squid-js/src/ocean/utils/WebServiceConnector.ts

import fetch, { BodyInit, RequestInit, Response } from 'node-fetch'
import * as fs from 'fs'

import { Instantiable, InstantiableConfig } from '../../Instantiable.abstract'

import save = require('save-file')

/**
 * Provides a common interface to web services.
 */
export class WebServiceConnector extends Instantiable {
    constructor(config: InstantiableConfig) {
        super()
        this.setInstanceConfig(config)
    }

    public post(url: string, payload: BodyInit): Promise<Response> {
        return this.fetch(url, {
            method: 'POST',
            body: payload,
            headers: {
                'Content-type': 'application/json'
            }
        })
    }

    public get(url: string): Promise<Response> {
        return this.fetch(url, {
            method: 'GET',
            headers: {
                'Content-type': 'application/json'
            }
        })
    }

    public put(url: string, payload: BodyInit): Promise<Response> {
        return this.fetch(url, {
            method: 'PUT',
            body: payload,
            headers: {
                'Content-type': 'application/json'
            }
        })
    }

    public async downloadFile(
        url: string,
        destination?: string,
        index?: number
    ): Promise<string> {
        const response = await this.get(url)
        if (!response.ok) {
            throw new Error('Response error.')
        }
        let filename
        try {
            filename = response.headers
                .get('content-disposition')
                .match(/attachment;filename=(.+)/)[1]
        } catch {
            try {
                filename = url.split('/').pop()
            } catch {
                filename = `file${index}`
            }
        }

        if (destination) {
            await new Promise(async (resolve, reject) => {
                fs.mkdirSync(destination, { recursive: true })
                const fileStream = fs.createWriteStream(
                    `${destination}${filename}`
                )
                response.body.pipe(fileStream)
                response.body.on('error', reject)
                fileStream.on('finish', resolve)
            })

            return destination
        } else {
            save(await response.arrayBuffer(), filename)
        }
    }

    private async fetch(url: string, opts: RequestInit): Promise<Response> {
        const result = await fetch(url, opts)
        if (!result.ok) {
            this.logger.error(`Error requesting [${opts.method}] ${url}`)
            this.logger.error(`Response message: \n${await result.text()}`)
            throw result
        }
        return result
    }
}