<?php
/**
 * Time-Based Theme Switcher Plugin
 *
 * @license GPL 2 (http://gnu.org)
 * @author  Your Name
 */

if(!defined('DOKU_INC')) die();

class action_plugin_timeswitcher extends DokuWiki_Action_Plugin {

    /**
     * Register hooks
     */
    public function register(Doku_Event_Handler $controller) {
        // Hook early into the template system setup lifecycle
        $controller->register_hook('TPL_METAHEADERS_OUTPUT', 'BEFORE', $this, 'switch_theme');
        $controller->register_hook('DOKUWIKI_STARTED', 'BEFORE', $this, 'switch_theme');
        
        // Break cache payloads so themes toggle instantly on every page hit
        $controller->register_hook('PARSER_CACHE_USE', 'BEFORE', $this, 'bypass_cache');
    }

    /**
     * Prevent page caching so the server can switch themes dynamically
     */
    public function bypass_cache(Doku_Event $event, $param) {
        $event->preventDefault();
        $event->stopPropagation();
        $event->result = false;
    }

    /**
     * Switch theme based on system preference or browser time calculation
     */
    public function switch_theme(Doku_Event $event, $param) {
        global $conf;

        // FIXED: Explicitly mapping config values to DokuWiki's native nested plugin structure
        $dayTheme   = isset($conf['plugin']['timeswitcher']['day_template'])   ? $conf['plugin']['timeswitcher']['day_template']   : 'was';
        $nightTheme = isset($conf['plugin']['timeswitcher']['night_template']) ? $conf['plugin']['timeswitcher']['night_template'] : 'wasdark';
        $startStr   = isset($conf['plugin']['timeswitcher']['night_start'])    ? $conf['plugin']['timeswitcher']['night_start']    : '20:00';
        $endStr     = isset($conf['plugin']['timeswitcher']['night_end'])      ? $conf['plugin']['timeswitcher']['night_end']      : '06:00';

        // 1. Direct System Theme Preference Detection
        $themePref = null;
        if (isset($_GET['theme_init'])) {
            $themePref = $_GET['theme_init'];
        } elseif (isset($_COOKIE['user_theme_pref'])) {
            $themePref = $_COOKIE['user_theme_pref'];
        }

        if ($themePref === 'dark') {
            $conf['template'] = $nightTheme;
            return;
        } elseif ($themePref === 'light') {
            $conf['template'] = $dayTheme;
            return;
        }

        // 2. Fallback Time-Based Logic (Runs only if theme detection data is unavailable)
        $browserOffsetMinutes = null;
        if (isset($_GET['tz_init'])) {
            $browserOffsetMinutes = (int)$_GET['tz_init'];
        } elseif (isset($_COOKIE['user_tz_offset'])) {
            $browserOffsetMinutes = (int)$_COOKIE['user_tz_offset'];
        }

        if ($browserOffsetMinutes !== null) {
            $userTimestamp = time() - ($browserOffsetMinutes * 60);
            $currentHour   = (int)gmdate('G', $userTimestamp);
            $currentMinute = (int)gmdate('i', $userTimestamp);
        } else {
            $currentHour   = (int)date('G');
            $currentMinute = (int)date('i');
        }

        list($sH, $sM) = explode(':', $startStr);
        list($eH, $eM) = explode(':', $endStr);

        $start   = ($sH * 60) + $sM;
        $end     = ($eH * 60) + $eM;
        $current = ($currentHour * 60) + $currentMinute;

        $isNight = false;
        if ($start < $end) {
            if ($current >= $start && $current < $end) $isNight = true;
        } else {
            if ($current >= $start || $current < $end) $isNight = true;
        }

        // Apply theme assignment cleanly to the core rendering template property
        $conf['template'] = $isNight ? $nightTheme : $dayTheme;
    }
}