install

#!/bin/sh
# SPDX-License-Identifier: GPL-3.0-only
#
# This file is part of the denv project: https://github.com/tomeichlersmith/denv
#
# Copyright (C) 2021 denv contributors
#
# denv is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 3
# as published by the Free Software Foundation.
#
# denv is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with denv; if not, see <http://www.gnu.org/licenses/>.

# POSIX
set -o errexit
set -o nounset

if [ -n "${DENV_DEBUG+x}" ]; then
  set -o xtrace
fi

_denv_info() {
  printf "\033[32;1m INFO: \033[0m\033[32m%s\n" "$1"
  shift
  while [ "$#" -gt "0" ]; do
    printf '       %s\n' "$1"
    shift
  done
  printf "\033[0m"
}

# print each argument on its own line with the first line
# prefixed with "ERROR: ".
_denv_error() {
  printf >&2 "\033[1;31mERROR: \033[0m\033[31m%s\n" "$1"
  shift
  while [ "$#" -gt "0" ]; do
    printf >&2 "       %s\n" "$1"
    shift
  done
  printf >&2 "\033[0m"
}

# print the question passed to us and process user input
# continues in infinite loop if user is not explicitly answering yes or no
# Arguments
#  1 - question to ask the user (yes or no)
# Output
#  returns 0 if user answers yes and 1 if user answers no
_denv_user_confirm() {
  question="$*"
  while true; do
    printf "\033[1m%s\033[0m [Y/n] " "${question}"
    read -r ans </dev/tty
    case "${ans}" in
      Y|y|yes)
        return 0
        ;;
      N|n|no)
        return 1
        ;;
      *)
        _denv_error "${ans} is not one of Y, y, yes, N, n, or no."
        ;;
    esac
  done
}

# Print usage to stdout.
# Arguments:
#   None
# Outputs:
#   print usage with examples.
show_help() {
  cat << EOF
install --prefix /usr/local

Options:
  --prefix/-p:    base bath where all files will be deployed (default /usr/local if root, ~/.local if not)
  --devel/-d:   symlink to install location rather than copy, helpful for testing during development
                ignored if not in the repository
  --next/-n:    install HEAD of main branch rather than last release
  --help/-h:    show this message
  -v:     show more verbosity
EOF
}

version=v1.1.1
next=0
verbose=0
devel=0
prefix=""

# Parse arguments
while [ "$#" -gt 0 ]; do
  case $1 in
    -h | --help)
      # Call a "show_help" function to display a synopsis, then exit.
      show_help
      exit
      ;;
    -v | --verbose)
      shift
      verbose=1
      ;;
    -d | --devel)
      shift
      devel=1
      ;;
    -n | --next)
      shift
      next=1
      ;;
    -p | --prefix)
      if [ -n "$2" ]; then
        [ -d "$2" ] || mkdir -p "$2"
        prefix="$(cd "$2" && pwd -P)"
        shift
        shift
      fi
      ;;
    *) # Default case: If no more options then break out of the loop.
      break ;;
  esac
done

# set verbosity
if [ "${verbose}" -ne 0 ]; then
  set -o xtrace
fi

if  [ -z "${prefix}" ]; then
  prefix="/usr/local"
  # in case we're not root, just default to the home directory
  if [ "$(id -u || true)" -ne 0 ]; then
    prefix="${HOME}/.local"
  fi
fi

if [ ! -d "${prefix}" ] && ! mkdir "${prefix}"; then
  _denv_error "Cannot create ${prefix}, permission denied."
  exit 1
fi

if [ ! -w "${prefix}" ]; then
  _denv_error "Cannot write into ${prefix}, permission denied"
  exit 1
fi

completion_dest_path="${prefix}/share/bash-completion/completions/"
dest_path="${prefix}/bin"
man_dest_path="${prefix}/share/man/man1"

# get current dir
curr_dir=$(dirname "$0")
cd "${curr_dir}" || exit 1

# make sure destination is writable
if [ ! -d "${dest_path}" ]; then
  mkdir -p "${dest_path}"
fi
if [ ! -d "${man_dest_path}" ]; then
  mkdir -p "${man_dest_path}"
fi
if [ ! -d "${completion_dest_path}" ]; then
  mkdir -p "${completion_dest_path}"
fi

