import { MessageChannel, type MessagePort as NodeMessagePort } from 'node:worker_threads'
import type { InlineWorkerContext, Procedure } from './types'
import { InlineWorkerRunner } from './runner'
import { debug, getFileIdFromUrl, getRunnerOptions } from './utils'

interface SharedInlineWorkerContext extends Omit<InlineWorkerContext, 'onmessage' | 'postMessage' | 'self' | 'global'> {
  onconnect: Procedure | null
  self: SharedInlineWorkerContext
  global: SharedInlineWorkerContext
}

function convertNodePortToWebPort(port: NodeMessagePort): MessagePort {
  if (!('addEventListener' in port)) {
    Object.defineProperty(port, 'addEventListener', {
      value(...args: any[]) {
        return this.addListener(...args)
      },
      configurable: true,
      enumerable: true,
    })
  }
  if (!('removeEventListener' in port)) {
    Object.defineProperty(port, 'removeEventListener', {
      value(...args: any[]) {
        return this.removeListener(...args)
      },
      configurable: true,
      enumerable: true,
    })
  }
  if (!('dispatchEvent' in port)) {
    const emit = port.emit.bind(port)
    Object.defineProperty(port, 'emit', {
      value(event: any) {
        if (event.name === 'message')
          (port as any).onmessage?.(event)
        if (event.name === 'messageerror')
          (port as any).onmessageerror?.(event)
        return emit(event)
      },
      configurable: true,
      enumerable: true,
    })
    Object.defineProperty(port, 'dispatchEvent', {
      value(event: any) {
        return this.emit(event)
      },
      configurable: true,
      enumerable: true,
    })
  }
  return port as any as MessagePort
}

export function createSharedWorkerConstructor(): typeof SharedWorker {
  const runnerOptions = getRunnerOptions()

  return class SharedWorker extends EventTarget {
    static __VITEST_WEB_WORKER__ = true

    private _vw_workerTarget = new EventTarget()
    private _vw_name: string
    private _vw_workerPort: MessagePort

    public onerror: null | Procedure = null

    public port: MessagePort

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

      const name = typeof options === 'string' ? options : options?.name

      // should be equal to SharedWorkerGlobalScope
      const context: SharedInlineWorkerContext = {
        onconnect: null,
        name,
        close: () => this.port.close(),
        dispatchEvent: (event: Event) => {
          return this._vw_workerTarget.dispatchEvent(event)
        },
        addEventListener: (...args) => {
          return this._vw_workerTarget.addEventListener(...args)
        },
        removeEventListener: this._vw_workerTarget.removeEventListener,
        get self() {
          return context
        },
        get global() {
          return context
        },
      }

      const channel = new MessageChannel()
      this.port = convertNodePortToWebPort(channel.port1)
      this._vw_workerPort = convertNodePortToWebPort(channel.port2)

      this._vw_workerTarget.addEventListener('connect', (e) => {
        context.onconnect?.(e)
      })

      const runner = new InlineWorkerRunner(runnerOptions, context)

      const id = getFileIdFromUrl(url)

      this._vw_name = id

      runner.resolveUrl(id).then(([, fsPath]) => {
        this._vw_name = name ?? fsPath

        debug('initialize shared worker %s', this._vw_name)

        return runner.executeFile(fsPath).then(() => {
          // worker should be new every time, invalidate its sub dependency
          runnerOptions.moduleCache.invalidateSubDepTree([fsPath, runner.mocker.getMockPath(fsPath)])
          this._vw_workerTarget.dispatchEvent(
            new MessageEvent('connect', {
              ports: [this._vw_workerPort],
            }),
          )
          debug('shared worker %s successfully initialized', this._vw_name)
        })
      }).catch((e) => {
        debug('shared 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)
      })
    }
  }
}