stdlib.sh

# These are the commands available in an .envrc context
set -e
direnv="%s"

DIRENV_LOG_FORMAT="${DIRENV_LOG_FORMAT-direnv: %%s}"

# Usage: log_status [<message> ...]
#
# Logs a status message. Acts like echo,
# but wraps output in the standard direnv log format
# (controlled by $DIRENV_LOG_FORMAT), and directs it
# to stderr rather than stdout.
#
# Example:
#
#    log_status "Loading ..."
#
log_status() {
  if [[ -n $DIRENV_LOG_FORMAT ]]; then
    local msg="$*"
    printf "${DIRENV_LOG_FORMAT}\n" "$msg" >&2
  fi
}

# Usage: has <command>
#
# Returns 0 if the <command> is available. Returns 1 otherwise. It can be a
# binary in the PATH or a shell function.
#
# Example:
#
#    if has curl; then
#      echo "Yes we do"
#    fi
#
has() {
  type "$1" &>/dev/null
}

# Usage: expand_path <rel_path> [<relative_to>]
#
# Outputs the absolute path of <rel_path> relaitve to <relative_to> or the 
# current directory.
#
# Example:
#
#    cd /usr/local/games
#    expand_path ../foo
#    # output: /usr/local/foo
#
expand_path() {
  "$direnv" expand_path "$@"
}

# Usage: dotenv [<dotenv>]
#
# Loads a ".env" file into the current environment
#
dotenv() {
  eval "$("$direnv" dotenv bash "$@")"
}

# Usage: user_rel_path <abs_path>
#
# Transforms an absolute path <abs_path> into a user-relative path if
# possible.
#
# Example:
#
#    echo $HOME
#    # output: /home/user
#    user_rel_path /home/user/my/project
#    # output: ~/my/project
#    user_rel_path /usr/local/lib
#    # output: /usr/local/lib
#
user_rel_path() {
  local path="${1#-}"

  if [ -z "$path" ]; then return; fi

  if [ -n "$HOME" ]; then
    local rel_path="${path#$HOME}"
    if [ "$rel_path" != "$path" ]; then
      path="~${rel_path}"
    fi
  fi

  echo "$path"
}

# Usage: find_up <filename>
#
# Outputs the path of <filename> when searched from the current directory up to 
# /. Returns 1 if the file has not been found.
#
# Example:
#
#    cd /usr/local/my
#    mkdir -p project/foo
#    touch bar
#    cd project/foo
#    find_up bar
#    # output: /usr/local/my/bar
#
find_up() {
  (
    cd "$(pwd -P 2>/dev/null)"
    while true; do
      if [ -f "$1" ]; then
        echo "$PWD/$1"
        return 0
      fi
      if [ "$PWD" = "/" ] || [ "$PWD" = "//" ]; then
        return 1
      fi
      cd ..
    done
  )
}

# Usage: source_env <file_or_dir_path>
#
# Loads another ".envrc" either by specifying its path or filename.
source_env() {
  local rcfile="$1"
  local rcpath="${1/#\~/$HOME}"
  if ! [ -f "$rcpath" ]; then
    rcfile="$rcfile/.envrc"
    rcpath="$rcpath/.envrc"
  fi
  log_status "loading $rcfile"
  pushd "$(pwd -P 2>/dev/null)" > /dev/null
    pushd "$(dirname "$rcpath")" > /dev/null
    . "./$(basename "$rcpath")"
    popd > /dev/null
  popd > /dev/null
}

# Usage: source_up [<filename>]
#
# Loads another ".envrc" if found with the find_up command.
#
source_up() {
  local file="$1"
  if [ -z "$file" ]; then
    file=".envrc"
  fi
  local path="$(cd .. && find_up "$file")"
  if [ -n "$path" ]; then
    source_env "$(user_rel_path "$path")"
  fi
}

# Usage: direnv_load <command-generating-dump-output>
#   e.g: direnv_load opam-env exec -- direnv dump
#
# Applies the environment generated by running <argv> as a
# command. This is useful for adopting the environment of a child
# process - cause that process to run "direnv dump" and then wrap
# the results with direnv_load.
#
direnv_load() {
  exports="$("$direnv" apply_dump <("$@"))"
  if test "$?" -ne 0; then
    exit 1
  fi
  eval "$exports"
}

# Usage: PATH_add <path>
#
# Prepends the expanded <path> to the PATH environment variable. It prevents a
# common mistake where PATH is replaced by only the new <path>.
#
# Example:
#
#    pwd
#    # output: /home/user/my/project
#    PATH_add bin
#    echo $PATH
#    # output: /home/user/my/project/bin:/usr/bin:/bin
#
PATH_add() {
  export PATH="$(expand_path "$1"):$PATH"
}

