use std::cmp::Ordering;
use std::io::prelude::*;
use std::io::stdin;

mod command;
mod consts;
mod json;
mod state;

use command::*;
use state::*;

fn main() {
    for line in stdin().lock().lines() {
        let round_number = line.expect("Failed to read line from stdin: {}");
        let command =
            match json::read_state_from_json_file(&format!("./rounds/{}/state.json", round_number))
            {
                Ok(state) => choose_command(&state),
                Err(e) => {
                    eprintln!("WARN: State file could not be parsed: {}", e);
                    Command::Nothing
                }
            };
        println!("C;{};{}", round_number, command);
    }
}

fn choose_command(state: &GameState) -> Command {
    /* TODO:
     * - Simulate both player and opponent moves
     */
    let player_moves = state.valid_moves(0);
    let naive_result = player_moves
        .into_iter()
        .map(|player_move| {
            let mut state = state.clone();
            state.update([player_move, Command::Accelerate]);
            (player_move, state)
        })
        .flat_map(|(player_move, state)| {
            state.valid_moves(0).into_iter().map(move |second_move| {
                let mut second_move_state = state.clone();
                second_move_state.update([second_move, Command::Accelerate]);
                (player_move, second_move_state)
            })
        })
        .max_by(|(_, a), (_, b)| compare_states(a, b))
        .unwrap()
        .0;
    naive_result
}

fn compare_states(a: &GameState, b: &GameState) -> Ordering {
    if a.status == GameStatus::PlayerOneWon && b.status == GameStatus::PlayerOneWon {
        a.players[0].speed.cmp(&b.players[0].speed)
    } else if a.status == GameStatus::PlayerOneWon {
        Ordering::Greater
    } else if b.status == GameStatus::PlayerOneWon {
        Ordering::Less
    } else {
        let weighted_position_a = a.players[0].position.x + a.players[0].boosts * 2;
        let weighted_position_b = b.players[0].position.x + b.players[0].boosts * 2;

        weighted_position_a
            .cmp(&weighted_position_b)
            .then(a.players[0].speed.cmp(&b.players[0].speed))
            .then(a.players[0].position.x.cmp(&b.players[0].position.x))
            .then(a.players[0].boosts.cmp(&b.players[0].boosts))
    }
}