#!/usr/bin/env bash
#
# Summary: Install a Ruby version using ruby-build
#
# Usage: rbenv install [-f] [-kvp] <version>
#        rbenv install [-f] [-kvp] <definition-file>
#        rbenv install -l|--list
#
#   -l/--list          List all available versions
#   -f/--force         Install even if the version appears to be installed already
#   -s/--skip-existing Skip if the version appears to be installed already
#
#   ruby-build options:
#
#   -k/--keep          Keep source tree in $RBENV_BUILD_ROOT after installation
#                      (defaults to $RBENV_ROOT/sources)
#   -v/--verbose       Verbose mode: print compilation status to stdout
#   -p/--patch         Apply a patch from stdin before building
#
# For detailed information on installing Ruby versions with
# ruby-build, including a list of environment variables for adjusting
# compilation, see: https://github.com/sstephenson/ruby-build#usage
#
set -e
[ -n "$RBENV_DEBUG" ] && set -x

# Provide rbenv completions
if [ "$1" = "--complete" ]; then
  exec ruby-build --definitions
fi

if [ -z "$RBENV_ROOT" ]; then
  RBENV_ROOT="${HOME}/.rbenv"
fi

# Load shared library functions
eval "$(ruby-build --lib)"

usage() {
  # We can remove the sed fallback once rbenv 0.4.0 is widely available.
  rbenv-help install 2>/dev/null || sed -ne '/^#/!q;s/.//;s/.//;1,4d;p' < "$0"
  [ -z "$1" ] || exit "$1"
}

definitions() {
  local query="$1"
  ruby-build --definitions | $(type -p ggrep grep | head -1) -F "$query" || true
}

indent() {
  sed 's/^/  /'
}

unset FORCE
unset SKIP_EXISTING
unset KEEP
unset VERBOSE
unset HAS_PATCH

parse_options "$@"
for option in "${OPTIONS[@]}"; do
  case "$option" in
  "h" | "help" )
    usage 0
    ;;
  "l" | "list" )
    echo "Available versions:"
    definitions | indent
    exit
    ;;
  "f" | "force" )
    FORCE=true
    ;;
  "s" | "skip-existing" )
    SKIP_EXISTING=true
    ;;
  "k" | "keep" )
    [ -n "${RBENV_BUILD_ROOT}" ] || RBENV_BUILD_ROOT="${RBENV_ROOT}/sources"
    ;;
  "v" | "verbose" )
    VERBOSE="-v"
    ;;
  "p" | "patch" )
    HAS_PATCH="-p"
    ;;
  "version" )
    exec ruby-build --version
    ;;
  * )
    usage 1
    ;;
  esac
done

unset VERSION_NAME

# The first argument contains the definition to install. If the
# argument is missing, try to install whatever local app-specific
# version is specified by rbenv. Show usage instructions if a local
# version is not specified.
DEFINITION="${ARGUMENTS[0]}"
[ -n "$DEFINITION" ] || DEFINITION="$(rbenv-local 2>/dev/null || true)"
[ -n "$DEFINITION" ] || usage 1


# Define `before_install` and `after_install` functions that allow
# plugin hooks to register a string of code for execution before or
# after the installation process.
declare -a before_hooks after_hooks

before_install() {
  local hook="$1"
  before_hooks["${#before_hooks[@]}"]="$hook"
}

after_install() {
  local hook="$1"
  after_hooks["${#after_hooks[@]}"]="$hook"
}

OLDIFS="$IFS"
IFS=$'\n' scripts=(`rbenv-hooks install`)
IFS="$OLDIFS"
for script in "${scripts[@]}"; do source "$script"; done


# Set VERSION_NAME from $DEFINITION, if it is not already set. Then
# compute the installation prefix.
[ -n "$VERSION_NAME" ] || VERSION_NAME="${DEFINITION##*/}"
PREFIX="${RBENV_ROOT}/versions/${VERSION_NAME}"

[ -d "${PREFIX}" ] && PREFIX_EXISTS=1

# If the installation prefix exists, prompt for confirmation unless
# the --force option was specified.
if [ -d "${PREFIX}/bin" ]; then
  if [ -z "$FORCE" ] && [ -z "$SKIP_EXISTING" ]; then
    echo "rbenv: $PREFIX already exists" >&2
    read -p "continue with installation? (y/N) "

    case "$REPLY" in
    y* | Y* ) ;;
    * ) exit 1 ;;
    esac
  elif [ -n "$SKIP_EXISTING" ]; then
    # Since we know the ruby version is already installed, and are opting to
    # not force installation of existing versions, we just `exit 0` here to
    # leave things happy
    exit 0
  fi
fi

# If RBENV_BUILD_ROOT is set, always pass keep options to ruby-build.
if [ -n "${RBENV_BUILD_ROOT}" ]; then
  export RUBY_BUILD_BUILD_PATH="${RBENV_BUILD_ROOT}/${VERSION_NAME}"
  KEEP="-k"
fi

# Set RUBY_BUILD_CACHE_PATH to $RBENV_ROOT/cache, if the directory
# exists and the variable is not already set.
if [ -z "${RUBY_BUILD_CACHE_PATH}" ] && [ -d "${RBENV_ROOT}/cache" ]; then
  export RUBY_BUILD_CACHE_PATH="${RBENV_ROOT}/cache"
fi

# Default RBENV_VERSION to the globally-specified Ruby version. (The
# REE installer requires an existing Ruby installation to run. An
# unsatisfied local .ruby-version file can cause the installer to
# fail.)
export RBENV_VERSION="$(rbenv-global 2>/dev/null || true)"


# Execute `before_install` hooks.
for hook in "${before_hooks[@]}"; do eval "$hook"; done

# Plan cleanup on unsuccessful installation.
cleanup() {
  [ -z "${PREFIX_EXISTS}" ] && rm -rf "$PREFIX"
}

trap cleanup SIGINT

# Invoke `ruby-build` and record the exit status in $STATUS.
STATUS=0
ruby-build $KEEP $VERBOSE $HAS_PATCH "$DEFINITION" "$PREFIX" || STATUS="$?"

# Display a more helpful message if the definition wasn't found.
if [ "$STATUS" == "2" ]; then
  { candidates="$(definitions "$DEFINITION")"
    if [ -n "$candidates" ]; then
      echo
      echo "The following versions contain \`$DEFINITION' in the name:"
      echo "$candidates" | indent
    fi
    echo
    echo "You can list all available versions with \`rbenv install --list'."
    echo
    echo "If the version you're looking for is not present, first try upgrading"
    echo "ruby-build. If it's still missing, open a request on the ruby-build"
    echo "issue tracker: https://github.com/sstephenson/ruby-build/issues"
  } >&2
fi

# Execute `after_install` hooks.
for hook in "${after_hooks[@]}"; do eval "$hook"; done

# Run `rbenv-rehash` after a successful installation.
if [ "$STATUS" == "0" ]; then
  rbenv-rehash
else
  cleanup
fi

exit "$STATUS"