//! The map contains all the items that make up the world.
//!
//! There are two main structs to look out for, the first being [Map]. This is the interaction point
//! for most parts of the program. It contains the actual elements that are drawn on the screen. and
//! can be changed by the user.
//! The second is [MapData] and it contains the data that can be saved/loaded and distributed. Every
//! map item has an internal item that it can be dereferenced to and can be used to construct this
//! exact item in the same world elsewhere or at a different time. This is often different from the
//! item that is being drawn. An example would be the [PolygonRoom], which contains a triangulated
//! version of itself, so it can be drawn without always having to compute the triangles every frame.
//! It's data type however [PolygonRoomData] contains only the raw polygon data, not the triangulated
//! version, since that is enough to create the same [PolygonRoom] again.

pub mod data;
pub mod icon;
pub mod icon_renderer;
pub mod mappable;
pub mod room;
pub mod wall;

pub use data::MapData;
pub use icon::*;
pub use mappable::Mappable;
pub use room::*;
pub use wall::*;

use crate::transform::Transform;
use icon_renderer::IconRenderer;
use raylib::drawing::RaylibDrawHandle;
use raylib::{RaylibHandle, RaylibThread};
use std::rc::Rc;

/// The map containing all map elements that are seen on the screen.
pub struct Map {
    rooms: Vec<Room>,
    walls: Vec<Wall>,
    icons: Vec<Icon>,
    icon_renderer: Rc<IconRenderer>,
}

impl Map {
    /// Create a new, empty map/world.
    pub fn new(rl: &mut RaylibHandle, rlt: &RaylibThread) -> Self {
        Self {
            rooms: Vec::new(),
            walls: Vec::new(),
            icons: Vec::new(),
            icon_renderer: Rc::new(IconRenderer::new(rl, rlt)),
        }
    }

    /// Add a room to the map. Currently, holes are not supported in the polygon, but this might
    /// change later.
    pub fn push_room(&mut self, room_data: RoomData) {
        self.rooms.push(Room::from_data(room_data));
    }

    /// Add a wall to the world.
    pub fn push_wall(&mut self, wall_data: WallData) {
        /* Check for intersections with any wall that was arleady created so the wall ends can be
         * rendered properly.
         */
        let mut start_intersects = false;
        let mut end_intersects = false;
        for wall in &self.walls {
            if wall.data().contains_collinear(wall_data.start) {
                start_intersects = true;
            }
            if wall.data().contains_collinear(wall_data.end) {
                end_intersects = true;
            }

            // Currently, additional intersections can be ignored, since it is just a yes-no-question
            if start_intersects && end_intersects {
                break;
            }
        }

        self.walls
            .push(Wall::from_data(wall_data, start_intersects, end_intersects));
    }

    /// Add an icon to the world.
    pub fn push_icon(&mut self, icon: Icon) {
        self.icons.push(icon);
    }

    /// Draw all elements of the map to the screen. This should be called after the background of the
    /// map has already been drawn.
    pub fn draw(&self, rld: &mut RaylibDrawHandle, transform: &Transform) {
        for element in self.elements() {
            element.draw(rld, transform);
        }
    }

    /// Get the icon-renderer that is currently used to render the icons.
    pub fn icon_renderer(&self) -> Rc<IconRenderer> {
        self.icon_renderer.clone()
    }

    /// Retain all map elements that fulfill the given predicate, removing everything else.
    pub fn retain<F>(&mut self, mut f: F)
    where
        F: FnMut(&dyn Mappable) -> bool,
    {
        // Call retain on all vectors containing the maps actual types.
        self.rooms.retain(|p| f(p as &dyn Mappable));
        self.walls.retain(|w| f(w as &dyn Mappable));
        self.icons.retain(|i| f(i as &dyn Mappable));
    }

    /// Iterator over all elements as objects when an operation needs to go over all elements of the
    /// map.
    pub fn elements(&self) -> impl Iterator<Item = &dyn Mappable> {
        self.rooms
            .iter()
            .map(|p| p as &dyn Mappable)
            .chain(self.walls.iter().map(|w| w as &dyn Mappable))
            .chain(self.icons.iter().map(|i| i as &dyn Mappable))
    }

    /// Iterator over all elements, but the individual elements can be mutated. It is however
    /// impossible to add or remove elements in this way. For that, use the dedicated functions.
    pub fn elements_mut(&mut self) -> impl Iterator<Item = &mut dyn Mappable> {
        self.rooms
            .iter_mut()
            .map(|p| p as &mut dyn Mappable)
            .chain(self.walls.iter_mut().map(|w| w as &mut dyn Mappable))
            .chain(self.icons.iter_mut().map(|i| i as &mut dyn Mappable))
    }

    /// Get the rooms of this map.
    pub fn rooms(&self) -> &Vec<Room> {
        &self.rooms
    }

    /// Get the walls of this map.
    pub fn walls(&self) -> &Vec<Wall> {
        &self.walls
    }

    /// Get the icons of this map.
    pub fn icons(&self) -> &Vec<Icon> {
        &self.icons
    }

    /// Replace the internal map data with the data provided. (Load and replace)
    pub fn set_data(&mut self, data: MapData) {
        // Remove all data.
        self.icons.clear();
        self.rooms.clear();
        self.walls.clear();

        // Add all data from the map data.
        self.add_data(data);
    }

    /// Add the data provided to the current data on the map. All elements will remain, with the
    /// additional elements being pushed also.
    pub fn add_data(&mut self, data: MapData) {
        for i in data.icons {
            self.push_icon(Icon::from_data(i, self.icon_renderer.clone()))
        }
        for p in data.rooms {
            self.push_room(p);
        }
        for w in data.walls {
            self.push_wall(w);
        }
    }
}