games-express-api/middleware/advancedResults.js

const advancedResults = (model, populate) => async (req, res, next) => {
    if (req.originalUrl.indexOf('admin') === -1)
        req.query = {
            ...req.query,
            $and: [{accessedBy: {$elemMatch: {user: req.user.id}}}],
        }


    if (req.query.search === undefined) req.query.search = ''
    if (req.query.search)
        req.query = {...req.query, $text: {$search: req.query.search}}

    const filterAndInGame = ['genre', 'os', 'developer', 'publisher', 'series', 'intel', 'wine', 'controller', 'store', 'soundtrack', 'playStatus', 'rating', 'ratinggte', 'ratinglte', 'steamRating', 'steamRatinggte', 'steamRatinglte']

    filterAndInGame.map((filter) => {
        if (req.query[filter] === undefined) req.query[filter] = ''
        if (req.query[filter]) {
            let newFilter
            if (filter === 'os') {
                newFilter = req.query[filter].split(',').reduce((prev, curr, index, arr) => {
                    const key = `${[filter]}.${arr[index]}`.toLowerCase()
                    prev.push({[key]: true})
                    return prev
                }, [])
            } else if (filter === 'store' || filter === 'soundtrack' || filter === 'playStatus') {
                newFilter = req.query[filter].split(',').reduce((prev, curr) => {
                    prev.push({accessedBy: {$elemMatch: {[filter]: curr}}})
                    return prev
                }, [])
            } else if (filter === 'rating') {
                if (Object.hasOwn(req.query[filter], 'gte')) {
                    newFilter = req.query[filter]['gte'].split(',').reduce((prev, curr) => {
                        prev.push({accessedBy: {$elemMatch: {rating: {$gte: Number(curr)}}}})
                        return prev
                    }, [])
                    req.query.rating = `gte${req.query[filter]['gte']}`
                } else if (Object.hasOwn(req.query[filter], 'lte')) {
                    newFilter = req.query[filter]['lte'].split(',').reduce((prev, curr) => {
                        prev.push({accessedBy: {$elemMatch: {rating: {$lte: Number(curr)}}}})
                        return prev
                    }, [])
                    req.query.rating = `lte${req.query[filter]['lte']}`
                } else {
                    newFilter = req.query[filter].split(',').reduce((prev, curr) => {
                        prev.push({accessedBy: {$elemMatch: {rating: Number(curr)}}})
                        return prev
                    }, [])
                }
            } else if (filter === 'ratinggte') {
                newFilter = req.query[filter].split(',').reduce((prev, curr) => {
                    prev.push({accessedBy: {$elemMatch: {rating: {$gte: Number(curr)}}}})
                    return prev
                }, [])
                req.query.rating = req.query.ratinggte
            } else if (filter === 'ratinglte') {
                newFilter = req.query[filter].split(',').reduce((prev, curr) => {
                    prev.push({accessedBy: {$elemMatch: {rating: {$lte: Number(curr)}}}})
                    return prev
                }, [])
                req.query.rating = req.query.ratinglte
            } else if (filter === 'steamRating') {
                if (Object.hasOwn(req.query[filter], 'gte')) {
                    newFilter = req.query[filter]['gte'].split(',').reduce((prev, curr) => {
                        prev.push({steamRating: {$gte: Number(curr)}})
                        return prev
                    }, [])
                    req.query.steamRating = `gte${req.query[filter]['gte']}`
                } else if (Object.hasOwn(req.query[filter], 'lte')) {
                    newFilter = req.query[filter]['lte'].split(',').reduce((prev, curr) => {
                        prev.push({steamRating: {$lte: Number(curr)}})
                        return prev
                    }, [])
                    req.query.steamRating = `lte${req.query[filter]['lte']}`
                } else {
                    newFilter = req.query[filter].split(',').reduce((prev, curr) => {
                        prev.push({steamRating: Number(curr)})
                        return prev
                    }, [])
                }
            } else if (filter === 'steamRatinggte') {
                newFilter = req.query[filter].split(',').reduce((prev, curr) => {
                    prev.push({steamRating: {$gte: Number(curr)}})
                    return prev
                }, [])
                req.query.steamRating = req.query.steamRatinggte
            } else if (filter === 'steamRatinglte') {
                newFilter = req.query[filter].split(',').reduce((prev, curr) => {
                    prev.push({steamRating: {$lte: Number(curr)}})
                    return prev
                }, [])
                req.query.steamRating = req.query.steamRatinglte
            } else {
                newFilter = req.query[filter].split(',').reduce((prev, curr) => {
                    prev.push({[filter]: curr})
                    return prev
                }, [])
            }
            newFilter.forEach(element => req.query.$and.push(element))
        }
    })

