import * as bodyParser from "body-parser";
import * as cors from 'cors';
import * as express from "express";
import { initialize } from "express-openapi";
import { assignIn } from 'lodash';
import { Logger } from 'winston';
import { EventLayer } from "../lib/communication/eventLayer";
import { getDispatcher } from "../lib/dispatcher/nopeDispatcher";
import { apiDoc } from '../specs/apiDoc';
import { getBackendAccesors } from './getBackendAccessors';

export function startBackend(options: {
    port?: number,
    basePath?: string,
    logger?: Logger,
} = {}) {
    const app: express.Application = (express as any)();

    // Define the Default Options
    const defaults = {
        port: 3001,
        basePath: '/api'
    }
    // Mix the Options.
    const opts = assignIn(defaults, options);

    app.use(bodyParser.json());
    app.use(cors());

    initialize({
        apiDoc: apiDoc('Backend API', '1.0.0', opts.basePath),
        app,
        paths: './dist/open-api',
        routesGlob: '**/*.{ts,js}',
        routesIndexFileRegExp: /(?:index)?\.[tj]s$/,
        dependencies: {
            _dispatcher: getDispatcher('backend', new EventLayer())
        },
    });

    app.use(((err, req, res, next) => {
        res.status(err.status).json(err);
    }) as express.ErrorRequestHandler);

    const server = app.listen(opts.port);

    const accessor = getBackendAccesors(app);

    if (options.logger) {
        options.logger.info('Server Running on http://localhost:' + opts.port.toString() + opts.basePath);
        options.logger.info('API Documentation available on http://localhost:' + opts.port.toString() + opts.basePath + '/api-docs');
        options.logger.debug('Checkout http://localhost:3000/docs')
    }

    return {
        app,
        // Accessor for the Server
        accessor,
        // Function to extract the Definitions.
        definitionUri: opts.basePath + '/api-docs',
        // Function to Close the Server
        close() {
            server.close();
        }
    }
}