#!/bin/sh

# install location and source files
: ${DEST:=$(realpath "$HOME")}
: ${SRC:=$(dirname "$(realpath "$0")")}

# confirm XDG vars we care about are set up
: ${LOCAL:=.local} # NOTE: needed for bin, which has no xdg var
: ${XDG_DATA_HOME:=$DEST/$LOCAL/share}
: ${XDG_CONFIG_HOME:=$DEST/.config}
: ${XDG_STATE_HOME:=$DEST/$LOCAL/state}
: ${XDG_CACHE_HOME:=$DEST/.cache}

# these are the vars we actually use
share="${XDG_DATA_HOME#$DEST/}"
etc="${XDG_CONFIG_HOME#$DEST/}"
state="${XDG_STATE_HOME#$DEST/}"
cache="${XDG_CACHE_HOME#$DEST/}"

# test
devnull=/dev/null
if [ "$1" = "test" ]; then
    echo "Running test -- no changes will be applied"
    devnull=/dev/stdout
    _cd() {
        cd $*;
        echo "-- cd $* --> $PWD";
    }
    alias cd="_cd"
    alias mkdir="echo -- mkdir"
    alias ln="echo -- ln"
    alias rm="echo -- rm"
    alias sh="echo -- sh"
fi

# ensure ostype
# NOTE: copied from .zshenv
if [ -z "$OSTYPE" ]; then
    OSTYPE=$(uname -s | tr '[:upper:]' '[:lower:]')
fi

# accomodate multiple userlands
# XXX: assuming GNU by default
# TODO: test for GNU, fallback to POSIX instead (no -n)
lnargs=-sfnv
case "$OSTYPE" in
    freebsd*)       lnargs=-sFhv;;
    netbsd|openbsd*)    lnargs=-sfhv;;
esac

cd "$DEST"

# create preferred folder structure
mkdir -pm 760 "$share" "$etc" "$state" "$cache"
ln $lnargs "$DEST/$etc" "$LOCAL/etc"
mkdir -p "$LOCAL/bin" "$share/fonts" "$share/themes" "$share/icons"

# clean out old links
# TODO: doesn't remove dead links if realpath fails; this happens if the link
#       target doesn't exist under busybox
find . "$share" "$etc" \
     "$LOCAL/bin" "$share/fonts" "$share/themes" "$share/icons" \
     "$etc/gnupg" .ssh .termux \
     -xdev -mindepth 1 -maxdepth 1 -type l -exec sh -c '
       r="$(realpath "{}")"
       [ "${r#'"$SRC"'/}" != "$r" ] &&
         '"$([ "$1" = test ] && echo 'echo +++ ')"'unlink "{}"' \;

cd "$SRC" >$devnull

l() {
    # TODO: use install?
    d="$DEST/${1:-$x}"
    [ -L "$d" -o \! -e "$d" ] && ln $lnargs "$SRC/${2:-$x}" "$d" ||
      echo "!!! File exists and is not a link: $1"
}

# generic links
find base  -mindepth 1 -maxdepth 1 | while read -r x; do l "${x#base/}"; done
find bin   -mindepth 1 -maxdepth 1 | while read -r x; do l "$LOCAL/$x"; done
find share -mindepth 1 -maxdepth 1 | while read -r x; do l "$share${x#share}"; done
find etc   -mindepth 1 -maxdepth 1 | while read -r x; do l "$etc${x#etc}"; done

# xorg/wayland resources
find gui -mindepth 1 -maxdepth 1 | while read -r y; do
    case "${y#gui/}" in
        icons|themes)
            find "$y" -mindepth 1 -maxdepth 2 -type d | while read -r x; do
                [ ! -e "$x/index.theme" ] && continue
                command -v gtk-update-icon-cache >$devnull 2>&1 &&
                  gtk-update-icon-cache -f "$x"
                l "$share${y#gui}/$(basename "$x")"
            done
            ;;
        fonts)
            find "$y" -mindepth 1 -maxdepth 2 -type d | while read -r x; do
                command -v mkfontscale >$devnull 2>&1 && mkfontscale "$x"
                command -v mkfontdir >$devnull 2>&1 && mkfontdir "$x"
                [ "$(head -1 "$x/fonts.scale" >$devnull 2>&1)" = 0 ] &&
                  rm "$x/fonts.scale"
                [ "$(head -1 "$x/fonts.dir" >$devnull 2>&1)" = 0 ] &&
                  rm "$x/fonts.dir"
                l "$share${y#gui}/$(basename "$x")"
            done
            ;;
        *)
            find "$y" -mindepth 1 -maxdepth 1 | while read -r x; do
                l "$share${x#gui}"
            done
            ;;
    esac
done

# gpg
if command -v gpg >$devnull 2>&1; then
    mkdir -pm 700 "$DEST/$etc/gnupg"
    find gnupg -mindepth 1 -maxdepth 1 \! -name '*.gpg' | while read -r x; do
        l "$etc/$x"
    done
    find gnupg -mindepth 1 -maxdepth 1 -name '*.gpg' | while read -r x; do
        gpg --import "$x"
    done
fi

# ssh
find ssh -mindepth 1 -maxdepth 1 | while read -r x; do
  l ".$x"; done

# termux, assume it if android
if [ $(uname -o) = 'Android' ]; then
    mkdir -p "$DEST/.termux"
    find termux -mindepth 1 -maxdepth 1 | while read -r x; do l ".$x"; done
    l '.termux/font.ttf' "$share/fonts/Dina-ttf/Dina.ttf"
fi

# vim: sts=4 sw=4 et