#!/bin/sh

: ${RCM_LIB:=$(dirname "$0")/../share/rcm}
. "$RCM_LIB/rcm.sh"

link_or_copy() {
  $DEBUG "link_or_copy $1"
  local sigil="$1"

  if [ "x$sigil" = "xX" ]; then
    echo "$CP"
  else
    echo "$LN"
  fi
}

link_file() {
  local src="$1"
  local dest="$2"
  local sigil="$3"

  if [ -h "$dest" ]; then
    $RM -f "$dest"
  fi

  action="$(link_or_copy "$sigil")"
  $DEBUG "$action $src $dest"
  $action "$src" "$dest"
}

replace_file() {
  local src="$1"
  local dest="$2"
  local sigil="$3"

  $DEBUG replace_file "$1" "$2" $3

  $RM -rf "$dest"
  link_file "$src" "$dest" "$sigil"
}

is_nested() {
  echo "$1" | sed "s:$DEST_DIR/::" | grep -q '/'
}

is_identical() {
  diff -q -s "$1" "$2" > /dev/null
}

handle_dir() {
  local dest="$1"

  $DEBUG "handle_dir $1"

  dirname "$dest" | xargs $MKDIR -p
}

handle_file() {
  local src="$1"
  local dest="$2"
  local sigil="$3"

  $DEBUG "handle_file $1 $2 $3"

  if [ -e "$dest" ]; then
    if is_identical "$src" "$dest"; then
      $VERBOSE "identical $dest"
    elif [ $REPLACE_ALL -eq 1 ]; then
      replace_file "$src" "$dest" "$sigil"
    else
      $PROMPT "overwrite ${dest}? [ynaq]"
      read overwrite
      case "$overwrite" in
        a) REPLACE_ALL=1
           replace_file "$src" "$dest" "$sigil"
           ;;
        y) replace_file "$src" "$dest" "$sigil" ;;
        q) exit 1 ;;
        *) $VERBOSE "skipping $dest" ;;
      esac
    fi
  else
    link_file "$src" "$dest" "$sigil"
  fi
}

show_help() {
  local exit_code=${1:-0}

  $PRINT "Usage: rcup [-CVqvfhikK] [-I EXCL_PAT] [-x EXCL_PAT] [-t TAG] [-d DOT_DIR]"
  $PRINT "see rcup(1) and rcm(5) for more details"

  exit $exit_code
}

handle_command_line() {
  local arg_tags=
  local verbosity=0
  local version=0
  local run_hooks=1
  local dotfiles_dirs=
  local files=
  local excludes=
  local includes=
  local always_copy=0
  local symlink_dirs=
  REPLACE_ALL=0

  while getopts CVqvfhikKI:x:S:t:d: opt; do
    case "$opt" in
      C) always_copy=1 ;;
      d) dotfiles_dirs="$dotfiles_dirs $OPTARG" ;;
      f) REPLACE_ALL=1 ;;
      h) show_help ;;
      i) REPLACE_ALL=0 ;;
      I) includes="$includes $OPTARG" ;;
      k) run_hooks=1 ;;
      K) run_hooks=0 ;;
      q) verbosity=$(($verbosity - 1)) ;;
      t) arg_tags="$arg_tags $OPTARG" ;;
      S) symlink_dirs="$symlink_dirs $OPTARG";;
      v) verbosity=$(($verbosity + 1)) ;;
      V) version=1 ;;
      x) excludes="$excludes $OPTARG" ;;
    esac
  done
  shift $(($OPTIND-1))

  if [ $always_copy -eq 1 ]; then
    LN="$CP"
  fi

  handle_common_flags rcup $version $verbosity

  tags="${arg_tags:-$TAGS}"
  DOTFILES_DIRS="${dotfiles_dirs:-$DOTFILES_DIRS}"
  RUN_HOOKS=$run_hooks
  files="$@"

  for tag in $tags; do
    LS_ARGS="$LS_ARGS -t $tag"
  done
  for dotfiles_dir in $DOTFILES_DIRS; do
    LS_ARGS="$LS_ARGS -d $dotfiles_dir"
  done
  for exclude in $excludes; do
    LS_ARGS="$LS_ARGS -x $exclude"
  done
  for include in $includes; do
    LS_ARGS="$LS_ARGS -I $include"
  done
  for symlink_dir in $symlink_dirs; do
    LS_ARGS="$LS_ARGS -S $symlink_dir"
  done
  LS_ARGS="$LS_ARGS $files"

  $DEBUG "LS_ARGS: $LS_ARGS"
}

LS_ARGS=-F

handle_command_line "$@"
: ${DOTFILES_DIRS:=$DOTFILES_DIRS $DEFAULT_DOTFILES_DIR}

run_hooks pre up

dests_and_srcs="$(lsrc $LS_ARGS)"

saved_ifs="$IFS"
IFS='
'
for dest_and_src in $dests_and_srcs; do
  IFS=:
  set -- $dest_and_src
  IFS="$saved_ifs"
  dest="$1"
  src="$2"
  sigil="$3"

  if is_nested "$dest"; then
    handle_dir "$dest"
  fi

  handle_file "$src" "$dest" "$sigil"
done

run_hooks post up