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

enum QueryType {
    Song = 0,
    Artist,
    Tag,
}

// const sequelizeOps: any = {
//     [api.QueryFilterOp.Eq]: Op.eq,
//     [api.QueryFilterOp.Ne]: Op.ne,
//     [api.QueryFilterOp.In]: Op.in,
//     [api.QueryFilterOp.NotIn]: Op.notIn,
//     [api.QueryFilterOp.Like]: Op.like,
//     [api.QueryElemOp.And]: Op.and,
//     [api.QueryElemOp.Or]: Op.or,
// };

// const sequelizeProps: any = {
//     [QueryType.Song]: {
//         [api.QueryElemProperty.songTitle]: "title",
//         [api.QueryElemProperty.songId]: "id",
//         [api.QueryElemProperty.artistName]: "$Artists.name$",
//         [api.QueryElemProperty.artistId]: "$Artists.id$",
//         [api.QueryElemProperty.albumName]: "$Albums.name$",
//     },
//     [QueryType.Artist]: {
//         [api.QueryElemProperty.songTitle]: "$Songs.title$",
//         [api.QueryElemProperty.songId]: "$Songs.id$",
//         [api.QueryElemProperty.artistName]: "name",
//         [api.QueryElemProperty.artistId]: "id",
//         [api.QueryElemProperty.albumName]: "$Albums.name$",
//     },
//     [QueryType.Tag]: {
//         [api.QueryElemProperty.songTitle]: "$Songs.title$",
//         [api.QueryElemProperty.songId]: "$Songs.id$",
//         [api.QueryElemProperty.artistName]: "$Artists.name$",
//         [api.QueryElemProperty.artistId]: "$Artists.id$",
//         [api.QueryElemProperty.albumName]: "$Albums.name$",
//     }
// };

// const sequelizeOrderColumns: any = {
//     [QueryType.Song]: {
//         [api.OrderByType.Name]: 'title',
//         [api.OrderByType.ArtistRanking]: '$Rankings.rank$',
//         [api.OrderByType.TagRanking]: '$Rankings.rank$',
//     },
//     [QueryType.Artist]: {
//         [api.OrderByType.Name]: 'name'
//     },
//     [QueryType.Tag]: {
//         [api.OrderByType.Name]: 'name'
//     },
// }

// // Returns the "where" clauses for Sequelize, per object type.
// const getSequelizeWhere = (queryElem: api.QueryElem, type: QueryType) => {
//     var where: any = {
//         [Op.and]: []
//     };

//     if (queryElem.prop && queryElem.propOperator && queryElem.propOperand) {
//         // Visit a filter-like subquery leaf.
//         where[Op.and].push({
//             [sequelizeProps[type][queryElem.prop]]: {
//                 [sequelizeOps[queryElem.propOperator]]: queryElem.propOperand
//             }
//         });
//     }
//     if (queryElem.childrenOperator && queryElem.children) {
//         // Recursively visit a nested subquery.

//         const children = queryElem.children.map((child: api.QueryElem) => getSequelizeWhere(child, type));
//         where[Op.and].push({
//             [sequelizeOps[queryElem.childrenOperator]]: children
//         });
//     }

//     return where;
// }

// function getSequelizeOrder(order: api.Ordering, type: QueryType) {
//     const ascstring = order.ascending ? 'ASC' : 'DESC';

//     return [
//         [ sequelizeOrderColumns[type][order.orderBy.type], ascstring ]
//     ];
// }

export const QueryEndpointHandler: EndpointHandler = async (req: any, res: any) => {
    if (!api.checkQueryRequest(req.body)) {
        const e: EndpointError = {
            internalMessage: 'Invalid Query request: ' + JSON.stringify(req.body),
            httpStatus: 400
        };
        throw e;
    }
    const reqObject: api.QueryRequest = req.body;

    // try {
    //     const songLimit = reqObject.offsetsLimits.songLimit;
    //     const songOffset = reqObject.offsetsLimits.songOffset;
    //     const tagLimit = reqObject.offsetsLimits.tagLimit;
    //     const tagOffset = reqObject.offsetsLimits.tagOffset;
    //     const artistLimit = reqObject.offsetsLimits.artistLimit;
    //     const artistOffset = reqObject.offsetsLimits.artistOffset;

