import config from "config";
import Controller from "../Controller";
import {REQUIRE_ADMIN_MIDDLEWARE, REQUIRE_AUTH_MIDDLEWARE} from "../auth/AuthComponent";
import User from "../auth/models/User";
import {Request, Response} from "express";
import {BadRequestError, NotFoundHttpError} from "../HttpError";
import Mail from "../Mail";
import {ACCOUNT_REVIEW_NOTICE_MAIL_TEMPLATE} from "../Mails";
import UserEmail from "../auth/models/UserEmail";

export default class BackendController extends Controller {
    private static readonly menu: BackendMenuElement[] = [];

    public static registerMenuElement(element: BackendMenuElement): void {
        this.menu.push(element);
    }

    public constructor() {
        super();
        if (User.isApprovalMode()) {
            BackendController.registerMenuElement({
                getLink: async () => Controller.route('accounts-approval'),
                getDisplayString: async () => {
                    const pendingUsersCount = (await User.select()
                        .where('approved', false)
                        .get()).length;
                    return `Accounts approval (${pendingUsersCount})`;
                },
                getDisplayIcon: async () => 'user-check',
            });
        }
    }

    public getRoutesPrefix(): string {
        return '/backend';
    }

    public routes(): void {
        this.get('/', this.getIndex, 'backend', REQUIRE_AUTH_MIDDLEWARE, REQUIRE_ADMIN_MIDDLEWARE);
        if (User.isApprovalMode()) {
            this.get('/accounts-approval', this.getAccountApproval, 'accounts-approval', REQUIRE_AUTH_MIDDLEWARE, REQUIRE_ADMIN_MIDDLEWARE);
            this.post('/accounts-approval/approve', this.postApproveAccount, 'approve-account', REQUIRE_AUTH_MIDDLEWARE, REQUIRE_ADMIN_MIDDLEWARE);
            this.post('/accounts-approval/reject', this.postRejectAccount, 'reject-account', REQUIRE_AUTH_MIDDLEWARE, REQUIRE_ADMIN_MIDDLEWARE);
        }
    }

    protected async getIndex(req: Request, res: Response): Promise<void> {
        res.render('backend/index', {
            menu: await Promise.all(BackendController.menu.map(async m => ({
                link: await m.getLink(),
                display_string: await m.getDisplayString(),
                display_icon: await m.getDisplayIcon(),
            }))),
        });
    }

    protected async getAccountApproval(req: Request, res: Response): Promise<void> {
        const accounts = await User.select().where('approved', 0).with('mainEmail').get();
        res.render('backend/accounts_approval', {
            accounts: User.isApprovalMode() ? accounts : 0,
        });
    }

    protected async postApproveAccount(req: Request, res: Response): Promise<void> {
        const {account, email} = await this.accountRequest(req);

        account.approved = true;
        await account.save();

        await new Mail(ACCOUNT_REVIEW_NOTICE_MAIL_TEMPLATE, {
            approved: true,
            link: config.get<string>('base_url') + Controller.route('auth'),
        }).send(email!.email!);

        req.flash('success', `Account successfully approved.`);
        res.redirectBack(Controller.route('accounts-approval'));
    }

    protected async postRejectAccount(req: Request, res: Response): Promise<void> {
        const {account, email} = await this.accountRequest(req);

        await account.delete();

        await new Mail(ACCOUNT_REVIEW_NOTICE_MAIL_TEMPLATE, {
            approved: false,
        }).send(email!.email!);

        req.flash('success', `Account successfully deleted.`);
        res.redirectBack(Controller.route('accounts-approval'));
    }

    protected async accountRequest(req: Request): Promise<{
        account: User,
        email: UserEmail,
    }> {
        if (!req.body.user_id) throw new BadRequestError('Missing user_id field', 'Check your form', req.url);
        const account = await User.select().where('id', req.body.user_id).with('mainEmail').first();
        if (!account) throw new NotFoundHttpError('User', req.url);
        const email = await account.mainEmail.get();

        return {
            account: account,
            email: email!,
        };
    }
}

export interface BackendMenuElement {
    /**
     * Returns the link of this menu element (usually using {@code Controller.route})
     */
    getLink(): Promise<string>;

    /**
     * The string part of the link display
     */
    getDisplayString(): Promise<string>;

    /**
     * An optional feather icon name
     */
    getDisplayIcon(): Promise<string | null>;
}