import type { RelativeTime, TimeStamp } from '@openobserve/browser-core'
import { getRelativeTime, isNumber } from '@openobserve/browser-core'
import type { RumPerformanceNavigationTiming } from './performanceObservable'
import { RumPerformanceEntryType, supportPerformanceTimingEvent } from './performanceObservable'

export function getNavigationEntry(): RumPerformanceNavigationTiming {
  if (supportPerformanceTimingEvent(RumPerformanceEntryType.NAVIGATION)) {
    const navigationEntry = performance.getEntriesByType(
      RumPerformanceEntryType.NAVIGATION
    )[0] as unknown as RumPerformanceNavigationTiming
    if (navigationEntry) {
      return navigationEntry
    }
  }

  const timings = computeTimingsFromDeprecatedPerformanceTiming()
  const entry: RumPerformanceNavigationTiming = {
    entryType: RumPerformanceEntryType.NAVIGATION as const,
    initiatorType: 'navigation' as const,
    name: window.location.href,
    startTime: 0 as RelativeTime,
    duration: timings.loadEventEnd,
    decodedBodySize: 0,
    encodedBodySize: 0,
    transferSize: 0,
    workerStart: 0 as RelativeTime,
    toJSON: () => ({ ...entry, toJSON: undefined }),
    ...timings,
  }

  return entry
}

export type TimingsFromDeprecatedPerformanceTiming = {
  -readonly [key in keyof Omit<PerformanceTiming, 'toJSON'>]: RelativeTime
}

export function computeTimingsFromDeprecatedPerformanceTiming() {
  const result: Partial<TimingsFromDeprecatedPerformanceTiming> = {}
  const timing = performance.timing

  for (const key in timing) {
    if (isNumber(timing[key as keyof PerformanceTiming])) {
      const numberKey = key as keyof TimingsFromDeprecatedPerformanceTiming
      const timingElement = timing[numberKey] as TimeStamp
      result[numberKey] = timingElement === 0 ? (0 as RelativeTime) : getRelativeTime(timingElement)
    }
  }
  return result as TimingsFromDeprecatedPerformanceTiming
}