import { Request as ExpressRequest, Response as ExpressResponse } from 'express'
import { isObj } from 'exotic'
import { LoggingMetaType } from './typings'
import { Timer } from './Timer'
import { trace } from './trace'

// put in typings...
export interface OneUrl {
  full: string
  host: string
}
export type ExpressRequestWithMeta = ExpressRequest & {
  timer?: Timer
  meta?: LoggingMetaType
  oneUrl: OneUrl
}
export type ExpressResponseWithMeta = ExpressResponse & {
  meta?: LoggingMetaType
}

/**
 * @todo move to own filee
 */
export class Tracer {
  static init(req: ExpressRequestWithMeta, appName: string) {
    const tracer = new Tracer(req, appName)
    return tracer
  }

  req: ExpressRequestWithMeta
  spans: Map<string, any> = new Map()
  appName: string

  constructor(req: ExpressRequestWithMeta, appName: string) {
    this.appName = appName
    this.req = req
  }

  get meta() {
    return this.req.meta
  }

  get headers() {
    return {
      ...this.req.headers,
      ...this.req.res!.getHeaders(),
    } as any
  }

  start(spanName: string) {
    const timer = Timer.init()
    this.spans.set(spanName, { timer })
    return this
  }
  finish(spanName: string) {
    const span = this.spans.get(spanName)
    const { timer } = span
    // @todo `get url` to fallback?
    const url = isObj(this.req.oneUrl) === true ? this.req.oneUrl.full : '@@EMPTY'
    trace({ appName: this.appName, spanName, timer, url, headers: this.headers, meta: this.req.meta })
  }
}