#
# Initializes Prezto.
#
# Authors:
#   Sorin Ionescu <sorin.ionescu@gmail.com>
#

#
# Version Check
#

# Check for the minimum supported version.
min_zsh_version='4.3.17'
if ! autoload -Uz is-at-least || ! is-at-least "$min_zsh_version"; then
  printf "prezto: old shell detected, minimum required: %s\n" "$min_zsh_version" >&2
  return 1
fi
unset min_zsh_version

# zprezto convenience updater
# The function is surrounded by ( ) instead of() { } so it starts in a subshell
# and won't affect the environment of the calling shell
zprezto-update() (
  cannot-fast-forward() {
    local STATUS="$1"
    [[ -n "${STATUS}" ]] && printf "%s\n" "${STATUS}"
    printf "Unable to fast-forward the changes. You can fix this by "
    printf "running\ncd '%s' and then\n'git pull' " "${ZPREZTODIR}"
    printf "to manually pull and possibly merge in changes\n"
  }
  cd -q -- "${ZPREZTODIR}" || return 7
  local orig_branch="$(git symbolic-ref HEAD 2>/dev/null | cut -d '/' -f 3)"
  if [[ "$orig_branch" == "master" ]]; then
    git fetch || return "$?"
    local UPSTREAM=$(git rev-parse '@{u}')
    local LOCAL=$(git rev-parse @)
    local REMOTE=$(git rev-parse "$UPSTREAM")
    local BASE=$(git merge-base @ "$UPSTREAM")
    if [[ $LOCAL == $REMOTE ]]; then
      printf "There are no updates.\n"
      return 0
    elif [[ $LOCAL == $BASE ]]; then
      printf "There is an update availible. Trying to pull.\n\n"
      if git pull --ff-only; then
        printf "Syncing submodules\n"
        git submodule update --recursive
        return $?
      else
        cannot-fast-forward
        return 1
      fi
    elif [[ $REMOTE == $BASE ]]; then
      cannot-fast-forward "Commits in master that aren't in upstream."
      return 1
    else
      cannot-fast-forward "Upstream and local have diverged."
      return 1
    fi
  else
    printf "zprezto install at '%s' is not on the master branch " "${ZPREZTODIR}"
    printf "(you're on '%s')\nUnable to automatically update.\n" "${orig_branch}"
    return 1
  fi
  return 1
)
#
# Module Loader
#

# Loads Prezto modules.
pmodload() {
  local -a pmodules
  local pmodule
  local pfunction_glob='^([_.]*|prompt_*_setup|README*|*~)(-.N:t)'

  # $argv is overridden in the anonymous function.
  pmodules=("$argv[@]")

  # Add functions to $fpath.
  fpath=(${pmodules:+$ZPREZTODIR/modules/${^pmodules}/functions(/FN)} $fpath)

  function {
    local pfunction

    # Extended globbing is needed for listing autoloadable function directories.
    setopt LOCAL_OPTIONS EXTENDED_GLOB

    # Load Prezto functions.
    for pfunction in $ZPREZTODIR/modules/${^pmodules}/functions/$~pfunction_glob; do
      autoload -Uz "$pfunction"
    done
  }

  # Load Prezto modules.
  for pmodule in "$pmodules[@]"; do
    if zstyle -t ":prezto:module:$pmodule" loaded 'yes' 'no'; then
      continue
    elif [[ ! -d "$ZPREZTODIR/modules/$pmodule" ]]; then
      print "$0: no such module: $pmodule" >&2
      continue
    else
      if [[ -s "$ZPREZTODIR/modules/$pmodule/init.zsh" ]]; then
        source "$ZPREZTODIR/modules/$pmodule/init.zsh"
      fi

      if (( $? == 0 )); then
        zstyle ":prezto:module:$pmodule" loaded 'yes'
      else
        # Remove the $fpath entry.
        fpath[(r)${ZPREZTODIR}/modules/${pmodule}/functions]=()

        function {
          local pfunction

          # Extended globbing is needed for listing autoloadable function
          # directories.
          setopt LOCAL_OPTIONS EXTENDED_GLOB

          # Unload Prezto functions.
          for pfunction in $ZPREZTODIR/modules/$pmodule/functions/$~pfunction_glob; do
            unfunction "$pfunction"
          done
        }

        zstyle ":prezto:module:$pmodule" loaded 'no'
      fi
    fi
  done
}

#
# Prezto Initialization
#

# This finds the directory prezto is installed to so plugin managers don't need
# to rely on dirty hacks to force prezto into a directory. Additionally, it
# needs to be done here because inside the pmodload function ${0:h} evaluates to
# the current directory of the shell rather than the prezto dir.
ZPREZTODIR=${0:h}

# Source the Prezto configuration file.
if [[ -s "${ZDOTDIR:-$HOME}/.zpreztorc" ]]; then
  source "${ZDOTDIR:-$HOME}/.zpreztorc"
fi

# Disable color and theme in dumb terminals.
if [[ "$TERM" == 'dumb' ]]; then
  zstyle ':prezto:*:*' color 'no'
  zstyle ':prezto:module:prompt' theme 'off'
fi

# Load Zsh modules.
zstyle -a ':prezto:load' zmodule 'zmodules'
for zmodule ("$zmodules[@]") zmodload "zsh/${(z)zmodule}"
unset zmodule{s,}

# Autoload Zsh functions.
zstyle -a ':prezto:load' zfunction 'zfunctions'
for zfunction ("$zfunctions[@]") autoload -Uz "$zfunction"
unset zfunction{s,}

# Load Prezto modules.
zstyle -a ':prezto:load' pmodule 'pmodules'
pmodload "$pmodules[@]"
unset pmodules