#!/usr/bin/env bash

THEME_PROMPT_HOST='\H'
SCM_THEME_PROMPT_DIRTY=' ✗'
SCM_THEME_PROMPT_CLEAN=' ✓'
SCM_THEME_PROMPT_PREFIX=' |'
SCM_THEME_PROMPT_SUFFIX='|'

SCM_GIT='git'
SCM_GIT_CHAR='±'

SCM_HG='hg'
SCM_HG_CHAR='☿'

SCM_SVN='svn'
SCM_SVN_CHAR='⑆'

SCM_NONE='NONE'
SCM_NONE_CHAR='○'

RVM_THEME_PROMPT_PREFIX=' |'
RVM_THEME_PROMPT_SUFFIX='|'

VIRTUALENV_THEME_PROMPT_PREFIX=' |'
VIRTUALENV_THEME_PROMPT_SUFFIX='|'

RBENV_THEME_PROMPT_PREFIX=' |'
RBENV_THEME_PROMPT_SUFFIX='|'

RBFU_THEME_PROMPT_PREFIX=' |'
RBFU_THEME_PROMPT_SUFFIX='|'

function scm {
  if [[ -f .git/HEAD ]]; then SCM=$SCM_GIT
  elif [[ -n "$(git symbolic-ref HEAD 2> /dev/null)" ]]; then SCM=$SCM_GIT
  elif [[ -d .hg ]]; then SCM=$SCM_HG
  elif [[ -n "$(hg root 2> /dev/null)" ]]; then SCM=$SCM_HG
  elif [[ -d .svn ]]; then SCM=$SCM_SVN
  else SCM=$SCM_NONE
  fi
}

function scm_prompt_char {
  if [[ -z $SCM ]]; then scm; fi
  if [[ $SCM == $SCM_GIT ]]; then SCM_CHAR=$SCM_GIT_CHAR
  elif [[ $SCM == $SCM_HG ]]; then SCM_CHAR=$SCM_HG_CHAR
  elif [[ $SCM == $SCM_SVN ]]; then SCM_CHAR=$SCM_SVN_CHAR
  else SCM_CHAR=$SCM_NONE_CHAR
  fi
}

function scm_prompt_vars {
  scm
  scm_prompt_char
  SCM_DIRTY=0
  SCM_STATE=''
  [[ $SCM == $SCM_GIT ]] && git_prompt_vars && return
  [[ $SCM == $SCM_HG ]] && hg_prompt_vars && return
  [[ $SCM == $SCM_SVN ]] && svn_prompt_vars && return
}

function scm_prompt_info {
  scm
  scm_prompt_char
  SCM_DIRTY=0
  SCM_STATE=''
  [[ $SCM == $SCM_GIT ]] && git_prompt_info && return
  [[ $SCM == $SCM_HG ]] && hg_prompt_info && return
  [[ $SCM == $SCM_SVN ]] && svn_prompt_info && return
}

function git_prompt_vars {
  SCM_GIT_AHEAD=''
  SCM_GIT_BEHIND=''
  SCM_GIT_STASH=''
  local status="$(git status -bs --porcelain 2> /dev/null)"
  if [[ -n "$(grep -v ^# <<< "${status}")" ]]; then
    SCM_DIRTY=1
    SCM_STATE=${GIT_THEME_PROMPT_DIRTY:-$SCM_THEME_PROMPT_DIRTY}
  else
    SCM_DIRTY=0
    SCM_STATE=${GIT_THEME_PROMPT_CLEAN:-$SCM_THEME_PROMPT_CLEAN}
  fi
  SCM_PREFIX=${GIT_THEME_PROMPT_PREFIX:-$SCM_THEME_PROMPT_PREFIX}
  SCM_SUFFIX=${GIT_THEME_PROMPT_SUFFIX:-$SCM_THEME_PROMPT_SUFFIX}
  local ref=$(git symbolic-ref HEAD 2> /dev/null)
  SCM_BRANCH=${ref#refs/heads/}
  SCM_CHANGE=$(git rev-parse HEAD 2>/dev/null)
  local ahead_re='.+ahead ([0-9]+).+'
  local behind_re='.+behind ([0-9]+).+'
  [[ "${status}" =~ ${ahead_re} ]] && SCM_GIT_AHEAD=" ${SCM_GIT_AHEAD_CHAR}${BASH_REMATCH[1]}"
  [[ "${status}" =~ ${behind_re} ]] && SCM_GIT_BEHIND=" ${SCM_GIT_BEHIND_CHAR}${BASH_REMATCH[1]}"
  local stash_count="$(git stash list | wc -l | tr -d ' ')"
  [[ "${stash_count}" -gt 0 ]] && SCM_GIT_STASH=" {${stash_count}}"
}

