const { performance, createHistogram } = require('perf_hooks')
const util = require('util')
const Logger = require('../Logger')

const histograms = new Map()

function createRequestScopedFindOptions(findOptions, funcName) {
  if (!findOptions || typeof findOptions !== 'object' || Array.isArray(findOptions)) {
    return findOptions
  }

  return {
    ...findOptions,
    logging: (query, time) => Logger.info(`[${funcName}] ${query} Elapsed time: ${time}ms`),
    benchmark: true
  }
}

function profile(asyncFunc, isFindQuery = true, funcName = asyncFunc.name) {
  if (!histograms.has(funcName)) {
    const histogram = createHistogram()
    histogram.values = []
    histograms.set(funcName, histogram)
  }
  const histogram = histograms.get(funcName)

  return async (...args) => {
    const requestArgs = isFindQuery ? [createRequestScopedFindOptions(args[0], funcName), ...args.slice(1)] : args

    if (isFindQuery) {
      const findOptions = requestArgs[0]
      Logger.info(`[${funcName}] findOptions:`, util.inspect(findOptions, { depth: null }))
    }
    const start = performance.now()
    try {
      const result = await asyncFunc(...requestArgs)
      return result
    } catch (error) {
      Logger.error(`[${funcName}] failed`)
      throw error
    } finally {
      const end = performance.now()
      const duration = Math.round(end - start)
      histogram.record(duration)
      histogram.values.push(duration)
      Logger.info(`[${funcName}] duration: ${duration}ms`)
      Logger.info(`[${funcName}] histogram values:`, histogram.values)
      Logger.info(`[${funcName}] histogram:`, histogram)
    }
  }
}

module.exports = { profile }