db.event.aggregate([
    {
        $addFields: {
            convertedDate: {
                $dateFromString: {
                    dateString: "$start",
                    format: "%Y-%m-%d %H:%M:%S"
                }
            }
        } }
    ,
    { $sort: { "convertedDate": 1 } },
    {
        $lookup: {
            from: 'performer',
            localField: 'performers',
            foreignField: '_id',
            as: 'performers',
            pipeline: [
                { $sort: { name: 1 } }
            ]
        }
    },
    {
        $lookup: {
            from: 'venue',
            localField: 'venues',
            foreignField: '_id',
            as: 'venues',
            pipeline: [
                { $sort: { name: 1 } }
            ]
        }
    },
    {
        $match: {
            $or: [
                { title: { $regex: ".*bee.*", $options: "i" } },
                { performers: { $elemMatch: { name: { $regex: ".*bee.*", $options: "i" } } } },
                { venues: { $elemMatch: { name: { $regex: ".*bee.*", $options: "i" } } } }
            ]
        }
    },
    {
        $group: {
            _id: 0,
            performers: {
                $addToSet: {
                    $filter: {
                        input: "$performers",
                        as: "performer",
                        cond: {
                            $and: [
                                { $ne: ["$$performer", []] },
                                { $regexMatch: { input: "$$performer.name", regex: /.*bee.*/i } }
                            ]
                        }
                    }
                }
            },
            venues: {
                $addToSet: {
                    $filter: {
                        input: "$venues",
                        as: "venue",
                        cond: {
                            $and: [
                                { $ne: ["$$venue", []] },
                                { $regexMatch: { input: "$$venue.name", regex: /.*bee.*/i } }
                            ]
                        }
                    }
                }
            },
            events: {
                $addToSet: {
                    uid: "$uid",
                    title: "$title",
                    type: "$type",
                    start: {
                        $dateFromString: {
                            dateString: "$start",
                            format: "%Y-%m-%d %H:%M:%S"
                        }
                    },
                    performers: {
                        names: {
                            $slice: ["$performers.name", 7]
                        },
                        total: {
                            $size: "$performers"
                        }
                    },
                    venue: {
                        $first: "$venues.name"
                    },
                    country: {
                        $first: "$venues.country.name"
                    },
                    state: {
                        $first: "$venues.state.name"
                    },
                    city: {
                        $first: "$venues.city.name"
                    }
                }
            }
        }
    },
    {
        $unwind: {
            path: "$performers", preserveNullAndEmptyArrays: false
        }
    },
    {
        $sort: { "performers.name": 1 }
    },
    {
        $group: {
            _id: "$_id",
            performers: { $push: "$performers" },
            venues: { $first: "$venues" },
            events: { $first: "$events" }
        }
    },
    {
        $unwind: {
            path: "$venues",
            preserveNullAndEmptyArrays: false
        }
    },
    { $sort: { "venues.name": 1 } },
    {
        $group:
            {
                _id: "$_id",
                performers: { $first: "$performers" },
                venues: { $push: "$venues" },
                events: { $first: "$events" }
            }
    },
    { $unwind: "$events" },
    { $sort: { "events.start": 1 } },
    {
        $group:
            {
                _id: "$_id",
                performers: { $first: "$performers" },
                venues: { $first: "$venues" },
                events: { $push: "$events" }
            }
    },
    {
        $project: {
            _id: 0,
            performers: { $slice: ["$performers", 3] },
            events: { $slice: ["$events", 3] },
            venues: { $slice: ["$venues", 3] }
        }
    }
])