#!/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_data.sh

function usage() {
  echo -e "Usage: dotbare fcheckout [-h] [-a] [-b] [-c] ...\n"
  echo -e "Reset/Unstage the selected staged file"
  echo -e "Or reset the commit to certain point\n"
  echo -e "optional arguments:"
  echo -e "  -h\t\tshow this help message and exit"
  echo -e "  -a\t\tsearch all files instead of just modified files"
  echo -e "  -b\t\tcheckout branch"
  echo -e "  -c\t\tcheckout single commits"
}

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

while getopts ":habc" 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 "${branch}" ]]; then
  # checkout branch
  selected_branch=$(/usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" branch -a | \
    awk '{
      if ($0 ~ /\*.*\(HEAD.*/) {
        gsub(/\* /, "", $0)
        print "\033[32m" $0 "\033[0m"
      } else if (match($1, "\\*") != 0) {
        print "\033[32m" $2 "\033[0m"
      } else {
        gsub(/^[ \t]+/, "", $0)
        print $0
      }
    }' | \
    fzf --no-multi --header='select a branch to checkout' \
    --preview="/usr/bin/git --git-dir=${DOTBARE_DIR} --work-tree=${DOTBARE_TREE} log --oneline --graph --color=always --decorate=short {}")
  [[ -z "${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=$(get_commit)
  [[ -z "${selected_commits}" ]] && exit 0
  /usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" checkout "${selected_commits}"
  exit 0
else
  # checkout files (reset file changes back to HEAD)
  if [[ -n "${all_files}" ]]; then
    selected_files=$(/usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" ls-files --full-name --directory "${DOTBARE_TREE}" | \
      fzf --multi --header='select a file to checkout version in HEAD' --preview "head -50 ${DOTBARE_TREE}/{}" | \
      awk -v home="${DOTBARE_TREE}" '{print home "/" $0}')
  else
    selected_files=$(/usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" diff --name-status | \
      awk '{print "\033[31m" $1 " " $2}' | \
      fzf --multi --header='select a file to checkout version in HEAD' \
      --preview "echo {} | awk '{print \$2}' | \
        xargs -I __ /usr/bin/git --git-dir=${DOTBARE_DIR} --work-tree=${DOTBARE_TREE} diff --color=always ${DOTBARE_TREE}/__" | \
      awk -v home="${DOTBARE_TREE}" '{print home "/" $2}')
  fi
  [[ -z "${selected_files}" ]] && exit 0
  while IFS= read -r line; do
    echo "(dryrun) dotbare checkout -- ${line}"
  done <<< "${selected_files}"
  confirm=$(get_confirmation "Confirm?")
  [[ "${confirm}" != 'y' ]] && exit 0
  while IFS= read -r line; do
    /usr/bin/git --git-dir="${DOTBARE_DIR}" --work-tree="${DOTBARE_TREE}" checkout -- "${line}"
    echo "${line} checkout success"
  done <<< "${selected_files}"
fi