# if files are available here, install files in dest directory
if [ -e "${curr_dir}/denv" ]; then
  if [ "${devel}" -ne 0 ]; then
    copy="ln -sf"
    if ! ${copy} "${PWD}/denv" "${dest_path}"; then
      _denv_error "Copying to ${dest_path} failed." \
        "Do you have permission to write there?"
      exit 1
    fi
    ${copy} "${PWD}/_denv_entrypoint" "${dest_path}"
  else
    copy="install -m 0644"
    if ! install -m 0775 denv "${dest_path}"; then
      _denv_error "Copying to ${dest_path} failed." \
        "Do you have permission to write there?"
      exit 1
    fi
    install -m 0775 _denv_entrypoint "${dest_path}"
  fi
  if [ -e "man" ]; then
    for file in "${PWD}"/man/man1/*; do
      ${copy} "${file}" "${man_dest_path}"
    done
  fi
  if [ -e "completions" ]; then
    for file in "${PWD}"/completions/*; do
      ${copy} "${file}" "${completion_dest_path}"
    done
  fi
else
  # files are not here so we are going to download from github
  _denv_info "Checking dependencies..."
  # check that we have base dependencies
  if ! { command -v curl > /dev/null || command -v wget > /dev/null; } || ! command -v tar > /dev/null; then
    _denv_error "Online install depends on 'tar' and either 'curl' or 'wget'" \
      "Ensure these dependencies are installed and then rerun the online install."
    exit 1
  fi

  if command -v curl > /dev/null 2>&1; then
    download="curl -sLo"
  elif command -v wget > /dev/null 2>&1; then
    download="wget -qO"
  fi

  _denv_info "Downloading..."
  if [ "${next}" -eq 0 ]; then
    release_ver="tomeichlersmith/denv/archive/refs/tags/${version}.tar.gz"
    release_name=$(echo "${release_ver}" | grep -Eo '[0-9]+\.[0-9]+\.[0-9]+\.tar\.gz$')
  else
   release_ver="tomeichlersmith/denv/archive/refs/heads/main.tar.gz"
   release_name="main"
  fi
  # go in tmp
  tmp_dir="$(mktemp -d)"
  cd "${tmp_dir}"
  # download our target
  ${download} "${release_name}" "https://github.com/${release_ver}"
  # uncompress
  _denv_info "Unpacking..."
  if [ "${verbose}" -ne 0 ]; then
    tar xvf "${release_name}"
  else
    tar xf "${release_name}"
  fi
  # enter source
  cd "denv-$(echo "${release_name}" | sed 's|.tar.gz||' || true)"

  # deploy
  copy="install -m 0644"
  if ! install -m 0775 denv "${dest_path}"; then
    _denv_error "Copying to ${dest_path} failed." \
      "Do you have permission to write there?"
    exit 1
  fi
  install -m 0775 _denv_entrypoint "${dest_path}"
  if [ -e "man" ]; then
    for file in "${PWD}"/man/man1/*; do
      ${copy} "${file}" "${man_dest_path}"
    done
  fi
  if [ -e "completions" ]; then
    for file in "${PWD}"/completions/*; do
      ${copy} "${file}" "${completion_dest_path}"
    done
  fi

  # securely delete unneeded files
  cd
  if [ -n "${tmp_dir}" ] && [ -e "${tmp_dir}" ]; then
    rm -rf "${tmp_dir}"
  fi
fi

# double check that the installation is functional
unset DENV_INSTALL_FAILURE
for executable in "denv" "_denv_entrypoint"; do
  if [ -x "${dest_path}/${executable}" ] && [ -f "${dest_path}/${executable}" ]; then
    continue
  fi
  _denv_error "'${executable}' does not exist as an executable file at '${dest_path}/${executable}'"
  DENV_INSTALL_FAILURE=1
done

if [ -z "${DENV_INSTALL_FAILURE+x}" ]; then
  _denv_info "Successfully installed denv to ${dest_path}"
else
  _denv_error "Installation corrupted!"
fi

case "${PATH}" in
  *"${dest_path}"*)
    _denv_info "Found ${dest_path} in PATH, you're all set!"
    ;;
  *)
    _denv_error "Unable to find ${dest_path} in PATH."
    if _denv_user_confirm "Should we update your current shell's profile accordingly?"; then
      case "${SHELL}" in
        *bash)
          # update ~/.bashrc since that's the only one I know is always sourced
          {
            echo ""
            echo "# add the path to the installation of denv to PATH"
            echo "export PATH=\"\${PATH}:${dest_path}\""
          } >> ~/.bashrc
          _denv_info "Open a new terminal to get the updated PATH (or '. ~/.bashrc' directly)." 
          ;;
        *zsh)
          {
            echo ""
            echo "# add the path to the installation of denv to list of executable paths"
            echo "path+=(\"${dest_path}\")"
            echo "export PATH"
          } >> ~/.zshrc
          _denv_info "Open a new terminal to get the updated PATH (or '. ~/.zshrc' directly)." 
          ;;
        *)
          _denv_error "Current shell ${SHELL} is not known." \
            "You are responsible for adding the destination to your PATH." \
            "Feel free to open an issue with the solution: https://github.com/tomeichlersmith/denv/issues/new/choose"
          ;;
      esac
    else
      _denv_info "Be sure that directory in is your \$PATH environment variable for denv to work." \
        "A common way to do this is to update the definition of PATH in your shell profile." \
        "For example, you could put the following line at the bottom of your ~/.bashrc file." \
        "  export PATH=\"\${PATH}:${dest_path}\""
    fi
    ;;
esac