#!/usr/bin/env bash
# install-theme.sh — restore the NexusOS desktop theme wiring.
#
# The theme *assets* live in this repo (assets/themes/).
# This script recreates everything OUTSIDE the repo that makes the desktop
# actually use them: symlinks, xfconf (xsettings + xfwm4), and the canonical
# lines in the GTK 3/4 settings.ini files.
#
# Idempotent and safe: re-running only fixes drift; any real file it would
# replace with a symlink is backed up to <file>.bak-YYYYMMDD first.
#
# Usage:  ./assets/themes/install-theme.sh        (apply + reload)
#         ./assets/themes/install-theme.sh --no-reload
set -euo pipefail

REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
RELOAD=1
[[ "${1:-}" == "--no-reload" ]] && RELOAD=0
STAMP="$(date +%Y%m%d)"

# Canonical values — keep in sync with assets/themes/NexusOS/index.theme
GTK_THEME="NexusOS"
ICON_THEME="NexusOS"
CURSOR_THEME="DMZ-White"
CURSOR_SIZE="24"
FONT_NAME="Ubuntu 10"

say() { printf '  %s\n' "$*"; }

# link <target> <linkname> : make linkname a symlink to target, backing up
# any pre-existing real file/dir that isn't already the correct link.
link() {
    local target="$1" linkname="$2"
    mkdir -p "$(dirname "$linkname")"
    if [[ -L "$linkname" && "$(readlink -f "$linkname")" == "$(readlink -f "$target")" ]]; then
        say "ok    $linkname"
        return
    fi
    if [[ -e "$linkname" || -L "$linkname" ]]; then
        mv "$linkname" "$linkname.bak-$STAMP"
        say "backup $linkname -> $linkname.bak-$STAMP"
    fi
    ln -sfn "$target" "$linkname"
    say "link  $linkname -> $target"
}

# set_ini <file> <key> <value> : ensure key=value under [Settings],
# creating the file/section/key as needed, replacing in place otherwise.
set_ini() {
    local file="$1" key="$2" value="$3"
    if [[ ! -f "$file" ]]; then
        mkdir -p "$(dirname "$file")"
        printf '[Settings]\n%s=%s\n' "$key" "$value" > "$file"
        say "create $file ($key)"
        return
    fi
    if grep -qE "^${key}=" "$file"; then
        sed -i "s|^${key}=.*|${key}=${value}|" "$file"
    else
        sed -i "0,/^\[Settings\]/s//[Settings]\n${key}=${value}/" "$file"
    fi
    say "ini   $file : $key=$value"
}

xset() {  # xfconf set, creating the prop with the right type if absent
    local channel="$1" prop="$2" type="$3" val="$4"
    command -v xfconf-query >/dev/null || return 0
    xfconf-query -c "$channel" -p "$prop" -n -t "$type" -s "$val" 2>/dev/null \
        || xfconf-query -c "$channel" -p "$prop" -s "$val" 2>/dev/null || true
    say "xfconf $channel$prop = $val"
}

echo "NexusOS theme — restoring wiring from $REPO"

echo "[1/4] Symlinks"
link "$REPO/assets/themes/NexusOS"          "$HOME/.themes/NexusOS"
link "$REPO/assets/themes/NexusOS-icons"    "$HOME/.icons/NexusOS"
link "$REPO/assets/themes/gtk3-user-overrides.css" "$HOME/.config/gtk-3.0/gtk.css"

echo "[2/4] xfconf (xsettings + xfwm4)"
xset xsettings /Net/ThemeName       string "$GTK_THEME"
xset xsettings /Net/IconThemeName   string "$ICON_THEME"
xset xsettings /Gtk/CursorThemeName string "$CURSOR_THEME"
xset xsettings /Gtk/CursorThemeSize int    "$CURSOR_SIZE"
xset xsettings /Gtk/FontName        string "$FONT_NAME"
xset xfwm4     /general/theme       string "$GTK_THEME"

echo "[3/4] GTK 3 / GTK 4 settings.ini"
for f in "$HOME/.config/gtk-3.0/settings.ini" "$HOME/.config/gtk-4.0/settings.ini"; do
    set_ini "$f" gtk-theme-name        "$GTK_THEME"
    set_ini "$f" gtk-icon-theme-name   "$ICON_THEME"
    set_ini "$f" gtk-cursor-theme-name "$CURSOR_THEME"
    set_ini "$f" gtk-cursor-theme-size "$CURSOR_SIZE"
    set_ini "$f" gtk-font-name         "$FONT_NAME"
done

echo "[4/4] Icon caches"
gtk-update-icon-cache -f -t "$HOME/.icons/NexusOS" 2>/dev/null \
    && say "ok    NexusOS icon cache rebuilt" \
    || say "WARN  NexusOS icon cache rebuild failed"
INH="$(grep -i '^Inherits=' "$REPO/assets/themes/NexusOS-icons/index.theme" 2>/dev/null | cut -d= -f2)"
if [[ -n "$INH" ]]; then
    INH_OK=0
    for dir in /usr/share/icons ~/.icons ~/.local/share/icons; do
        [[ -d "$dir/$INH" ]] && { INH_OK=1; INH_DIR="$dir/$INH"; break; }
    done
    if [[ "$INH_OK" == 1 ]]; then
        say "ok    icon fallback '$INH' found"
        if sudo -n gtk-update-icon-cache -f -t "$INH_DIR" 2>/dev/null; then
            say "ok    $INH icon cache rebuilt"
        else
            say "note  $INH cache skipped (no passwordless sudo — run manually if needed)"
        fi
    else
        say "WARN  icon fallback '$INH' not installed — icons may be missing"
    fi
fi

echo "[5/5] Sanity"
for dir in /usr/share/icons ~/.icons ~/.local/share/icons; do
    [[ -d "$dir/$CURSOR_THEME" ]] && { say "ok    cursor '$CURSOR_THEME' found"; CUR_OK=1; break; }
done
[[ "${CUR_OK:-0}" == 1 ]] || say "WARN  cursor theme '$CURSOR_THEME' not installed — will fall back"

if [[ "$RELOAD" == 1 ]] && command -v xfconf-query >/dev/null && [[ -n "${DISPLAY:-}" ]]; then
    xfconf-query -c xsettings -p /Net/ThemeName -s "Adwaita" 2>/dev/null || true
    xfconf-query -c xsettings -p /Net/ThemeName -s "$GTK_THEME" 2>/dev/null || true
    command -v xfdesktop   >/dev/null && (xfdesktop --reload >/dev/null 2>&1 &) || true
    command -v xfce4-panel >/dev/null && (xfce4-panel -r    >/dev/null 2>&1 &) || true
    echo "Reloaded. (some already-running apps may need a restart)"
else
    echo "Done. Skipped live reload (no X session or --no-reload)."
fi