import type { CloneOption, DefineWorkerOptions, Procedure } from './types'
import { startWebWorkerModuleRunner } from './runner'
import { createMessageEvent, debug, getFileIdFromUrl } from './utils'

export function createWorkerConstructor(options?: DefineWorkerOptions): typeof Worker {
  const cloneType = () =>
    (options?.clone ?? process.env.VITEST_WEB_WORKER_CLONE ?? 'native') as CloneOption

  return class Worker extends EventTarget {
    static __VITEST_WEB_WORKER__ = true

    private _vw_workerTarget = new EventTarget()
    private _vw_insideListeners = new Map<string, EventListenerOrEventListenerObject>()

    private _vw_outsideListeners = new Map<string, EventListenerOrEventListenerObject>()

    private _vw_name: string
    private _vw_messageQueue: any[] | null = []

    public onmessage: null | Procedure = null
    public onmessageerror: null | Procedure = null
    public onerror: null | Procedure = null

    constructor(url: URL | string, options?: WorkerOptions) {
      super()

      let selfProxy: typeof globalThis

      // should be in sync with DedicatedWorkerGlobalScope, but without globalThis
      const context = {
        onmessage: null as null | ((e: MessageEvent) => void),
        onmessageerror: null,
        onerror: null,
        onlanguagechange: null,
        onoffline: null,
        ononline: null,
        onrejectionhandled: null,
        onrtctransform: null,
        onunhandledrejection: null,
        origin: typeof location !== 'undefined' ? location.origin : 'http://localhost:3000',
        crossOriginIsolated: false,
        name: options?.name || '',
        close: () => this.terminate(),
        dispatchEvent: (event: Event) => {
          return this._vw_workerTarget.dispatchEvent(event)
        },
        addEventListener: (...args: any[]) => {
          if (args[1]) {
            this._vw_insideListeners.set(args[0], args[1])
          }
          return this._vw_workerTarget.addEventListener(...(args as [any, any]))
        },
        removeEventListener: (...args: any[]) => {
          return this._vw_workerTarget.removeEventListener(...(args as [any, any]))
        },
        postMessage: (...args: any[]) => {
          if (!args.length) {
            throw new SyntaxError('"postMessage" requires at least one argument.')
          }

          debug('posting message %o from the worker %s to the main thread', args[0], this._vw_name)
          const event = createMessageEvent(args[0], args[1], cloneType())
          this.dispatchEvent(event)
        },
        get self() {
          return selfProxy
        },
      }

      selfProxy = new Proxy(context, {
        get(target, prop, receiver) {
          if (Reflect.has(target, prop)) {
            return Reflect.get(target, prop, receiver)
          }
          return globalThis[prop as 'crypto']
        },
      }) as any

      this._vw_workerTarget.addEventListener('message', (e) => {
        context.onmessage?.(e as MessageEvent)
      })

      this.addEventListener('message', (e) => {
        this.onmessage?.(e)
      })

      this.addEventListener('messageerror', (e) => {
        this.onmessageerror?.(e)
      })

      const fileId = getFileIdFromUrl(url)

      this._vw_name = fileId

      const runner = startWebWorkerModuleRunner(context)
      runner.mocker
        .resolveId(fileId)
        .then(({ url, id: resolvedId }) => {
          this._vw_name = options?.name ?? url
          debug('initialize worker %s', this._vw_name)

          return runner.import(url).then(() => {
            runner._invalidateSubTreeById([resolvedId, runner.mocker.getMockPath(resolvedId)])
            const q = this._vw_messageQueue
            this._vw_messageQueue = null
            if (q) {
              q.forEach(([data, transfer]) => this.postMessage(data, transfer), this)
            }
            debug('worker %s successfully initialized', this._vw_name)
          })
        })
        .catch((e) => {
          debug('worker %s failed to initialize: %o', this._vw_name, e)
          const EventConstructor = globalThis.ErrorEvent || globalThis.Event
          const error = new EventConstructor('error', {
            error: e,
            message: e.message,
          })
          this.dispatchEvent(error)
          this.onerror?.(error)
          console.error(e)
        })
    }

    addEventListener(
      type: string,
      callback: EventListenerOrEventListenerObject | null,
      options?: boolean | AddEventListenerOptions,
    ): void {
      if (callback) {
        this._vw_outsideListeners.set(type, callback)
      }
      return super.addEventListener(type, callback, options)
    }

    postMessage(...args: [any, StructuredSerializeOptions | Transferable[] | undefined]): void {
      if (!args.length) {
        throw new SyntaxError('"postMessage" requires at least one argument.')
      }

      const [data, transferOrOptions] = args
      if (this._vw_messageQueue != null) {
        debug('worker %s is not yet initialized, queue message %s', this._vw_name, data)
        this._vw_messageQueue.push([data, transferOrOptions])
        return
      }

      debug('posting message %o from the main thread to the worker %s', data, this._vw_name)

      const event = createMessageEvent(data, transferOrOptions, cloneType())
      if (event.type === 'messageerror') {
        this.dispatchEvent(event)
      } else {
        this._vw_workerTarget.dispatchEvent(event)
      }
    }

    terminate() {
      debug('terminating worker %s', this._vw_name)
      this._vw_outsideListeners.forEach((fn, type) => {
        this.removeEventListener(type, fn)
      })
      this._vw_insideListeners.forEach((fn, type) => {
        this._vw_workerTarget.removeEventListener(type, fn)
      })
    }
  }
}