logs_working_pre_refactor.js

const MinHeap = require('min-heap')

module.exports = class Sorter {
	constructor(logSources, printer, async = false) {
		this.heap = new MinHeap
		this.min = null
		this.logsObj = {}
		this.currentMinLog = null
		this.complete = false
		this.logSources = logSources
		this.printer = printer
    this.async = async
	}

	initialSetup() {
    this.async ? this.startAsync() : this.startSync()
	}

  startSync() {
    this.logSources.map((source) => {
      const logEntry = source.pop()
      const date = logEntry.date.getTime()
      logEntry.source = source
      this.insertIntoLogsObj(date, logEntry)
      this.heap.insert(date)
    })
    this.loopLogs()
  }

  async startAsync() {
    await Promise.all(this.logSources.map(this.buildlogObjAsync.bind(this)))
    this.loopLogsAsync()
  }

  async start() {

  }

	loopLogs() {
		while(!this.complete) {
			const min = this.heap.removeHead()
			if(!min) {
				this.complete = true
				return this.printer.done()
			}
			const currentMinLog = this.logsObj[min]
			if(currentMinLog.length) {
				currentMinLog.forEach((log) => this.printAndPop(log))
			} else {
				this.printAndPop(currentMinLog)
			}
		}
	}

  async loopLogsAsync() {
    while(!this.complete) {
      const min = this.heap.removeHead()
      // the heap does not refelct the logsObject
      // the heap is empty while the logsObj is not
      if(!min) {
        this.complete = true
        return this.printer.done()
      }
      const currentMinLog = this.logsObj[min]
      if(currentMinLog.length) {
				await currentMinLog.forEach((log) => this.printAndPopAsync(log))
			} else {
				await this.printAndPopAsync(currentMinLog)
			}
    }
  }

	printAndPop(currentMinLog) {
		this.printer.print(currentMinLog)
		const src = currentMinLog.source
		const nextLog = src.pop()
		if(!nextLog) { return }
		const date = nextLog.date.getTime()
		nextLog.source = src
		this.insertIntoLogsObj(date, nextLog)
		this.heap.insert(date)
	}

  async printAndPopAsync(currentMinLog) {
    this.printer.print(currentMinLog)
    const src = currentMinLog.source
    const nextLog = await src.popAsync()
    if(!nextLog) { return }
    const date = nextLog.date.getTime()
    nextLog.source = src
    this.insertIntoLogsObj(date, nextLog)
    this.heap.insert(date)
  }

	insertIntoLogsObj(date, logEntry) {
		if(date in this.logsObj) {
			const oldLogEntry = this.logsObj[date]
			this.logsObj[date] = Array.isArray(oldLogEntry) ?  oldLogEntry.concat(logEntry) : [oldLogEntry, logEntry]
		} else {
			this.logsObj[date] = logEntry
		}
	}

  async buildlogObjAsync(source) {
    const logEntry = await source.popAsync()
    const date = logEntry.date.getTime()
    logEntry.source = source
    this.logsObj[date] = logEntry
    this.heap.insert(date)
  }

}