#!/usr/bin/env bash
#
# init or migrate the git bare repo
#
# @params
# Globals
#   ${mydir}: current dir of the script
#   ${confirm}: confirm status of the user
#   ${post_hooks}: array of post checkout actions to perform
#   ${remote_url}; remote_url to clone and migrate
# Arguments
#   -h|--help: show help message and exit
#   -u URL|--url URL: specify remote dotfiles url to init
#   -s|--select: clone submodules after checkout
#   -y|--yes: confirm action by default and skip confirmation

set -e
set -f

mydir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
source "${mydir}"/../helper/set_variable.sh
source "${mydir}"/../helper/get_confirmation.sh

function usage() {
  echo -e "Usage: dotbare finit [-h] [-y] [-s] [-u URL] ...

Init the git bare repository if doesn't exist or migrate existing dotfiles to current system.
The bare repository will be initialised under \$DOTBARE_DIR, default to \$HOME/.cfg if not set.
It will track \$DOTBARE_TREE, default to \$HOME if not set.

Migration example:
dotbare finit -u URL --submodule

Default: init the bare repository at $DOTBARE_DIR.

Optional arguments:
  -h, --help\t\tshow this help message and exit.
  -u URL, --url URL\tmigrate existing dotfiles from remote git repo to current system.
  -s, --submodule\tclone submodules during migration.
  -y, --yes\t\tacknowledge all actions that will be taken and skip confirmation."
}

remote_url=""
post_hooks=()
confirm=""

while [[ "$#" -gt 0 ]]; do
  case "$1" in
    -s|--submodule)
      [[ ! "${post_hooks[*]}" =~ submodule ]] && \
        post_hooks+=("submodule")
      shift
      ;;
    -u|--url)
      [[ -z "$2" ]] && echo "Invalid option: $1" >&2 && usage && exit 1
      remote_url="$2"
      shift
      shift
      ;;
    -y|--yes)
      confirm='y'
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      echo "Invalid option: $1" >&2
      usage
      exit 1
      ;;
  esac
done

if [[ -z "${remote_url}" ]]; then
  echo "git bare repository will be initialised at ${DOTBARE_DIR}"
  echo "git bare repository will be tracking ${DOTBARE_TREE}"
  [[ -z "${confirm}" ]] && confirm=$(get_confirmation)
  [[ "${confirm}" != 'y' ]] && exit 1

  if [[ -d "${DOTBARE_DIR}" ]]; then
    echo "${DOTBARE_DIR} already exist"
    exit 1
  else
    git init --bare "${DOTBARE_DIR}"
    git --git-dir "${DOTBARE_DIR}" --work-tree "${DOTBARE_TREE}" \
      config --local status.showUntrackedFiles no
  fi
else
  [[ ! -d "${DOTBARE_TREE}" ]] && mkdir -p "${DOTBARE_TREE}"
  cd "${DOTBARE_TREE}"
  git clone --bare "${remote_url}" "${DOTBARE_DIR}"

  set +e
  while ! git --git-dir "${DOTBARE_DIR}" --work-tree "${DOTBARE_TREE}" checkout 2> /dev/null; do
    echo "Resolving conflicts ..."
    git --git-dir "${DOTBARE_DIR}" --work-tree "${DOTBARE_TREE}" checkout 2>&1 \
      | awk '{
          if ($0 ~ /[\t].*/) {
            gsub(/^[\t]/, "", $0)
            print $0
          }
        }' \
      | xargs -I __ "${mydir}"/fbackup -p __ -m 2> /dev/null
    if git --git-dir "${DOTBARE_DIR}" --work-tree "${DOTBARE_TREE}" checkout 2> /dev/null; then
      echo "All conflicts resolved"
      break
    fi
  done
  set -e

  git --git-dir "${DOTBARE_DIR}" --work-tree "${DOTBARE_TREE}" \
    config --local status.showUntrackedFiles no
  echo "File checkout succeeded"

  for hook in "${post_hooks[@]}"; do
    case "${hook}" in
      submodule)
        echo "Cloning submodules ..."
        git --git-dir "${DOTBARE_DIR}" --work-tree "${DOTBARE_TREE}" \
          submodule update --init --recursive
        ;;
    esac
  done

  echo "Migration completed"
  exit 0
fi