import {Unit} from '../lifecycle/Unit'
import {Injectable, Inject, StaticInstantiable} from '../di'
import {Logging} from '../service/Logging'
import {Middlewares} from '../service/Middlewares'
import {CanonicalResolver} from '../service/Canonical'
import {Middleware} from '../http/routing/Middleware'
import {AuthRequiredMiddleware} from './middleware/AuthRequiredMiddleware'
import {GuestRequiredMiddleware} from './middleware/GuestRequiredMiddleware'
import {SessionAuthMiddleware} from './middleware/SessionAuthMiddleware'
import {ViewEngine} from '../views/ViewEngine'
import {SecurityContext} from './context/SecurityContext'
import {LoginProvider, LoginProviderConfig} from './provider/LoginProvider'
import {Config} from '../service/Config'
import {ErrorWithContext, hasOwnProperty} from '../util'
import {Route} from '../http/routing/Route'

@Injectable()
export class Authentication extends Unit {
    @Inject()
    protected readonly logging!: Logging

    @Inject()
    protected readonly middleware!: Middlewares

    @Inject()
    protected readonly config!: Config

    protected providers: {[name: string]: LoginProvider<LoginProviderConfig>} = {}

    getProvider(name: string): LoginProvider<LoginProviderConfig> {
        const provider = this.providers[name]
        if ( !provider ) {
            throw new ErrorWithContext('Invalid auth provider name: ' + name, { name })
        }

        return provider
    }

    async up(): Promise<void> {
        this.middleware.registerNamespace('@auth', this.getMiddlewareResolver())

        this.container().onResolve<ViewEngine>(ViewEngine)
            .then((engine: ViewEngine) => {
                engine.registerGlobalFactory('user', req => {
                    return () => req?.make<SecurityContext>(SecurityContext)?.getUser()
                })
            })

        const config = this.config.get('auth.providers', {})
        const middleware = this.config.get('auth.middleware', SessionAuthMiddleware)

        if ( !(middleware?.prototype instanceof Middleware) ) {
            throw new ErrorWithContext('Auth middleware must extend Middleware base class', {
                providedValue: middleware,
                configKey: 'auth.middleware',
            })
        }

        for ( const name in config ) {
            if ( !hasOwnProperty(config, name) ) {
                continue
            }

            if ( this.providers[name] ) {
                this.logging.warn(`Registering duplicate authentication provider: ${name}`)
            }

            this.logging.verbose(`Registered authentication provider: ${name}`)
            this.providers[name] = this.make(config[name].driver, name, config[name].config)

            Route.group(`/auth/${name}`, () => {
                this.providers[name].routes()
            }).pre(middleware)
        }
    }

    protected getMiddlewareResolver(): CanonicalResolver<StaticInstantiable<Middleware>> {
        return (key: string) => {
            return ({
                required: AuthRequiredMiddleware,
                guest: GuestRequiredMiddleware,
                web: SessionAuthMiddleware,
            })[key]
        }
    }
}