Aggregation in mongodb and group by 15 min - node.js

Question

I have a Schema in mongodb like:
INPUT
{
_id: ObjectId("5e05c1089b3e4e333cee8c39"),
name:"Alex",
activity:[
{
_id: ObjectId("5e05c1089b3e4e333cee8c39"),
type: 'run',
start_timestamp: ISODate("2020-01-11T11:34:59.804Z"),
end_timestamp: ISODate("2020-01-11T11:40:00.804Z")
},
{
_id: ObjectId("5e05c1089b3e4e333cee8c40"),
type: 'stop',
start_timestamp: ISODate("2020-01-11T11:40:00.804Z"),
end_timestamp: ISODate("2020-01-11T11:42:00.804Z")
},
{
_id: ObjectId("5e05c1089b3e4e333cee8c41"),
type: 'wait',
start_timestamp: ISODate("2020-01-11T11:42:00.804Z"),
end_timestamp: ISODate("2020-01-11T11:52:00.804Z")
},
{
_id: ObjectId("5e05c1089b3e4e333cee8c41"),
type: 'stop',
start_timestamp: ISODate("2020-01-11T11:52:00.804Z"),
end_timestamp: ISODate("2020-01-11T12:02:00.804Z")
},
{
_id: ObjectId("5e05c1089b3e4e333cee8c41"),
type: 'sleep',
start_timestamp: ISODate("2020-01-11T12:02:00.804Z"),
end_timestamp: ISODate("2020-01-11T12:48:00.804Z")
}
]
}
This is a schema for a man activity, i need to find brake-up of every 15 minute (brake-up duration in minute),i have found a solution stackoverflow but here only single timestamp but in my case there are 2 timestamp and first i have to calculate duration and then group by according to 15 minute
OUTPUT
[
{
_id: "2020-01-11T11:34 to 2020-01-11T11:49" ,
duration: "15 min",
"brake-up":{
run:"6 min",
stop:"2 min",
wait:"7 min"
}
},
{
_id: "2020-01-11T11:49 to 2020-01-11T12:04" ,
duration: 15 min,
"brake-up":{
wait:"3 min"
stop:"10 min"
sleep:"2 min"
}
{
_id: "2020-01-11T12:04 to 2020-01-11T12:19" ,
duration: 15 min,
"brake-up":{
sleep:"15 min"
}
}
]
Thanks

Answer 1

It's a bit tedious solution.
Explanation
I assume activity.type not repeated inside X min break-up
I assume start_timestamp and end_timestamp as is (don't ignore seconds:milliseconds)
We calculate min / max dates from start_timestamp and end_timestamp
We calculate how many 15 min breaks are between min / max dates
We create from and to variables that includes X min break-up from min / max dates
For each from and to, we filter activities
Once we filter, we calculate waste time taking in mind from and to and start_timestamp and end_timestamp dates
We create Array with activity + waste time and transform it into object
db.collection.aggregate([
{
$project: {
root: "$$ROOT",
duration: {
$toInt: 15
},
"start": {
$reduce: {
"input": "$activity",
initialValue: ISODate("2100-01-01"),
in: {
$min: [
"$$value",
"$$this.start_timestamp",
"$$this.end_timestamp"
]
}
}
},
"end": {
$reduce: {
"input": "$activity",
initialValue: ISODate("1970-01-01"),
in: {
$max: [
"$$value",
"$$this.start_timestamp",
"$$this.end_timestamp"
]
}
}
}
}
},
{
$addFields: {
interval: {
$range: [
0,
{
$round: {
$divide: [
{
$toLong: {
$subtract: [
"$end",
"$start"
]
}
},
{
$multiply: [
"$duration",
60,
1000
]
}
]
}
},
1
]
}
}
},
{
$unwind: "$interval"
},
{
$addFields: {
from: {
$add: [
"$start",
{
$multiply: [
"$interval",
{
$multiply: [
"$duration",
60,
1000
]
}
]
}
]
},
to: {
$min: [
"$end",
{
$add: [
"$start",
{
$multiply: [
{
$add: [
"$interval",
1
]
},
{
$multiply: [
"$duration",
60,
1000
]
}
]
}
]
}
]
},
activity: "$root.activity"
}
},
{
$addFields: {
activity: {
$filter: {
input: "$activity",
cond: {
$or: [
{
$and: [
{
$gte: [
"$$this.start_timestamp",
"$from"
]
},
{
$lte: [
"$$this.end_timestamp",
"$to"
]
}
]
},
{
$and: [
{
$lte: [
"$$this.start_timestamp",
"$to"
]
},
{
$gte: [
"$$this.end_timestamp",
"$from"
]
}
]
}
]
}
}
}
}
},
{
$project: {
_id: {
$concat: [
{
$toString: "$from"
},
" to ",
{
$toString: "$to"
}
]
},
name: "$root.name",
duration: {
$concat: [
{
$toString: "$duration"
},
" min"
]
},
"brake-up": {
$map: {
input: "$activity",
in: {
k: "$$this.type",
v: {
$round: {
$divide: [
{
"$subtract": [
{
$min: [
"$$this.end_timestamp",
"$to"
]
},
{
$max: [
"$$this.start_timestamp",
"$from"
]
}
]
},
{
$multiply: [
60,
1000
]
}
]
}
}
}
}
}
}
},
{
$unwind: "$brake-up"
},
{
$group: {
_id: {
_id: "$_id",
duration: "$duration",
name: "$name",
"brake-up-k": "$brake-up.k"
},
"brake-up-v": {
$sum: "$brake-up.v"
}
}
},
{
$group: {
_id: {
_id: "$_id._id",
duration: "$_id.duration",
name: "$_id.name"
},
"brake-up": {
$push: {
k: "$_id.brake-up-k",
v: {
$concat: [
{
$toString: "$brake-up-v"
},
" min"
]
}
}
}
}
},
{
$project: {
_id: "$_id._id",
name: "$_id.name",
duration: "$_id.duration",
"brake-up": {
$arrayToObject: "$brake-up"
}
}
},
{
$sort: {
_id: 1
}
}
])
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