dot

#!/bin/bash

# ================================= #
#              _       _            #
#           __| | ___ | |_          #
#          / _` |/ _ \| __|         #
#         | (_| | (_) | |_          #
#          \__,_|\___/ \__|         #
#          dotfiles manager         #
# ================================= #

# ==================== GLOBAL VARS ====================

# file extension for packages
PACKAGE_EXTENSION="pkd"

# dotfiles path
DOT_DIR="$HOME/dotfiles"

# ==================== SUBCOMMANDS / FUNCTIONS ====================

# ========== HELP MESSAGE ==========

function cmd_help() {
  case "$1" in
  dot)
    echo -e "Description"
    echo -e "\t Dotfiles manager"
    echo -e "\nUsage"
    echo -e "\t$(basename "$2") [options] <subcommand>"
    echo -e "\nOptions"
    echo -e "\t-h, --help\t this helpfule message"
    echo -e "\nSubcommands"
    echo -e "\tstow\t\t manages symlinks"
    echo -e "\tdump\t\t dumps static configs"
    ;;
  stow)
    echo -e "Description"
    echo -e "\t Symlink manager (wraps Gnu Stow)"
    echo -e "\nUsage"
    echo -e "\t$(basename "$2") stow [options] <package> [<package> ...]"
    echo -e "\nOptions"
    echo -e "\t-h, --help\t\t this helpful message"
    echo -e "\t-a, --all\t\t stow all packages"
    echo -e "\t-t, --test\t\t testing mode, no change to file system"
    echo -e "\t-e, --exclude\t exclude packages passed"
    echo -e "\t-d, --delete\t delete existing links"
    echo -e "\nArguments"
    echo -e "\t<package>\t\t package basename to stow"
    ;;
  dump)
    echo -e "Description"
    echo -e "\t Dumps unlinked configs:"
    echo -e "\t\t-Brewfile  (list of brew packages)"
    echo -e "\t\t-Crontab   (cronjob settings)"
    echo -e "\nUsage"
    echo -e "\t$(basename "$2") dump [options]"
    echo -e "\nOptions"
    echo -e "\t-h, --help\t this helpful message"
    ;;
  *)
    echo "Unknown help message '$1'"
    exit 1
    ;;
  esac
  exit 0
}

# ========== STOW SUBCOMMAND ==========

# Check for Gnu Stow in path
function stow_check() {
  if ! (which stow >/dev/null); then
    echo -n "Gnu Stow not found in path, install it? (may require sudo) [Y/n]: "
    read -r IN
    IN=$(echo "$IN" | awk -F " " '{print tolower($0)}')
    if [ "$IN" == "y" ]; then
      # try install with brew
      if (which brew >/dev/null); then
        if _=$(brew install stow 2>&1); then
          echo "Installed with 'brew install stow'"
          echo
          return
        else
          echo "Installing with 'brew install stow' failed"
        fi
      fi
      # gain sudo
      if ! _=$(sudo -n true 2>&1); then
        echo -n "Need sudo. "
        if ! (sudo echo -n ""); then
          echo ""
          echo "Sudo failed, Exiting..."
          exit 1
        fi
      fi
      # try installing with apt
      if (which apt >/dev/null); then
        if _=$(sudo apt install -y stow 2>&1); then
          echo "Installed with 'sudo apt install stow'"
          echo
          sudo -k
          return
        else
          echo "Installing with 'sudo apt install stow' failed"
        fi
      fi
      # install failed, exit cleanly
      sudo -k
      echo -e "Failed to install, Exiting..."
      exit 1
    else
      # install denied, exit cleanly
      echo -e "Exiting..."
      exit 0
    fi
  fi
}

