jormaechea/open-api-mocker

'use strict';

const fs = require('fs');
const path = require('path');
const YAML = require('js-yaml');
const chokidar = require('chokidar');
const EventEmitter = require('events');
const logger = require('lllog')();

const OpenAPISchemaNotFound = require('../errors/openapi-schema-not-found-error');
const OpenAPISchemaMalformed = require('../errors/openapi-schema-malformed-error');

module.exports = class LocalSchemaLoader extends EventEmitter {

    load(schemaPath) {

        this.schemaPath = path.isAbsolute(schemaPath) ? schemaPath : path.join(process.cwd(), schemaPath);

        try {
            fs.accessSync(this.schemaPath, fs.constants.R_OK);
        } catch(e) {
            throw new OpenAPISchemaNotFound(`Schema not found in ${this.schemaPath}`);
        }

        if(this.schemaPath.match(/\.ya?ml$/)) {
            try {
                return YAML.load(fs.readFileSync(this.schemaPath));
            } catch(e) {
                throw new OpenAPISchemaMalformed(e.message);
            }
        }

        try {
            return JSON.parse(fs.readFileSync(this.schemaPath));
        } catch(e) {
            throw new OpenAPISchemaMalformed(e.message);
        }
    }

    watch() {
        logger.info('Watching changes...');
        chokidar.watch(this.schemaPath)
            .on('change', () => {
                setTimeout(async () => this.emit('schema-changed'), 100);
            });
    }

};