# Usage: path_add <varname> <path>
#
# Works like PATH_add except that it's for an arbitrary <varname>.
path_add() {
  local old_paths="${!1}"
  local path="$(expand_path "$2")"

  if [ -z "$old_paths" ]; then
    old_paths="$path"
  else
    old_paths="$path:$old_paths"
  fi

  export $1="$old_paths"
}

# Usage: load_prefix <prefix_path>
#
# Expands some common path variables for the given <prefix_path> prefix. This is
# useful if you installed something in the <prefix_path> using
# $(./configure --prefix=<prefix_path> && make install) and want to use it in 
# the project.
#
# Variables set:
#
#    CPATH
#    LD_LIBRARY_PATH
#    LIBRARY_PATH
#    MANPATH
#    PATH
#    PKG_CONFIG_PATH
#
# Example:
#
#    ./configure --prefix=$HOME/rubies/ruby-1.9.3
#    make && make install
#    # Then in the .envrc
#    load_prefix ~/rubies/ruby-1.9.3
#
load_prefix() {
  local path="$(expand_path "$1")"
  path_add CPATH "$path/include"
  path_add LD_LIBRARY_PATH "$path/lib"
  path_add LIBRARY_PATH "$path/lib"
  path_add MANPATH "$path/man"
  path_add MANPATH "$path/share/man"
  path_add PATH "$path/bin"
  path_add PKG_CONFIG_PATH "$path/lib/pkgconfig"
}

# Usage: layout <type>
#
# A semantic dispatch used to describe common project layouts.
#
layout() {
  local name=$1
  shift
  eval "layout_$name" "$@"
}

# Usage: layout go
#
# Sets the GOPATH environment variable to the current directory.
#
layout_go() {
  path_add GOPATH "$PWD"
  PATH_add bin
}

# Usage: layout node
#
# Adds "$PWD/node_modules/.bin" to the PATH environment variable.
layout_node() {
  PATH_add node_modules/.bin
}

# Usage: layout perl
#
# Setup environment variables required by perl's local::lib
# See http://search.cpan.org/dist/local-lib/lib/local/lib.pm for more details
#
layout_perl() {
  local libdir="$PWD/.direnv/perl5"
  export LOCAL_LIB_DIR="$libdir"
  export PERL_MB_OPT="--install_base '$libdir'"
  export PERL_MM_OPT="INSTALL_BASE=$libdir"
  path_add PERL5LIB "$libdir/lib/perl5"
  path_add PERL_LOCAL_LIB_ROOT "$libdir"
  PATH_add "$libdir/bin"
}

# Usage: layout python <python_exe>
#
# Creates and loads a virtualenv environment under
# "$PWD/.direnv/python-$python_version".
# This forces the installation of any egg into the project's sub-folder.
#
# It's possible to specify the python executable if you want to use different
# versions of python.
#
layout_python() {
  local python="${1:-python}"
  local old_env="$PWD/.direnv/virtualenv"
  unset PYTHONHOME
  if [[ -d $old_env && $python = "python" ]]; then
    export VIRTUAL_ENV="$old_virtualenv"
  else
    local python_version=$("$python" -c "import platform as p;print(p.python_version())")
    export VIRTUAL_ENV="$PWD/.direnv/python-$python_version"
    if [[ ! -d $VIRTUAL_ENV ]]; then
      virtualenv "--python=$python" "$VIRTUAL_ENV"
    fi
  fi
  PATH_add "$VIRTUAL_ENV/bin"
}

# Usage: layout python3
#
# A shortcut for $(layout python python3)
#
layout_python3() {
  layout_python python3
}

# Usage: layout ruby
#
# Sets the GEM_HOME environment variable to "$PWD/.direnv/ruby/RUBY_VERSION".
# This forces the installation of any gems into the project's sub-folder.
# If you're using bundler it will create wrapper programs that can be invoked
# directly instead of using the $(bundle exec) prefix.
#
layout_ruby() {
  if ruby -e "exit Gem::VERSION > '2.2.0'" 2>/dev/null; then
    export GEM_HOME="$PWD/.direnv/ruby"
  else
    local ruby_version="$(ruby -e"puts (defined?(RUBY_ENGINE) ? RUBY_ENGINE : 'ruby') + '-' + RUBY_VERSION")"
    export GEM_HOME="$PWD/.direnv/ruby-${ruby_version}"
  fi
  export BUNDLE_BIN="$PWD/.direnv/bin"

  PATH_add "$GEM_HOME/bin"
  PATH_add "$BUNDLE_BIN"
}

# Usage: use <program_name> [<version>]
#
# A semantic command dispatch intended for loading external dependencies into
# the environment.
#
# Example:
#
#    use_ruby() {
#      echo "Ruby $1"
#    }
#    use ruby 1.9.3
#    # output: Ruby 1.9.3
#
use() {
  local cmd="$1"
  log_status "using $*"
  shift
  "use_$cmd" "$@"
}

# Usage: use rbenv
#
# Loads rbenv which add the ruby wrappers available on the PATH.
#
use_rbenv() {
  eval "$(rbenv init -)"
}

# Usage: rvm [...]
#
# Should work just like in the shell if you have rvm installed.#
#
rvm() {
  unset rvm
  if [ -n "${rvm_scripts_path:-}" ]; then
    source "${rvm_scripts_path}/rvm"
  elif [ -n "${rvm_path:-}" ]; then
    source "${rvm_path}/scripts/rvm"
  else
    source "$HOME/.rvm/scripts/rvm"
  fi
  rvm "$@"
}

## Load the global ~/.direnvrc if present
if [ -f "$HOME/.direnvrc" ]; then
  source_env "~/.direnvrc" >&2
fi