pub mod collision;

pub mod common;

mod grid;

pub mod physics;

pub mod time;

use integral_geometry::Size;

use land2d::Land2D;

use crate::{

    collision::{CollisionData, CollisionProcessor, ContactData},

    common::{GearAllocator, GearData, GearDataAggregator, GearDataProcessor, GearId, Millis},

    physics::{PhysicsData, PhysicsProcessor},

    time::TimeProcessor,

};

pub struct JoinedData {

    gear_id: GearId,

    physics: PhysicsData,

    collision: CollisionData,

    contact: ContactData,

}

pub struct World {

    allocator: GearAllocator,

    physics: PhysicsProcessor,

    collision: CollisionProcessor,

    time: TimeProcessor,

}

macro_rules! processor_map {

    ( $data_type: ident => $field: ident ) => {

        impl GearDataAggregator<$data_type> for World {

            fn find_processor(&mut self) -> &mut GearDataProcessor<$data_type> {

                &mut self.$field

            }

        }

    };

}

processor_map!(PhysicsData => physics);

processor_map!(CollisionData => collision);

impl World {

    pub fn new(world_size: Size) -> Self {

        Self {

            allocator: GearAllocator::new(),

            physics: PhysicsProcessor::new(),

            collision: CollisionProcessor::new(world_size),

            time: TimeProcessor::new(),

        }

    }

    #[inline]

    pub fn new_gear(&mut self) -> Option<GearId> {

        self.allocator.alloc()

    }

    #[inline]

    pub fn delete_gear(&mut self, gear_id: GearId) {

        self.physics.remove(gear_id);

        self.collision.remove(gear_id);

        self.time.cancel(gear_id);

        self.allocator.free(gear_id)

    }

    pub fn step(&mut self, time_step: Millis, land: &Land2D<u32>) {

        let updates = self.physics.process(time_step);

        let collision = self.collision.process(land, &updates);

        let events = self.time.process(time_step);

    }

    pub fn add_gear_data<T>(&mut self, gear_id: GearId, data: T)

    where

        T: GearData,

        Self: GearDataAggregator<T>,

    {

        self.find_processor().add(gear_id, data);

    }

}

#[cfg(test)]

mod tests {

    use crate::{

        collision::{CircleBounds, CollisionData},

        physics::PhysicsData,

        World,

    };

    use fpnum::{fp, FPNum, FPPoint};

    use integral_geometry::Size;

    use land2d::Land2D;

    #[test]

    fn data_flow() {

        let world_size = Size::new(2048, 2048);

        let mut world = World::new(world_size);

        let gear_id = 46631;

        world.add_gear_data(

            gear_id,

            PhysicsData {

                position: FPPoint::zero(),

                velocity: FPPoint::unit_y(),

            },

        );

        world.add_gear_data(

            gear_id,

            CollisionData {

                bounds: CircleBounds {

                    center: FPPoint::zero(),

                    radius: fp!(10),

                },

            },

        );

        let land = Land2D::new(Size::new(world_size.width - 2, world_size.height - 2), 0);

        world.step(fp!(1), &land);

    }

}