import { endpoint } from '@octokit/endpoint';
import getUserAgent from 'universal-user-agent';
import isPlainObject from 'is-plain-object';
import nodeFetch from 'node-fetch';
import { RequestError } from '@octokit/request-error';

const VERSION = "0.0.0-development";

function getBufferResponse(response) {
    return response.arrayBuffer();
}

function fetchWrapper(requestOptions) {
    if (isPlainObject(requestOptions.body) ||
        Array.isArray(requestOptions.body)) {
        requestOptions.body = JSON.stringify(requestOptions.body);
    }
    let headers = {};
    let status;
    let url;
    const fetch = (requestOptions.request && requestOptions.request.fetch) || nodeFetch;
    return fetch(requestOptions.url, Object.assign({
        method: requestOptions.method,
        body: requestOptions.body,
        headers: requestOptions.headers,
        redirect: requestOptions.redirect
    }, requestOptions.request))
        .then(response => {
        url = response.url;
        status = response.status;
        for (const keyAndValue of response.headers) {
            headers[keyAndValue[0]] = keyAndValue[1];
        }
        if (status === 204 || status === 205) {
            return;
        }
        // GitHub API returns 200 for HEAD requsets
        if (requestOptions.method === "HEAD") {
            if (status < 400) {
                return;
            }
            throw new RequestError(response.statusText, status, {
                headers,
                request: requestOptions
            });
        }
        if (status === 304) {
            throw new RequestError("Not modified", status, {
                headers,
                request: requestOptions
            });
        }
        if (status >= 400) {
            return response
                .text()
                .then(message => {
                const error = new RequestError(message, status, {
                    headers,
                    request: requestOptions
                });
                try {
                    Object.assign(error, JSON.parse(error.message));
                }
                catch (e) {
                    // ignore, see octokit/rest.js#684
                }
                throw error;
            });
        }
        const contentType = response.headers.get("content-type");
        if (/application\/json/.test(contentType)) {
            return response.json();
        }
        if (!contentType || /^text\/|charset=utf-8$/.test(contentType)) {
            return response.text();
        }
        return getBufferResponse(response);
    })
        .then(data => {
        return {
            status,
            url,
            headers,
            data
        };
    })
        .catch(error => {
        if (error instanceof RequestError) {
            throw error;
        }
        throw new RequestError(error.message, 500, {
            headers,
            request: requestOptions
        });
    });
}

function withDefaults(oldEndpoint, newDefaults) {
    const endpoint = oldEndpoint.defaults(newDefaults);
    const newApi = function (route, parameters) {
        const endpointOptions = endpoint.merge(route, parameters);
        if (!endpointOptions.request || !endpointOptions.request.hook) {
            return fetchWrapper(endpoint.parse(endpointOptions));
        }
        const request = (route, parameters) => {
            return fetchWrapper(endpoint.parse(endpoint.merge(route, parameters)));
        };
        Object.assign(request, {
            endpoint,
            defaults: withDefaults.bind(null, endpoint)
        });
        return endpointOptions.request.hook(request, endpointOptions);
    };
    return Object.assign(newApi, {
        endpoint,
        defaults: withDefaults.bind(null, endpoint)
    });
}

const request = withDefaults(endpoint, {
    headers: {
        "user-agent": `octokit-request.js/${VERSION} ${getUserAgent()}`
    }
});

export { request };