require("dotenv").config({
    path: require("path").resolve(
        process.cwd(),
        `.env.${process.env.NODE_ENV || "development"}`
    ),
});
const {isNil} = require('lodash');
const aws4 = require("aws4");
const {Connection, Client} = require("@opensearch-project/opensearch");
const {defaultProvider} = require("@aws-sdk/credential-provider-node");

const createAwsConnector = (credentials, region) => {
    class AmazonConnection extends Connection {
        buildRequestObject(params) {
            const request = super.buildRequestObject(params);
            request.service = "es";
            request.region = region;
            request.headers = request.headers || {};
            request.headers["host"] = request.hostname;

            return aws4.sign(request, credentials);
        }
    }

    return {
        Connection: AmazonConnection,
    };
};

const getClient = async () => {

    // We have manual configuration for OpenSearch,
    // Return a client using these custom credentials
    if (
        !isNil(process.env.OPEN_SEARCH_PASSWORD) &&
        !isNil(process.env.OPEN_SEARCH_USER) &&
        !isNil(process.env.OPEN_SEARCH_HOST) &&
        !isNil(process.env.OPEN_SEARCH_PROTOCOL)
    ) {
        // The URI is currently being stored in its entirety, so strip protocol prior to rebuilding it.
        const hostUrl = process.env.OPEN_SEARCH_HOST.replace(/^https?:\/\//i, '');
        const node = `${process.env.OPEN_SEARCH_PROTOCOL}://${process.env.OPEN_SEARCH_USER}:${process.env.OPEN_SEARCH_PASSWORD}@${hostUrl}`;

        return new Client({
            node,
        });
    }

    // Default to the AWS Credentials Provider.
    const credentials = await defaultProvider()();
    return new Client({
        ...createAwsConnector(credentials, "ca-central-1"),
        node: process.env.OPEN_SEARCH_HOST,
    });
};

module.exports = {getClient};