use bevy::prelude::{ColorMaterial, Entity, Handle, SystemLabel};

// constants
pub const ARENA_WIDTH: u32 = 10;
pub const ARENA_HEIGHT: u32 = 10;

// basic game components
#[derive(Default, Copy, Clone, Eq, PartialEq, Hash)]
pub struct Position {
    pub x: i32,
    pub y: i32,
}

pub struct GridSize {
    pub width: f32,
    pub height: f32,
}

impl GridSize {
    pub fn square(x: f32) -> GridSize {
        Self {
            width: x,
            height: x,
        }
    }
}

#[derive(PartialEq, Copy, Clone, Debug)]
pub enum Direction {
    Left,
    Up,
    Right,
    Down,
}

impl Direction {
    pub fn opposite(self) -> Self {
        match self {
            Self::Left => Self::Right,
            Self::Right => Self::Left,
            Self::Up => Self::Down,
            Self::Down => Self::Up,
        }
    }
}

// material resource
pub struct Materials {
    pub head_material: Handle<ColorMaterial>,
    pub segment_material: Handle<ColorMaterial>,
    pub food_material: Handle<ColorMaterial>,
}

// food!
pub struct Food;

// snake-related components
#[derive(Debug)]
pub struct SnakeHead {
    pub intention: Direction,
    pub direction: Direction,
}

pub struct SnakeSegment;

// snake-related resources
#[derive(Default)]
pub struct SnakeSegments {
    pub segments: Vec<Entity>,
}

#[derive(Default)]
pub struct LastTailPosition {
    pub pos: Option<Position>,
}

// snake phase labels
#[derive(SystemLabel, Debug, Hash, PartialEq, Eq, Clone)]
pub enum SnakeMovement {
    Input,
    Movement,
    Eating,
    Growth,
}

// events
pub struct GrowthEvent;
pub struct GameOverEvent;