import path from 'path'

import loadEmscriptenModuleNode from './internal/load-emscripten-module-node.js'
import runPipelineEmscripten from './internal/run-pipeline-emscripten.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'

function windowsToEmscriptenPath (filePath: string): string {
  // Following mount logic in itkJSPost.js
  const fileBasename = path.basename(filePath)
  const containingDir = path.dirname(filePath)
  let mountedPath = '/'
  const splitPath = containingDir.split(path.sep)
  for (let ii = 1; ii < splitPath.length; ii++) {
    mountedPath += splitPath[ii]
    mountedPath += '/'
  }
  mountedPath += fileBasename
  return mountedPath
}

function replaceArgumentsWithEmscriptenPaths (
  args: string[],
  mountDirs: Set<string>
): string[] {
  if (typeof process === 'undefined' || process.platform !== 'win32') {
    return args
  }
  return args.map((arg) => {
    for (const mountDir of mountDirs) {
      if (arg.startsWith(mountDir)) {
        return windowsToEmscriptenPath(arg)
      }
    }
    return arg
  })
}

async function runPipelineNode (
  pipelinePath: string,
  args: string[],
  outputs: PipelineOutput[],
  inputs: PipelineInput[] | null,
  mountDirs?: Set<string>
): Promise<RunPipelineResult> {
  const Module = (await loadEmscriptenModuleNode(
    pipelinePath
  )) as PipelineEmscriptenModule
  const mountedDirs: Set<string> = new Set()
  const unmountable: Set<string> = new Set()
  if (typeof mountDirs !== 'undefined') {
    mountDirs.forEach((dir) => {
      mountedDirs.add(Module.mountDir(dir))
    })
    /**
     * Identify mountable dirs. Some paths may be parent to others.
     * Only keep the parent paths, to avoid error when unmounting.
     */
    Array.from(mountedDirs)
      .filter((x, _, a) => a.every((y) => x === y || !x.includes(y)))
      .forEach((dir) => unmountable.add(dir)
      )
  }
  if (typeof mountDirs !== 'undefined') {
    args = replaceArgumentsWithEmscriptenPaths(args, mountDirs)
  }
  const result = runPipelineEmscripten(Module, args, outputs, inputs)
  if (typeof mountDirs !== 'undefined') {
    unmountable.forEach((dir) => {
      Module.unmountDir(dir)
    })
  }
  return result
}

export default runPipelineNode