    //     const songs = (songLimit && songLimit > 0) && await models.Song.findAll({
    //         // NOTE: have to disable limit and offset because of bug: https://github.com/sequelize/sequelize/issues/11938.
    //         // Custom pagination is implemented before responding.
    //         where: getSequelizeWhere(reqObject.query, QueryType.Song),
    //         order: getSequelizeOrder(reqObject.ordering, QueryType.Song),
    //         include: [ models.Artist, models.Album, models.Tag, models.Ranking ],
    //         //limit: reqObject.limit,
    //         //offset: reqObject.offset,
    //     })
    //     const artists = (artistLimit && artistLimit > 0) && await models.Artist.findAll({
    //         // NOTE: have to disable limit and offset because of bug: https://github.com/sequelize/sequelize/issues/11938.
    //         // Custom pagination is implemented before responding.
    //         where: getSequelizeWhere(reqObject.query, QueryType.Artist),
    //         order: getSequelizeOrder(reqObject.ordering, QueryType.Artist),
    //         include: [models.Song, models.Album, models.Tag],
    //         //limit: reqObject.limit,
    //         //offset: reqObject.offset,
    //     })
    //     const tags = (tagLimit && tagLimit > 0) && await models.Tag.findAll({
    //         // NOTE: have to disable limit and offset because of bug: https://github.com/sequelize/sequelize/issues/11938.
    //         // Custom pagination is implemented before responding.
    //         where: getSequelizeWhere(reqObject.query, QueryType.Tag),
    //         order: getSequelizeOrder(reqObject.ordering, QueryType.Tag),
    //         include: [models.Song, models.Album, models.Artist],
    //         //limit: reqObject.limit,
    //         //offset: reqObject.offset,
    //     })

    //     const response: api.QueryResponse = {
    //         songs: ((songLimit || -1) <= 0) ? [] : await Promise.all(songs.map(async (song: any) => {
    //             const artists = song.getArtists();
    //             const tags = song.getTags();
    //             const rankings = song.getRankings();
    //             return <api.SongDetails>{
    //                 songId: song.id,
    //                 title: song.title,
    //                 storeLinks: song.storeLinks,
    //                 artists: (await artists).map((artist: any) => {
    //                     return <api.ArtistDetails>{
    //                         artistId: artist.id,
    //                         name: artist.name,
    //                     }
    //                 }),
    //                 tags: (await tags).map((tag: any) => {
    //                     return <api.TagDetails>{
    //                         tagId: tag.id,
    //                         name: tag.name,
    //                     }
    //                 }),
    //                 rankings: await (await rankings).map(async (ranking: any) => {
    //                     const maybeTagContext: api.TagDetails | undefined = await ranking.getTagContext();
    //                     const maybeArtistContext: api.ArtistDetails | undefined = await ranking.getArtistContext();
    //                     const maybeContext = maybeTagContext || maybeArtistContext;
    //                     return <api.RankingDetails>{
    //                         rankingId: ranking.id,
    //                         type: api.ItemType.Song,
    //                         rankedId: song.id,
    //                         context: maybeContext,
    //                         value: ranking.value,
    //                     }
    //                 })
    //             };
    //         }).slice(songOffset || 0, (songOffset || 0) + (songLimit || 10))),
    //         // TODO: custom pagination due to bug mentioned above
    //         artists: ((artistLimit || -1) <= 0) ? [] : await Promise.all(artists.map(async (artist: any) => {
    //             return <api.ArtistDetails>{
    //                 artistId: artist.id,
    //                 name: artist.name,
    //             };
    //         }).slice(artistOffset || 0, (artistOffset || 0) + (artistLimit || 10))),
    //         tags: ((tagLimit || -1) <= 0) ? [] : await Promise.all(tags.map(async (tag: any) => {
    //             return <api.TagDetails>{
    //                 tagId: tag.id,
    //                 name: tag.name,
    //             };
    //         }).slice(tagOffset || 0,  (tagOffset || 0) + (tagLimit || 10))),
    //     };
    //     res.send(response);
    // } catch (e) {
    //     catchUnhandledErrors(e);
    // }

    throw "NOTIMPLEMENTED";
}