"use strict";

import http from "http";
import https from "https";
import { URL } from "url"

import { Logger } from "@ethersproject/logger";
import { version } from "./_version";
const logger = new Logger(version);

export type GetUrlResponse = {
    statusCode: number,
    statusMessage: string;
    headers: { [ key: string] : string };
    body: string;
};

export type Options = {
    method?: string,
    body?: string
    headers?: { [ key: string] : string },
};

function getResponse(request: http.ClientRequest): Promise<GetUrlResponse> {
    return new Promise((resolve, reject) => {
        request.once("response", (resp: http.IncomingMessage) => {
            const response: GetUrlResponse = {
                statusCode: resp.statusCode,
                statusMessage: resp.statusMessage,
                headers: Object.keys(resp.headers).reduce((accum, name) => {
                    let value = resp.headers[name];
                    if (Array.isArray(value)) {
                        value = value.join(", ");
                    }
                    accum[name] = value;
                    return accum;
                }, <{ [ name: string ]: string }>{ }),
                body: null
            };
            resp.setEncoding("utf8");

            resp.on("data", (chunk: string) => {
                if (response.body == null) { response.body = ""; }
                response.body += chunk;
            });

            resp.on("end", () => {
                resolve(response);
            });

            resp.on("error", (error) => {
                (<any>error).response = response;
                reject(error);
            });
        });

        request.on("error", (error) => { reject(error); });
    });
}

export async function getUrl(href: string, options?: Options): Promise<GetUrlResponse> {
    if (options == null) { options = { }; }

    // @TODO: Once we drop support for node 8, we can pass the href
    //        firectly into request and skip adding the components
    //        to this request object
    const url = new URL(href);

    const request = {
        protocol: url.protocol,
        hostname: url.hostname,
        port: url.port,
        path: (url.pathname + url.search),

        method: (options.method || "GET"),
        headers: (options.headers || { }),
    };

    let req: http.ClientRequest = null;
    switch (url.protocol) {
        case "http:":
            req = http.request(request);
            break;
        case "https:":
            req = https.request(request);
            break;
        default:
            logger.throwError(`unsupported protocol ${ url.protocol }`, Logger.errors.UNSUPPORTED_OPERATION, {
                protocol: url.protocol,
                operation: "request"
            });
    }

    if (options.body) {
        req.write(options.body);
    }
    req.end();

    const response = await getResponse(req);
    return response;
}