jormaechea/open-api-mocker

'use strict';

const Path = require('./path');
const PathsStruct = require('./structs');

const { knownHttpMethods } = require('../utils/http-methods');
const enhanceStructValidationError = require('../utils/enhance-struct-validation-error');

class Parser {

    parse(schema) {

        const { paths } = schema;

        if(!paths)
            return [];

        this.validatePaths(paths);

        return Object.entries(paths)
            .map(([uri, operations]) => this.parsePath(uri, operations))
            .reduce((acum, operations) => (acum.length ? [...acum, ...operations] : operations), []);
    }

    validatePaths(paths) {

        try {
            return PathsStruct(paths);
        } catch(e) {
            throw enhanceStructValidationError(e, 'paths');
        }
    }

    parsePath(uri, operations) {

        const pathLevelParameters = operations.parameters || [];

        return Object.entries(operations)
            .map(([httpMethod, operationData]) => this.parseOperation(uri, httpMethod, operationData, pathLevelParameters))
            .filter(Boolean);
    }

    parseOperation(uri, httpMethod, { parameters, requestBody, responses }, pathLevelParameters) {

        if(!knownHttpMethods.includes(httpMethod.toLowerCase()))
            return;

        return new Path({
            uri,
            httpMethod,
            parameters: [
                ...(parameters || []),
                ...pathLevelParameters
            ],
            requestBody,
            responses
        });
    }

}

module.exports = Parser;