import * as api from '../../client/src/api';
import { EndpointError, EndpointHandler, catchUnhandledErrors } from './types';
import Knex from 'knex';

export const ModifyTagEndpointHandler: EndpointHandler = async (req: any, res: any, knex: Knex) => {
    if (!api.checkModifyTagRequest(req)) {
        const e: EndpointError = {
            internalMessage: 'Invalid ModifyTag request: ' + JSON.stringify(req.body),
            httpStatus: 400
        };
        throw e;
    }
    const reqObject: api.ModifyTagRequest = req.body;
    const { id: userId } = req.user;

    console.log("User ", userId, ": Modify Tag ", reqObject);

    await knex.transaction(async (trx) => {
        try {
            // Start retrieving the parent tag.
            const parentTagPromise = reqObject.parentId ?
                trx.select('id')
                    .from('tags')
                    .where({ 'user': userId })
                    .where({ 'id': reqObject.parentId })
                    .then((ts: any) => ts.map((t: any) => t['tagId'])) :
                (async () => { return [] })();

            // Start retrieving the tag itself.
            const tagPromise = trx.select('id')
                .from('tags')
                .where({ 'user': userId })
                .where({ id: req.params.id })
                .then((r: any) => (r && r[0]) ? r[0]['id'] : undefined)

            // Wait for the requests to finish.
            var [tag, parent] = await Promise.all([tagPromise, parentTagPromise]);;

            // Check that we found all objects we need.
            if ((reqObject.parentId && !parent) ||
                !tag) {
                const e: EndpointError = {
                    internalMessage: 'Tag or parent does not exist for ModifyTag request: ' + JSON.stringify(req.body),
                    httpStatus: 400
                };
                throw e;
            }

            // Modify the tag.
            await trx('tags')
                .where({ 'user': userId })
                .where({ 'id': req.params.id })
                .update({
                    name: reqObject.name,
                    parentId: reqObject.parentId || null,
                })

            // Respond to the request.
            res.status(200).send();

        } catch (e) {
            catchUnhandledErrors(e);
            trx.rollback();
        }
    })
}