function svn_prompt_vars {
  if [[ -n $(svn status 2> /dev/null) ]]; then
    SCM_DIRTY=1
      SCM_STATE=${SVN_THEME_PROMPT_DIRTY:-$SCM_THEME_PROMPT_DIRTY}
  else
    SCM_DIRTY=0
      SCM_STATE=${SVN_THEME_PROMPT_CLEAN:-$SCM_THEME_PROMPT_CLEAN}
  fi
  SCM_PREFIX=${SVN_THEME_PROMPT_PREFIX:-$SCM_THEME_PROMPT_PREFIX}
  SCM_SUFFIX=${SVN_THEME_PROMPT_SUFFIX:-$SCM_THEME_PROMPT_SUFFIX}
  SCM_BRANCH=$(svn info 2> /dev/null | awk -F/ '/^URL:/ { for (i=0; i<=NF; i++) { if ($i == "branches" || $i == "tags" ) { print $(i+1); break }; if ($i == "trunk") { print $i; break } } }') || return
  SCM_CHANGE=$(svn info 2> /dev/null | sed -ne 's#^Revision: ##p' )
}

function hg_prompt_vars {
    if [[ -n $(hg status 2> /dev/null) ]]; then
      SCM_DIRTY=1
        SCM_STATE=${HG_THEME_PROMPT_DIRTY:-$SCM_THEME_PROMPT_DIRTY}
    else
      SCM_DIRTY=0
        SCM_STATE=${HG_THEME_PROMPT_CLEAN:-$SCM_THEME_PROMPT_CLEAN}
    fi
    SCM_PREFIX=${HG_THEME_PROMPT_PREFIX:-$SCM_THEME_PROMPT_PREFIX}
    SCM_SUFFIX=${HG_THEME_PROMPT_SUFFIX:-$SCM_THEME_PROMPT_SUFFIX}
    SCM_BRANCH=$(hg summary 2> /dev/null | grep branch: | awk '{print $2}')
    SCM_CHANGE=$(hg summary 2> /dev/null | grep parent: | awk '{print $2}')
}

function rvm_version_prompt {
  if which rvm &> /dev/null; then
    rvm=$(rvm tools identifier) || return
    echo -e "$RVM_THEME_PROMPT_PREFIX$rvm$RVM_THEME_PROMPT_SUFFIX"
  fi
}

function rbenv_version_prompt {
  if which rbenv &> /dev/null; then
    rbenv=$(rbenv version-name) || return
    echo -e "$RBENV_THEME_PROMPT_PREFIX$rbenv$RBENV_THEME_PROMPT_SUFFIX"
  fi
}

function rbfu_version_prompt {
  if [[ $RBFU_RUBY_VERSION ]]; then
    echo -e "${RBFU_THEME_PROMPT_PREFIX}${RBFU_RUBY_VERSION}${RBFU_THEME_PROMPT_SUFFIX}"
  fi
}

function chruby_version_prompt {
  if declare -f -F chruby &> /dev/null; then
    if declare -f -F chruby_auto &> /dev/null; then
      chruby_auto
    fi
    chruby=$(ruby --version | awk '{print $1, $2;}') || return
    echo -e "$CHRUBY_THEME_PROMPT_PREFIX$chruby$CHRUBY_THEME_PROMPT_SUFFIX"
  fi
}

function ruby_version_prompt {
  echo -e "$(rbfu_version_prompt)$(rbenv_version_prompt)$(rvm_version_prompt)$(chruby_version_prompt)"
}

function virtualenv_prompt {
  if [[ -n "$VIRTUAL_ENV" ]]; then
    virtualenv=`basename "$VIRTUAL_ENV"`
    echo -e "$VIRTUALENV_THEME_PROMPT_PREFIX$virtualenv$VIRTUALENV_THEME_PROMPT_SUFFIX"
  fi
}

# backwards-compatibility
function git_prompt_info {
  git_prompt_vars
  echo -e "$SCM_PREFIX$SCM_BRANCH$SCM_STATE$SCM_SUFFIX"
}

function svn_prompt_info {
  svn_prompt_vars
  echo -e "$SCM_PREFIX$SCM_BRANCH$SCM_STATE$SCM_SUFFIX"
}

function hg_prompt_info() {
  hg_prompt_vars
  echo -e "$SCM_PREFIX$SCM_BRANCH:${SCM_CHANGE#*:}$SCM_STATE$SCM_SUFFIX"
}

function scm_char {
  scm_prompt_char
  echo -e "$SCM_CHAR"
}

function prompt_char {
    scm_char
}