feat: help screen + main dispatch

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2 files changed, 75 insertions, 1 deletions

diff --git a/tests/wallp.bats b/tests/wallp.bats
index ad4b9bf..0d6fc7e 100644
--- a/tests/wallp.bats
+++ b/tests/wallp.bats
@@ -237,3 +237,33 @@ teardown() {
   [ "$status" -eq 1 ]
   [[ "$output" == *"no display"* ]]
 }
+
+@test "bare invocation shows help" {
+  unset WAYLAND_DISPLAY
+  run main
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"Usage"* ]]
+}
+
+@test "unknown flag errors with help" {
+  unset WAYLAND_DISPLAY
+  run main --bogus
+  [ "$status" -eq 1 ]
+  [[ "$output" == *"Usage"* ]]
+}
+
+@test "bootstrap on missing conf exits zero without setting wallpaper" {
+  unset WAYLAND_DISPLAY
+  run main --restore
+  [ "$status" -eq 0 ]
+  [ ! -e "$HOME/.cache/wallp/H.pid" ]
+}
+
+@test "theme flag honored through main with restore" {
+  unset WAYLAND_DISPLAY
+  mkdir -p "$HOME/.config/wallp"
+  printf '%s\n' 'OUTPUT_H=DP-1' 'OUTPUT_V=DP-3' \
+    'DEFAULT_H=/dh.png' 'DEFAULT_V=/dv.png' > "$HOME/.config/wallp/wallp.conf"
+  main --restore --theme tflag
+  [ "$(cat "$HOME/.config/wallp/theme")" = "tflag" ]
+}
diff --git a/wallp b/wallp
index 11bcf80..d021c2b 100644
--- a/wallp
+++ b/wallp
@@ -241,8 +241,52 @@ do_set() {
   finalize "$(resolve_theme "$flag_theme")"
 }
 
+show_help() {
+  local text="wallp — unified wallpaper manager
+
+Usage:
+  wallp                      Show this help
+  wallp --help | -h          Show this help
+  wallp --set                Interactive (qarma) wallpaper selection
+  wallp --set H=<file>       Set horizontal screen only
+  wallp --set V=<file>       Set vertical screen only
+  wallp --set H=<f> V=<f>    Set both screens
+  wallp --restore            Restore last session (defaults if none)
+  wallp --theme <name>       Override theme (with --set or --restore)
+
+Config: ~/.config/wallp/wallp.conf"
+  if [ -n "${WAYLAND_DISPLAY:-}" ] && command -v qarma >/dev/null 2>&1; then
+    qarma --info --title="wallp help" --text="$text" 2>/dev/null
+  else
+    printf '%s\n' "$text"
+  fi
+}
+
 main() {
-  return 0
+  local action="" flag_theme="" set_args=()
+  while [ "$#" -gt 0 ]; do
+    case "$1" in
+      --help|-h) show_help; return 0 ;;
+      --set)     action="set" ;;
+      --restore) action="restore" ;;
+      --theme)   shift; flag_theme="${1:-}";
+                 [ -z "$flag_theme" ] && { echo "wallp: --theme needs a name" >&2; return 1; } ;;
+      H=*|V=*)   set_args+=("$1") ;;
+      *)         echo "wallp: unknown argument '$1'" >&2; show_help; return 1 ;;
+    esac
+    shift
+  done
+
+  if [ -z "$action" ]; then show_help; return 0; fi
+
+  load_conf; local rc=$?
+  if [ "$rc" -eq 10 ]; then return 0; fi   # bootstrapped, no change
+  if [ "$rc" -ne 0 ]; then return 1; fi
+
+  case "$action" in
+    set)     do_set "$flag_theme" "${set_args[@]}" ;;
+    restore) do_restore "$flag_theme" ;;
+  esac
 }
 
 if [ "${BASH_SOURCE[0]}" = "$0" ]; then main "$@"; fi