#!/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.
  -t --temp-dir        [arg] Dir to use for temp files.

  -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)
TERM="xterm"

# Functions
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() {
  # Set env
  local b2_bucket="${arg_b}"
  local b2_cmd="$(find_b2_cmd)"
  local b2_id="${arg_i}"
  local b2_key="${arg_k}"
  local date="$(date '+%F_%H%M%z')"
  local github_account="${arg_g}"
  local temp_dir="${arg_t:-}"
  if [[ "$temp_dir" == "" ]]; then
    temp_dir="$(mktemp -d)"
  fi
  
  # 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 ${repo}"
    git clone --mirror \
      "https://github.com/${github_account}/${repo}.git" \
      "${temp_dir}/${repo}-${date}.git"

    # 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}"
}

# 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

# 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