#!/bin/sh
# Update dotfiles and some other common repositories.
# This script accepts no arguments, but accepts additional repositories through the REPOS_TO_UPDATE environment variable

set -eu

#
# Setup functions and variables
#

# global name of script
script="${0##*/}"

cleanup() {
   exit
}

# update_list_append from https://superuser.com/questions/39751/add-directory-to-path-if-its-not-already-there
# checks if a path is already in the PATH and if it exists
update_list_append() {
   if [ -d "$1" ]; then
      # shellcheck disable=SC3010
      if command '[[' > /dev/null 2>&1 && [[ ":$REPOS_TO_UPDATE:" != *":$1:"* ]]; then
         REPOS_TO_UPDATE="${REPOS_TO_UPDATE:+"$REPOS_TO_UPDATE:"}$1"
      else
         REPOS_TO_UPDATE="$REPOS_TO_UPDATE:$1"
      fi
   fi
}

# Do the arguments contain a search?
# Usage: contains search "${array[@]}"
contains() {
   search="$1"; shift
   split="$1"; shift
   array="$1"; shift

   ifs="$IFS"
   IFS="$split"
   for str in $array; do
      if [ "$str" = "$search" ]; then
         IFS="$ifs"
         return 0
      fi
   done
   IFS="$ifs"
   return 1
}

# Shorten the repo name to use a ~ for the home dir instead of the absolute path
pretty_path() {
   arg="$1"

   case "$arg" in
      # If the arg starts with our home dir,
      "$HOME"*)
         # replace the home dir part with a ~
         printf '~%s' "$(printf '%s' "$arg" | sed -E 's/^.{'"${#HOME}"'}//')"
         ;;

      # Otherwise,
      *)
         # Just print the arg
         printf '%s' "${arg}"
         ;;
   esac | # Pass through some other filters
      sed -E 's_/+$__' | # Remove trailing slash
      tr -s '/' # Remove duplicate slashes
}

# Warn about incomplete changes to a repository
do_checks() {
   repo_pretty="$1"
   shift

   # Uncommitted changes
   if ! "$@" diff --quiet; then
      echo "${yellow}Warning: Working tree for $repo_pretty is dirty${nc}"
   fi

   # Unpushed changes
   unpushed="$("$@" for-each-ref --format=" %(refname:short) %(push:track)" refs/heads)"
   if echo "$unpushed" | grep -Fq ahead; then
      printf '%s' "${yellow}Warning: Unpushed commits in $repo_pretty on branches:"
      printf '%s' "$unpushed" | tr '\n' ','
      echo "${nc}"
   fi
}

do_pull() {
   update_dotfiles="${update_dotfiles:-false}"

   # Which repos have we updated so far
   updated=''

   #
   # Main loop: `git pull` everything mentioned in the REPOS_TO_UPDATE variable
   #

   repo=''
   for repo in "$@"; do
      if [ -n "$repo" ]; then
         repo_pretty="$(pretty_path "$repo")"
         repo="$(realpath "$repo" 2>/dev/null)"
         repo="$(git -C "$repo" rev-parse --show-toplevel 2> /dev/null || true)"
         if  [ -n "$repo" ]; then
            if ! contains "$repo" ':' "$updated"; then
               # Pull the repository
               echo " Pulling ${green}$repo_pretty${nc}‥"
               if ! timeout 10 git -C "$repo" pull; then
                  exit=$#
                  if [ "$ignore_git_errors" != true ]; then
                     return "$exit"
                  fi
               fi

               updated="$repo:$updated"

               # Warn about incomplete changes to a repository
               do_checks "$repo_pretty" git -C "$repo"
               did_updates=true
               if [ "$update_dotfiles" = 'false' ]; then
                  echo
               fi
            fi
         fi
      fi
   done

   # update dotfiles repo separately bc it's a bare repo
   if [ "$update_dotfiles" = true ]; then
      # check for dotfiles updates
      ${did_updates:-false} && echo
      echo " Updating ${green}dotfiles${nc}…"
      dotfiles pull
      do_checks "$(dotfiles rev-parse --git-dir)" dotfiles
   fi
}

main() {
   trap cleanup INT

   # Check for git
   if ! command -v git > /dev/null; then
      echo "$script: git is not installed, please install git and try again" >&2
      exit 1
   fi

   # Set colors
   if command -v tput > /dev/null; then
      yellow="$(tput setaf 3)"
      green="$(tput setaf 2)"
      nc="$(tput sgr0)"
   elif [ -n "$TERMUX_VERSION" ]; then
      yellow=""
      green=""
      nc="(B"
   fi

   # Default repos to update
   ignore_git_errors=false
   if [ $# = 0 ]; then
      # Default paths to check
      REPOS_TO_UPDATE="${REPOS_TO_UPDATE:-}"

      set -- "$@" \
         "${DOCS_DIR:-}" \
         "$HOME/bin" \
         "${NIXOS_DIR:-}" \
         "$HOME/code/faust-ideas" \
         "$HOME/code/nixvim-config" \
         "$HOME/.config/nvim"

      split="$IFS"
      IFS=':'
      for dir in $REPOS_TO_UPDATE; do
         set -- "$dir" "$@"
      done
      IFS="$split"

      update_dotfiles=true
   else
      ignore_git_errors="${IGNORE_GIT_ERRORS:-true}"
   fi

   do_pull "$@"
}

main "$@"