dotfiles/install.sh

#!/bin/sh
set -e

DOTFILES="$(dirname "$(realpath "$0")")"
TARGET="$HOME"

[ -r "$DOTFILES/config.local" ] && . "$DOTFILES/config.local"
GIT_USER="${GIT_USER:-Fernando Schauenburg}"
GIT_EMAIL="${GIT_EMAIL:-dev@schauenburg.me}"

main() {
  IS_DRY_RUN=yes
  while getopts 'fht:' opt; do case "$opt" in
    f) unset IS_DRY_RUN;;
    t) TARGET="$OPTARG";;
    h) usage; exit 0;;
    *) usage; exit 1;;
  esac done

  check_dependencies
  greeting
  make_dirs
  stow_home
  link_config
  git_user_config
  nvim_plugins
}

check_dependencies() {
  for cmd in stow readlink; do
    if ! command -v "$cmd" >/dev/null 2>&1; then
      error "Dependency \`$cmd\` not found."
      exit 1
    fi
  done
}

greeting() {
  dry_run && {
    warn "Performing dry run (use -f to actually make changes)."
    warn
  }

  info "Deploying dotfiles:"
  info "  Source: $cyan$DOTFILES$rst"
  info "  Target: $cyan$TARGET$rst"
  info "  Git user: $yellow$GIT_USER <$GIT_EMAIL>$rst"

  if [ -t 0 -a -t 1 ]; then
    info
    info "Press ENTER to continue (CTRL-C to cancel)..."
    read k
  fi
}

make_dirs() {
  heading 'create auxiliary directories'
  while read item; do
    dir="$TARGET/$item"
    if [ ! -d "$dir" ]; then
      echo "${yellow}MKDIR:$rst $dir"
      dry_run || mkdir -p "$dir"
    fi
  done <<EOF
.local/share/less/
.local/share/python/
.local/share/nvim/shada/
.local/share/zsh/
.local/etc/git/
EOF
}

link_config() {
  heading 'link .config directory'

  link="$TARGET/.config"
  dotfiles_config="$DOTFILES/config"
  backup="$TARGET/old_dot_config"

  if [ "$(readlink "$link")" != "$dotfiles_config" ]; then
    if [ -d "$link" ]; then
      echo "${red}WARNING:$rst moving existing '$link' to '$backup'"
      dry_run || mv "$link" "$backup"
    fi

    echo "${yellow}LINK:$rst $link $blue=>$rst $dotfiles_config"
    dry_run || ln -s "$dotfiles_config" "$link"
  fi
}

stow_home() {
  heading 'stow home directory'
  stow -v${IS_DRY_RUN:+n} --no-folding -d "$DOTFILES" -t "$TARGET" home 2>&1 \
    | sed -E \
      -e "s/^(WARNING:)/$red\1$rst/" \
      -e "s/^([^:]+:)/$yellow\1$rst/" \
      -e "s/=>/$blue=>$rst/"
}

git_user_config() {
  heading 'git user configuration'
  config_file="$TARGET/.local/etc/git/config.user"
  temp_git="$(mktemp)"
  cat >"$temp_git" <<EOF
#         *************************************
#         *       DO NOT EDIT THIS FILE       *
#         *************************************
#
# This file was generated by the bootstrap script and any changes will be
# overwritten the next time it is run. For local settings, use this instead:
#
#   ~/.local/etc/git/config
#
EOF
  git config -f "$temp_git" user.name "${GIT_USER}"
  git config -f "$temp_git" user.email "${GIT_EMAIL}"

  if ! diff "$config_file" "$temp_git" >/dev/null 2>&1; then
    if [ -f "$config_file" ]; then action=OVERWRITE; else action=CREATE; fi
    echo "$yellow$action:$rst $config_file with contents of $temp_git:"
    echo "$cyan"
    cat "$temp_git"
    echo "$rst"
    dry_run || cp -f "$temp_git" "$config_file"
  fi
}

nvim_plugins() {
  heading 'nvim plugins'
  if command -v nvim >/dev/null 2>&1; then
    dry_run || {
      warn "installing neovim plugins..."
      nvim --headless -c 'autocmd User PackerComplete quitall' -c 'PackerSync'
    }
  else
    error "neovim is not installed; skipping plugin installation..."
  fi
}

###############################################################################
# Helper Functions
###############################################################################

if [ -t 1 ]; then
  rst=$(tput      sgr0)
  red=$(tput      setaf  1)
  green=$(tput    setaf  2)
  yellow=$(tput   setaf  3)
  blue=$(tput     setaf  4)
  magenta=$(tput  setaf  5)
  cyan=$(tput     setaf  6)
else
  rst=''
  red=''
  green=''
  yellow=''
  blue=''
  magenta=''
  cyan=''
fi

dry_run() { [ -n "$IS_DRY_RUN" ]; }

usage() {
  echo "Usage: $(basename $0) [-h] [-f] [-t <target>]"
  echo ""
  echo "  -h  print this help and exit"
  echo "  -f  modify filesystem rather than dry run"
  echo "  -t  set <target> directory (default: \$HOME)"
}

heading()   { printf '%s\n' "${blue}=====  $1  ==========${rst}"; }
info()      { printf '%s ' "$@";                            printf '\n'; }
warn()      { printf '%s ' "${yellow}$@${rst}";             printf '\n'; }
error()     { printf '%s ' "${red}$@${rst}";                printf '\n'; }

main "$@"