import {ErrorWithContext} from '../../util'
import {ResolvedRouteHandler, Route} from './Route'
import {Injectable} from '../../di'

/**
 * Class representing a resolved route that a request is mounted to.
 */
@Injectable()
export class ActivatedRoute {
    /**
     * The parsed params from the route definition.
     *
     * @example
     * If the route definition is like `/something/something/:paramName1/:paramName2/etc`
     * and the request came in on `/something/something/foo/bar/etc`, then the params
     * would be:
     *
     * ```typescript
     * {
     *     paramName1: 'foo',
     *     paramName2: 'bar',
     * }
     * ```
     */
    public readonly params: {[key: string]: string}

    /**
     * The resolved function that should handle the request for this route.
     */
    public readonly handler: ResolvedRouteHandler

    /**
     * Pre-middleware that should be applied to the request on this route.
     */
    public readonly preflight: ResolvedRouteHandler[]

    /**
     * Post-middleware that should be applied to the request on this route.
     */
    public readonly postflight: ResolvedRouteHandler[]

    constructor(
        /** The route this ActivatedRoute refers to. */
        public readonly route: Route,

        /** The request path that activated that route. */
        public readonly path: string,
    ) {
        const params = route.extract(path)
        if ( !params ) {
            const error = new ErrorWithContext('Cannot get params for route. Path does not match.')
            error.context = {
                matchedRoute: String(route),
                requestPath: path,
            }
            throw error
        }

        this.params = params
        this.preflight = route.resolvePreflight()
        this.handler = route.resolveHandler()
        this.postflight = route.resolvePostflight()
    }
}