#!/bin/bash
# Central theme switcher (basic/.config/themes/scripts/switch-theme.sh).
#
# Usage: switch-theme.sh <theme-id>   e.g. switch-theme.sh catppuccin-mocha
#
# Retargets the tracked `current` symlink to themes/<theme-id> and reloads
# every consumer that can be reloaded. Because `current` lives in the repo,
# the switch is a reviewable git change; re-stowing is not required since
# all consumers resolve through ~/.config/themes/current at runtime.
#
# A future non-Catppuccin theme only needs its own themes/<theme-id>/
# directory plus a row in themes/registry.conf — this script stays untouched.

set -euo pipefail

usage() {
    echo "usage: $(basename "$0") <theme-id>" >&2
    echo "available:" >&2
    ls -1 "$(repo_root)/basic/.config/themes/themes" 2>/dev/null | grep -v '^registry.conf$' | sed 's/^/  /' >&2 || true
}

repo_root() {
    local src="$0"
    if command -v readlink >/dev/null 2>&1; then
        src="$(readlink -f "$0")"
    fi
    cd "$(dirname "$src")/../../../.." && pwd
}

main() {
    [[ $# -eq 1 ]] || { usage; exit 1; }
    local theme_id="$1"
    if [[ ! "$theme_id" =~ ^[a-z0-9][a-z0-9-]*$ ]]; then
        echo "error: invalid theme-id '$theme_id'" >&2
        exit 1
    fi

    local root
    root="$(repo_root)"
    local dest="$root/basic/.config/themes/themes/$theme_id"
    local link="$root/basic/.config/themes/current"

    [[ -d "$dest" ]] || { echo "error: unknown theme '$theme_id' (no $dest)" >&2; usage; exit 1; }

    ln -sfn "themes/$theme_id" "$link"
    echo "theme switched: current -> themes/$theme_id"

    # Best-effort live reloads; every step is guarded so the switch
    # succeeds even on machines without a running compositor.
    if command -v hyprctl >/dev/null 2>&1; then
        hyprctl reload >/dev/null 2>&1 || true
    fi
    if command -v tmux >/dev/null 2>&1 && [[ -n "${TMUX:-}" ]]; then
        tmux source-file "$HOME/.config/tmux/tmux.conf" >/dev/null 2>&1 || true
    fi
    if pgrep -x waybar >/dev/null 2>&1; then
        pkill -x waybar >/dev/null 2>&1 || true
        (waybar >/dev/null 2>&1 &) || true
    fi
    echo "note: restart Neovim (or :colorscheme \$THEME_NVIM_COLORSCHEME) and open a new shell to pick up theme.env.sh."
}

main "$@"