資料依據時間區間做分類

data-classify-with-time-period.js

const getRandomTime = () => Math.floor(Math.random() * 10000)
const time = Date.now()

const data = [
  { timestamp: time + getRandomTime(), message: 'hello1', user: 'user1' },
  { timestamp: time + getRandomTime(), message: 'hello2', user: 'user2' },
  { timestamp: time + getRandomTime(), message: 'hello3', user: 'user3' },
  { timestamp: time + getRandomTime(), message: 'hello4', user: 'user1' },
  { timestamp: time + getRandomTime(), message: 'hello5', user: 'user2' },
  { timestamp: time + getRandomTime(), message: 'hello6', user: 'user3' },
  { timestamp: time + getRandomTime(), message: 'hello7', user: 'user1' },
  { timestamp: time + getRandomTime(), message: 'hello8', user: 'user2' },
  { timestamp: time + getRandomTime(), message: 'hello9', user: 'user3' },
  { timestamp: time + getRandomTime(), message: 'hello10', user: 'user1' }
]

const start = time
const end = time + 5 * 1000
const duration = 1000

const users = ['user1', 'user2']

let expectResponse = []

for (let i = start; i <= end; i += duration) {
  let usersCount = []

  for (let user of users) {
    const messageCount = data.reduce((counts, message) => {
      if (
        message.timestamp >= i &&
        message.timestamp < i + duration &&
        message.user === user
      ) {
        return counts + 1
      } else {
        return counts
      }
    }, 0)
    usersCount.push({ id: user, count: messageCount })
  }

  expectResponse.push({
    start: i,
    messagesCount: usersCount
  })
}

/* Output Data Format
[
    {
        start: 12344444
        messagesCount:[
            {id:'user1',count:2},
            {id:'user2',count:4},
            {id:'user3',count:5}
        ]
    },
    {
        start: 12354444,
            {id:'user1',count:1},
            {id:'user2',count:1},
            {id:'user3',count:0}
        
    },
    {
        start: 12364444,
            {id:'user1',count:3},
            {id:'user2',count:2},
            {id:'user3',count:1}
        
    }
]
*/