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use crate::envs::{CloneBuild, EnvStructure, Environment, Successor};
use crate::feedback::Reward;
use crate::logging::StatsLogger;
use crate::spaces::{
ArraySpace, BooleanSpace, BoxSpace, FiniteSpace, IndexSpace, IndexedTypeSpace, IntervalSpace,
PowerSpace, ProductSpace, Space, TupleSpace2,
};
use crate::utils::coord_vector::CoordVector;
use crate::Prng;
use enum_map::{enum_map, Enum, EnumMap};
use rand::distributions::Standard;
use rand::prelude::*;
use relearn_derive::Indexed;
use serde::{Deserialize, Serialize};
use slice_of_array::SliceFlatExt;
use std::fmt::{self, Display};
pub type Cell = Option<Fruit>;
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Indexed)]
pub enum CellView {
Empty,
Apple,
Cherry,
OtherAgent,
}
impl From<Cell> for CellView {
fn from(cell: Cell) -> Self {
match cell {
None => Self::Empty,
Some(Fruit::Apple) => Self::Apple,
Some(Fruit::Cherry) => Self::Cherry,
}
}
}
impl Display for CellView {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(
f,
"{}",
match self {
Self::Empty => ' ',
Self::Apple => 'A',
Self::Cherry => 'C',
Self::OtherAgent => 'O',
}
)
}
}
pub type GridVec = CoordVector<usize, 2>;
const fn wrapping_sub(a: GridVec, b: GridVec, size: GridVec) -> GridVec {
let CoordVector([ai, aj]) = a;
let CoordVector([bi, bj]) = b;
let CoordVector([si, sj]) = size;
CoordVector([(si + ai - bi) % si, (sj + aj - bj) % sj])
}
fn grid_view<const W: usize, const H: usize, const VW: usize, const VH: usize>(
cells: &[[Cell; W]; H],
pos: GridVec,
other_agent_pos: GridVec,
) -> Box<[[CellView; VW]; VH]> {
let mut view = Box::new([[CellView::Empty; VW]; VH]);
let rel = wrapping_sub(pos, CoordVector([VH / 2, VW / 2]), CoordVector([H, W]));
for i in 0..VH {
let cells_row = cells[(rel[0] + i) % H];
for j in 0..VW {
view[i][j] = cells_row[(rel[1] + j) % W].into();
}
}
let other_rel_pos = wrapping_sub(other_agent_pos, rel, CoordVector([H, W]));
if other_rel_pos[0] < VH && other_rel_pos[1] < VW {
assert_eq!(view[other_rel_pos[0]][other_rel_pos[1]], CellView::Empty);
view[other_rel_pos[0]][other_rel_pos[1]] = CellView::OtherAgent;
}
view
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Enum)]
pub enum Fruit {
Apple,
Cherry,
}
impl Distribution<Fruit> for Standard {
fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Fruit {
if rng.gen() {
Fruit::Apple
} else {
Fruit::Cherry
}
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Enum)]
enum Player {
Principal,
Assistant,
}
#[derive(Debug)]
pub struct FruitGameState<const W: usize, const H: usize> {
cells: Box<[[Cell; W]; H]>,
positions: EnumMap<Player, GridVec>,
goal: Fruit,
remaining: EnumMap<Fruit, usize>,
}
impl<const W: usize, const H: usize> FruitGameState<W, H> {
fn observe<const VW: usize, const VH: usize>(
&self,
) -> <JointObsSpace<VW, VH> as Space>::Element {
let principal_view = grid_view(
&self.cells,
self.positions[Player::Principal],
self.positions[Player::Assistant],
);
let CoordVector(principal_pos) = self.positions[Player::Principal];
let goal_is_apple = match self.goal {
Fruit::Apple => true,
Fruit::Cherry => false,
};
let principal_obs = PrincipalObs {
visible_grid: principal_view,
position: principal_pos,
goal_is_apple,
};
let assistant_view = grid_view(