    let query

// Copy req.query
    const reqQuery = {...req.query}

// Fields to exclude
    const removeFields = [
        'select',
        'series',
        'developer',
        'publisher',
        'sort',
        'limit',
        'page',
        'search',
        'os',
        'playStatus',
        'store',
        'soundtrack',
        'genre',
        'controller',
        'rating',
        'ratinggte',
        'ratinglte',
        'steamRating',
        'steamRatinggte',
        'steamRatinglte',
    ]

// Loop over removeFields and delete them from reqQuery
    removeFields.forEach((param) => delete reqQuery[param])

    filterAndInGame.forEach((param) => {
        if (req.query[param] === '') delete reqQuery[param]
    })

// Create query String
    let queryStr = JSON.stringify(reqQuery)

// Create operators like gt, gte, etc...
    queryStr = queryStr.replace(
        /\b(gt|gte|lt|lte|in|all)\b/g,
        (match) => `$${match}`,
    )

    queryStr = queryStr.replace(/\$\$/g, '$')

    const total = await model.countDocuments(reqQuery)

// Finding resource
    query = model.find(JSON.parse(queryStr))

// Select Fields
    if (req.query.select) {
        const fields = req.query.select.split(',').join(' ')
        query = query.select(fields)
    }

// Sort
    if (req.query.sort) {
        const sortBy = req.query.sort.split(',').join(' ')
        query = query.sort(sortBy)
    } else {
        query = query.sort('series title')
    }

// Pagination
    let page = parseInt(req.query.page, 10) || 1
    const limit = parseInt(req.query.limit, 10) || 10

// This block figures out how many total pages there will be and if
// the client is calling a page larger than the total pages
    let pages
    if (limit === 1) pages = total
    else if (total === 0) pages = 1
    else if (total % limit === 0) pages = (total - (total % limit)) / limit
    else pages = (total - (total % limit)) / limit + 1
    if (page > pages) page = pages

    const startIndex = (page - 1) * limit
    const endIndex = page * limit

    query = query.skip(startIndex).limit(limit)

    if (populate) {
        query = query.populate(populate)
    }

// Executing query
    const results = await query

// Pagination result
    const pagination = {}

    if (endIndex < total) {
        pagination.next = {
            page: page + 1,
        }
    }

    if (startIndex > 0) {
        pagination.prev = {
            page: page - 1,
        }
    }

    res.advancedResults = {
        success: true,
        searchParams: req.query.search,
        count: {
            gamesPerPage: results.length,
            totalGames: total,
            currentPage: page,
            pages,
            limit,
        },
        filters: {
            series: req.query.series,
            playStatus: req.query.playStatus,
            genre: req.query.genre,
            os: req.query.os,
            store: req.query.store,
            developer: req.query.developer,
            controller: req.query.controller,
            publisher: req.query.publisher,
            soundtrack: req.query.soundtrack,
            intel: req.query.intel,
            wine: req.query.wine,
            rating: req.query.rating,
            steamRating: req.query.steamRating,
        },
        pagination,
        data: results,
    }

    next()
}

export default advancedResults