use std::collections::{HashMap, HashSet};

use bevy::prelude::*;
use bevy_rapier2d::prelude::*;
use derive_more::{Deref, DerefMut};
pub use mapgen::Map;
use mapgen::{geometry::Rect as MRect, MapFilter, TileType};
use maze_generator::{prelude::*, recursive_backtracking::RbGenerator};
use rand::prelude::StdRng;

use crate::{
    core::{Coordinates, Player, PointLike},
    exploration::{ExplorationType, Mappable},
    log::Log,
    utils::target_and_other,
    visibility::BlocksVisibility,
};

impl From<mapgen::geometry::Point> for Coordinates {
    fn from(point: mapgen::geometry::Point) -> Self {
        Self((point.x as f32, point.y as f32))
    }
}

#[derive(Clone, Debug, Default, Reflect)]
#[reflect(Component)]
pub struct AreaTag;

#[derive(Clone, Debug, Default, Reflect)]
#[reflect(Component)]
pub struct MapObstruction;

#[derive(Clone, Debug, Default, Reflect)]
#[reflect(Component)]
pub struct Portal;

pub trait ITileType {
    fn blocks_motion(&self) -> bool;
    fn blocks_visibility(&self) -> bool;
}

impl ITileType for TileType {
    fn blocks_motion(&self) -> bool {
        match self {
            TileType::Wall => true,
            TileType::Floor => false,
        }
    }

    fn blocks_visibility(&self) -> bool {
        match self {
            TileType::Wall => true,
            TileType::Floor => false,
        }
    }
}

#[derive(Clone, Debug)]
pub struct MapConfig {
    pub autospawn_portals: bool,
    pub describe_undescribed_areas: bool,
    pub speak_area_descriptions: bool,
    pub start_revealed: bool,
}

impl Default for MapConfig {
    fn default() -> Self {
        Self {
            autospawn_portals: true,
            describe_undescribed_areas: false,
            speak_area_descriptions: true,
            start_revealed: false,
        }
    }
}

#[derive(Bundle)]
pub struct PortalBundle {
    pub coordinates: Coordinates,
    pub portal: Portal,
    pub exploration_type: ExplorationType,
    pub mappable: Mappable,
    pub transform: Transform,
    pub global_transform: GlobalTransform,
}

impl Default for PortalBundle {
    fn default() -> Self {
        Self {
            coordinates: Default::default(),
            portal: Default::default(),
            exploration_type: ExplorationType::Portal,
            mappable: Default::default(),
            transform: Default::default(),
            global_transform: Default::default(),
        }
    }
}

#[derive(Bundle, Clone, Default)]
pub struct MapBundle {
    pub map: Map,
    pub children: Children,
    pub transform: Transform,
    pub global_transform: GlobalTransform,
}

pub struct GridBuilder {
    width_in_rooms: u32,
    height_in_rooms: u32,
    room_width: u32,
    room_height: u32,
}

impl GridBuilder {
    pub fn new(
        width_in_rooms: u32,
        height_in_rooms: u32,
        room_width: u32,
        room_height: u32,
    ) -> Box<GridBuilder> {
        Box::new(GridBuilder {
            width_in_rooms,
            height_in_rooms,
            room_width,
            room_height,
        })
    }
}

impl MapFilter for GridBuilder {
    fn modify_map(&self, _rng: &mut StdRng, map: &Map) -> Map {
        let mut map = map.clone();
        let mut generator = RbGenerator::new(None);
        let maze = generator.generate(self.width_in_rooms as i32, self.height_in_rooms as i32);
        let total_height = (self.room_height + 1) * self.height_in_rooms + 1;
        for y in 0..self.height_in_rooms {
            for x in 0..self.width_in_rooms {
                let x_offset = x * (self.room_width + 1);
                let y_offset = total_height - (y * (self.room_height + 1)) - self.room_height - 2;
                let room = MRect::new_i32(
                    x_offset as i32 + 1,
                    y_offset as i32 + 1,
                    self.room_width as i32,
                    self.room_height as i32,
                );
                map.add_room(room);
                let coords = maze_generator::prelude::Coordinates::new(x as i32, y as i32);
                if let Some(field) = maze.get_field(&coords) {
                    let half_width = self.room_width / 2;
                    let half_height = self.room_height / 2;
                    use maze_generator::prelude::Direction::*;
                    if field.has_passage(&North) {
                        let x = x_offset + half_width;
                        let y = y_offset + self.room_height;
                        map.set_tile(x as usize, y as usize, TileType::Floor);
                    }
                    if field.has_passage(&South) {
                        let x = x_offset + half_width;
                        let y = y_offset;
                        map.set_tile(x as usize, y as usize, TileType::Floor);
                    }
                    if field.has_passage(&East) {
                        let x = x_offset + self.room_width;
                        let y = y_offset + half_height;
                        map.set_tile(x as usize, y as usize, TileType::Floor);
                    }
                    if field.has_passage(&West) {
                        let x = x_offset;
                        let y = y_offset + half_height;
                        map.set_tile(x as usize, y as usize, TileType::Floor);
                    }
                }
            }
        }
        map
    }
}

