#!/bin/bash
#
# checkout files/commits/branches using fzf
#
# @params
# Globals
#   ${mydir}: current directory of the script, used for imports
#   ${all_files}: search all tracked files instead of just the modified files
#   ${branch}: checkout branch
#   ${selected_branch}: selected_branch to switch
#   ${selected_files}: selected_files to checkout to the version in HEAD
# Arguments
#   -h: show help message
#   -a: search all files instead of just the modified files
#   -b: search branch and checkout branch
#   -c: search commits and checkout commits

set -e

mydir="${0%/*}"
source "${mydir}"/../helper/set_variable.sh
source "${mydir}"/../helper/get_confirmation.sh
source "${mydir}"/../helper/git_query.sh

function usage() {
  echo -e "Usage: dotbare fcheckout [-h] [-a] [-b] [-c] ...\n"
  echo -e "Checkout files/commits/branch using fzf"
  echo -e "By default: checkout files back to HEAD (Reset changes back to HEAD)\n"
  echo -e "optional arguments:"
  echo -e "  -h\t\tshow this help message and exit"
  echo -e "  -a\t\tsearch all files and select a commit to checkout for selected files"
  echo -e "  -b\t\tcheckout branch"
  echo -e "  -c\t\tcheckout commit"
}

all_files=""
branch=""
commits=""

while getopts ":habcC" opt
do
  case "$opt" in
    a)
      all_files='true'
      break
      ;;
    b)
      branch='true'
      break
      ;;
    c)
      commits='true'
      break
      ;;
    h)
      usage
      exit 0
      ;;
    *)
      echo "Invalid option: ${OPTARG}" >&2
      usage
      exit 1
      ;;
  esac
done

if [[ -n "${branch}" ]]; then
  # checkout branch
  selected_branch=$(get_branch 'Select a branch to checkout')
  [[ -z "${selected_branch}" ]] && exit 0
  /usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" checkout "${selected_branch}"
  exit 0
elif [[ -n "${commits}" ]]; then
  # checkout commits
  selected_commits=$(get_commit 'Select a commit to checkout')
  [[ -z "${selected_commits}" ]] && exit 0
  /usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" checkout "${selected_commits}"
  exit 0
else
  # checkout files (reset file changes back to HEAD)
  if [[ -z "${all_files}" ]]; then
    selected_files=$(get_modified_file 'select a file to checkout version in HEAD' | tr '\n' ' ')
    [[ -z "${selected_files}" ]] && exit 0
    echo "(dryrun) dotbare checkout -- ${selected_files}"
    confirm=$(get_confirmation "Confirm?")
    [[ "${confirm}" != 'y' ]] && exit 0
    /usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" checkout -- ${selected_files}
  else
    selected_files=$(get_git_file 'select a file to checkout' | tr '\n' ' ')
    echo "${selected_files}"
    [[ -z "${selected_files}" ]] && exit 0
    # continue select a commit and then checkout the file back to the selected commit
    selected_commits=$(/usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" \
    log --oneline --color=always --decorate=short \
      | fzf --no-multi --header="${header}" --preview "echo {} \
          | awk '{print \$1}' \
          | xargs -I __ /usr/bin/git --git-dir=${DOTBARE_DIR} --work-tree=${DOTBARE_TREE} \
            diff --color=always __ $selected_files" \
      | awk '{print $1}')
    [[ -z "${selected_commits}" ]] && exit 0
    echo "(dryrun) dotbare checkout ${selected_commits} -- ${selected_files}"
    confirm=$(get_confirmation "Confirm?")
    [[ "${confirm}" != 'y' ]] && exit 0
    /usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" checkout "${selected_commits}" ${selected_files}
  fi
fi