# Copyright (C) Dominik Picheta. All rights reserved.
# BSD License. Look at license.txt for more info.

import system except TResult

import httpclient, parseopt, os, osproc, pegs, tables, parseutils,
       strtabs, json, algorithm, sets, uri, sugar, sequtils

import strutils except toLower
from unicode import toLower
from sequtils import toSeq

import nimblepkg/packageinfo, nimblepkg/version, nimblepkg/tools,
       nimblepkg/download, nimblepkg/config, nimblepkg/common,
       nimblepkg/publish, nimblepkg/options, nimblepkg/packageparser,
       nimblepkg/cli, nimblepkg/packageinstaller, nimblepkg/reversedeps,
       nimblepkg/nimscriptexecutor, nimblepkg/init

import nimblepkg/nimscriptwrapper

proc refresh(options: Options) =
  ## Downloads the package list from the specified URL.
  ##
  ## If the download is not successful, an exception is raised.
  let parameter =
    if options.action.typ == actionRefresh:
      options.action.optionalURL
    else:
      ""

  if parameter.len > 0:
    if parameter.isUrl:
      let cmdLine = PackageList(name: "commandline", urls: @[parameter])
      fetchList(cmdLine, options)
    else:
      if parameter notin options.config.packageLists:
        let msg = "Package list with the specified name not found."
        raise newException(NimbleError, msg)

      fetchList(options.config.packageLists[parameter], options)
  else:
    # Try each package list in config
    for name, list in options.config.packageLists:
      fetchList(list, options)

proc checkInstallFile(pkgInfo: PackageInfo,
                      origDir, file: string): bool =
  ## Checks whether ``file`` should be installed.
  ## ``True`` means file should be skipped.

  for ignoreFile in pkgInfo.skipFiles:
    if ignoreFile.endswith("nimble"):
      raise newException(NimbleError, ignoreFile & " must be installed.")
    if samePaths(file, origDir / ignoreFile):
      result = true
      break

  for ignoreExt in pkgInfo.skipExt:
    if file.splitFile.ext == ('.' & ignoreExt):
      result = true
      break

  if file.splitFile().name[0] == '.': result = true

proc checkInstallDir(pkgInfo: PackageInfo,
                     origDir, dir: string): bool =
  ## Determines whether ``dir`` should be installed.
  ## ``True`` means dir should be skipped.
  for ignoreDir in pkgInfo.skipDirs:
    if samePaths(dir, origDir / ignoreDir):
      result = true
      break

  let thisDir = splitPath(dir).tail
  assert thisDir != ""
  if thisDir[0] == '.': result = true
  if thisDir == "nimcache": result = true

proc copyWithExt(origDir, currentDir, dest: string,
                 pkgInfo: PackageInfo): seq[string] =
  ## Returns the filenames of the files that have been copied
  ## (their destination).
  result = @[]
  for kind, path in walkDir(currentDir):
    if kind == pcDir:
      result.add copyWithExt(origDir, path, dest, pkgInfo)
    else:
      for iExt in pkgInfo.installExt:
        if path.splitFile.ext == ('.' & iExt):
          createDir(changeRoot(origDir, dest, path).splitFile.dir)
          result.add copyFileD(path, changeRoot(origDir, dest, path))

proc copyFilesRec(origDir, currentDir, dest: string,
                  options: Options, pkgInfo: PackageInfo): HashSet[string] =
  ## Copies all the required files, skips files specified in the .nimble file
  ## (PackageInfo).
  ## Returns a list of filepaths to files which have been installed.
  result = initSet[string]()
  let whitelistMode =
          pkgInfo.installDirs.len != 0 or
          pkgInfo.installFiles.len != 0 or
          pkgInfo.installExt.len != 0
  if whitelistMode:
    for file in pkgInfo.installFiles:
      let src = origDir / file
      if not src.existsFile():
        if options.prompt("Missing file " & src & ". Continue?"):
          continue
        else:
          raise NimbleQuit(msg: "")
      createDir(dest / file.splitFile.dir)
      result.incl copyFileD(src, dest / file)

    for dir in pkgInfo.installDirs:
      # TODO: Allow skipping files inside dirs?
      let src = origDir / dir
      if not src.existsDir():
        if options.prompt("Missing directory " & src & ". Continue?"):
          continue
        else:
          raise NimbleQuit(msg: "")
      result.incl copyDirD(origDir / dir, dest / dir)

    result.incl copyWithExt(origDir, currentDir, dest, pkgInfo)
  else:
    for kind, file in walkDir(currentDir):
      if kind == pcDir:
        let skip = pkgInfo.checkInstallDir(origDir, file)

        if skip: continue
        # Create the dir.
        createDir(changeRoot(origDir, dest, file))

        result.incl copyFilesRec(origDir, file, dest, options, pkgInfo)
      else:
        let skip = pkgInfo.checkInstallFile(origDir, file)

        if skip: continue

        result.incl copyFileD(file, changeRoot(origDir, dest, file))

  result.incl copyFileD(pkgInfo.mypath,
            changeRoot(pkgInfo.mypath.splitFile.dir, dest, pkgInfo.mypath))

