use bevy::prelude::*;
use serde::{Deserialize, Serialize};

use crate::components::GridPos;

/// World units per tile. Tiled maps are expected to use the same tile size,
/// other sizes are scaled to fit.
pub const TILE_SIZE: f32 = 32.0;

#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum Dir {
    North,
    #[default]
    South,
    East,
    West,
}

impl Dir {
    /// Grid delta, with `y` pointing down like in Tiled.
    pub fn delta(self) -> (i32, i32) {
        match self {
            Dir::North => (0, -1),
            Dir::South => (0, 1),
            Dir::East => (1, 0),
            Dir::West => (-1, 0),
        }
    }
}

/// Converts a grid position to the center of the tile in Bevy world space (y up).
pub fn grid_to_world(pos: GridPos) -> Vec2 {
    Vec2::new(
        pos.x as f32 * TILE_SIZE + TILE_SIZE / 2.0,
        -(pos.y as f32 * TILE_SIZE + TILE_SIZE / 2.0),
    )
}