import fetch from "node-fetch";
import * as responses from "./responses";
import * as queryString from "qs";

export default class {
	readonly baseUrl: string;

	requestId: number;

	readonly baseHeaders: { [key: string]: string };

	constructor(baseUrl: string) {
		this.baseUrl = baseUrl;
		this.requestId = 0;
		this.baseHeaders = {
			"Content-Type": "application/json; charset=utf-8",
		};
	}

	buildHeaders() {
		return {
			...this.baseHeaders,
		};
	}

	async call<T>(method: string, path: string, body?: string): Promise<responses.BaseResponse<T>> {
		return this.callAny(method, path, body);
	}

	async callAny(method: string, path: string, body?: string) {
		const url = `${this.baseUrl}${path}`;
		const requestId = ++this.requestId;
		if (requestId) {
			// 警告回避用。requestIdはそのうちデバッグで使うかも程度
		}
		const headers = this.buildHeaders();
		const response = await fetch(url, {
			method,
			headers,
			body,
		});
		// 403は"認可失敗"で、無効なトークン等でトークンの認可に失敗した場合に返ってくる仕様があり、
		// 本仕様に準じて、これだけ専用エラーを発行
		// TODO: 現状は401が返ってきてしまうこともあるようなので、まとめてトラップしてしまう
		if (response.status === 403 || response.status === 401) {
			const error = new responses.PermissionDeniedError(response);
			await error.tryParse();
			throw error;
		}
		if (response.status < 200 || response.status >= 300) {
			const error = new responses.AkashicError(response);
			await error.tryParse();
			throw error;
		}
		return response.json();
	}

	qs(
		params: NodeJS.Dict<
			string | number | boolean | ReadonlyArray<string> | ReadonlyArray<number> | ReadonlyArray<boolean> | null
		>
	) {
		return queryString.stringify(params);
	}
}