this.turtle.penup();
        this.turtle.goto(this.x_pos, this.y_pos - this.radius);
        this.turtle.pendown();
        this.turtle.circle(this.radius);
    }
    
    distance(x1, y1, x2, y2) {
        return(Math.sqrt(((x1-x2) * (x1-x2)) + ((y1-y2) * (y1-y2))))
    }
}

class Hider {
    constructor(radius, speed, x_pos, y_pos) {
        this.radius = radius;
        this.speed = speed;
        this.x_pos = x_pos;
        this.y_pos = y_pos;
    }
    
    move(list_hunters, list_hiders) {
        let x_dir = 0;
        let y_dir = 0;
        
        for(let i in list_hunters) {
            // x_dir += 1 / ((this.x_pos - list_hunters[i].x_pos) ** 2 + 1) 
            // y_dir += 1 / ((this.y_pos - list_hunters[i].y_pos) ** 2 + 1)
            let strength = 1 / (this.distance(this.x_pos, this.y_pos, list_hunters[i].x_pos, list_hunters[i].y_pos)**2);
            x_dir += strength * (this.x_pos - list_hunters[i].x_pos)
            y_dir += strength * (this.y_pos - list_hunters[i].y_pos)
        }
        
        let magnitude = this.distance(0,0,x_dir,y_dir);
        console.log(x_dir, y_dir, magnitude)
        x_dir = x_dir / magnitude;
        y_dir = y_dir / magnitude;
        console.log(x_dir, y_dir, magnitude)
        
        this.x_pos += x_dir * this.speed;
        this.y_pos += y_dir * this.speed;
        
        // if(this.x_pos > bounds) {
        //     this.x_pos = bounds
        // }
        // if(this.x_pos < -bounds) {
        //     this.x_pos = -bounds
        // }
        // if(this.y_pos > bounds) {
        //     this.y_pos = bounds
        // }
        // if(this.y_pos < -bounds) {
        //     this.y_pos = -bounds
        // }
        let pos_mag = this.distance(0,0,this.x_pos,this.y_pos);
        if(pos_mag > bounds) {
            this.x_pos *= bounds / pos_mag;
            this.y_pos *= bounds / pos_mag;
        }
    }
    
    draw() {
        turtle.penup();
        turtle.goto(this.x_pos, this.y_pos - this.radius);
        turtle.pendown();
        turtle.circle(this.radius);
    }
    
    distance(x1, y1, x2, y2) {
        return(Math.sqrt(((x1-x2) * (x1-x2)) + ((y1-y2) * (y1-y2))))
    }
}

let hunters = [];
let hiders = [];
for(let i = num_hunters; i > 0; i--) {
    let r = 5 + random() * 3;
    let s = 2 + random() * 3;
    let radius = random() * hunter_spawn_bounds;
    let theta = random() * Math.PI * 2;
    let x = radius * Math.cos(theta);
    let y = radius * Math.sin(theta);
    let rand_hunter = new Hunter(r,s,x,y);
    hunters.push(rand_hunter);
}
for(let i = num_hiders; i > 0; i--) {
    let r = 0.2 + random() * 0.4;
    // let s = -1 + Math.random() * 2;
    let s = random();
    let radius = random() * hider_spawn_bounds;
    let theta = random() * Math.PI * 2;
    let x = radius * Math.cos(theta);
    let y = radius * Math.sin(theta);
    let rand_hider = new Hider(r,s,x,y);
    hiders.push(rand_hider);
}

function walk(i) {
    if(hiders.length == 0){
        return false;
    }
    for(let j in hunters) {
        if(draw_hunters == 1) {
            hunters[j].draw();
        }
        list_hiders = hunters[j].move(hunters, hiders);
    }
    for(let j in hiders) {
        if(draw_hiders == 1) {
            hiders[j].draw();           
        }
        hiders[j].move(hunters, hiders);
    }
    return i < ticks;
}