use bevy::prelude::*;
use rustc_hash::FxHashMap;

use crate::constants::ITILE_SIZE;

/// Packed floor tile data for efficient storage. ~35 bytes vs 76 bytes tuple.
#[derive(Clone, Copy, Debug)]
pub struct FloorTileData {
    pub id: u8,
    /// bit0=can_stand_in, bit1=can_stand_on, bit2=visibly_transparent
    pub flags: u8,
    pub astar_weight: u8,
    pub visible_range: [u32; 8],
}

impl Default for FloorTileData {
    fn default() -> Self {
        Self {
            id: 0,
            flags: 0b001,
            astar_weight: 0,
            visible_range: [0; 8],
        }
    }
}

impl FloorTileData {
    pub fn new(
        id: u8,
        can_stand_in: bool,
        can_stand_on: bool,
        visibly_transparent: bool,
        astar_weight: u8,
        visible_range: [u32; 8],
    ) -> Self {
        let mut flags = 0u8;
        if can_stand_in {
            flags |= 0b001;
        }
        if can_stand_on {
            flags |= 0b010;
        }
        if visibly_transparent {
            flags |= 0b100;
        }
        Self {
            id,
            flags,
            astar_weight,
            visible_range,
        }
    }

    #[inline]
    pub fn can_stand_in(&self) -> bool {
        self.flags & 0b001 != 0
    }
    #[inline]
    pub fn can_stand_on(&self) -> bool {
        self.flags & 0b010 != 0
    }
    #[inline]
    pub fn visibly_transparent(&self) -> bool {
        self.flags & 0b100 != 0
    }

    #[inline]
    pub fn set_can_stand_in(&mut self, value: bool) {
        if value {
            self.flags |= 0b001;
        } else {
            self.flags &= !0b001;
        }
    }

    #[inline]
    pub fn set_can_stand_on(&mut self, value: bool) {
        if value {
            self.flags |= 0b010;
        } else {
            self.flags &= !0b010;
        }
    }

    #[inline]
    pub fn set_visibly_transparent(&mut self, value: bool) {
        if value {
            self.flags |= 0b100;
        } else {
            self.flags &= !0b100;
        }
    }
}

/// Packed fixture tile data. ~18 bytes vs 48 bytes tuple.
#[derive(Clone, Copy, Debug)]
pub struct FixtureTileData {
    pub id: u8,
    /// bit0=can_stand_in, bit1=can_stand_on
    pub flags: u8,
    pub visible_range: [u32; 8],
}

impl Default for FixtureTileData {
    fn default() -> Self {
        Self {
            id: 0,
            flags: 0,
            visible_range: [0; 8],
        }
    }
}

impl FixtureTileData {
    pub fn new(id: u8, can_stand_in: bool, can_stand_on: bool, visible_range: [u32; 8]) -> Self {
        let mut flags = 0u8;
        if can_stand_in {
            flags |= 0b001;
        }
        if can_stand_on {
            flags |= 0b010;
        }
        Self {
            id,
            flags,
            visible_range,
        }
    }

    #[inline]
    pub fn can_stand_in(&self) -> bool {
        self.flags & 0b001 != 0
    }
    #[inline]
    pub fn can_stand_on(&self) -> bool {
        self.flags & 0b010 != 0
    }
}

/// Tile map using FxHashMap for fast lookups. No Arc wrapper - single-threaded access.
#[derive(Resource, Default)]
pub struct TileMap {
    pub floor_tiles: FxHashMap<IVec3, FloorTileData>,
    pub fixture_tiles: FxHashMap<IVec3, FixtureTileData>,
    pub item_tiles: FxHashMap<IVec3, Vec<u32>>,
}

impl TileMap {
    pub fn new() -> Self {
        Self::default()
    }

    #[inline]
    pub fn get_floor(&self, pos: &IVec3) -> Option<&FloorTileData> {
        self.floor_tiles.get(pos)
    }

    #[inline]
    pub fn get_fixture(&self, pos: &IVec3) -> Option<&FixtureTileData> {
        self.fixture_tiles.get(pos)
    }

    #[inline]
    pub fn has_floor(&self, pos: &IVec3) -> bool {
        self.floor_tiles.contains_key(pos)
    }

    #[inline]
    pub fn has_fixture(&self, pos: &IVec3) -> bool {
        self.fixture_tiles.contains_key(pos)
    }

    #[inline]
    pub fn insert_floor(&mut self, pos: IVec3, tile: FloorTileData) {
        self.floor_tiles.insert(pos, tile);
    }

    #[inline]
    pub fn insert_fixture(&mut self, pos: IVec3, tile: FixtureTileData) {
        self.fixture_tiles.insert(pos, tile);
    }

    #[inline]
    pub fn insert_item(&mut self, pos: IVec3, entity_id: u32) {
        self.item_tiles.entry(pos).or_default().push(entity_id);
    }

    #[inline]
    pub fn remove_item(&mut self, pos: &IVec3) -> Option<Vec<u32>> {
        self.item_tiles.remove(pos)
    }

    #[inline]
    pub fn get_floor_mut(&mut self, pos: &IVec3) -> Option<&mut FloorTileData> {
        self.floor_tiles.get_mut(pos)
    }
}