mg

#!/bin/bash

DEBUG=0
VERBOSE=0
CMDS="args|b|br|co|db|nb|pb|pr|rbm|web"
BRANCH_PREFIX="dlb-"
BRANCH_URL_SAFE=""

REPO=`git remote -v | grep -m 1 "(push)" | sed -E "s/.*github\.com[:/](.*)(\.git| ).*/\1/"`

_arg_branch_or_current() {
  shift

  if [ "$DEBUG" -eq 1 ]; then
    echo "[Debug][_arg_branch_or_current]: \$0=$0,\$1=$1,\$2=$2,\$3=$3"
  fi

  if [ -n "$1" ]; then
    BRANCH=$1
    BRANCH_URL_SAFE=`echo $BRANCH | tr -d "\n" | jq -sRr @uri`
    echo "Using branch '$BRANCH' (url: $BRANCH_URL_SAFE)"
  else
    BRANCH=`git rev-parse --abbrev-ref HEAD`
    BRANCH_URL_SAFE=`echo $BRANCH | tr -d "\n" | jq -sRr @uri`
    echo "No branch specified, using current branch '$BRANCH' (url: $BRANCH_URL_SAFE)"
  fi
}

_arg_branch_or_empty() {
  shift

  if [ "$DEBUG" -eq 1 ]; then
    echo "[Debug][_arg_branch_or_empty]: \$0=$0,\$1=$1,\$2=$2,\$3=$3"
  fi

  if [ -n "$1" ]; then
    BRANCH=$1
    echo "Using branch '$BRANCH'"
  else
    BRANCH=
  fi
}

_usage() {
  echo "Usage: mg [-hv]

  b
    list local branches

  br
    list my remote branches

  co [branch]
    checkout existing branch

  db [branch]
    delete specified (or current) branch from local and remote

  nb <branch>
    create and checkout new branch

  pb [branch]
    push specified (or current) branch to remote

  pr [branch]
    initiate a pull request on specified (or current) branch

  rbm [branch]
    rebase master into specified (or current) branch

  web
    open current branch in GitHub" 1>&2;
  exit 1
}

_version() {
  echo "MagicGit v0.1 (dbechrd)"
  exit 0
}

# DEBUG: This is for debugging argument passing, not useful in production
args() {
  printf "%s" options:
  while getopts a:b:c:d:e:f:g:h:i:j:k:l:m:n:o:p:q:r:s:t:u:v:w:x:y:z: OPTION "$@"; do
    printf "\n -%s '%s'" $OPTION $OPTARG
  done
  shift $((OPTIND - 1))
  printf "\narg: '%s'" "$@"
  echo
}

# List branches
b() {
  git branch
}

# List branches
br() {
  git branch --remote | grep $BRANCH_PREFIX
}

# Checkout existing branch
co() {
  _arg_branch_or_current $@
  echo "[Local] Checking out branch '$BRANCH'"
  git checkout $BRANCH
}

# Delete branch from local and remote
db() {
  _arg_branch_or_current $@

  read -p "[Remote] Deleting branch '$BRANCH'. Proceed [y/N]: " yn
  case $yn in
    [Yy])
      git push -d origin $BRANCH
      ;;
    [Nn]*)
      ;;
  esac

  # Note: This will only delete the branch if detected as fully merged into
  #       master.
  read -p "[Local] FORCE deleting branch '$BRANCH'. Proceed [y/N]: " yn
  case $yn in
    [Yy])
      local have_main=$(git branch --list main)
      if [[ -n ${have_main} ]]; then
        git switch main 2>/dev/null
      else
        git switch master 2>/dev/null
      fi
      git branch -D $BRANCH
      ;;
    [Nn]*)
      ;;
  esac
}

# Create and checkout branch
nb() {
  _arg_branch_or_empty $@
  if [ "$BRANCH" == "" ]; then
    echo "No branch name specified"
    return 1
  fi
  echo "[Local] Creating branch '$BRANCH_PREFIX$BRANCH'"
  git checkout -b $BRANCH_PREFIX$BRANCH
}

# Push the branch to remote
pb() {
  _arg_branch_or_current $@
  echo "[Remote] Pushing branch '$BRANCH' to [Remote] '$REPO'"
  git push origin -u $BRANCH
}

# Initiate a pull request for the current branch
pr() {
  _arg_branch_or_current $@
  open "https://github.com/$REPO/compare/$BRANCH_URL_SAFE?quick_pull=1"
  echo "[GitHub] Creating pull request for branch '$BRANCH' in '$REPO'"
}

# Rebase master from remote
rbm() {
  # Alternatively, define an alias in your bashrc:
  # alias rbm='git co master && git pull && git co - && git rebase master'

  #local repo=`git remote -v | grep -m 1 "(push)" | sed -e "s/.*github.com[:/]\(.*\)\.git.*/\1/"`
  #local branch=`git name-rev --name-only HEAD`
  _arg_branch_or_current $@
  echo "[Local] Checking out master"
  git checkout master
  echo "[Local] Pulling changes from [Remote] '$REPO'/master"
  git pull --ff-only
  echo "[Local] Switching back to branch '$BRANCH'"
  git checkout $BRANCH
  echo "[Local] Rebasing branch '$BRANCH' from master"
  git rebase origin/master
}

# Open current branch in GitHub
web() {
  _arg_branch_or_current $@
  local giturl=$(git config --get remote.origin.url)
  echo $giturl
  if [ "$giturl" = "" ]; then
    echo "Not a git repository or no remote.origin.url set"
    exit 1
  fi
  giturl=${giturl/git\@github\.com\:/https://github.com/}
  giturl=${giturl/\.git/\/tree/}
  #local branch="$(git symbolic-ref HEAD 2>/dev/null)" || branch="(unnamed branch)"
  #branch=${branch##refs/heads/}
  giturl=$giturl/tree/$BRANCH
  echo "[GitHub] Opening repo in web browser: '$giturl'."
  open $giturl
}

default() {
  if [ -z "${v}" ]; then
    _version
  elif [ -n "${v}" ]; then
    _usage
  fi
}

# Note: Use "x:" to require option; "x" to not require option; and
#       leading ":" to silence option errors.
while getopts "dhv" opt; do
  case "${opt}" in
    d)
      DEBUG=1
      ;;
    h)
      _help
      ;;
    v)
      #v=${OPTARG}
      _version
      ;;
    *)
      _usage
      ;;
  esac
done

# DEBUG: Print command line args
if [ "$DEBUG" -eq 1 ]; then
  echo "[Debug][   cmd_line_args] \$1=$1, \$2=$2, \$3=$3"
fi

shift $((OPTIND-1))

# DEBUG: Print command line args after switches have been eaten
if [ "$DEBUG" -eq 1 ]; then
  echo "[Debug][post_switch_args] \$1=$1, \$2=$2, \$3=$3"
fi

if [[ "$1" == "help" ]]; then
  _usage
elif [[ $1 =~ ^($CMDS)$ ]]; then
  if [[ $VERBOSE -eq 1 ]]; then
    echo "Executing [$1]"
  fi
  "$1" "$@"
else
  echo "Invalid command '$1'" >&2
  echo "'`basename $0` help' for help"
fi