function cmd_stow() {

  # stowignore file
  STOWIGNORE="$DOT_DIR/.stowignore"

  # package regex
  PACKAGE_REGEX=("$DOT_DIR"/*."$PACKAGE_EXTENSION")

  # default args
  STOW_ARGUMENTS=(
    "--target=$HOME"
    "--dir=$DOT_DIR"
    "--dotfiles"
    "-v"
  )

  # help message
  if [[ $1 == "-h" || $1 == "--help" ]] || (($# == 0)); then
    cmd_help stow "$0"
  fi

  # check for stow
  stow_check

  # init variables
  ALL_FLAG=false
  EXCLUDE_FLAG=false
  TARGETS=()

  # parse arguments
  for ARG in "$@"; do
    case "$ARG" in
    -a | --all)
      ALL_FLAG=true
      ;;
    -t | --test)
      STOW_ARGUMENTS+=("--no")
      ;;
    -e | --exclude)
      EXCLUDE_FLAG=true
      ;;
    -d | --delete)
      STOW_ARGUMENTS+=("--delete")
      ;;
    -h | --help)
      cmd_help stow "$0"
      ;;
    *)
      if ! [ -d "$DOT_DIR/$ARG.$PACKAGE_EXTENSION" ]; then
        echo -e "Package Not Found: $ARG.$PACKAGE_EXTENSION"
        exit 1
      fi
      TARGETS+=("$ARG.$PACKAGE_EXTENSION")
      ;;
    esac
  done

  # read stowignore file
  if ! [ -f "$STOWIGNORE" ]; then
    echo "stowignore '$STOWIGNORE' not found"
    exit 1
  fi
  while IFS= read -r LINE; do
    # Skip empty lines and lines starting with #
    [[ -z $LINE || $LINE =~ ^[[:space:]]*# ]] && continue
    STOW_ARGUMENTS+=("--ignore=$LINE")
  done <"$STOWIGNORE"

  if $ALL_FLAG; then
    for pkg in "${PACKAGE_REGEX[@]}"; do
      pkg=$(basename "$pkg")
      STOW_ARGUMENTS+=("$pkg")
    done
  elif $EXCLUDE_FLAG; then
    for pkg in "${PACKAGE_REGEX[@]}"; do
      pkg=$(basename "$pkg")
      skip=false
      for target in "${TARGETS[@]}"; do
        if [[ $pkg == "$target" ]]; then
          skip=true
          break
        fi
      done
      if ! $skip; then
        STOW_ARGUMENTS+=("$pkg")
      fi
    done
  else
    for TARGET in "${TARGETS[@]}"; do
      STOW_ARGUMENTS+=("$TARGET")
    done
  fi

  \stow "${STOW_ARGUMENTS[@]}"
}

# ========== DUMP SUBCOMMAND ==========

function cmd_dump() {
  # filepaths
  STORAGE_DIR="$DOT_DIR/_dumps"
  BREW_PATH="${STORAGE_DIR}/Brewfile"
  CRON_PATH="${STORAGE_DIR}/Cronjobs"

  if (($# != 0)); then
    if [[ $1 == "-h" || $1 == "--help" ]]; then
      cmd_help dump "$0"
    else
      echo "Dump takes no arguments"
      exit 1
    fi
  fi

  # dump brewfile
  rm -f "$BREW_PATH"

  if (brew bundle dump --no-vscode --file="$BREW_PATH"); then
    echo "Dumping brew bundle"
  else
    echo "FAILED: could not dump brew bundle"
    exit 1
  fi

  # dump cron jobs

  if (crontab -l >"$CRON_PATH"); then
    echo "Dumping crontab"
  else
    echo "FAILED: could not dump crontab"
    exit 1
  fi
}

# ==================== SUBCOMMAND PARSER ====================

if (($# == 0)); then
  cmd_help dot "$0"
fi

case "$1" in
-h | --help)
  cmd_help dot "$0"
  ;;
stow)
  shift
  cmd_stow "$@"
  ;;
dump)
  shift
  cmd_dump "$@"
  ;;
*)
  echo "Unkown subcommand '$1'"
  exit 1
  ;;
esac