&self.cells,
self.positions[Player::Assistant],
self.positions[Player::Principal],
);
let CoordVector(assistant_pos) = self.positions[Player::Assistant];
let assistant_obs = AssistantObs {
visible_grid: assistant_view,
position: assistant_pos,
};
(principal_obs, assistant_obs)
}
fn step(&mut self, action: Move, player: Player) -> f64 {
let pos = &mut self.positions[player];
*pos = action.apply(*pos, CoordVector([H, W]));
let cell = self.cells[pos[0]][pos[1]].take();
match cell {
None => 0.0,
Some(fruit) => {
self.remaining[fruit] -= 1;
if fruit == self.goal {
1.0
} else {
-1.0
}
}
}
}
fn is_terminal(&self) -> bool {
self.remaining.values().all(|&count| count == 0)
}
}
pub type VisibleGridSpace<const W: usize, const H: usize> =
BoxSpace<PowerSpace<PowerSpace<IndexedTypeSpace<CellView>, W>, H>>;
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct PrincipalObs<const W: usize, const H: usize> {
pub visible_grid: Box<[[CellView; W]; H]>,
pub position: [usize; 2],
pub goal_is_apple: bool,
}
impl<const W: usize, const H: usize> Display for PrincipalObs<W, H> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let [i, j] = &self.position;
writeln!(
f,
"[{}] ({} {})",
if self.goal_is_apple { 'A' } else { 'C' },
i,
j
)?;
for row in self.visible_grid.iter() {
for cell in row {
write!(f, "{}", cell)?;
}
writeln!(f)?;
}
Ok(())
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, ProductSpace, FiniteSpace)]
#[element(PrincipalObs<W, H>)]
pub struct PrincipalObsSpace<const W: usize, const H: usize> {
pub visible_grid: VisibleGridSpace<W, H>,
pub position: ArraySpace<IndexSpace, 2>,
pub goal_is_apple: BooleanSpace,
}
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct AssistantObs<const W: usize, const H: usize> {
pub visible_grid: Box<[[CellView; W]; H]>,
pub position: [usize; 2],
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, ProductSpace, FiniteSpace)]
#[element(AssistantObs<W, H>)]
pub struct AssistantObsSpace<const W: usize, const H: usize> {
pub visible_grid: VisibleGridSpace<W, H>,
pub position: ArraySpace<IndexSpace, 2>,
}
pub type JointObsSpace<const VW: usize, const VH: usize> =
TupleSpace2<PrincipalObsSpace<VW, VH>, AssistantObsSpace<VW, VH>>;
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Indexed)]
pub enum Move {
Still,
Up,
Down,
Left,
Right,
}
impl Default for Move {
fn default() -> Self {
Self::Still
}
}
impl Move {
const fn apply(self, pos: GridVec, size: GridVec) -> GridVec {
let CoordVector([i, j]) = pos;
let CoordVector([si, sj]) = size;
match self {
Move::Still => pos,
Move::Up => CoordVector([(si - 1 + i) % si, j]),
Move::Down => CoordVector([(i + 1) % si, j]),
Move::Left => CoordVector([i, (sj - 1 + j) % sj]),
Move::Right => CoordVector([i, (j + 1) % sj]),
}
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub struct FruitGame<const W: usize, const H: usize, const VW: usize, const VH: usize> {
pub num_fruit: usize,
}
impl<const W: usize, const H: usize, const VW: usize, const VH: usize> FruitGame<W, H, VW, VH> {
#[must_use]
pub const fn new(num_fruit: usize) -> Self {
Self { num_fruit }
}
}
impl<const W: usize, const H: usize, const VW: usize, const VH: usize> Default
for FruitGame<W, H, VW, VH>
{
fn default() -> Self {
let target_inv_density = 2;
