use std::{f32::consts::PI, f64::consts::TAU};

use macroquad::{prelude::*, rand::gen_range};

use crate::{
    asteroids::Asteroid,
    nn::{ActivationFunc, NN},
    HEIGHT, WIDTH,
};
const NUM_KEYS: usize = 4;
const INPUTS_PER_ASTEROID: usize = 4;
const NUM_ASTEROIDS: usize = 1;
const INPUTS_FOR_SHIP: usize = 2;
const VALUES_PER_MEMORY: usize = 1;
const NUM_MEMORIES: usize = 0;
#[derive(Default)]
pub struct Player {
    pub pos: Vec2,
    vel: Vec2,
    acc: f32,
    pub dir: Vec2,
    rot: f32,
    drag: f32,
    bullets: Vec<Bullet>,
    asteroids: Vec<Option<Asteroid>>,
    inputs: Vec<f32>,
    pub outputs: Vec<f32>,
    last_shot: u32,
    shot_interval: u32,
    pub brain: Option<NN>,
    alive: bool,
    pub lifespan: u32,
    pub shots: u32,
    memory: std::collections::VecDeque<f32>,
}

impl Player {
    pub fn new(
        config: Option<Vec<usize>>,
        mut_rate: Option<f32>,
        activ: Option<ActivationFunc>,
    ) -> Self {
        Self {
            brain: match config {
                Some(mut c) => {
                    c.retain(|&x| x != 0);
                    // Number of inputs
                    c.insert(
                        0,
                        (INPUTS_PER_ASTEROID * NUM_ASTEROIDS)
                            + INPUTS_FOR_SHIP
                            + (VALUES_PER_MEMORY * NUM_MEMORIES),
                    );
                    // Number of outputs
                    c.push(
                        NUM_KEYS
                            + if NUM_MEMORIES > 0 {
                                VALUES_PER_MEMORY
                            } else {
                                0
                            },
                    );
                    Some(NN::new(c, mut_rate.unwrap(), activ.unwrap()))
                }
                _ => None,
            },
            dir: vec2(0., -1.),
            rot: 1.5 * PI,

            // Change scaling when passing inputs if this is changed
            drag: 0.001,
            shot_interval: 18,
            alive: true,
            shots: 4,
            // 4 outputs, 1 for memory
            outputs: vec![0.; NUM_KEYS + VALUES_PER_MEMORY],
            memory: vec![0.; VALUES_PER_MEMORY * NUM_MEMORIES].into(),

            ..Default::default()
        }
    }

    pub fn check_player_collision(&mut self, asteroid: &Asteroid) -> bool {
        // Save the asteroid to our asteroids
        self.asteroids.push(Some(asteroid.clone()));

        if asteroid.check_collision(self.pos, 8.) || self.lifespan > 3600 && self.brain.is_some() {
            self.alive = false;
            return true;
        }
        false
    }

    pub fn consider_asteroids(pos: Vec2, asteroids: &mut Vec<Option<Asteroid>>) {
        // Consider the closest asteroids first
        asteroids.sort_by_key(|ast| match ast {
            None => i32::MAX,
            Some(ast) => (dist_wrapping(ast.pos, pos, ast.radius) * 100.) as i32,
        });
        // Cull if there are too may asteroids
        *asteroids = asteroids.iter().cloned().take(NUM_ASTEROIDS).collect();
        // Insert if there are not enought asteroids
        if asteroids.len() < NUM_ASTEROIDS {
            for _ in 0..NUM_ASTEROIDS - asteroids.len() {
                asteroids.push(None);
            }
        }
        assert_eq!(asteroids.len(), NUM_ASTEROIDS);
    }

    pub fn check_bullet_collisions(&mut self, asteroid: &mut Asteroid) -> bool {
        for bullet in &mut self.bullets {
            if asteroid.check_collision(bullet.pos, 0.) {
                asteroid.alive = false;
                bullet.alive = false;
                return true;
            }
        }
        false
    }

    pub fn update(&mut self) {
        self.lifespan += 1;
        self.last_shot += 1;
        self.acc = 0.;
        self.outputs = vec![0.; 4];
        let mut keys = vec![false; 4];
        self.inputs = vec![];
        // Insert all the asteroid data
        Self::consider_asteroids(self.pos, &mut self.asteroids);
        for ast in &self.asteroids {
            if let Some(ast) = ast {
                self.inputs.extend_from_slice(&[
                    // Distance to asteroid
                    dist_wrapping(ast.pos, self.pos, ast.radius),
                    // Angle to asteroid
                    self.dir.angle_between(ast.pos - self.pos),
                    // Asteroid velocity x
                    (ast.vel - self.vel).x * 0.6,
                    // Asteroid velocity y
                    (ast.vel - self.vel).y * 0.6,
                ]);
            } else {
                self.inputs.extend_from_slice(&[0., 0., 0., 0.]);
            }
        }
        assert_eq!(self.inputs.len(), NUM_ASTEROIDS * INPUTS_PER_ASTEROID);
        // Insert the ship data
        self.inputs.push(self.rot / TAU as f32);
        self.inputs.push(
            (self.shot_interval as f32 - self.last_shot as f32).max(0.) / self.shot_interval as f32,
        );
        // Insert the memories
        for memory in &self.memory {
            self.inputs.push(memory.min(1.).max(-1.));
        }
        // Run the brain
        if let Some(brain) = &self.brain {
            assert_eq!(self.inputs.len(), brain.config[0] - 1);
            self.outputs = brain.feed_forward(&self.inputs);
            if NUM_MEMORIES > 0 {
                self.memory.push_back(self.outputs[self.outputs.len() - 1]);
                self.memory.pop_front();
            }
            keys = self
                .outputs
                .iter()
                .map(|&x| {
                    x > if brain.activ_func == ActivationFunc::Sigmoid {
                        0.85
                    } else {
                        0.
                    }
                })
                .collect();
        }
        if keys[0] || self.brain.is_none() && is_key_down(KeyCode::Right) {
            // RIGHT
            self.rot = (self.rot + 0.1 + TAU as f32) % TAU as f32;
            self.dir = vec2(self.rot.cos(), self.rot.sin());
        }
        if keys[1] || self.brain.is_none() && is_key_down(KeyCode::Left) {
            // LEFT
            self.rot = (self.rot - 0.1 + TAU as f32) % TAU as f32;
            self.dir = vec2(self.rot.cos(), self.rot.sin());
        }
        if keys[2] || self.brain.is_none() && is_key_down(KeyCode::Up) {
            // THROTTLE
            self.acc = 0.14;
        }
        if keys[3] || self.brain.is_none() && is_key_down(KeyCode::Space) {
            if self.last_shot > self.shot_interval {
                self.last_shot = 0;
                self.shots += 1;
                self.bullets.push(Bullet {
                    pos: self.pos + self.dir * 20.,
                    vel: self.dir * 8.5 + self.vel,
                    alive: true,
                    travelled: Vec2::new(0., 0.),
                });
            }
        }

