#![feature(proc_macro_hygiene, decl_macro)]

#[macro_use] extern crate rocket;
#[macro_use] extern crate rocket_contrib;
#[macro_use] extern crate serde_derive;

use rocket_contrib::json::Json;
use pathfinding::grid::Grid;

mod battlesnake;

#[get("/")]
fn index() -> &'static str {
    "Hello, world!"
}

#[get("/ping")]
fn ping() -> &'static str {
    "OK - Pneuma online"
}

#[post("/begin", format = "json", data = "<msg>")]
fn begin(msg: Json<battlesnake::SnakeRequest>) -> Json<battlesnake::StartResponse> {
    Json(battlesnake::StartResponse{
        color: "#5ce8c3".to_string(),
        head_type: "beluga".to_string(),
        tail_type: "skinny".to_string(),
    })
}

#[post("/move", format = "json", data = "<msg>")]
fn make_move(msg: Json<battlesnake::SnakeRequest>) -> Json<battlesnake::MoveResponse> {
    let mut g = Grid::new(msg.board.height, msg.board.width);
    g.fill();

    for sn in &msg.board.snakes {
        for bd in &sn.body {
            g.remove_vertex((bd.x, bd.y))
        }
    }

    let target = find_target(&msg, &g);

    // do pathfinding?

    battlesnake::MoveResponse {
        move_field: "up".to_string(),
    }
}

fn find_target(gs: &battlesnake::SnakeRequest, g: &Grid) -> &battlesnake::Coord {
    let head = gs.you.body[0];
    if gs.you.health > 30 {
        let mut lowestScore: usize = 99999;
        let mut coord: &battlesnake::Coord;

        for food in &gs.board.food {
            let score = g.distance(&(head.x, head.y), &(food.x, food.y));
            if score < lowestScore {
                lowestScore = score;
                coord = food;
            }
        }

        return coord;
    }

    return gs.you.body.last().unwrap();
}

fn main() {
    rocket::ignite().mount("/", routes![
        index,
        begin,
        ping,
    ]).launch();
}