import ObjectLoader from '@speckle/objectloader'
import Converter from './converter/Converter'

/**
 * Helper wrapper around the ObjectLoader class, with some built in assumptions.
 */

export default class ViewerObjectLoader {
  constructor(parent, objectUrl, authToken, enableCaching) {
    this.objectUrl = objectUrl
    this.viewer = parent
    this.token = null
    try {
      this.token = authToken || localStorage.getItem('AuthToken')
    } catch (error) {
      // Accessing localStorage may throw when executing on sandboxed document, ignore.
    }

    if (!this.token) {
      console.warn(
        'Viewer: no auth token present. Requests to non-public stream objects will fail.'
      )
    }

    // example url: `https://staging.speckle.dev/streams/a75ab4f10f/objects/f33645dc9a702de8af0af16bd5f655b0`
    const url = new URL(objectUrl)

    const segments = url.pathname.split('/')
    if (
      segments.length < 5 ||
      url.pathname.indexOf('streams') === -1 ||
      url.pathname.indexOf('objects') === -1
    ) {
      throw new Error('Unexpected object url format.')
    }

    this.serverUrl = url.origin
    this.streamId = segments[2]
    this.objectId = segments[4]

    this.loader = new ObjectLoader({
      serverUrl: this.serverUrl,
      token: this.token,
      streamId: this.streamId,
      objectId: this.objectId,
      options: { enableCaching }
    })

    this.converter = new Converter(this.loader)

    this.lastAsyncPause = Date.now()
    this.existingAsyncPause = null
    this.cancel = false
  }

  async asyncPause() {
    // Don't freeze the UI
    if (Date.now() - this.lastAsyncPause >= 100) {
      this.lastAsyncPause = Date.now()
      await new Promise((resolve) => setTimeout(resolve, 0))
    }
  }

  async load() {
    let first = true
    let current = 0
    let total = 0
    let viewerLoads = 0
    let firstObjectPromise = null
    const parsedObjects = [] // Temporary until refactor
    for await (const obj of this.loader.getObjectIterator()) {
      if (this.cancel) {
        this.viewer.emit('load-progress', {
          progress: 1,
          id: this.objectId,
          url: this.objectUrl
        }) // to hide progress bar, easier on the frontend
        this.viewer.emit('load-cancelled', { id: this.objectId, url: this.objectUrl })
        return
      }
      await this.converter.asyncPause()
      if (first) {
        // console.log(obj)
        firstObjectPromise = this.converter.traverseAndConvert(
          obj,
          async (objectWrapper) => {
            await this.converter.asyncPause()
            objectWrapper.meta.__importedUrl = this.objectUrl
            parsedObjects.push(objectWrapper) // Temporary until refactor
            viewerLoads++
          }
        )
        first = false
        total = obj.totalChildrenCount
      }
      current++
      this.viewer.emit('load-progress', {
        progress: current / (total + 1),
        id: this.objectId
      })
    }

    if (firstObjectPromise) {
      await firstObjectPromise
    }

    // Geometry.applyWorldTransform(parsedObjects)
    // Temporary until refactor
    for (let k = 0; k < parsedObjects.length; k++) {
      await this.converter.asyncPause()
      this.viewer.sceneManager.addObject(parsedObjects[k])
    }
    await this.viewer.sceneManager.postLoadFunction()
    this.viewer.emit('load-complete')

    if (viewerLoads === 0) {
      console.warn(`Viewer: no 3d objects found in object ${this.objectId}`)
      this.viewer.emit('load-warning', {
        message: `No displayable objects found in object ${this.objectId}.`
      })
    }
  }

  async unload() {
    this.cancel = true
    await this.viewer.sceneManager.removeImportedObject(this.objectUrl)
  }

  cancelLoad() {
    this.cancel = true
  }
}