#!/bin/sh
# Set a new wallpaper everywhere: main layer, blurred backdrop, wallust colors.
#
# Usage: theme-switcher.sh <wallpaper|path> [--palette P] [--threshold T]
#                              [--saturation S] [--colorspace C]
#
# The chosen palette/threshold are persisted to ~/.cache/wallust_runtime so
# that apply-colors.sh reproduces them after a reboot. The main wallpaper is
# cached by awww itself, so it is also restored on the next boot.

set -eu
CACHE="${XDG_CACHE_HOME:-$HOME/.cache}"
STATE="$CACHE/wallust_runtime"
WP=""; palette=""; threshold=""; sat=""; cs=""

while [ $# -gt 0 ]; do
    case "$1" in
        --palette|-p)    palette="$2";   shift 2 ;;
        --threshold|-t)  threshold="$2"; shift 2 ;;
        --saturation)    sat="$2";       shift 2 ;;
        --colorspace|-c) cs="$2";        shift 2 ;;
        *)               WP="${WP:-$1}"; shift ;;
    esac
done

[ -n "$WP" ] || { echo "usage: $0 <wallpaper> [--palette P] [--threshold T]" >&2; exit 1; }
case "$WP" in
    /*) ;;
    *)  WP="$HOME/Pictures/wallpapers/$WP" ;;
esac
[ -f "$WP" ] || { echo "no such wallpaper: $WP" >&2; exit 1; }

# Remember the last used wallpaper so apply-colors.sh reproduces it on reboot.
echo "$WP" > "$CACHE/current_wallpaper"

# Persist palette/threshold for the next boot.
: > "$STATE"
[ -n "$palette" ]   && echo "palette=$palette"     >> "$STATE"
[ -n "$threshold" ] && echo "threshold=$threshold" >> "$STATE"
[ -n "$sat" ]       && echo "saturation=$sat"      >> "$STATE"
[ -n "$cs" ]        && echo "colorspace=$cs"       >> "$STATE"

# Main wallpaper (awww caches it -> restored automatically on next boot).
awww img "$WP"

# Regenerate colors, sync backdrop, reload live apps.
"$HOME/.config/niri/apply-colors.sh"

# Refresh niri's own theme (focus ring, etc.) live.
matugen image "$WP" 2>/dev/null || true
niri msg action reload-config 2>/dev/null || true