#!/bin/bash

# Script to backup git repo(s) to Backblaze B2

# Usage
read -r -d '' __usage <<-'EOF' || true
Options:
  -b --b2-bucket       [arg] Backblaze B2 bucket name.
  -i --b2-id           [arg] Backblaze B2 account ID.
  -k --b2-key          [arg] Backblaze B2 application key.
  -g --github-account  [arg] GitHub account name.
  -p --https-password  [arg] GitHub account password (for private repos)
  -t --temp-dir        [arg] Dir to use for temp files.
  -s --use-https             Use HTTPS to clone instead of SSH

  -h --help                  This page.
EOF
__helptext='NOTE: --temp-dir defaults to "$(mktemp -d)" if not specified.'

# Load BASH3 Boilerplate functions
source bash3boilerplate/main.sh

# Color fix for rxvt-unicode (tell b3bp we're xterm)
if [[ "${TERM}" =~ rxvt-unicode-.*color ]]; then
  TERM="xterm"
fi

# Functions
function clone_repository() {
  # Clone the repo using either HTTPS or SSH
  local repo="${1:-}"
  local repo_url=""
  if [[ "${arg_s}" == "1" ]]; then
    # Use HTTPS
    repo_url="github.com/${__github_account}/${repo}.git"
    if [[ "${arg_p:-}" != "" ]]; then
      repo_url="https://${__github_account}:${arg_p}@${repo_url}"
    else
      repo_url="https://${repo_url}"
    fi
  else
    # Use SSH
    repo_url="git@github.com:${__github_account}/${repo}.git"
  fi
  git clone --mirror \
    "${repo_url}" \
    "${__temp_dir}/${repo}-${__date}.git"
}
function compress_repository() {
  # Move to repository dir so relative paths are used in the archive
  local repo_source="${1:-}"
  local archive_dest="${2:-}"
  local repo_path="$(dirname "$(realpath "${repo_source}")")"
  local repo_source="$(basename "$(realpath "${repo_source}")")"
  local archive_dest="$(realpath "${archive_dest}")"
  pushd "${repo_path}" >/dev/null
  
  # Create archive
  tar cpzf "${archive_dest}" "${repo_source}"
  
  # Done
  popd >/dev/null
}
function find_b2_cmd() {
  if which backblaze-b2 >/dev/null 2>&1; then
    # Arch Linux uses this name
    echo "backblaze-b2"
  elif which b2 > /dev/null 2>&1; then
    echo "b2"
  else
    __b3bp_log error "B2 command-line tool not found"
    exit 1
  fi
}
function fix_repository_name() {
  # Remove '.git' from the name (if present)
  local repository="${1:-}"
  if [[ "${repository: -4:4}" == ".git" ]]; then
    repository="${repository:0: -4}"
  fi
  echo "${repository}"
}
function main() {
  # Create the __temp_dir
  mkdir -p "${__temp_dir}"

  # Authorize B2 account
  "${__b2_cmd}" authorize-account "${__b2_id}" "${__b2_key}"

  # Loop over repos
  for repo in "${@}"; do
    repo="$(fix_repository_name "${repo}")"

    echo "Backing up ${repo}"

    # Clone repo
    echo "Cloning ${repo}"
    clone_repository "${repo}"

    # Compress repo
    echo "Compressing ${repo}"
    compress_repository "${__temp_dir}/${repo}-${__date}.git" \
      "${__temp_dir}/${repo}-${__date}.git.tgz"

    # Upload repo
    echo "Uploading ${repo}"
    "${__b2_cmd}" upload-file "${__b2_bucket}" \
      "${__temp_dir}/${repo}-${__date}.git.tgz" \
      "${__github_account}/${repo}-${__date}.git.tgz"

    # Cleanup
    /bin/rm "${__temp_dir}/${repo}-${__date}.git.tgz"
    /bin/rm -rf "${__temp_dir}/${repo}-${__date}.git"
    
    # Done
    echo "Successfully backed up ${repo}"
  done

  # Remove __temp_dir (if empty)
  /bin/rmdir --ignore-fail-on-non-empty "${__temp_dir}"
}

# Set env
__b2_bucket="${arg_b}"
__b2_cmd="$(find_b2_cmd)"
__b2_id="${arg_i}"
__b2_key="${arg_k}"
__date="$(date '+%F_%H%M%z')"
__github_account="${arg_g}"
__temp_dir="${arg_t:-}"
if [[ "$__temp_dir" == "" ]]; then
  __temp_dir="$(mktemp -d)"
fi

# Check args
__run="yes"
if [[ "${arg_h}" == "0" ]]; then
  # Show missing arg warnings only if help arg isn't specified
  [[ -z "${arg_b:-}" ]] && echo "B2 bucket not specified" && __run="no"
  [[ -z "${arg_i:-}" ]] && echo "B2 ID not specified" && __run="no"
  [[ -z "${arg_k:-}" ]] && echo "B2 Key not specified" && __run="no"
  [[ -z "${arg_g:-}" ]] && echo "GitHub account not specified" && __run="no"
  [[ "${#}" == "0" ]] && echo "No repos specified" && __run="no"
fi

# Debug
#echo "== Debug =="
#echo "b: [${arg_b}]"
#echo "i: [${arg_i}]"
#echo "k: [${arg_k}]"
#echo "g: [${arg_g}]"
#echo "t: [${arg_t}]"
#echo "p: [${arg_p}]"
#echo ""
#echo "s: [${arg_s}]"
#echo "h: [${arg_h}]"
#echo ""
#echo "r: [${@}]"
#echo "== Debug =="

# Show help or run backups
if [[ "${arg_h}" = 1 ]] || [[ "${__run}" == "no" ]]; then
  # -h or --help used or missing argument(s), show usage and exit
  help "Usage: ${__base} [options] repo(s)..."
else
  # Backup repo(s)
  main "${@}"
fi
exit 0