import { InstantiableCanonical } from './InstantiableCanonical.ts'
import { CanonicalDefinition } from './Canonical.ts'
import Middleware from '../http/Middleware.ts'
import { Unit } from '../lifecycle/decorators.ts'

/**
 * Canonical unit which loads and instantiates application middleware.
 * @extends InstantiableCanonical
 */
@Unit()
export default class Middlewares extends InstantiableCanonical<Middleware> {
    protected base_path = './app/http/middleware'
    protected canonical_item = 'middleware'
    protected suffix = '.middleware.ts'

    public async init_canonical_item(def: CanonicalDefinition) {
        const item = await super.init_canonical_item(def)
        if ( !(item instanceof Middleware) ) {
            throw new TypeError(`Invalid middleware definition: ${def.original_name}. Middleware must extend from Daton's base Middleware class.`)
        }

        return item
    }
}