import { FilterStats, MAX_FILE_REQUESTS } from "builder-util"
import { realpathSync } from "fs"
import { lstat, lstatSync, readdir } from "fs-extra"
import * as path from "path"
import asyncPool from "tiny-async-pool"
import { excludedNames, FileMatcher } from "../fileMatcher"
import { Packager } from "../packager"
import { FileCopyHelper } from "./AppFileWalker"
import { NodeModuleInfo } from "./packageDependencies"
import { resolveFunction } from "./resolve"

const excludedFiles = new Set(
  [
    ".DS_Store",
    "node_modules" /* already in the queue */,
    "CHANGELOG.md",
    "ChangeLog",
    "changelog.md",
    "Changelog.md",
    "Changelog",
    "binding.gyp",
    ".npmignore",
    "node_gyp_bins",
  ].concat(excludedNames.split(","))
)

const topLevelExcludedFiles = new Set([
  "karma.conf.js",
  ".coveralls.yml",
  "README.md",
  "readme.markdown",
  "README",
  "readme.md",
  "Readme.md",
  "Readme",
  "readme",
  "test",
  "tests",
  "__tests__",
  "powered-test",
  "example",
  "examples",
  ".bin",
])

/** @internal */
export class NodeModuleCopyHelper extends FileCopyHelper {
  constructor(matcher: FileMatcher, packager: Packager) {
    super(matcher, matcher.isEmpty() ? null : matcher.createFilter(), packager)
  }

  async collectNodeModules(moduleInfo: NodeModuleInfo, nodeModuleExcludedExts: Array<string>, destination: string): Promise<Array<string>> {
    const filter = this.filter
    const metadata = this.metadata

    const onNodeModuleFile = await resolveFunction(this.packager.appInfo.type, this.packager.config.onNodeModuleFile, "onNodeModuleFile")

    const result: Array<string | undefined> = []
    const queue: Array<string> = []
    const emptyDirs: Set<string> = new Set()
    const symlinkFiles: Map<string, number> = new Map()
    const tmpPath = moduleInfo.dir
    const moduleName = moduleInfo.name
    queue.length = 1
    // The path should be corrected in Windows that when the moduleName is Scoped packages named.
    const depPath = path.normalize(tmpPath)
    queue[0] = depPath

    while (queue.length > 0) {
      const dirPath = queue.pop()!

      const childNames = await readdir(dirPath)
      childNames.sort()

      const isTopLevel = dirPath === depPath
      const dirs: Array<string> = []
      // our handler is async, but we should add sorted files, so, we add file to result not in the mapper, but after map
      const sortedFilePaths = await asyncPool(MAX_FILE_REQUESTS, childNames, async name => {
        const filePath = path.join(dirPath, name)

        const forceIncluded = onNodeModuleFile != null && !!onNodeModuleFile(filePath)

        if (excludedFiles.has(name) || name.startsWith("._")) {
          return null
        }

        // check if filematcher matches the files array as more important than the default excluded files.
        const fileMatched = filter != null && filter(dirPath, lstatSync(dirPath))
        if (!fileMatched || !forceIncluded || !!this.packager.config.disableDefaultIgnoredFiles) {
          for (const ext of nodeModuleExcludedExts) {
            if (name.endsWith(ext)) {
              return null
            }
          }

          // noinspection SpellCheckingInspection
          if (isTopLevel && (topLevelExcludedFiles.has(name) || (moduleName === "libui-node" && (name === "build" || name === "docs" || name === "src")))) {
            return null
          }

          if (dirPath.endsWith("build")) {
            if (name === "gyp-mac-tool" || name === "Makefile" || name.endsWith(".mk") || name.endsWith(".gypi") || name.endsWith(".Makefile")) {
              return null
            }
          } else if (dirPath.endsWith("Release") && (name === ".deps" || name === "obj.target")) {
            return null
          } else if (name === "src" && (dirPath.endsWith("keytar") || dirPath.endsWith("keytar-prebuild"))) {
            return null
          } else if (dirPath.endsWith("lzma-native") && (name === "build" || name === "deps")) {
            return null
          }
        }

        return lstat(filePath).then((stat: FilterStats) => {
          stat.moduleName = moduleName
          stat.moduleRootPath = destination
          stat.moduleFullFilePath = path.join(destination, path.relative(depPath, filePath))
          if (filter != null && !filter(filePath, stat)) {
            return null
          }

          if (!stat.isDirectory()) {
            metadata.set(filePath, stat)
          }
          const consumerResult = this.handleFile(filePath, dirPath, stat)
          if (consumerResult == null) {
            if (stat.isDirectory()) {
              dirs.push(name)
              return null
            } else {
              return filePath
            }
          } else {
            return consumerResult.then(it => {
              // asarUtil can return modified stat (symlink handling)
              if ((it == null ? stat : it).isDirectory()) {
                dirs.push(name)
                return null
              } else {
                return filePath
              }
            })
          }
        })
      })

      let isEmpty = true
      for (const child of sortedFilePaths) {
        if (child != null) {
          result.push(child)
          if (this.metadata.get(child)?.isSymbolicLink()) {
            symlinkFiles.set(child, result.length - 1)
          }
          isEmpty = false
        }
      }

      if (isEmpty) {
        emptyDirs.add(dirPath)
      }

      dirs.sort()
      for (const child of dirs) {
        queue.push(dirPath + path.sep + child)
      }
    }

    for (const [file, index] of symlinkFiles) {
      const resolvedPath = realpathSync(file)
      if (emptyDirs.has(resolvedPath)) {
        // delete symlink file if target is a empty dir
        result[index] = undefined
      }
    }
    return result.filter((it): it is string => it !== undefined)
  }
}