git_utils

#!/bin/bash
#
# Common methods for use with git scripts.
# Open-sourced at https://github.com/cooperka/build-scripts.

BUILD_SCRIPT_VERSION=2.5.2

# Load custom settings.
source ./git_utils.cfg

# Perform any initialization and let the user know what's about to happen.
# @param $@ Description of what's about to happen.
init_safe() {
  verify_origin

  echo "$@"
  prompt 'Continue?'

  print_status "Initializing..."
  git stash save "WIP before running build script v${BUILD_SCRIPT_VERSION}"
  git fetch "origin"
}

# @see init_safe()
init_with_warning() {
  echo 'Note: Please stash before continuing. Any existing changes will be lost.'
  echo 'Note: This is a destructive action! It will overwrite the online branch.'
  echo;

  init_safe $1
}

# Assert that remote `origin` points to the real origin repo.
verify_origin() {
  local index_remote="$(git remote -v | grep "${GIT_REPO_FULL_NAME}.git" | cut -f1 | xargs)"
  if [[ "${index_remote}" != 'origin origin' ]]; then
    abort_with_message "Remote \`origin\` must point to ${GIT_REPO_FULL_NAME}."
  fi
}

# @param $1 Name of the branch to rebase.
# @param $2 Name of the branch to rebase on.
rebase_branch() {
  print_status "Rebasing $1 on $2..."

  checkout_fresh "$1"
  git rebase "origin/$2"
}

# @param $1 Name of the branch to reset.
# @param $2 Name of the branch to reset to.
reset_branch() {
  print_status "Resetting $1 to $2..."

  checkout_fresh "$1"
  git reset --hard "origin/$2"
}

# @param $1 Name of the branch to push.
# @param $2 Extra args, e.g. -f to force push.
push_branch() {
  block_push_to_master "$1"
  print_status "Pushing $1 to origin..."

  git push "origin" "$1" "$2"
}

# @param $1 version name to push as tag name
push_tag() {
  print_status "Pushing tag $1..."

  git tag -f "$1"
  git push "origin" "$1"

  if [[ "$?" -ne 0 ]]; then
    abort_with_message 'Failed to push tag (likely already exists on origin).'
  fi
}

# @param $1 Name of the branch to checkout and reset.
checkout_fresh() {
  print_status "Checking out $1 (will overwrite any local version)..."

  git checkout -B "$1" "origin/$1"
}

# @param $1 Message to prompt user before waiting for 'y' input
prompt() {
  read -p "$1 [yn] " -n 1 -r
  echo
  if [[ ! "$REPLY" =~ ^[Yy]$ ]]; then
    abort_with_message 'User aborted.'
  fi
}

# @param $1 Message to print.
print_status() {
  echo;
  echo "[Build Script] $1"
}

# @param $1 Name of the branch to push.
block_push_to_master() {
  if [[ ${GIT_ALLOW_PUSH_TO_MASTER} != true && "$1" == 'master' ]]; then
    abort_with_message 'Cannot push to master without review.'
  fi
}

# @param $1 Message explaining the error.
abort_with_message() {
    echo;
    echo "Error: $1"
    exit 1
}

# @param $1 URL to open
open_url() {
  python -mwebbrowser "$1"
}

# "Cut" a branch, force-pushing the code from the source branch onto the destination branch.
# Useful for releasing a version of your app and keeping that code somewhere else (to allow easier patch releases when necessary).
#
# @param $1 Name of the branch to cut (destination).
# @param $2 Name of the branch to cut from (source).
cut_branch() {
  init_with_warning "About to cut $1 from $2."

  block_push_to_master "$1"

  reset_branch "$1" "$2"
  push_branch "$1" '-f'
}

# See cut_branch for description.
# In addition, bump the version before pushing the branch.
#
# @param $1 Name of the branch to cut.
# @param $2 Name of the branch to cut from.
# @param $3 Name of new version. Change will be applied by your custom perform_version_bump method.
cut_branch_with_version_bump() {
  if ! function_exists 'perform_version_bump'; then
    abort_with_message '`perform_version_bump` not defined. You must define it yourself in git_utils.cfg.'
  fi

  block_push_to_master "$1"

  rebase_branch "$1" "$2"

  print_status "Bumping version to $3..."
  perform_version_bump "$3" "${PWD}"

  push_branch "$1" '-f'
}

# @param $1 Name of the function to check for.
# @return true if the specified function exists as a shell function.
function_exists() {
  declare -f "$1" > /dev/null
  return "$?"
}