.bash_prompt

# Add `. ~/.bash_prompt` to your ~/.bash_profile

# Credits:
# https://gist.github.com/insin/1425703
RED="\[\033[0;31m\]"
YELLOW="\[\033[0;33m\]"
GREEN="\[\033[0;32m\]"
BLUE="\[\033[0;34m\]"
CYAN="\[\033[0;36m\]"
LIGHT_CYAN="\[\033[1;36m\]"
LIGHT_RED="\[\033[1;31m\]"
LIGHT_GREEN="\[\033[1;32m\]"
LIGHT_BLUE="\[\033[1;34m\]"
WHITE="\[\033[1;37m\]"
LIGHT_GRAY="\[\033[0;37m\]"
COLOR_NONE="\[\e[0m\]"
BOLD="\[\033[1m\]"
UNBOLD="\[\033[0m\]"

# Detect whether the current directory is a git repository.
function is_git_repository {
  git branch > /dev/null 2>&1
}

# Determine the branch/state information for this git repository.
function set_git_branch {
  # Capture the output of the "git status" command.
  git_status="$(git status 2> /dev/null)"

  # Set color based on clean/staged/dirty.
  if [[ ${git_status} =~ "working directory clean" ]]; then
    state="${GREEN}"
  elif [[ ${git_status} =~ "Changes to be committed" ]]; then
    state="${YELLOW}"
  else
    state="${LIGHT_RED}"
  fi

  # Set arrow icon based on status against remote.
  remote_pattern="# Your branch is (.*) of"
  if [[ ${git_status} =~ ${remote_pattern} ]]; then
    if [[ ${BASH_REMATCH[1]} == "ahead" ]]; then
      remote="↑"
    else
      remote="↓"
    fi
  else
    remote=""
  fi
  diverge_pattern="# Your branch and (.*) have diverged"
  if [[ ${git_status} =~ ${diverge_pattern} ]]; then
    remote=":arrow_up_down:"
  fi
  branch="$(git rev-parse --abbrev-ref HEAD)"

  # Set the final branch string.
  BRANCH="${state}(${branch})${remote}${COLOR_NONE}"
}

function set_prompt() {
  # Set the BRANCH variable.
  if is_git_repository ; then
    set_git_branch
  else
    BRANCH=''
  fi

  export PS1="\n${CYAN}\u ${COLOR_NONE}\w ${BRANCH}\n\$ "
}

PROMPT_COMMAND=set_prompt