MongoDB aggregate $group $sum that matches date inside array of objects - mongodb

Question

I'll explain my problem here and i'll put a tldr at the bottom summarizing the question.
We have a collection called apple_receipt, since we have some apple purchases in our application. That document has some fields that we will be using on this aggregation. Those are: price, currency, startedAt and history. Price, currency and startedAt are self-explanatory. History is a field that is an array of objects containing a price and startedAt. So, what we are trying to accomplish is a query that gets every document between a date of our choice, for example: 06-06-2020 through 10-10-2022 and get the total price combined of all those receipts that have a startedAt between that. We have a document like this:
{
price: 12.9,
currency: 'BRL',
startedAt: 2022-08-10T16:23:42.000+00:00
history: [
{
price: 12.9,
startedAt: 2022-05-10T16:23:42.000+00:00
},
{
price: 12.9,
startedAt: 2022-06-10T16:23:42.000+00:00
},
{
price: 12.9,
startedAt: 2022-07-10T16:23:42.000+00:00
}
]
}
If we query between dates 06-06-2022 to 10-10-2022, we would have a return like this: totalPrice: 38,7.
-total price of the 3 objects that have matched the date inside that value range-
I have tried this so far:
AppleReceipt.aggregate([
{
$project: {
price: 1,
startedAt: 1,
currency: 1,
history: 1,
}
},
{
$unwind: {
path: "$history",
preserveNullAndEmptyArrays: true,
}
},
{
$match: {
$or: [
{ startedAt: {$gte: new Date(filters.begin), $lt: new Date(filters.end)} },
]
}
},
{
$group: {
_id: "$_id",
data: { $push: '$$ROOT' },
totalAmountHelper: { $sum: '$history.price' }
}
},
{
$unwind: "$data"
},
{
$addFields: {
totalAmount: { $add: ['$totalAmountHelper', '$data.price'] }
}
}
])
It does bring me the total value but I couldn't know how to take into consideration the date to make the match stage to only get the sum of the documents that are between that date.
tl;dr: Want to make a query that gets the total sum of the prices of all documents that have startedAt between the dates we choose. Needs to match the ones inside history field - which is an array of objects, and also the startedAt outside of the history field.

Answer 1

https://mongoplayground.net/p/lOvRbX24QI9
db.collection.aggregate([
{
$set: {
"history_total": {
"$reduce": {
"input": "$history",
"initialValue": 0,
"in": {
$sum: [
{
"$cond": {
"if": {
$and: [
{
$gte: [
new Date("2022-06-06"),
{
$dateFromString: {
dateString: "$$this.startedAt"
}
}
]
},
{
$lt: [
{
$dateFromString: {
dateString: "$$this.startedAt"
}
},
new Date("2022-10-10")
]
},
]
},
"then": "$$this.price",
"else": 0
}
},
"$$value",
]
}
}
}
}
},
{
$set: {
"history_total": {
"$sum": [
"$price",
"$history_total"
]
}
}
}
])
Result:
[
{
"_id": ObjectId("5a934e000102030405000000"),
"currency": "BRL",
"history": [
{
"price": 12.9,
"startedAt": "2022-05-10T16:23:42.000+00:00"
},
{
"price": 12.9,
"startedAt": "2022-06-10T16:23:42.000+00:00"
},
{
"price": 12.9,
"startedAt": "2022-07-10T16:23:42.000+00:00"
}
],
"history_total": 325.79999999999995,
"price": 312.9,
"startedAt": "2022-08-10T16:23:42.000+00:00"
}
]
Kudos goes to #user20042973