use std::ops::{self, Index, IndexMut};

use bevy::{
    ecs::component::Component,
    math::{Dir3, IVec3, InvalidDirectionError},
};
use overload::overload;

use super::BlockRegion;

#[derive(Component, Clone, Copy, PartialEq, Eq, Hash, Debug)]
pub struct BlockPos {
    pub x: i32,
    pub y: i32,
    pub z: i32,
}

impl BlockPos {
    pub const ORIGIN: BlockPos = Self::new(0, 0, 0);

    pub const fn new(x: i32, y: i32, z: i32) -> Self {
        Self { x, y, z }
    }

    pub fn region(self) -> BlockRegion {
        BlockRegion::new_unchecked(self, self)
    }

    pub fn distance_to(self, other: Self) -> f32 {
        (self.distance_to_squared(other) as f32).sqrt()
    }

    pub fn distance_to_squared(self, other: Self) -> i32 {
        IVec3::distance_squared(self.into(), other.into())
    }

    pub fn direction_to(self, other: Self) -> Result<Dir3, InvalidDirectionError> {
        Dir3::new((other - self).as_vec3())
    }

    pub fn min(self, rhs: Self) -> Self {
        Self::new(self.x.min(rhs.x), self.y.min(rhs.y), self.z.min(rhs.z))
    }

    pub fn max(self, rhs: Self) -> Self {
        Self::new(self.x.max(rhs.x), self.y.max(rhs.y), self.z.max(rhs.z))
    }

    pub fn offset(self, x: i32, y: i32, z: i32) -> Self {
        Self::new(self.x + x, self.y + y, self.z + z)
    }
}

impl std::fmt::Display for BlockPos {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "[{}, {}, {}]", self.x, self.y, self.z)
    }
}

// Offsetting

overload!((l: BlockPos) + (r: IVec3) -> BlockPos { BlockPos::new(l.x + r.x, l.y + r.y, l.z + r.z) });
overload!((l: BlockPos) - (r: IVec3) -> BlockPos { BlockPos::new(l.x - r.x, l.y - r.y, l.z - r.z) });
overload!((s: &mut BlockPos) += (v: IVec3) { s.x += v.x; s.y += v.y; s.z += v.z; });
overload!((s: &mut BlockPos) -= (v: IVec3) { s.x -= v.x; s.y -= v.y; s.z -= v.z; });

// Difference

overload!((l: BlockPos) - (r: BlockPos) -> IVec3 { IVec3::new(l.x - r.x, l.y - r.y, l.z - r.z) });

// Indexing

impl Index<usize> for BlockPos {
    type Output = i32;
    fn index(&self, index: usize) -> &Self::Output {
        match index {
            0 => &self.x,
            1 => &self.y,
            2 => &self.z,
            _ => panic!("index out of bounds"),
        }
    }
}

impl IndexMut<usize> for BlockPos {
    fn index_mut(&mut self, index: usize) -> &mut Self::Output {
        match index {
            0 => &mut self.x,
            1 => &mut self.y,
            2 => &mut self.z,
            _ => panic!("index out of bounds"),
        }
    }
}

// Conversion

impl From<(i32, i32, i32)> for BlockPos {
    fn from((x, y, z): (i32, i32, i32)) -> Self {
        Self::new(x, y, z)
    }
}
impl From<BlockPos> for (i32, i32, i32) {
    fn from(BlockPos { x, y, z }: BlockPos) -> Self {
        (x, y, z)
    }
}

impl From<[i32; 3]> for BlockPos {
    fn from([x, y, z]: [i32; 3]) -> Self {
        Self::new(x, y, z)
    }
}
impl From<BlockPos> for [i32; 3] {
    fn from(BlockPos { x, y, z }: BlockPos) -> Self {
        [x, y, z]
    }
}

impl From<IVec3> for BlockPos {
    fn from(IVec3 { x, y, z }: IVec3) -> Self {
        Self::new(x, y, z)
    }
}
impl From<BlockPos> for IVec3 {
    fn from(BlockPos { x, y, z }: BlockPos) -> Self {
        Self::new(x, y, z)
    }
}