        self.vel += self.acc * self.dir - self.drag * self.vel.length() * self.vel;
        self.pos += self.vel;
        if self.pos.x.abs() > WIDTH * 0.5 + 10. {
            self.pos.x *= -1.;
        }
        if self.pos.y.abs() > HEIGHT * 0.5 + 10. {
            self.pos.y *= -1.;
        }

        for bullet in &mut self.bullets {
            bullet.update();
        }
        self.bullets.retain(|b| b.alive);
        self.asteroids = vec![];
    }

    pub fn draw(&self, color: Color, debug: bool) {
        let p1 = self.pos + self.dir * 20.;
        let p2 = self.pos + self.dir.rotate(vec2(-18., -12.667));
        let p3 = self.pos + self.dir.rotate(vec2(-18., 12.667));
        let p4 = self.pos + self.dir.rotate(vec2(-10., -10.));
        let p5 = self.pos + self.dir.rotate(vec2(-10., 10.));
        let p6 = self.pos + self.dir * -25.;
        let p7 = self.pos + self.dir.rotate(vec2(-10., -6.));
        let p8 = self.pos + self.dir.rotate(vec2(-10., 6.));
        draw_line(p1.x, p1.y, p2.x, p2.y, 2., color);
        draw_line(p1.x, p1.y, p3.x, p3.y, 2., color);
        draw_line(p4.x, p4.y, p5.x, p5.y, 2., color);
        if self.acc > 0. && gen_range(0., 1.) < 0.4 {
            draw_triangle_lines(p6, p7, p8, 2., color);
        }
        if debug {
            let mut debug_asteroids = self.asteroids.clone();
            Self::consider_asteroids(self.pos, &mut debug_asteroids);
            for asteroid in &debug_asteroids {
                if let Some(ast) = asteroid {
                    draw_circle_lines(ast.pos.x, ast.pos.y, ast.radius, 1., RED);
                    // let p = self.pos
                    //     + self.dir.rotate(Vec2::from_angle(self.asteroid_data[0].1))
                    //         * self.asteroid_data[0].0
                    //         * WIDTH;
                    draw_line(self.pos.x, self.pos.y, ast.pos.x, ast.pos.y, 1., RED);
                }
            }

            // Draw raycasts

            // for (i, r) in self.raycasts.iter().enumerate() {
            //     let dir = Vec2::from_angle(PI / 4. * i as f32).rotate(self.dir);
            //     draw_line(
            //         self.pos.x,
            //         self.pos.y,
            //         self.pos.x + dir.x * 100. / r,
            //         self.pos.y + dir.y * 100. / r,
            //         1.,
            //         GRAY,
            //     );
            // }
        }

        for bullet in &self.bullets {
            bullet.draw(color);
        }
    }

    pub fn draw_brain(&self, width: f32, height: f32, bias: bool) {
        if let Some(brain) = &self.brain {
            brain.draw(width, height, &self.inputs, &self.outputs, bias);
        }
    }
}

struct Bullet {
    pos: Vec2,
    vel: Vec2,
    alive: bool,
    travelled: Vec2,
}

impl Bullet {
    fn update(&mut self) {
        self.pos += self.vel;
        if self.pos.x.abs() > WIDTH * 0.5 {
            self.pos.x *= -1.;
        }
        if self.pos.y.abs() > HEIGHT * 0.5 {
            self.pos.y *= -1.;
        }
        self.travelled += self.vel;
        if self.travelled.length() >= (WIDTH * WIDTH + HEIGHT * HEIGHT).sqrt() / 2. {
            self.alive = false;
        }
    }
    fn draw(&self, c: Color) {
        draw_circle(self.pos.x, self.pos.y, 2., Color::new(c.r, c.g, c.b, 0.9));
    }
}

// Distance in a toroidal space:
// https://blog.demofox.org/2017/10/01/calculating-the-distance-between-points-in-wrap-around-toroidal-space/
fn dist_wrapping(a: Vec2, b: Vec2, r: f32) -> f32 {
    let mut dx = (a.x - b.x).abs();
    let mut dy = (a.y - b.y).abs();

    if dx > (WIDTH as f32 / 2.) {
        dx = WIDTH as f32 - dx;
    }
    if dy > (HEIGHT as f32 / 2.) {
        dy = HEIGHT as f32 - dy;
    }
    ((dx * dx + dy * dy).sqrt() - r) / (WIDTH * WIDTH + HEIGHT * HEIGHT).sqrt()
}