lib/src/http/kernel/module/ParseIncomingBodyHTTPModule.ts

import {HTTPKernelModule} from "../HTTPKernelModule"
import {HTTPKernel} from "../HTTPKernel"
import * as Busboy from "busboy"
import {Request} from "../../lifecycle/Request"
import {infer, uuid_v4} from "@extollo/util"
import {Files} from "../../../service/Files"
import {Config} from "../../../service/Config"
import {Logging} from "../../../service/Logging"
import {Injectable, Inject, Container} from "@extollo/di"

@Injectable()
export class ParseIncomingBodyHTTPModule extends HTTPKernelModule {
    static register(kernel: HTTPKernel) {
        const files = <Files> Container.getContainer().make(Files)
        const logging = <Logging> Container.getContainer().make(Logging)
        if ( !files.hasFilesystem() ) {
            logging.warn(`No default filesystem is configured. This means request files will not be uploaded.`)
        }

        kernel.register(this).first()
    }

    @Inject()
    protected readonly files!: Files

    @Inject()
    protected readonly config!: Config

    @Inject()
    protected readonly logging!: Logging

    public async apply(request: Request): Promise<Request> {
        const contentType = request.getHeader('content-type')
        const contentTypes = (Array.isArray(contentType) ? contentType : [contentType])
            .filter(Boolean).map(x => x!.toLowerCase().split(';')[0])
        if ( !contentType ) return request

        if (
            contentTypes.includes('multipart/form-data')
            || contentTypes.includes('application/x-www-form-urlencoded')
        ) {
            return this.applyBusboy(request)
        }

        if ( contentTypes.includes('application/json') ) {
            return this.applyJSON(request)
        }

        return request
    }

    /**
     * Parse the request body as JSON.
     * @param request
     */
    public async applyJSON(request: Request): Promise<Request> {
        await new Promise<void>((res, rej) => {
            let data = ''

            request.toNative().on('data', chunk => {
                data += chunk
            })

            request.toNative().on('end', () => {
                try {
                    const body = JSON.parse(data)
                    for ( const key in body ) {
                        if ( !body.hasOwnProperty(key) ) continue
                        request.parsedInput[key] = body[key]
                    }
                    res()
                } catch (e) {
                    rej(e)
                }
            })
        })

        return request
    }

    /**
     * Parse the request body using Busboy. This assumes the request contents are multipart.
     * @param request
     */
    public async applyBusboy(request: Request): Promise<Request> {
        const config = this.config.get('server.uploads', {})

        await new Promise<void>((res, rej) => {
            const busboy = new Busboy({
                headers: request.toNative().headers,
            })

            busboy.on('field', (field, val) => {
                request.parsedInput[field] = infer(val)
            })

            busboy.on('file', async (field, file, filename, encoding, mimetype) => {
                if ( !this.files.hasFilesystem() ) return

                if ( !config?.enable ) {
                    this.logging.warn(`Skipping uploaded file '${filename}' because uploading is disabled. Set the server.uploads.enable config to allow uploads.`)
                    file.resume()
                    return
                }

                if ( config?.filter?.mimetype ) {
                    const rex = new RegExp(config.filter.mimetype)
                    if ( !rex.test(mimetype) ) {
                        this.logging.debug(`Skipping uploaded file '${filename}' because the mimetype does not match the configured filter: (${config.filter.mimetype} -> ${mimetype})`)
                        file.resume()
                        return
                    }
                }

                if ( config?.filter?.filename ) {
                    const rex = new RegExp(config.filter.filename)
                    if ( !rex.test(filename) ) {
                        this.logging.debug(`Skipping uploaded file '${filename}' because the file name does not match the configured filter: (${config.filter.filename} -> ${filename})`)
                        file.resume()
                        return
                    }
                }

                const fs = this.files.getFilesystem()
                const storePath = `${config.filesystemPrefix ? config.filesystemPrefix : ''}${(config.filesystemPrefix && !config.filesystemPrefix.endsWith('/')) ? '/' : ''}${field}-${uuid_v4()}`
                this.logging.verbose(`Uploading file in field ${field} to ${fs.getPrefix()}${storePath}`)
                file.pipe(await fs.putStoreFileAsStream({ storePath }))  // FIXME might need to revisit this to ensure we don't res() before pipe finishes

                request.uploadedFiles[field] = request.parsedInput[field] = fs.getPath(storePath)
            })

            busboy.on('finish', () => {
                this.logging.debug(`Parsed body input: ${JSON.stringify(request.parsedInput)}`)
                res()
            })

            busboy.on('error', rej)

            request.toNative().pipe(busboy)
        })

        return request
    }
}