proc install(packages: seq[PkgTuple],
             options: Options,
             doPrompt = true): tuple[deps: seq[PackageInfo], pkg: PackageInfo]
proc processDeps(pkginfo: PackageInfo, options: Options): seq[PackageInfo] =
  ## Verifies and installs dependencies.
  ##
  ## Returns the list of PackageInfo (for paths) to pass to the compiler
  ## during build phase.
  result = @[]
  assert(not pkginfo.isMinimal, "processDeps needs pkginfo.requires")
  display("Verifying",
          "dependencies for $1@$2" % [pkginfo.name, pkginfo.specialVersion],
          priority = HighPriority)

  var pkgList {.global.}: seq[tuple[pkginfo: PackageInfo, meta: MetaData]] = @[]
  once: pkgList = getInstalledPkgsMin(options.getPkgsDir(), options)
  var reverseDeps: seq[tuple[name, version: string]] = @[]
  for dep in pkginfo.requires:
    if dep.name == "nimrod" or dep.name == "nim":
      let nimVer = getNimrodVersion()
      if not withinRange(nimVer, dep.ver):
        let msg = "Unsatisfied dependency: " & dep.name & " (" & $dep.ver & ")"
        raise newException(NimbleError, msg)
    else:
      let resolvedDep = dep.resolveAlias(options)
      display("Checking", "for $1" % $resolvedDep, priority = MediumPriority)
      var pkg: PackageInfo
      var found = findPkg(pkgList, resolvedDep, pkg)
      # Check if the original name exists.
      if not found and resolvedDep.name != dep.name:
        display("Checking", "for $1" % $dep, priority = MediumPriority)
        found = findPkg(pkgList, dep, pkg)
        if found:
          display("Warning:", "Installed package $1 should be renamed to $2" %
                  [dep.name, resolvedDep.name], Warning, HighPriority)

      if not found:
        display("Installing", $resolvedDep, priority = HighPriority)
        let toInstall = @[(resolvedDep.name, resolvedDep.ver)]
        let (pkgs, installedPkg) = install(toInstall, options)
        result.add(pkgs)

        pkg = installedPkg # For addRevDep

        # This package has been installed so we add it to our pkgList.
        pkgList.add((pkg, readMetaData(pkg.getRealDir())))
      else:
        display("Info:", "Dependency on $1 already satisfied" % $dep,
                priority = HighPriority)
        result.add(pkg)
        # Process the dependencies of this dependency.
        result.add(processDeps(pkg.toFullInfo(options), options))
      reverseDeps.add((pkg.name, pkg.specialVersion))

  # Check if two packages of the same name (but different version) are listed
  # in the path.
  var pkgsInPath: StringTableRef = newStringTable(modeCaseSensitive)
  for pkgInfo in result:
    if pkgsInPath.hasKey(pkgInfo.name) and
       pkgsInPath[pkgInfo.name] != pkgInfo.version:
      raise newException(NimbleError,
        "Cannot satisfy the dependency on $1 $2 and $1 $3" %
          [pkgInfo.name, pkgInfo.version, pkgsInPath[pkgInfo.name]])
    pkgsInPath[pkgInfo.name] = pkgInfo.version

  # We add the reverse deps to the JSON file here because we don't want
  # them added if the above errorenous condition occurs
  # (unsatisfiable dependendencies).
  # N.B. NimbleData is saved in installFromDir.
  for i in reverseDeps:
    addRevDep(options.nimbleData, i, pkginfo)

proc buildFromDir(pkgInfo: PackageInfo, paths, args: seq[string]) =
  ## Builds a package as specified by ``pkgInfo``.
  if pkgInfo.bin.len == 0:
    raise newException(NimbleError,
        "Nothing to build. Did you specify a module to build using the" &
        " `bin` key in your .nimble file?")
  var args = args
  let realDir = pkgInfo.getRealDir()
  for path in paths: args.add("--path:\"" & path & "\" ")
  for bin in pkgInfo.bin:
    let outputOpt = "-o:\"" & pkgInfo.getOutputDir(bin) & "\""
    display("Building", "$1/$2 using $3 backend" %
            [pkginfo.name, bin, pkgInfo.backend], priority = HighPriority)

    let outputDir = pkgInfo.getOutputDir("")
    if not existsDir(outputDir):
      createDir(outputDir)

    try:
      doCmd("\"" & getNimBin() & "\" $# --noBabelPath $# $# \"$#\"" %
            [pkgInfo.backend, join(args, " "), outputOpt,
             realDir / bin.changeFileExt("nim")])
    except NimbleError:
      let currentExc = (ref NimbleError)(getCurrentException())
      let exc = newException(BuildFailed, "Build failed for package: " &
                             pkgInfo.name)
      let (error, hint) = getOutputInfo(currentExc)
      exc.msg.add("\nDetails:\n" & error)
      exc.hint = hint
      raise exc

proc removePkgDir(dir: string, options: Options) =
  ## Removes files belonging to the package in ``dir``.
  try:
    var nimblemeta = parseFile(dir / "nimblemeta.json")
    if not nimblemeta.hasKey("files"):
      raise newException(JsonParsingError,
                         "Meta data does not contain required info.")
    for file in nimblemeta["files"]:
      removeFile(dir / file.str)

    removeFile(dir / "nimblemeta.json")

    # If there are no files left in the directory, remove the directory.
    if toSeq(walkDirRec(dir)).len == 0:
      removeDir(dir)
    else:
      display("Warning:", ("Cannot completely remove $1. Files not installed " &
              "by nimble are present.") % dir, Warning, HighPriority)

    if nimblemeta.hasKey("binaries"):
      # Remove binaries.
      for binary in nimblemeta["binaries"]:
        removeFile(options.getBinDir() / binary.str)