let num_fruit_types = 2;
let num_fruit = W * H / (target_inv_density * num_fruit_types);
Self { num_fruit }
}
}
impl<const W: usize, const H: usize, const VW: usize, const VH: usize> CloneBuild
for FruitGame<W, H, VW, VH>
{
}
impl<const W: usize, const H: usize, const VW: usize, const VH: usize> EnvStructure
for FruitGame<W, H, VW, VH>
{
type ObservationSpace = JointObsSpace<VW, VH>;
type ActionSpace = TupleSpace2<IndexedTypeSpace<Move>, IndexedTypeSpace<Move>>;
type FeedbackSpace = TupleSpace2<IntervalSpace<Reward>, IntervalSpace<Reward>>;
fn observation_space(&self) -> Self::ObservationSpace {
let visible_grid = VisibleGridSpace::default();
let position = ArraySpace::new([IndexSpace::new(H), IndexSpace::new(W)]);
let principal_obs_space = PrincipalObsSpace {
visible_grid,
position,
goal_is_apple: BooleanSpace,
};
let assistant_obs_space = AssistantObsSpace {
visible_grid,
position,
};
TupleSpace2(principal_obs_space, assistant_obs_space)
}
fn action_space(&self) -> Self::ActionSpace {
Default::default()
}
fn feedback_space(&self) -> Self::FeedbackSpace {
let reward_range = IntervalSpace::new(Reward(-2.0), Reward(2.0));
TupleSpace2(reward_range, reward_range)
}
fn discount_factor(&self) -> f64 {
0.95
}
}
impl<const W: usize, const H: usize, const VW: usize, const VH: usize> Environment
for FruitGame<W, H, VW, VH>
{
type State = FruitGameState<W, H>;
type Observation = <JointObsSpace<VW, VH> as Space>::Element;
type Action = (Move, Move);
type Feedback = (Reward, Reward);
fn initial_state(&self, rng: &mut Prng) -> Self::State {
let mut cells = Box::new([[None; W]; H]);
let cells_slice = cells.flat_mut();
let num_cells = cells_slice.len();
assert!(num_cells != 0, "game grid must be nonempty");
let prefix = &mut cells_slice[..num_cells - 1];
prefix[0..self.num_fruit].fill(Some(Fruit::Apple));
prefix[self.num_fruit..2 * self.num_fruit].fill(Some(Fruit::Cherry));
prefix.shuffle(rng);
let origin = CoordVector([H / 2, W / 2]);
*cells_slice.last_mut().unwrap() = cells_slice[origin[0] * W + origin[1]].take();
FruitGameState {
cells,
positions: enum_map! {
Player::Principal => origin,
Player::Assistant => origin,
},
goal: rng.gen(),
remaining: enum_map! {
Fruit::Apple => self.num_fruit,
Fruit::Cherry => self.num_fruit,
},
}
}
fn observe(&self, state: &Self::State, _rng: &mut Prng) -> Self::Observation {
state.observe()
}
fn step(
&self,
mut state: Self::State,
action: &Self::Action,
_rng: &mut Prng,
logger: &mut dyn StatsLogger,
) -> (Successor<Self::State>, Self::Feedback) {
let (principal_action, assistant_action) = *action;
let reward_principal = state.step(principal_action, Player::Principal);
let reward_assistant = state.step(assistant_action, Player::Assistant);
let mut reward_logger = logger.with_scope("reward").group();
reward_logger.log_scalar("principal", reward_principal);
reward_logger.log_scalar("assistant", reward_assistant);
let reward = Reward(reward_principal + reward_assistant);
let successor = if state.is_terminal() {
Successor::Terminate
} else {
Successor::Continue(state)
};
(successor, (reward, reward))
}
}
#[cfg(test)]
mod tests {
use super::super::super::testing;
use super::*;
#[test]
fn run_default() {
testing::check_structured_env(&FruitGame::<5, 5, 5, 5>::new(4), 1000, 0);
}
}