import ResponseFactory from './ResponseFactory.ts'
import {Request} from '../Request.ts'
import {file_server} from '../../external/std.ts'
import {HTTPStatus} from '../../const/http.ts'
import {Logging} from '../../service/logging/Logging.ts'
import {Injectable} from '../../../../di/src/decorator/Injection.ts'
import {PathLike, universal_path} from '../../support/UniversalPath.ts'

/**
 * Response factory to send the contents of a file given its path.
 * @extends ResponseFactory
 */
@Injectable()
export default class FileResponseFactory extends ResponseFactory {
    constructor(
        protected readonly logger: Logging,

        /**
         * The path to the file to be sent.
         * @type string
         */
        public readonly path: PathLike,
    ) { super() }

    /**
     * Write this response factory to the given request's response.
     * @param {Request} request
     * @return Request
     */
    public async write(request: Request): Promise<Request> {
        request = await super.write(request)

        const path = typeof this.path === 'string' ? universal_path(this.path) : this.path

        const content = await file_server.serveFile(request.to_native, path.to_local)
        const length = content.headers && content.headers.get('content-length')

        if ( content.headers && content.body && length ) {
            request.response.body = content.body
            request.response.headers.set('Content-Length', length)

            if ( path.content_type )
                request.response.headers.set('Content-Type', path.content_type)
        } else {
            this.logger.debug(`Tried to serve file that does not exist: ${path}`)
            request.response.status = HTTPStatus.NOT_FOUND
        }

        return request
    }
}