      # Search for an older version of the package we are removing.
      # So that we can reinstate its symlink.
      let (pkgName, _) = getNameVersion(dir)
      let pkgList = getInstalledPkgsMin(options.getPkgsDir(), options)
      var pkgInfo: PackageInfo
      if pkgList.findPkg((pkgName, newVRAny()), pkgInfo):
        pkgInfo = pkgInfo.toFullInfo(options)
        for bin in pkgInfo.bin:
          let symlinkDest = pkgInfo.getRealDir() / bin
          let symlinkFilename = options.getBinDir() / bin.extractFilename
          discard setupBinSymlink(symlinkDest, symlinkFilename, options)
    else:
      display("Warning:", ("Cannot completely remove $1. Binary symlinks may " &
                          "have been left over in $2.") %
                          [dir, options.getBinDir()])
  except OSError, JsonParsingError:
    display("Warning", "Unable to read nimblemeta.json: " &
            getCurrentExceptionMsg(), Warning, HighPriority)
    if not options.prompt("Would you like to COMPLETELY remove ALL files " &
                          "in " & dir & "?"):
      raise NimbleQuit(msg: "")
    removeDir(dir)

proc vcsRevisionInDir(dir: string): string =
  ## Returns current revision number of HEAD if dir is inside VCS, or nil in
  ## case of failure.
  var cmd = ""
  if dirExists(dir / ".git"):
    cmd = "git -C " & quoteShell(dir) & " rev-parse HEAD"
  elif dirExists(dir / ".hg"):
    cmd = "hg --cwd " & quoteShell(dir) & " id -i"

  if cmd.len > 0:
    try:
      let res = doCmdEx(cmd)
      if res.exitCode == 0:
        result = string(res.output).strip()
    except:
      discard

proc installFromDir(dir: string, requestedVer: VersionRange, options: Options,
                    url: string): tuple[
                      deps: seq[PackageInfo],
                      pkg: PackageInfo
                    ] =
  ## Returns where package has been installed to, together with paths
  ## to the packages this package depends on.
  ## The return value of this function is used by
  ## ``processDeps`` to gather a list of paths to pass to the nim compiler.

  # Handle pre-`install` hook.
  if not options.depsOnly:
    cd dir: # Make sure `execHook` executes the correct .nimble file.
      if not execHook(options, true):
        raise newException(NimbleError, "Pre-hook prevented further execution.")

  var pkgInfo = getPkgInfo(dir, options)
  let realDir = pkgInfo.getRealDir()
  let binDir = options.getBinDir()
  var depsOptions = options
  depsOptions.depsOnly = false

  # Overwrite the version if the requested version is "#head" or similar.
  if requestedVer.kind == verSpecial:
    pkgInfo.specialVersion = $requestedVer.spe

  # Dependencies need to be processed before the creation of the pkg dir.
  result.deps = processDeps(pkgInfo, depsOptions)

  if options.depsOnly:
    result.pkg = pkgInfo
    return result

  display("Installing", "$1@$2" % [pkginfo.name, pkginfo.specialVersion],
          priority = HighPriority)

  # Build before removing an existing package (if one exists). This way
  # if the build fails then the old package will still be installed.
  if pkgInfo.bin.len > 0:
    let paths = result.deps.map(dep => dep.getRealDir())
    buildFromDir(pkgInfo, paths, options.action.passNimFlags & "-d:release")

  let pkgDestDir = pkgInfo.getPkgDest(options)
  if existsDir(pkgDestDir) and existsFile(pkgDestDir / "nimblemeta.json"):
    let msg = "$1@$2 already exists. Overwrite?" %
              [pkgInfo.name, pkgInfo.specialVersion]
    if not options.prompt(msg):
      raise NimbleQuit(msg: "")

    # Remove reverse deps.
    let pkgInfo = getPkgInfo(pkgDestDir, options)
    options.nimbleData.removeRevDep(pkgInfo)

    removePkgDir(pkgDestDir, options)
    # Remove any symlinked binaries
    for bin in pkgInfo.bin:
      # TODO: Check that this binary belongs to the package being installed.
      when defined(windows):
        removeFile(binDir / bin.changeFileExt("cmd"))
        removeFile(binDir / bin.changeFileExt(""))
      else:
        removeFile(binDir / bin)

  createDir(pkgDestDir)
  # Copy this package's files based on the preferences specified in PkgInfo.
  var filesInstalled = initSet[string]()
  iterInstallFiles(realDir, pkgInfo, options,
    proc (file: string) =
      createDir(changeRoot(realDir, pkgDestDir, file.splitFile.dir))
      let dest = changeRoot(realDir, pkgDestDir, file)
      filesInstalled.incl copyFileD(file, dest)
  )

  # Copy the .nimble file.
  let dest = changeRoot(pkgInfo.myPath.splitFile.dir, pkgDestDir,
                        pkgInfo.myPath)
  filesInstalled.incl copyFileD(pkgInfo.myPath, dest)

  var binariesInstalled = initSet[string]()
  if pkgInfo.bin.len > 0:
    # Make sure ~/.nimble/bin directory is created.
    createDir(binDir)
    # Set file permissions to +x for all binaries built,
    # and symlink them on *nix OS' to $nimbleDir/bin/
    for bin in pkgInfo.bin:
      if existsFile(pkgDestDir / bin):
        display("Warning:", ("Binary '$1' was already installed from source" &
                            " directory. Will be overwritten.") % bin, Warning,
                MediumPriority)

