dcp-install-links

#!/usr/bin/env bash

set -eo pipefail

readonly OS="$(uname -s)"
readonly DCP_CONFIG_DIR="${XDG_CONFIG_HOME:-${HOME}/.config}/dcp"
readonly WARNING_SHOWN_FLAG_PATH="${DCP_CONFIG_DIR}/symlink-warning-shown"

readonly NON_DCP_DOTFILES=(
  ".bash_login"
  ".profile"
  ".zlogin"
)

readonly PATH_MIGRATIONS=(
	"${HOME}/.dcp/conf/plugins:${DCP_CONFIG_DIR}/plugins.lst"
	"${HOME}/.dcp/conf/theme:${DCP_CONFIG_DIR}/zsh-theme"
)

log_warn() {
  printf '\033[2;39;49m%s %b%5s \033[0;35m%s \033[2;39m: \033[0m%s\n' \
         "$(date '+%F %T')" '\033[0;33m' "WARN" "$$" "$1" >&2
}

__ary_join() {
  local sep="$1"; shift
  printf '%s' "$1"; shift
  printf '%s' "${@/#/${sep}}"
}

__ln_snfv() {
  # Solaris' and OpenBSD's ln(1) don't have -v
  printf '%s -> %s\n' "$2" "$1" >&2

  # Solaris' doesn't have -n (or its equivalent -h)
  [[ -h "$2" ]] && rm -f "$2" || :

  ln -sf "$1" "$2"
}

find_dotfiles() {
  local path="$1"; shift
  find "${path}" -mindepth 1 "$@" -print0 2>/dev/null | sort -z
}

__link_dotfile() {
  local dotfile="${2:$((${#1} + 1))}"
  local link="${HOME}/.${dotfile}"
  local parent="$(dirname "${link}")"

  if [[ ! -d "${parent}" ]]; then
    mkdir -p "${parent}"
  fi

  if [[ ! -h "${link}" ]] && [[ -d "${link}" || -s "${link}" ]]; then
    log_warn "~/.${dotfile} is a directory or file of non-zero size, skipping"
  else
    __ln_snfv "$2" "${link}"
  fi
}

link_dotfile() {
  if [[ "${OS}" = "Darwin" ]]; then
    __link_dotfile "$@"
  else
    case "$(basename "$2")" in
      chunkwmrc|khdrc|macos)  : ;;
      *)                      __link_dotfile "$@"
    esac
  fi
}

standard_cleanup() {
  if [[ "${OS}" = "Darwin" ]]; then
    if [[ ! -e "${HOME}/.hushlogin" ]]; then
      touch "${HOME}/.hushlogin"
    fi
  else
    if [[ -h "${HOME}/.macos" ]]; then
      rm -f "${HOME}/.macos"
    fi
  fi

  local dotfile
  for dotfile in gitignore_global kwm osx; do
    if [[ -h "${HOME}/.${dotfile}" ]]; then
      rm -f "${HOME}/.${dotfile}"
    fi
  done
}

perform_migrations() {
  local migration old_path new_path
  local performed_migration="false"

  for migration in "${PATH_MIGRATIONS[@]}"; do
    IFS=':' read -r old_path new_path <<< "${migration}"

    if [[ -e "${old_path}" ]]; then
      if ! "${performed_migration}"; then
        log_warn "The ~/.dcp/conf directory is deprecated and will be removed soon."
        performed_migration="true"
      fi

      log_warn "Moving ${old_path} -> ${new_path}"
      mv "${old_path}" "${new_path}"
    fi
  done

  if "${performed_migration}"; then
    printf '\n' >&2
  fi
}

check_non_dcp() {
  local dotfile
  local result="false"

  for dotfile in "${NON_DCP_DOTFILES[@]}"; do
    if [[ -e "${HOME}/${dotfile}" ]]; then
      if ! "${result}"; then
        printf '\n' >&2
      fi

      result="true"

      log_warn "~/${dotfile} exists but is not provided by ~/.dcp"
    fi
  done

  "${result}"
}

__maybe_git_config() {
  if ! git config --global "$1" >/dev/null; then
    git config --global "$1" "$2"
  fi
}

configure_git() {
  git config --global "core.excludesfile" "${HOME}/.cvsignore"

  __maybe_git_config "color.ui" "true"
  __maybe_git_config "core.editor" "vim"
  __maybe_git_config "push.default" "matching"
  __maybe_git_config "grep.lineNumber" "true"
  __maybe_git_config "submodule.fetchJobs" "2"
  __maybe_git_config "core.attributesfile" "${HOME}/.gitattributes"

  if [[ ! -e "${HOME}/.gitattributes" ]]; then
    touch "${HOME}/.gitattributes"
  fi

  if [[ "${OS}" = "Darwin" ]]; then
    __maybe_git_config "core.trustctime" "false"
    __maybe_git_config "diff.mobileprovision.textconv" "openssl smime -inform der -verify -in"
    __maybe_git_config "diff.plist.textconv" "plutil -convert xml1 -o -"
    __maybe_git_config "diff.utf16.textconv" "iconv -f utf-16 -t utf-8"

    if ! grep -q '^\*\.mobileprovision' "${HOME}/.gitattributes"; then
      printf '*.mobileprovision diff=mobileprovision\n' >>"${HOME}/.gitattributes"
    fi
    if ! grep -q '^\*\.plist' "${HOME}/.gitattributes"; then
      printf '*.plist diff=plist\n' >>"${HOME}/.gitattributes"
    fi
  fi
}

print_warning() {
  local dotfiles
  dotfiles="$(__ary_join ", " "${NON_DCP_DOTFILES[@]}")"

  cat >&2 <<EOT

Having any of [${dotfiles}] should (in theory) be harmless.
That said, it can also really mess things up. It's good to examine their
contents and evaluate if they need to exist.

For example, RVM will persistently try to create ~/.zlogin to ensure that
it gets loaded, but this already happens in ~/.dcp/lib/post_init.sh, and the
code they put in ~/.zlogin will cause zsh to both start and exit with return
code 1 for login shells if you ever uninstall RVM. Not good!

This wall of warning text will only be shown once, unless you get rid of these
files then create them again at some point.
EOT
}

main() {
  standard_cleanup

  perform_migrations

  local dotfile

  while IFS='' read -d '' -r dotfile; do
    link_dotfile "${HOME}/.dcp/dot" "${dotfile}"
  done < <(
    find_dotfiles "${HOME}/.dcp/dot" -type f
  )

  printf '\n' >&2

  while IFS='' read -d '' -r dotfile; do
    link_dotfile "${HOME}/.vim" "${dotfile}"
  done < <(
    find_dotfiles "${HOME}/.vim" -maxdepth 1 -type f -name '*vimrc'
  )

  if ! check_non_dcp; then
    rm -f "${WARNING_SHOWN_FLAG_PATH}"
  elif [[ ! -e "${WARNING_SHOWN_FLAG_PATH}" ]]; then
    print_warning
    mkdir -p "$(dirname "${WARNING_SHOWN_FLAG_PATH}")"
    touch "${WARNING_SHOWN_FLAG_PATH}"
  fi

  if command -v git >/dev/null; then
    configure_git
  fi
}

main "$@"