import { TinyRpcClientAdapter, TinyRpcError } from "@hiogawa/tiny-rpc";
import { Result } from "@hiogawa/utils";

const GET_PAYLOAD_PARAM = "payload";

export function httpClientAdapter(opts: {
	url: string;
	pathsForGET?: string[];
	JSON?: Partial<JsonTransformer>;
	headers?: () => Promise<Record<string, string>> | Record<string, string>;
}): TinyRpcClientAdapter {
	const JSON: JsonTransformer = {
    parse: globalThis.JSON.parse,
    stringify: globalThis.JSON.stringify,
    ...opts.JSON,
  };
	return {
		send: async (data) => {
			const url = [opts.url, data.path].join("/");
			const payload = JSON.stringify(data.args);
			console.log("RPC Request:", payload);
			const method = opts.pathsForGET?.includes(data.path)
				? "GET"
				: "POST";

			const extraHeaders = opts.headers ? await opts.headers() : {};

			let req: Request;
			if (method === "GET") {
				req = new Request(
					url +
					"?" +
					new URLSearchParams({ [GET_PAYLOAD_PARAM]: payload }),
					{
						headers: extraHeaders
					}
				);
			} else {
				req = new Request(url, {
					method: "POST",
					body: payload,
					headers: {
						"content-type": "application/json; charset=utf-8",
						...extraHeaders
					},
					credentials: "include",
				});
			}
			let res: Response;
			res = await fetch(req);
			if (!res.ok) {
				// throw new Error(`HTTP error: ${res.status}`);
				throw new Error(
					JSON.stringify({
						status: res.status,
						statusText: res.statusText,
						data: { message: await res.text() },
						internal: true,
					})
				);
				// throw TinyRpcError.deserialize(res.status);
			}
			const result: Result<unknown, unknown> = JSON.parse(
				await res.text()
			);
			if (!result.ok) {
				throw TinyRpcError.deserialize(result.value);
			}
			return result.value;
		},
	};
}