      # Copy the binary file.
      filesInstalled.incl copyFileD(pkgInfo.getOutputDir(bin),
                                    pkgDestDir / bin)

      # Set up a symlink.
      let symlinkDest = pkgDestDir / bin
      let symlinkFilename = binDir / bin.extractFilename
      for filename in setupBinSymlink(symlinkDest, symlinkFilename, options):
        binariesInstalled.incl(filename)

  let vcsRevision = vcsRevisionInDir(realDir)

  # Save a nimblemeta.json file.
  saveNimbleMeta(pkgDestDir, url, vcsRevision, filesInstalled,
                 binariesInstalled)

  # Save the nimble data (which might now contain reverse deps added in
  # processDeps).
  saveNimbleData(options)

  # Return the dependencies of this package (mainly for paths).
  result.deps.add pkgInfo
  result.pkg = pkgInfo
  result.pkg.isInstalled = true
  result.pkg.myPath = dest

  display("Success:", pkgInfo.name & " installed successfully.",
          Success, HighPriority)

  # Run post-install hook now that package is installed. The `execHook` proc
  # executes the hook defined in the CWD, so we set it to where the package
  # has been installed.
  cd dest.splitFile.dir:
    discard execHook(options, false)

proc getDownloadInfo*(pv: PkgTuple, options: Options,
                      doPrompt: bool): (DownloadMethod, string,
                                        Table[string, string]) =
  if pv.name.isURL:
    let (url, metadata) = getUrlData(pv.name)
    return (checkUrlType(url), url, metadata)
  else:
    var pkg: Package
    if getPackage(pv.name, options, pkg):
      let (url, metadata) = getUrlData(pkg.url)
      return (pkg.downloadMethod.getDownloadMethod(), url, metadata)
    else:
      # If package is not found give the user a chance to refresh
      # package.json
      if doPrompt and
          options.prompt(pv.name & " not found in any local packages.json, " &
                         "check internet for updated packages?"):
        refresh(options)

        # Once we've refreshed, try again, but don't prompt if not found
        # (as we've already refreshed and a failure means it really
        # isn't there)
        return getDownloadInfo(pv, options, false)
      else:
        raise newException(NimbleError, "Package not found.")

proc install(packages: seq[PkgTuple],
             options: Options,
             doPrompt = true): tuple[deps: seq[PackageInfo], pkg: PackageInfo] =
  if packages == @[]:
    result = installFromDir(getCurrentDir(), newVRAny(), options, "")
  else:
    # Install each package.
    for pv in packages:
      let (meth, url, metadata) = getDownloadInfo(pv, options, doPrompt)
      let subdir = metadata.getOrDefault("subdir")
      let (downloadDir, downloadVersion) =
          downloadPkg(url, pv.ver, meth, subdir, options)
      try:
        result = installFromDir(downloadDir, pv.ver, options, url)
      except BuildFailed:
        # The package failed to build.
        # Check if we tried building a tagged version of the package.
        let headVer = getHeadName(meth)
        if pv.ver.kind != verSpecial and downloadVersion != headVer:
          # If we tried building a tagged version of the package then
          # ask the user whether they want to try building #head.
          let promptResult = doPrompt and
              options.prompt(("Build failed for '$1@$2', would you" &
                  " like to try installing '$1@#head' (latest unstable)?") %
                  [pv.name, $downloadVersion])
          if promptResult:
            let toInstall = @[(pv.name, headVer.toVersionRange())]
            result = install(toInstall, options, doPrompt)
          else:
            raise newException(BuildFailed,
              "Aborting installation due to build failure")
        else:
          raise

proc build(options: Options) =
  var pkgInfo = getPkgInfo(getCurrentDir(), options)
  nimScriptHint(pkgInfo)
  let deps = processDeps(pkginfo, options)
  let paths = deps.map(dep => dep.getRealDir())
  var args = options.action.compileOptions
  buildFromDir(pkgInfo, paths, args)

proc execBackend(options: Options) =
  let
    bin = options.action.file
    binDotNim = bin.addFileExt("nim")
  if bin == "":
    raise newException(NimbleError, "You need to specify a file.")

  if not (fileExists(bin) or fileExists(binDotNim)):
    raise newException(NimbleError,
      "Specified file, " & bin & " or " & binDotNim & ", does not exist.")

