#!/usr/bin/env bash

__rvm_gemset_handle_default()
{
  rvm_gemset_name="${rvm_gemset_separator:-@}${rvm_gemset_name:-}${rvm_gemset_separator:-@}"
  rvm_gemset_name="${rvm_gemset_name/${rvm_gemset_separator:-@}default${rvm_gemset_separator:-@}/}"
  # also does filter any extra rvm_gemset_separator from the gemset name
  rvm_gemset_name="${rvm_gemset_name//${rvm_gemset_separator:-@}/}"
}

__rvm_gemset_select_cli_validation()
{
  \typeset orig_gemset

  if ! builtin command -v gem > /dev/null
  then
    rvm_log "'gem' command not found, cannot select a gemset."
    return 0
  fi

  orig_gemset="${rvm_gemset_name:-}"
  __rvm_gemset_handle_default

  # No longer defaulting to 'sticky' gem sets.
  # Set 'rvm_sticky_flag=1' in ~/.rvmrc to enable.
  if [[ -z "${rvm_gemset_name:-}"  && "$orig_gemset" != "default" && ${rvm_sticky_flag:-0} -eq 1 ]]
  then
    if [[ -n "${rvm_ruby_gem_home:-}" ]]
    then
      rvm_gemset_name="$rvm_ruby_gem_home"
    elif [[ -n "${GEM_HOME:-}" ]]
    then
      rvm_gemset_name="$GEM_HOME"
    fi
    rvm_gemset_name="${rvm_gemset_name##*/}"
    rvm_gemset_name="${rvm_gemset_name#*${rvm_gemset_separator:-"@"}}"
  fi

  if [[ -z "${rvm_ruby_string:-}" && -n "${GEM_HOME:-}" && -n "${GEM_HOME%@*}" ]]
  then
    rvm_ruby_string="${GEM_HOME%@*}"
    rvm_ruby_string="${rvm_ruby_string##*/}"
  fi

  if [[ -z "${rvm_ruby_string:-}" ]]
  then
    rvm_error "Gemsets can not be used with non rvm controlled rubies (currently)."
    return 3
  fi
}

__rvm_gemset_select_only()
{
  rvm_ruby_gem_home="${rvm_gems_path:-"$rvm_path/gems"}/$rvm_ruby_string"

  : rvm_ignore_gemsets_flag:${rvm_ignore_gemsets_flag:=0}:
  if (( rvm_ignore_gemsets_flag ))
  then
    rvm_ruby_global_gems_path="${rvm_ruby_gem_home}"
    rvm_ruby_gem_path="${rvm_ruby_gem_home}"
    rvm_gemset_name=""
  else
    rvm_ruby_global_gems_path="${rvm_ruby_gem_home}${rvm_gemset_separator:-"@"}global"

    __rvm_gemset_handle_default
    [[ -z "$rvm_gemset_name" ]] ||
      rvm_ruby_gem_home="${rvm_ruby_gem_home}${rvm_gemset_separator:-"@"}${rvm_gemset_name}"

    if [[ "$rvm_gemset_name" == "global" ]]
    then
      rvm_ruby_gem_path="${rvm_ruby_gem_home}"
    else
      rvm_ruby_gem_path="${rvm_ruby_gem_home}:${rvm_ruby_global_gems_path}"
    fi
  fi

  if [[ -n "${rvm_gemset_name}" ]]
  then
    rvm_env_string="${rvm_ruby_string}@${rvm_gemset_name}"
  else
    rvm_env_string=${rvm_ruby_string}
  fi
  true # OSX --trace FIX
}

__rvm_gemset_select_validation()
{
  # If the gemset does not exist, then notify the user as such and abort the action.
  if
    [[ ! -d "${rvm_ruby_gem_home}" ]]
  then
    if
      (( ${rvm_gemset_create_on_use_flag:=0} == 0 && ${rvm_create_flag:=0} == 0 && ${rvm_delete_flag:=0} == 0 ))
    then
      rvm_expected_gemset_name="${rvm_gemset_name}"
      rvm_gemset_name=""
      __rvm_gemset_select_only
      return 2
    fi
  elif
    (( ${rvm_delete_flag:=0} == 1 ))
  then
    return 4
  fi

  case "${rvm_gemset_name}" in
    (*/*)
      rvm_error "Gemsets can not contain path separator '/'."
      return 5
      ;;
    (*:*)
      rvm_error "Gemsets can not contain PATH separator ':'."
      return 5
      ;;
  esac

  \typeset rvm_ruby_gem_home_254
  if [[ -n "${ZSH_VERSION:-}" ]]
  then rvm_ruby_gem_home_254="${rvm_ruby_gem_home[0,254]}"
  else rvm_ruby_gem_home_254="${rvm_ruby_gem_home:0:254}"
  fi
  if
    [[ "${rvm_ruby_gem_home}" != "${rvm_ruby_gem_home_254}" ]]
  then
    rvm_error "Gemset gem home to long ${#rvm_ruby_gem_home}."
    return 6
  fi
}

# Select a gemset based on CLI set options and environment.
__rvm_gemset_select_cli()
{
  __rvm_gemset_select_cli_validation &&
  __rvm_gemset_select ||
  return $?
}

__rvm_gemset_select()
{
  __rvm_gemset_select_only &&
  __rvm_gemset_select_validation ||
  return $?
}

__rvm_gemset_use_ensure()
{
  if
    [[ ! -d "$rvm_ruby_gem_home" ]] ||
    [[ -n "${rvm_expected_gemset_name}" && ! -d "${rvm_ruby_gem_home%@*}@${rvm_expected_gemset_name}" ]]
  then
    if
      (( ${rvm_gemset_create_on_use_flag:=0} == 1 || ${rvm_create_flag:=0} == 1 ))
    then
      gemset_create "${rvm_expected_gemset_name:-${rvm_gemset_name:-}}"
    else
      rvm_error "Gemset '${rvm_expected_gemset_name:-${rvm_gemset_name:-}}' does not exist, \
'rvm $rvm_ruby_string do rvm gemset create ${rvm_expected_gemset_name:-${rvm_gemset_name:-}}' first, or append '--create'."
      return 2
    fi
  fi
}

# Use a gemset specified by 'rvm_ruby_gem_home'
__rvm_gemset_use()
{
  if
    [[ "$(__rvm_env_string)" == "system" ]]
  then
    rvm_error "System ruby is not controlled by RVM, but you can use it with 'rvm automount', read more: 'rvm help mount'."
    return 2
  elif
    __rvm_gemset_select_cli
  then
    rvm_log "Using $rvm_ruby_string with gemset ${rvm_gemset_name:-default}"
    __rvm_use # Now ensure the selection takes effect for the environment.
  elif
    [[ -n "${rvm_expected_gemset_name}" ]]
  then
    __rvm_gemset_use_ensure
  else
    rvm_error "Gemset was not given.\n  Usage:\n    rvm gemset use <gemsetname>\n"
    return 1
  fi
}