fn add_map_colliders(mut commands: Commands, maps: Query<(Entity, &Map), Added<Map>>) {
    for (map_entity, map) in maps.iter() {
        commands.entity(map_entity).insert_bundle(RigidBodyBundle {
            body_type: RigidBodyType::Static,
            ..Default::default()
        });
        for x in 0..map.width {
            for y in 0..map.height {
                let tile = map.at(x, y);
                if tile.blocks_motion() {
                    let id = commands
                        .spawn_bundle(ColliderBundle {
                            shape: ColliderShape::cuboid(0.5, 0.5),
                            ..Default::default()
                        })
                        .insert(ColliderParent {
                            handle: map_entity.handle(),
                            pos_wrt_parent: Vec2::new(x as f32 + 0.5, y as f32 + 0.5).into(),
                        })
                        .insert(MapObstruction)
                        .id();
                    if tile.blocks_visibility() {
                        commands.entity(id).insert(BlocksVisibility);
                    }
                }
            }
        }
        for room in &map.rooms {
            let shape =
                ColliderShape::cuboid((room.width() / 2) as f32, (room.height() / 2) as f32);
            let position = Vec2::new(room.center().x(), room.center().y()).into();
            commands
                .spawn_bundle(ColliderBundle {
                    collider_type: ColliderType::Sensor,
                    shape: shape.clone(),
                    flags: ActiveEvents::INTERSECTION_EVENTS.into(),
                    ..Default::default()
                })
                .insert(ColliderParent {
                    handle: map_entity.handle(),
                    pos_wrt_parent: position,
                })
                .insert(shape.compute_aabb(&position))
                .insert(AreaTag);
        }
    }
}

fn portal_spawner(
    mut commands: Commands,
    map: Query<(Entity, &Map), Added<RigidBodyColliders>>,
    config: Res<MapConfig>,
) {
    for (entity, map) in map.iter() {
        if config.autospawn_portals {
            let mut portals: Vec<(f32, f32)> = vec![];
            for x in 1..map.width {
                for y in 1..map.height {
                    let mut spawn_portal = false;
                    if map.get_available_exits(x, y).len() > 2 {
                        let idx = (x, y).to_index(map.width);
                        if map.tiles[idx] == TileType::Floor
                            && (x > 1 && map.tiles[idx - 1] == TileType::Floor)
                            && (x < map.width - 2 && map.tiles[idx + 1] == TileType::Floor)
                            && (y > 1 && map.tiles[idx - map.width] == TileType::Wall)
                            && (y < map.height - 2 && map.tiles[idx + map.width] == TileType::Wall)
                        {
                            spawn_portal = true;
                        }
                        if map.tiles[idx] == TileType::Floor
                            && (x > 1 && map.tiles[idx - 1] == TileType::Wall)
                            && (x < map.width - 2 && map.tiles[idx + 1] == TileType::Wall)
                            && (y > 1 && map.tiles[idx - map.width] == TileType::Floor)
                            && (y < map.height - 2 && map.tiles[idx + map.width] == TileType::Floor)
                        {
                            spawn_portal = true;
                        }
                    }
                    if spawn_portal {
                        let x = x as f32;
                        let y = y as f32;
                        if !portals.contains(&(x, y)) {
                            portals.push((x, y));
                        }
                    }
                }
            }
            for portal in portals {
                let x = portal.0 as f32;
                let y = portal.1 as f32;
                let coordinates = Coordinates((x, y));
                let portal = commands
                    .spawn_bundle(PortalBundle {
                        coordinates,
                        ..Default::default()
                    })
                    .insert_bundle(ColliderBundle {
                        collider_type: ColliderType::Sensor,
                        shape: ColliderShape::cuboid(0.5, 0.5),
                        flags: ActiveEvents::INTERSECTION_EVENTS.into(),
                        ..Default::default()
                    })
                    .insert(ColliderPositionSync::Discrete)
                    .insert(ColliderParent {
                        handle: entity.handle(),
                        pos_wrt_parent: Vec2::new(x + 0.5, y + 0.5).into(),
                    })
                    .id();
                commands.entity(entity).push_children(&[portal]);
            }
        }
    }
}

fn area_description(
    mut events: EventReader<IntersectionEvent>,
    areas: Query<&AreaTag>,
    players: Query<&Player>,
    names: Query<&Name>,
    config: Res<MapConfig>,
    shapes: Query<&ColliderShape>,
    mut log: Query<&mut Log>,
) {
    for event in events.iter() {
        if event.intersecting {
            if let Some((area, other)) =
                target_and_other(event.collider1.entity(), event.collider2.entity(), &|v| {
                    areas.get(v).is_ok()
                })
            {
                if players.get(other).is_ok() {
                    if let Ok(mut log) = log.single_mut() {
                        if let Ok(name) = names.get(area) {
                            log.push(name.to_string());
                        } else if config.describe_undescribed_areas {
                            if let Ok(shape) = shapes.get(area) {
                                let aabb = shape.compute_local_aabb();
                                log.push(format!(
                                    "{}-by-{} area",
                                    aabb.extents().x,
                                    aabb.extents().y
                                ));
                            }
                        }
                    }
                }
            }
        }
    }
}

pub struct MapPlugin;

impl Plugin for MapPlugin {
    fn build(&self, app: &mut AppBuilder) {
        if !app.world().contains_resource::<MapConfig>() {
            app.insert_resource(MapConfig::default());
        }
        let config = app.world().get_resource::<MapConfig>().unwrap().clone();
        app.register_type::<Portal>()
            .add_system(add_map_colliders.system())
            .add_system(portal_spawner.system());
        if config.speak_area_descriptions {
            app.add_system_to_stage(CoreStage::PostUpdate, area_description.system());
        }
    }
}