  var pkgInfo = getPkgInfo(getCurrentDir(), options)
  nimScriptHint(pkgInfo)
  let deps = processDeps(pkginfo, options)

  var args = ""
  for dep in deps: args.add("--path:\"" & dep.getRealDir() & "\" ")
  for option in options.action.compileOptions:
    args.add("\"" & option & "\" ")

  let backend =
    if options.action.backend.len > 0:
      options.action.backend
    else:
      pkgInfo.backend

  if options.action.typ == actionCompile:
    display("Compiling", "$1 (from package $2) using $3 backend" %
            [bin, pkgInfo.name, backend], priority = HighPriority)
  else:
    display("Generating", ("documentation for $1 (from package $2) using $3 " &
            "backend") % [bin, pkgInfo.name, backend], priority = HighPriority)
  doCmd("\"" & getNimBin() & "\" $# --noNimblePath $# \"$#\"" %
        [backend, args, bin], showOutput = true)
  display("Success:", "Execution finished", Success, HighPriority)

proc search(options: Options) =
  ## Searches for matches in ``options.action.search``.
  ##
  ## Searches are done in a case insensitive way making all strings lower case.
  assert options.action.typ == actionSearch
  if options.action.search == @[]:
    raise newException(NimbleError, "Please specify a search string.")
  if needsRefresh(options):
    raise newException(NimbleError, "Please run nimble refresh.")
  let pkgList = getPackageList(options)
  var found = false
  template onFound {.dirty.} =
    echoPackage(pkg)
    if options.queryVersions:
      echoPackageVersions(pkg)
    echo(" ")
    found = true
    break forPkg

  for pkg in pkgList:
    block forPkg:
      for word in options.action.search:
        # Search by name.
        if word.toLower() in pkg.name.toLower():
          onFound()
        # Search by tag.
        for tag in pkg.tags:
          if word.toLower() in tag.toLower():
            onFound()

  if not found:
    display("Error", "No package found.", Error, HighPriority)

proc list(options: Options) =
  if needsRefresh(options):
    raise newException(NimbleError, "Please run nimble refresh.")
  let pkgList = getPackageList(options)
  for pkg in pkgList:
    echoPackage(pkg)
    if options.queryVersions:
      echoPackageVersions(pkg)
    echo(" ")

proc listInstalled(options: Options) =
  var h = initOrderedTable[string, seq[string]]()
  let pkgs = getInstalledPkgsMin(options.getPkgsDir(), options)
  for x in pkgs.items():
    let
      pName = x.pkginfo.name
      pVer = x.pkginfo.specialVersion
    if not h.hasKey(pName): h[pName] = @[]
    var s = h[pName]
    add(s, pVer)
    h[pName] = s

  h.sort(proc (a, b: (string, seq[string])): int = cmpIgnoreCase(a[0], b[0]))
  for k in keys(h):
    echo k & "  [" & h[k].join(", ") & "]"

type VersionAndPath = tuple[version: Version, path: string]

proc listPaths(options: Options) =
  ## Loops over the specified packages displaying their installed paths.
  ##
  ## If there are several packages installed, only the last one (the version
  ## listed in the packages.json) will be displayed. If any package name is not
  ## found, the proc displays a missing message and continues through the list,
  ## but at the end quits with a non zero exit error.
  ##
  ## On success the proc returns normally.
  cli.setSuppressMessages(true)
  assert options.action.typ == actionPath

  if options.action.packages.len == 0:
    raise newException(NimbleError, "A package name needs to be specified")

  var errors = 0
  let pkgs = getInstalledPkgsMin(options.getPkgsDir(), options)
  for name, version in options.action.packages.items:
    var installed: seq[VersionAndPath] = @[]
    # There may be several, list all available ones and sort by version.
    for x in pkgs.items():
      let
        pName = x.pkginfo.name
        pVer = x.pkginfo.specialVersion
      if name == pName:
        var v: VersionAndPath
        v.version = newVersion(pVer)
        v.path = x.pkginfo.getRealDir()
        installed.add(v)

    if installed.len > 0:
      sort(installed, cmp[VersionAndPath], Descending)
      # The output for this command is used by tools so we do not use display().
      echo installed[0].path
    else:
      display("Warning:", "Package '$1' is not installed" % name, Warning,
              MediumPriority)
      errors += 1
  if errors > 0:
    raise newException(NimbleError,
        "At least one of the specified packages was not found")

proc join(x: seq[PkgTuple]; y: string): string =
  if x.len == 0: return ""
  result = x[0][0] & " " & $x[0][1]
  for i in 1 ..< x.len:
    result.add y
    result.add x[i][0] & " " & $x[i][1]

proc getPackageByPattern(pattern: string, options: Options): PackageInfo =
  ## Search for a package file using multiple strategies.
  if pattern == "":
    # Not specified - using current directory
    result = getPkgInfo(os.getCurrentDir(), options)
  elif pattern.splitFile.ext == ".nimble" and pattern.existsFile:
    # project file specified
    result = getPkgInfoFromFile(pattern, options)
  elif pattern.existsDir:
    # project directory specified
    result = getPkgInfo(pattern, options)
  else:
    # Last resort - attempt to read as package identifier
    let packages = getInstalledPkgsMin(options.getPkgsDir(), options)
    let identTuple = parseRequires(pattern)
    var skeletonInfo: PackageInfo
    if not findPkg(packages, identTuple, skeletonInfo):
      raise newException(NimbleError,
          "Specified package not found"
      )
    result = getPkgInfoFromFile(skeletonInfo.myPath, options)

proc dump(options: Options) =
  cli.setSuppressMessages(true)
  let p = getPackageByPattern(options.action.projName, options)
  echo "name: ", p.name.escape
  echo "version: ", p.version.escape
  echo "author: ", p.author.escape
  echo "desc: ", p.description.escape
  echo "license: ", p.license.escape
  echo "skipDirs: ", p.skipDirs.join(", ").escape
  echo "skipFiles: ", p.skipFiles.join(", ").escape
  echo "skipExt: ", p.skipExt.join(", ").escape
  echo "installDirs: ", p.installDirs.join(", ").escape
  echo "installFiles: ", p.installFiles.join(", ").escape
  echo "installExt: ", p.installExt.join(", ").escape
  echo "requires: ", p.requires.join(", ").escape
  echo "bin: ", p.bin.join(", ").escape
  echo "binDir: ", p.binDir.escape
  echo "srcDir: ", p.srcDir.escape
  echo "backend: ", p.backend.escape

proc init(options: Options) =
  # Determine the package name.
  let pkgName =
    if options.action.projName != "":
      options.action.projName
    else:
      os.getCurrentDir().splitPath.tail.toValidPackageName()

