import crypto from "crypto";
import { ConnectedAccount } from "../entities";
import { OrmUtils } from "../imports";
import { ConnectedAccountSchema, ConnectionCallbackSchema } from "../schemas";
import { DiscordApiErrors } from "../util";

export default abstract class Connection {
	id: string;
	settings: { enabled: boolean };
	states: Map<string, string> = new Map();

	abstract init(): void;

	/**
	 * Generates an authorization url for the connection.
	 * @param args
	 */
	abstract getAuthorizationUrl(userId: string): string;

	/**
	 * Processes the callback
	 * @param args Callback arguments
	 */
	abstract handleCallback(params: ConnectionCallbackSchema): Promise<ConnectedAccount | null>;

	/**
	 * Gets a user id from state
	 * @param state the state to get the user id from
	 * @returns the user id associated with the state
	 */
	getUserId(state: string): string {
		if (!this.states.has(state)) throw DiscordApiErrors.INVALID_OAUTH_STATE;
		return this.states.get(state) as string;
	}

	/**
	 * Generates a state
	 * @param user_id The user id to generate a state for.
	 * @returns a new state
	 */
	createState(userId: string): string {
		const state = crypto.randomBytes(16).toString("hex");
		this.states.set(state, userId);

		return state;
	}

	/**
	 * Takes a state and checks if it is valid, and deletes it.
	 * @param state The state to check.
	 */
	validateState(state: string): void {
		if (!this.states.has(state)) throw DiscordApiErrors.INVALID_OAUTH_STATE;
		this.states.delete(state);
	}

	async createConnection(data: ConnectedAccountSchema): Promise<ConnectedAccount> {
		const ca = OrmUtils.mergeDeep(new ConnectedAccount(), data) as ConnectedAccount;
		await ca.save();
		return ca;
	}

	async hasConnection(userId: string, externalId: string): Promise<boolean> {
		const existing = await ConnectedAccount.findOne({
			where: {
				user_id: userId,
				external_id: externalId,
			},
		});

		return !!existing;
	}
}