import {HTTPKernel} from '../HTTPKernel'
import {Request} from '../../lifecycle/Request'
import {ActivatedRoute} from '../../routing/ActivatedRoute'
import {http} from '../../response/HTTPErrorResponseFactory'
import {HTTPStatus, withErrorContext} from '../../../util'
import {AbstractResolvedRouteHandlerHTTPModule} from './AbstractResolvedRouteHandlerHTTPModule'

/**
 * HTTP kernel module that runs the handler for the request's route.
 *
 * In most cases, this is the controller method defined by the route.
 */
export class ExecuteResolvedRouteHandlerHTTPModule extends AbstractResolvedRouteHandlerHTTPModule {
    public static register(kernel: HTTPKernel): void {
        kernel.register(this).core()
    }

    public async apply(request: Request): Promise<Request> {
        if ( request.hasInstance(ActivatedRoute) ) {
            const route = <ActivatedRoute<unknown, unknown[]>> request.make(ActivatedRoute)
            const params = route.resolvedParameters
            if ( !params ) {
                throw new Error('Attempted to call route handler without resolved parameters.')
            }

            await withErrorContext(async () => {
                const result = await route.handler
                    .tap(handler => handler(...params))
                    .apply(request)

                await this.applyResponseObject(result, request)
            }, {
                route,
            })
        } else {
            await http(HTTPStatus.NOT_FOUND).write(request)
            request.response.blockingWriteback(true)
        }

        return request
    }
}