  # Validate the package name.
  validatePackageName(pkgName)

  # Determine the package root.
  let pkgRoot =
    if pkgName == os.getCurrentDir().splitPath.tail:
      os.getCurrentDir()
    else:
      os.getCurrentDir() / pkgName

  let nimbleFile = (pkgRoot / pkgName).changeFileExt("nimble")

  if existsFile(nimbleFile):
    let errMsg = "Nimble file already exists: $#" % nimbleFile
    raise newException(NimbleError, errMsg)

  if options.forcePrompts != forcePromptYes:
    display(
      "Info:",
      "Package initialisation requires info which could not be inferred.\n" &
      "Default values are shown in square brackets, press\n" &
      "enter to use them.",
      priority = HighPriority
    )
  display("Using", "$# for new package name" % [pkgName.escape()],
    priority = HighPriority)

  # Determine author by running an external command
  proc getAuthorWithCmd(cmd: string): string =
    let (name, exitCode) = doCmdEx(cmd)
    if exitCode == QuitSuccess and name.len > 0:
      result = name.strip()
      display("Using", "$# for new package author" % [result],
        priority = HighPriority)

  # Determine package author via git/hg or asking
  proc getAuthor(): string =
    if findExe("git") != "":
      result = getAuthorWithCmd("git config --global user.name")
    elif findExe("hg") != "":
      result = getAuthorWithCmd("hg config ui.username")
    if result.len == 0:
      result = promptCustom(options, "Your name?", "Anonymous")
  let pkgAuthor = getAuthor()

  # Declare the src/ directory
  let pkgSrcDir = "src"
  display("Using", "$# for new package source directory" % [pkgSrcDir.escape()],
    priority = HighPriority)

  # Determine the type of package
  let pkgType = promptList(
    options,
    """Package type?
Library - provides functionality for other packages.
Binary  - produces an executable for the end-user.
Hybrid  - combination of library and binary

For more information see https://goo.gl/cm2RX5""",
    ["library", "binary", "hybrid"]
  )

  # Ask for package version.
  let pkgVersion = promptCustom(options, "Initial version of package?", "0.1.0")
  validateVersion(pkgVersion)

  # Ask for description
  let pkgDesc = promptCustom(options, "Package description?",
    "A new awesome nimble package")

  # Ask for license
  # License list is based on:
  # https://www.blackducksoftware.com/top-open-source-licenses
  var pkgLicense = options.promptList(
    """Package License?
This should ideally be a valid SPDX identifier. See https://spdx.org/licenses/.
""", [
    "MIT",
    "GPL-2.0",
    "Apache-2.0",
    "ISC",
    "GPL-3.0",
    "BSD-3-Clause",
    "LGPL-2.1",
    "LGPL-3.0",
    "EPL-2.0",
    # This is what npm calls "UNLICENSED" (which is too similar to "Unlicense")
    "Proprietary",
    "Other"
  ])

  if pkgLicense.toLower == "other":
    pkgLicense = promptCustom(options,
      """Package license?
Please specify a valid SPDX identifier.""",
      "MIT"
    )
  var pkgBackend = options.promptList(
    """Package Backend?
c    - Compile using C backend.
cpp  - Compile using C++ backend.
objc - Compile using Objective-C backend.
js   - Compile using JavaScript backend.""",
    ["c", "cpp", "objc", "js"]
  )

  # Ask for Nim dependency
  let nimDepDef = getNimrodVersion()
  let pkgNimDep = promptCustom(options, "Lowest supported Nim version?",
    $nimDepDef)
  validateVersion(pkgNimDep)

  createPkgStructure(
    (
      pkgName,
      pkgVersion,
      pkgAuthor,
      pkgDesc,
      pkgLicense,
      pkgBackend,
      pkgSrcDir,
      pkgNimDep,
      pkgType
    ),
    pkgRoot
  )

  display("Success:", "Package $# created successfully" % [pkgName], Success,
    HighPriority)

proc uninstall(options: Options) =
  if options.action.packages.len == 0:
    raise newException(NimbleError,
        "Please specify the package(s) to uninstall.")

