import { Board, Card, Hand, Pile, Stack, Suit } from "./types/cards";
import { clone } from "./fn";

const AGG: Suit = "spades";
const CUL: Suit = "hearts";
const TECH: Suit = "diamonds";
const MIL: Suit = "clubs";

type GameState = {
	mainPile: Pile;
	discardStack: Stack;
	deadPile: Pile;
	players: {
		hand: Hand;
		board: Board;
	}[];
	playerTurn: number;
	lastMove: Move;
	prevState: GameState | null;
};

type Move =
	| {
			type: "draw";
			fromPile: "main" | "discard";
	  }
	| { type: "play"; card: Card }
	| { type: "remove"; card: Card }
	| { type: "attack"; army: Card[] }
	| { type: "pass" };

type Action = Move | { type: "discard"; cards: Card[] };

const techTier = (techValue: number) => Math.ceil(techValue / 14);
const moveCost = (move: Move) => (move.type == "attack" ? move.army.length : 1);
const movesSpent = (state: GameState): number =>
	state.playerTurn != state.prevState?.playerTurn
		? 0
		: moveCost(state.lastMove) + movesSpent(state.prevState);

const value = (suit: Suit) => (board: Board) =>
	board
		.filter((card) => card.suit === suit)
		.reduce((v, card) => v + card.value, 0);

export const getNextState = (p: {
	state: GameState;
	move: Move;
}): GameState | { illegal: string } => {
	const { state, move } = p;

	const currentPlayer = state.players[state.playerTurn];

	const population = currentPlayer.board.thru(value(AGG));
	const culture = currentPlayer.board.thru(value(CUL));
	const tech = techTier(currentPlayer.board.thru(value(TECH)));

	const movesRemaining = tech - movesSpent(state);

	const newState = clone(state);
	if (move.type === "draw") {
		const pile =
			move.fromPile === "main"
				? newState.mainPile
				: newState.discardStack;

		if (pile.length === 0) {
			return {
				illegal: `The ${move.fromPile} pile is empty; cannot draw`,
			};
		}

		newState.players[newState.playerTurn].hand.push(pile.pop()!);
		if (movesRemaining == 1) {
			newState.playerTurn =
				(newState.playerTurn + 1) % newState.players.length;
		}
		return newState;
	}

	return { illegal: "idk bruh" };
};