import * as Comlink from 'comlink'

import createWorkerProxy from './create-worker-proxy.js'
import loadEmscriptenModuleMainThread from './internal/load-emscripten-module-main-thread.js'

import { simd } from 'wasm-feature-detect'

import InterfaceTypes from '../interface-types/interface-types.js'
import runPipelineEmscripten from './internal/run-pipeline-emscripten.js'
import getTransferables from '../get-transferables.js'
import BinaryStream from '../interface-types/binary-stream.js'
import BinaryFile from '../interface-types/binary-file.js'
import Image from '../interface-types/image.js'
import Mesh from '../interface-types/mesh.js'
import PolyData from '../interface-types/poly-data.js'

import PipelineEmscriptenModule from './pipeline-emscripten-module.js'
import PipelineOutput from './pipeline-output.js'
import PipelineInput from './pipeline-input.js'
import RunPipelineResult from './run-pipeline-result.js'
import RunPipelineOptions from './run-pipeline-options.js'
import imageTransferables from './internal/image-transferables.js'
import meshTransferables from './internal/mesh-transferables.js'
import polyDataTransferables from './internal/poly-data-transferables.js'
import TypedArray from '../typed-array.js'
import RunPipelineWorkerResult from './web-workers/run-pipeline-worker-result.js'
import { getPipelinesBaseUrl } from './pipelines-base-url.js'
import { getPipelinesQueryParams } from './pipelines-query-params.js'
import { getPipelineWorkerUrl } from './pipeline-worker-url.js'

// To cache loaded pipeline modules
const pipelineToModule: Map<string, PipelineEmscriptenModule> = new Map()

function defaultPipelineWorkerUrl (): string | URL | null {
  let result = getPipelineWorkerUrl()
  if (typeof result === 'undefined') {
    result = null
  }
  return result
}

function defaultPipelinesBaseUrl (): string {
  let result = getPipelinesBaseUrl()
  if (typeof result === 'undefined') {
    result = new URL('/pipelines', document.location.origin).href
  }
  return result as string
}

function defaultPipelinesQueryParams (): RunPipelineOptions['pipelineQueryParams'] {
  let result = getPipelinesQueryParams()
  if (typeof result === 'undefined') {
    result = {}
  }
  return result
}

async function loadPipelineModule (
  pipelinePath: string | URL,
  pipelineBaseUrl?: string | URL,
  pipelineQueryParams?: RunPipelineOptions['pipelineQueryParams']
): Promise<PipelineEmscriptenModule> {
  let moduleRelativePathOrURL: string | URL = pipelinePath as string
  let pipeline = pipelinePath as string
  if (typeof pipelinePath !== 'string') {
    moduleRelativePathOrURL = new URL(pipelinePath.href)
    pipeline = moduleRelativePathOrURL.href
  }
  if (pipelineToModule.has(pipeline)) {
    return pipelineToModule.get(pipeline) as PipelineEmscriptenModule
  } else {
    const pipelineModule = (await loadEmscriptenModuleMainThread(
      pipelinePath,
      pipelineBaseUrl?.toString() ?? defaultPipelinesBaseUrl(),
      pipelineQueryParams ?? defaultPipelinesQueryParams()
    )) as PipelineEmscriptenModule
    pipelineToModule.set(pipeline, pipelineModule)
    return pipelineModule
  }
}

async function runPipeline (
  pipelinePath: string | URL,
  args: string[],
  outputs: PipelineOutput[] | null,
  inputs: PipelineInput[] | null,
  options?: RunPipelineOptions
): Promise<RunPipelineResult> {
  if (!await simd()) {
    const simdErrorMessage = 'WebAssembly SIMD support is required -- please update your browser.'
    alert(simdErrorMessage)
    throw new Error(simdErrorMessage)
  }
  const webWorker = options?.webWorker ?? null

  if (webWorker === false) {
    const pipelineModule = await loadPipelineModule(
      pipelinePath.toString(),
      options?.pipelineBaseUrl,
      options?.pipelineQueryParams ?? defaultPipelinesQueryParams()
    )
    const result = runPipelineEmscripten(pipelineModule, args, outputs, inputs)
    return result
  }
  let worker = webWorker
  const pipelineWorkerUrl = options?.pipelineWorkerUrl ?? defaultPipelineWorkerUrl()
  const pipelineWorkerUrlString = typeof pipelineWorkerUrl !== 'string' && typeof pipelineWorkerUrl?.href !== 'undefined' ? pipelineWorkerUrl.href : pipelineWorkerUrl
  const { workerProxy, worker: usedWorker } = await createWorkerProxy(
    worker as Worker | null,
    pipelineWorkerUrlString as string | undefined | null,
    options?.pipelineQueryParams ?? defaultPipelinesQueryParams()
  )
  worker = usedWorker
  const transferables: Array<ArrayBuffer | TypedArray | null> = []
  if (!(inputs == null) && inputs.length > 0) {
    inputs.forEach(function (input) {
      if (input.type === InterfaceTypes.BinaryStream) {
        // Binary data
        const dataArray = (input.data as BinaryStream).data
        transferables.push(dataArray)
      } else if (input.type === InterfaceTypes.BinaryFile) {
        // Binary data
        const dataArray = (input.data as BinaryFile).data
        transferables.push(dataArray)
      } else if (input.type === InterfaceTypes.Image) {
        // Image data
        const image = input.data as Image
        if (image.data !== null) {
          transferables.push(...imageTransferables(image))
        }
      } else if (input.type === InterfaceTypes.Mesh) {
        // Mesh data
        const mesh = input.data as Mesh
        transferables.push(...meshTransferables(mesh))
      } else if (input.type === InterfaceTypes.PolyData) {
        // PolyData data
        const polyData = input.data as PolyData
        transferables.push(...polyDataTransferables(polyData))
      }
    })
  }
  const pipelineBaseUrl = options?.pipelineBaseUrl ?? defaultPipelinesBaseUrl()
  const pipelineBaseUrlString = typeof pipelineBaseUrl !== 'string' && typeof pipelineBaseUrl?.href !== 'undefined' ? pipelineBaseUrl.href : pipelineBaseUrl
  const transferedInputs = (inputs != null) ? Comlink.transfer(inputs, getTransferables(transferables, options?.noCopy)) : null
  const result: RunPipelineWorkerResult = await workerProxy.runPipeline(
    pipelinePath.toString(),
    pipelineBaseUrlString as string,
    args,
    outputs,
    transferedInputs,
    options?.pipelineQueryParams ?? defaultPipelinesQueryParams()
  )
  return {
    returnValue: result.returnValue,
    stdout: result.stdout,
    stderr: result.stderr,
    outputs: result.outputs,
    webWorker: worker
  }
}

export default runPipeline