import os
import subprocess

import flask
from flask_cors import CORS

PIECE_TYPE = [
    ("P", "pawn"),
    ("N", "knight"),
]
COLOR = [
    ("W", "white"),
    ("B", "black"),
]

HERE = os.path.abspath(os.path.dirname(__file__))
app = flask.Flask(__name__)
CORS(app)
engine = subprocess.Popen(
    ["cargo", "run"],
    stdin=subprocess.PIPE,
    stdout=subprocess.PIPE,
    cwd=os.path.join(HERE, "../rs"),
)


def reverse(zipped):
    return ((b, a) for a, b in zipped)


def make_piece(piece_str):
    piece_type, color = piece_str
    return {
        "piece_type": dict(PIECE_TYPE)[piece_type],
        "color": dict(COLOR)[color],
    }


def ask_engine(command):
    engine.stdin.write(f"{command}\n".encode("ascii"))
    engine.stdin.flush()
    reply = engine.stdout.readline().decode("ascii").strip()
    status, *result = reply.split(",")
    if status != "ok":
        flask.abort(400)
    return result


def parse_state(state_str):
    return {
        state_str[i + 2 : i + 4]: make_piece(state_str[i : i + 2])
        for i in range(0, len(state_str), 4)
    }


@app.route("/get_state/")
def get_state():
    (state_str,) = ask_engine("get_state")
    return flask.jsonify(parse_state(state_str))


@app.route("/get_moves/", methods=["POST"])
def get_moves():
    position_str = flask.request.json
    (moves_str,) = ask_engine(f"get_moves,{position_str}")
    moves = [moves_str[i : i + 2] for i in range(0, len(moves_str), 2)]
    return flask.jsonify(moves)


@app.route("/make_move/", methods=["POST"])
def make_move():
    source, target = flask.request.json
    (state_str,) = ask_engine(f"make_move,{source},{target}")
    return flask.jsonify(parse_state(state_str))


@app.route("/choose_move/", methods=["POST"])
def choose_move():
    color = dict(reverse(COLOR))[flask.request.json]
    move = ask_engine(f"choose_move,{color}")
    return flask.jsonify(move)


@app.route("/reset/", methods=["POST"])
def reset():
    (state_str,) = ask_engine("reset")
    return flask.jsonify(parse_state(state_str))


if __name__ == "__main__":
    app.run(debug=True, host="127.0.0.1", port=3000)