import { v1 as uuid } from "https://deno.land/std@0.213.0/uuid/mod.ts";

export type StoredUser = { discord_user_id: string; cri_login: string };
export class State {
	kv;
	constructor(kv: Deno.Kv) {
		this.kv = kv;
	}

	public static async from_dir(local_path: string) {
		await Deno.mkdir(local_path, { recursive: true });
		const kv = await Deno.openKv(local_path + "/kv");
		return new State(kv);
	}

	public async *users() {
		const query = this.kv.list({ prefix: ["users/"] });
		for await (const { value } of query) yield value as StoredUser;
	}

	public async users_count() {
		let result = 0;
		for await (const _ of this.users()) result += 1;
		return result;
	}

	public async get_user(discord_user_id: string) {
		const { value: user_uuid } = await this.kv.get(["users_by_discord_id/", discord_user_id]);
		if (user_uuid === null) return undefined;
		const { value: stored } = await this.kv.get(["users/", user_uuid as string]);
		return stored as StoredUser;
	}

	public async set_user(discord_user_id: string, cri_login: string) {
		await this.remove_user(discord_user_id);
		await this.add_user(discord_user_id, cri_login);
	}

	private async add_user(discord_user_id: string, cri_login: string) {
		const user_uuid = uuid.generate() as string;
		const stored: StoredUser = { discord_user_id, cri_login };
		await this.kv.set(["users/", user_uuid], stored);
		await this.kv.set(["users_by_discord_id/", discord_user_id], user_uuid);
	}

	private async remove_user(discord_user_id: string) {
		const { value: user_uuid } = await this.kv.get(["users_by_discord_id/", discord_user_id]);
		if (user_uuid === null) return undefined;
		await this.kv.delete(["users/", user_uuid as string]);
		await this.kv.delete(["users_by_discord_id/", discord_user_id]);
	}
}