# kvm.sh
# Source this file from you .bash-profile or script to use
# With inspriation from nvm.sh

SCRIPTPATH="$_"

_kvm_has() {
  type "$1" > /dev/null 2>&1
  return $?
}

# Make zsh glob matching behave same as bash
# This fixes the "zsh: no matches found" errors
if _kvm_has "unsetopt"; then
  unsetopt nomatch 2>/dev/null
  KVM_CD_FLAGS="-q"
fi

USERKREPATH="~/.kre"
USERKREPACKAGES="$USERKREPATH/packages"

# Traverse up in directory tree to find containing folder
_kvm_find_up() {
  local path
  path=$PWD
  while [ "$path" != "" ] && [ ! -f "$path/$1" ]; do
    path=${path%/*}
  done
  echo "$path"
}

_kvm_find_kvmrc() {
  local dir="$(_kvm_find_up '.kvmrc')"
  if [ -e "$dir/.kvmrc" ]; then
        echo "$dir/.kvmrc"
  fi
}

# Obtain kvm version from rc file
_kvm_rc_version() {
  local KVMRC_PATH="$(_kvm_find_kvmrc)"
  if [ -e "$KVMRC_PATH" ]; then
    _kvm_rc_version=`cat "$KVMRC_PATH" | head -n 1`
    echo "Found '$KVMRC_PATH' with version <$_kvm_rc_version>"
  fi
}

_kvm_find_latest() {
  echo "Determining latest version"

  local platform="mono45"
  local architecture="x86"

  if ! _kvm_has "curl"; then
    echo 'KVM Needs curl to proceed.' >&2;
    return 1
  fi

  local url="https://www.myget.org/F/aspnetvnext/api/v2/GetUpdates()?packageIds=%27KRE-$platform-$architecture%27&versions=%270.0%27&includePrerelease=true&includeAllVersions=false"
  local xml=$(curl -silent -u aspnetreadonly:4d8a2d9c-7b80-4162-9978-47e918c9658c $url)

  version=$(echo $xml | sed "s/.*<[a-zA-Z]:Version>\([^<]*\).*/\1/")

  echo $version
}

_kvm_strip_path() {
  echo "$1" | sed -e "s#$KVM_DIR/[^/]*$2[^:]*:##g" -e "s#:$KVM_DIR/[^/]*$2[^:]*##g" -e "s#$KVM_DIR/[^/]*$2[^:]*##g"
}

_kvm_prepend_path() {
  if [ -z "$1" ]; then
    echo "$2"
  else
    echo "$2:$1"
  fi
}

_kvm_download() {
  local packageName="$1"
  local destinationFolder="$2"
  echo "download $packageName $destinationFolder - TBD"
}

_kvm_unpack() {
  local file="$1"
  local destinationFolder="$2"
  echo "unpack $file $destinationFolder - TBD"
}

_kvm_requested_version_or_alias() {
  local versionOrAlias="$1"
  echo "Requested version or alias $versionOrAlias - TBD"
}

kvm()
{
  if [ $# -lt 1 ]; then
    kvm help
    return
  fi

  case $1 in
    "help" )
      echo ""
      echo "K Runtime Environment Version Manager - Build {{BUILD_NUMBER}}"
      echo ""
      echo "USAGE: kvm <command> [options]"
      echo ""
      echo "kvm upgrade"
      echo "install latest KRE from feed"
      echo "set 'default' alias to installed version"
      echo "add KRE bin to user PATH environment variable persistently"
      echo ""
      echo "kvm install <semver>|<alias>|<nupkg>"
      echo "install requested KRE from feed"
      echo "add KRE bin to path of current command line"
      echo ""
      echo "kvm use <semver>|<alias>|none [-p --persistent]"
      echo "<semver>|<alias>  add KRE bin to path of current command line   "
      echo "none              remove KRE bin from path of current command line"
      echo "-p --persistent   persist selected version to .kvmrc"
      echo ""
      echo "kvm list"
      echo "list KRE versions installed "
      echo ""
      echo "kvm alias"
      echo "list KRE aliases which have been defined"
      echo ""
      echo "kvm alias <alias>"
      echo "display value of named alias"
      echo ""
      echo "kvm alias <alias> <semver>"
      echo "set alias to specific version"
      echo ""
      echo ""
    ;;

    "upgrade" )
      [ $# -ne 1 ] && kvm help && return

      local version=$(_kvm_find_latest mono45 x86)
      kvm install $version
      kvm alias default $version
    ;;

    "install" )
      [ $# -ne 2 ] && kvm help && return

      local versionOrAlias="$2"

      if [ "$versionOrAlias" == *.nupkg ]; then
        local kreFullName=$(echo $versionOrAlias | sed "s/\(.*\)\.nupkg/\1/")
        local kreFolder="$USERKREPACKAGES/$kreFullName"
        local kreFile="$kreFolder/$kreFullName.nupkg"

        if [ -e "$kreFolder" ]; then
          echo "Target folder '$kreFolder' already exists"
        else
          mkdir "$kreFolder" > /dev/null 2>&1
          cp -a "$versionOrAlias" "$kreFile"
          _kvm_unpack "$kreFile" "$kreFolder"
        fi

        echo "Adding $kreBin to current PATH"

        # Strip other version from PATH
        PATH=`_kvm_strip_path "$PATH" "/bin"`
        # Prepend current version
        PATH=`_kvm_prepend_path "$PATH" "$kreBin"`
      else
        local kreFullName="$(_kvm_requested_version_or_alias $versionOrAlias)"
        local kreFolder="$USERKREPACKAGES/$kreFullName"

        _kvm_download "$kreFullName" "$kreFolder"
        kvm use "$versionOrAlias"
      fi
    ;;

    "use" )
      [ $# -gt 3 ] && kvm help && return
      [ $# -lt 2 ] && kvm help && return
      local version="$2"
      local persist="$3"
      echo "use $version - TBD ... "
    ;;

    "alias" )
      [ $# -gt 4 ] && kvm help && return

      local alias="$2"
      local semver="$3"

      echo "alias $alias $semver - TBD ..."
  esac
}