//! The rectangle room tool is a specialised tool to create rooms of rectangular shape and with the
//! sides of the room parallel to the x and y-axes. This is often useful, when a quick room creation
//! is necessary and the shape of the room does not have to be very special.

use super::Tool;
use crate::client::colours::DEFAULT_COLOURS;
use crate::client::map::Map;
use crate::client::transform::Transform;
use crate::client::FLOAT_MARGIN;
use crate::math::{Rect, Vec2};
use crate::net::{Cargo, Connection};
use crate::world::Room;
use float_cmp::ApproxEq;
use raylib::core::drawing::{RaylibDraw, RaylibDrawHandle};

/// The tool to create simple, rectangular rooms.
pub struct RectRoomTool {
    /// The rectangle that is currently being drawn by the user. Once it is finished, it will be
    /// pushed into the room_rects.
    unfinished_rect: Option<(Vec2<f64>, Vec2<f64>)>,
}

impl RectRoomTool {
    /// Create a new room tool where no rooms have been drawn yet. Should be created only once per
    /// program instance and by the editor.
    #[allow(clippy::new_without_default)]
    pub fn new() -> Self {
        Self {
            unfinished_rect: None,
        }
    }
}

/* Try to create a rectangle from the given points, but only if they don't create
 * a rectangle with no area.
 */
fn try_into_bounding_rect(pos1: Vec2<f64>, pos2: Vec2<f64>) -> Option<Rect<f64>> {
    let bounding_rect = Rect::bounding_rect(pos1, pos2);

    if !bounding_rect.area().approx_eq(0., FLOAT_MARGIN) {
        Some(bounding_rect)
    } else {
        None
    }
}

impl Tool for RectRoomTool {
    fn deactivate(&mut self) {
        self.unfinished_rect = None;
    }

    fn update(&mut self, _map: &Map, mouse_pos_m: &Vec2<f64>) {
        if let Some((_, ref mut pos2)) = &mut self.unfinished_rect {
            *pos2 = *mouse_pos_m;
        }
    }

    fn draw(&self, rld: &mut RaylibDrawHandle, transform: &Transform) {
        if let Some((pos1, pos2)) = self.unfinished_rect {
            rld.draw_rectangle_rec(
                transform.rect_m_to_px(&Rect::bounding_rect(pos1, pos2)),
                DEFAULT_COLOURS.room_selected,
            );
        }
    }

    fn place_single(
        &mut self,
        _map: &mut Map,
        server: &Connection<Cargo>,
        mouse_pos_m: &Vec2<f64>,
    ) {
        // Try to finish the rectangle if it has been started.
        if let Some((pos1, pos2)) = self.unfinished_rect {
            if let Some(rect) = try_into_bounding_rect(pos1, pos2) {
                server.send(Cargo::AddRoom(Room::new(rect.into())));
                self.unfinished_rect = None;
            }
        } else {
            self.unfinished_rect = Some((*mouse_pos_m, *mouse_pos_m));
        }
    }

    fn finish(&mut self, _map: &mut Map, server: &Connection<Cargo>) {
        if let Some((pos1, pos2)) = self.unfinished_rect {
            if let Some(rect) = try_into_bounding_rect(pos1, pos2) {
                server.send(Cargo::AddRoom(Room::new(rect.into())));
                self.unfinished_rect = None;
            }
        }
    }

    fn abort(&mut self) {
        self.unfinished_rect = None;
    }
}