'use strict'

const assert = require('node:assert').strict

const noop = Function.prototype

function omit(source, keys, target = { __proto__: null }) {
  for (const key of Object.keys(source)) {
    if (!keys.has(key)) {
      target[key] = source[key]
    }
  }
  return target
}

const IGNORED_START_PROPS = new Set([
  'end',
  'infos',
  'properties',
  'result',
  'status',
  'tasks',
  'timestamp',
  'type',
  'warnings',
])

exports.makeOnProgress = function ({ onRootTaskEnd = noop, onRootTaskStart = noop, onTaskUpdate = noop }) {
  const taskLogs = new Map()
  return function onProgress(event) {
    const { id, type } = event
    let taskLog
    if (type === 'start') {
      taskLog = omit(event, IGNORED_START_PROPS)
      taskLog.start = event.timestamp
      taskLog.status = 'pending'
      taskLogs.set(id, taskLog)

      const { parentId } = event
      if (parentId === undefined) {
        Object.defineProperty(taskLog, '$root', { value: taskLog })

        // start of a root task
        onRootTaskStart(taskLog)
      } else {
        // start of a subtask
        const parent = taskLogs.get(parentId)
        assert.notEqual(parent, undefined)

        // inject a (non-enumerable) reference to the parent and the root task
        Object.defineProperty(taskLog, { $parent: { value: parent }, $root: { value: parent.$root } })
        ;(parent.tasks ?? (parent.tasks = [])).push(taskLog)
      }
    } else {
      taskLog = taskLogs.get(id)
      assert.notEqual(taskLog, undefined)

      if (type === 'info' || type === 'warning') {
        const key = type + 's'
        const { data, message } = event
        ;(taskLog[key] ?? (taskLog[key] = [])).push({ data, message })
      } else if (type === 'property') {
        ;(taskLog.properties ?? (taskLog.properties = { __proto__: null }))[event.name] = event.value
      } else if (type === 'end') {
        taskLog.end = event.timestamp
        taskLog.result = event.result
        taskLog.status = event.status
      }

      if (type === 'end' && taskLog.$root === taskLog) {
        onRootTaskEnd(taskLog)
      }
    }

    onTaskUpdate(taskLog)
  }
}