  var pkgsToDelete: HashSet[PackageInfo]
  pkgsToDelete.init()
  # Do some verification.
  for pkgTup in options.action.packages:
    display("Looking", "for $1 ($2)" % [pkgTup.name, $pkgTup.ver],
            priority = HighPriority)
    let installedPkgs = getInstalledPkgsMin(options.getPkgsDir(), options)
    var pkgList = findAllPkgs(installedPkgs, pkgTup)
    if pkgList.len == 0:
      raise newException(NimbleError, "Package not found")

    display("Checking", "reverse dependencies", priority = HighPriority)
    for pkg in pkgList:
      # Check whether any packages depend on the ones the user is trying to
      # uninstall.
      if options.uninstallRevDeps:
        getAllRevDeps(options, pkg, pkgsToDelete)
      else:
        let
          revDeps = getRevDeps(options, pkg)
        var reason = ""
        for revDep in revDeps:
          if reason.len != 0: reason.add ", "
          reason.add("$1 ($2)" % [revDep.name, revDep.version])
        if reason.len != 0:
          reason &= " depend" & (if revDeps.len == 1: "s" else: "") & " on it"

        if len(revDeps - pkgsToDelete) > 0:
          display("Cannot", "uninstall $1 ($2) because $3" %
                  [pkgTup.name, pkg.specialVersion, reason], Warning, HighPriority)
        else:
          pkgsToDelete.incl pkg

  if pkgsToDelete.len == 0:
    raise newException(NimbleError, "Failed uninstall - no packages selected")

  var pkgNames = ""
  for pkg in pkgsToDelete.items:
    if pkgNames.len != 0: pkgNames.add ", "
    pkgNames.add("$1 ($2)" % [pkg.name, pkg.specialVersion])

  # Let's confirm that the user wants these packages removed.
  let msg = ("The following packages will be removed:\n  $1\n" &
            "Do you wish to continue?") % pkgNames
  if not options.prompt(msg):
    raise NimbleQuit(msg: "")

  for pkg in pkgsToDelete:
    # If we reach this point then the package can be safely removed.

    # removeRevDep needs the package dependency info, so we can't just pass
    # a minimal pkg info.
    removeRevDep(options.nimbleData, pkg.toFullInfo(options))
    removePkgDir(options.getPkgsDir / (pkg.name & '-' & pkg.specialVersion),
                 options)
    display("Removed", "$1 ($2)" % [pkg.name, $pkg.specialVersion], Success,
            HighPriority)

  saveNimbleData(options)

proc listTasks(options: Options) =
  let nimbleFile = findNimbleFile(getCurrentDir(), true)
  nimscriptwrapper.listTasks(nimbleFile, options)

proc developFromDir(dir: string, options: Options) =
  if options.depsOnly:
    raiseNimbleError("Cannot develop dependencies only.")

  cd dir: # Make sure `execHook` executes the correct .nimble file.
    if not execHook(options, true):
      raise newException(NimbleError, "Pre-hook prevented further execution.")

  var pkgInfo = getPkgInfo(dir, options)
  if pkgInfo.bin.len > 0:
    if "nim" in pkgInfo.skipExt:
      raiseNimbleError("Cannot develop packages that are binaries only.")

    display("Warning:", "This package's binaries will not be compiled " &
            "nor symlinked for development.", Warning, HighPriority)

  # Overwrite the version to #head always.
  pkgInfo.specialVersion = "#head"

  # Dependencies need to be processed before the creation of the pkg dir.
  discard processDeps(pkgInfo, options)

  # This is similar to the code in `installFromDir`, except that we
  # *consciously* not worry about the package's binaries.
  let pkgDestDir = pkgInfo.getPkgDest(options)
  if existsDir(pkgDestDir) and existsFile(pkgDestDir / "nimblemeta.json"):
    let msg = "$1@$2 already exists. Overwrite?" %
              [pkgInfo.name, pkgInfo.specialVersion]
    if not options.prompt(msg):
      raise NimbleQuit(msg: "")
    removePkgDir(pkgDestDir, options)

  createDir(pkgDestDir)
  # The .nimble-link file contains the path to the real .nimble file,
  # and a secondary path to the source directory of the package.
  # The secondary path is necessary so that the package's .nimble file doesn't
  # need to be read. This will mean that users will need to re-run
  # `nimble develop` if they change their `srcDir` but I think it's a worthy
  # compromise.
  let nimbleLinkPath = pkgDestDir / pkgInfo.name.addFileExt("nimble-link")
  let nimbleLink = NimbleLink(
    nimbleFilePath: pkgInfo.myPath,
    packageDir: pkgInfo.getRealDir()
  )
  writeNimbleLink(nimbleLinkPath, nimbleLink)

  # Save a nimblemeta.json file.
  saveNimbleMeta(pkgDestDir, dir, vcsRevisionInDir(dir), nimbleLinkPath)

  # Save the nimble data (which might now contain reverse deps added in
  # processDeps).
  saveNimbleData(options)

  display("Success:", (pkgInfo.name & " linked successfully to '$1'.") %
          dir, Success, HighPriority)

  # Execute the post-develop hook.
  cd dir:
    discard execHook(options, false)

proc develop(options: Options) =
  if options.action.packages == @[]:
    developFromDir(getCurrentDir(), options)
  else:
    # Install each package.
    for pv in options.action.packages:
      let name =
        if isURL(pv.name):
          parseUri(pv.name).path
        else:
          pv.name
      let downloadDir = getCurrentDir() / name
      if dirExists(downloadDir):
        let msg = "Cannot clone into '$1': directory exists." % downloadDir
        let hint = "Remove the directory, or run this command somewhere else."
        raiseNimbleError(msg, hint)

      let (meth, url, metadata) = getDownloadInfo(pv, options, true)
      let subdir = metadata.getOrDefault("subdir")

      # Download the HEAD and make sure the full history is downloaded.
      let ver =
        if pv.ver.kind == verAny:
          parseVersionRange("#head")
        else:
          pv.ver
      var options = options
      options.forceFullClone = true
      discard downloadPkg(url, ver, meth, subdir, options, downloadDir)
      developFromDir(downloadDir / subdir, options)

proc test(options: Options) =
  ## Executes all tests starting with 't' in the ``tests`` directory.
  ## Subdirectories are not walked.
  var
    files = toSeq(walkDir(getCurrentDir() / "tests"))
    tests, failures: int

  if files.len < 1:
    display("Warning:", "No tests found!", Warning, HighPriority)
    return

  files.sort((a, b) => cmp(a.path, b.path))

  for file in files:
    let (_, name, ext) = file.path.splitFile()
    if ext == ".nim" and name[0] == 't' and file.kind in {pcFile, pcLinkToFile}:
      var optsCopy = options.briefClone()
      optsCopy.action = Action(typ: actionCompile)
      optsCopy.action.file = file.path
      optsCopy.action.backend = "c"
      optsCopy.action.compileOptions = @[]
      optsCopy.action.compileOptions.add("-r")
      optsCopy.action.compileOptions.add("--path:.")
      let
        binFileName = file.path.changeFileExt(ExeExt)
        existsBefore = existsFile(binFileName)

      if options.continueTestsOnFailure:
        inc tests
        try:
          execBackend(optsCopy)
        except NimbleError:
          inc failures
      else:
        execBackend(optsCopy)

      let
        existsAfter = existsFile(binFileName)
        canRemove = not existsBefore and existsAfter
      if canRemove:
        removeFile(binFileName)

  if failures == 0:
    display("Success:", "All tests passed", Success, HighPriority)
  else:
    let error = "Only " & $(tests - failures) & "/" & $tests & " tests passed"
    display("Error:", error, Error, HighPriority)

proc check(options: Options) =
  ## Validates a package a in the current working directory.
  let nimbleFile = findNimbleFile(getCurrentDir(), true)
  var error: ValidationError
  var pkgInfo: PackageInfo
  var validationResult = false
  try:
    validationResult = validate(nimbleFile, options, error, pkgInfo)
  except:
    raiseNimbleError("Could not validate package:\n" & getCurrentExceptionMsg())

  if validationResult:
    display("Success:", pkgInfo.name & " is valid!", Success, HighPriority)
  else:
    display("Error:", error.msg, Error, HighPriority)
    display("Hint:", error.hint, Warning, HighPriority)
    display("Failure:", "Validation failed", Error, HighPriority)
    quit(QuitFailure)

proc doAction(options: Options) =
  if options.showHelp:
    writeHelp()
  if options.showVersion:
    writeVersion()

  if not existsDir(options.getNimbleDir()):
    createDir(options.getNimbleDir())
  if not existsDir(options.getPkgsDir):
    createDir(options.getPkgsDir)

  case options.action.typ
  of actionRefresh:
    refresh(options)
  of actionInstall:
    let (_, pkgInfo) = install(options.action.packages, options)
    if options.action.packages.len == 0:
      nimScriptHint(pkgInfo)
    if pkgInfo.foreignDeps.len > 0:
      display("Hint:", "This package requires some external dependencies.",
              Warning, HighPriority)
      display("Hint:", "To install them you may be able to run:",
              Warning, HighPriority)
      for i in 0..<pkgInfo.foreignDeps.len:
        display("Hint:", "  " & pkgInfo.foreignDeps[i], Warning, HighPriority)
  of actionUninstall:
    uninstall(options)
  of actionSearch:
    search(options)
  of actionList:
    if options.queryInstalled: listInstalled(options)
    else: list(options)
  of actionPath:
    listPaths(options)
  of actionBuild:
    build(options)
  of actionCompile, actionDoc:
    execBackend(options)
  of actionInit:
    init(options)
  of actionPublish:
    var pkgInfo = getPkgInfo(getCurrentDir(), options)
    publish(pkgInfo, options)
  of actionDump:
    dump(options)
  of actionTasks:
    listTasks(options)
  of actionDevelop:
    develop(options)
  of actionCheck:
    check(options)
  of actionNil:
    assert false
  of actionCustom:
    if not execHook(options, true):
      display("Warning", "Pre-hook prevented further execution.", Warning,
              HighPriority)
      return
    let isPreDefined = options.action.command.normalize == "test"

    var execResult: ExecutionResult[bool]
    if execCustom(options, execResult, failFast=not isPreDefined):
      if execResult.hasTaskRequestedCommand():
        doAction(execResult.getOptionsForCommand(options))
    else:
      # If there is no task defined for the `test` task, we run the pre-defined
      # fallback logic.
      if isPreDefined:
        test(options)
        # Run the post hook for `test` in case it exists.
        discard execHook(options, false)

when isMainModule:
  var error = ""
  var hint = ""

  try:
    parseCmdLine().doAction()
  except NimbleError:
    let currentExc = (ref NimbleError)(getCurrentException())
    (error, hint) = getOutputInfo(currentExc)
  except NimbleQuit:
    discard
  finally:
    try:
      removeDir(getNimbleTempDir())
    except OSError:
      let msg = "Couldn't remove Nimble's temp dir"
      display("Warning:", msg, Warning, MediumPriority)

  if error.len > 0:
    displayTip()
    display("Error:", error, Error, HighPriority)
    if hint.len > 0:
      display("Hint:", hint, Warning, HighPriority)
    quit(1)