class RPB_Admin {
  const OPT = 'rpb_options';
  static function init() {
    add_action('admin_menu', [__CLASS__,'menu']);
    add_action('admin_init', [__CLASS__,'register']);
  }
  static function menu(){
    add_options_page('RailPrice Bridge','RailPrice Bridge','manage_options','rpb', [__CLASS__,'render']);
  }
  static function register(){
    register_setting(self::OPT, self::OPT);
    add_settings_section('rpb_main','Einstellungen', '__return_false','rpb');
    // Für Tempo: Ein großes JSON-Feld
    add_settings_field('config','Konfiguration (JSON)',[__CLASS__,'field'],'rpb','rpb_main');
  }
  static function field(){
    $val = get_option(self::OPT, ['config'=>'']);
    echo '<textarea name="'.self::OPT.'[config]" rows="20" style="width:100%;">'.esc_textarea($val['config'] ?? '').'</textarea>';
    echo '<p>Beispiel siehe Doku: terminals, matrix, tariffs, provider</p>';
  }
  static function render(){
    echo '<div class="wrap"><h1>RailPrice Bridge</h1><form method="post" action="options.php">';
    settings_fields(self::OPT); do_settings_sections('rpb'); submit_button();
    echo '</form></div>';
  }
}
class RPB_Distance {
  static function init(){}
  static function km_between($a,$b){
    // $a=['lat'=>..,'lng'=>..], $b=['lat'=>..,'lng'=>..]
    $R=6371; $dLat=deg2rad($b['lat']-$a['lat']); $dLng=deg2rad($b['lng']-$a['lng']);
    $lat1=deg2rad($a['lat']); $lat2=deg2rad($b['lat']);
    $h = sin($dLat/2)**2 + cos($lat1)*cos($lat2)*sin($dLng/2)**2;
    return 2*$R*asin(min(1,sqrt($h)));
  }
  // TODO: add google/mapbox directions if provider configured.
}
class RPB_Calculator {
  static function init(){
    add_action('rest_api_init', function(){
      register_rest_route('railprice/v1','/quote',[
        'methods'=>'POST',
        'permission_callback'=>'__return_true',
        'callback'=>[__CLASS__,'quote']
      ]);
    });
    add_action('wp_enqueue_scripts',[__CLASS__,'enqueue']);
  }

  static function enqueue(){
    // Nur auf Seiten mit Buchungsformular (notfalls überall)
    wp_enqueue_script('rpb-bridge', RPB_URL.'assets/bridge.js', ['jquery'], RPB_VER, true);
    wp_localize_script('rpb-bridge','RPB',{ 'rest': esc_url_raw( rest_url('railprice/v1/quote') ) });
    wp_enqueue_style('rpb-bridge', RPB_URL.'assets/bridge.css', [], RPB_VER);
  }

  static function cfg(){
    $opt = get_option(RPB_Admin::OPT,[]);
    $cfg = json_decode($opt['config'] ?? '{}', true);
    return $cfg ?: [];
  }

  static function nearest($points, $ref){
    $best=null; $min=INF;
    foreach($points as $p){
      $d = RPB_Distance::km_between(['lat'=>$p['lat'],'lng'=>$p['lng']], $ref);
      if($d < $min){ $min=$d; $best=$p; }
    }
    return $best;
  }

  static function find_matrix_entry($cfg, $de_id, $ua_id){
    foreach($cfg['matrix'] as $m){
      if($m['de_id']===$de_id && $m['ua_id']===$ua_id) return $m;
    }
    return null;
  }

  static function quote($req){
    $cfg = self::cfg();
    $in  = $req->get_json_params();

    $pickup  = ['lat'=>floatval($in['pickup_lat']??0),'lng'=>floatval($in['pickup_lng']??0)];
    $dropoff = ['lat'=>floatval($in['dropoff_lat']??0),'lng'=>floatval($in['dropoff_lng']??0)];
    $adults  = max(0, intval($in['passenger_adult']??0));
    $kids    = max(0, intval($in['passenger_children']??0));

    // 1) DE-Terminal
    if(($cfg['routing']['de_terminal_mode']??'fixed')==='fixed'){
      $de = array_values(array_filter($cfg['terminals'], fn($t)=>$t['id']===$cfg['routing']['fixed_de_id']))[0] ?? null;
    } else {
      $de = self::nearest(array_filter($cfg['terminals'], fn($t)=>$t['side']==='DE'), $pickup);
    }
    // 2) UA-Terminal
    if(!empty($in['ua_terminal_id'])){
      $ua = array_values(array_filter($cfg['terminals'], fn($t)=>$t['id']===$in['ua_terminal_id']))[0] ?? null;
    } else {
      $ua = self::nearest(array_filter($cfg['terminals'], fn($t)=>$t['side']==='UA'), $dropoff);
    }
    if(!$de || !$ua) return new WP_Error('rpb_terminal','Terminal nicht gefunden', ['status'=>400]);

    // 3) Distanzen
    $km_vorlauf = RPB_Distance::km_between($pickup, ['lat'=>$de['lat'],'lng'=>$de['lng']]);
    $km_nachlauf= RPB_Distance::km_between(['lat'=>$ua['lat'],'lng'=>$ua['lng']], $dropoff);

    // 4) Mainrun
    $mx = self::find_matrix_entry($cfg, $de['id'], $ua['id']);
    if(!$mx) return new WP_Error('rpb_matrix','Keine Mainrun-Preise für dieses Paar', ['status'=>400]);
    $main_adult = floatval($mx['price_adult_40'] ?? 0);
    $main_child = floatval($mx['price_child_20'] ?? 0);
    $main_eur = ($adults * $main_adult) + ($kids * $main_child);

    // 5) Tarife
    $eur_km_de = floatval($cfg['tariffs']['eur_per_km_de'] ?? 0);
    $eur_km_ua = floatval($cfg['tariffs']['eur_per_km_ua'] ?? 0);

    $vorlauf_eur  = $km_vorlauf * $eur_km_de;
    $nachlauf_eur = $km_nachlauf * $eur_km_ua;

    $total = round($vorlauf_eur + $main_eur + $nachlauf_eur, 2);

    return [
      'currency' => $mx['currency'] ?? 'EUR',
      'total' => $total,
      'breakdown' => [
        'vorlauf_km' => round($km_vorlauf,1),
        'vorlauf_eur'=> round($vorlauf_eur,2),
        'mainrun_eur'=> round($main_eur,2),
        'nachlauf_km'=> round($km_nachlauf,1),
        'nachlauf_eur'=>round($nachlauf_eur,2),
      ],
      'used_de_id'=>$de['id'], 'used_ua_id'=>$ua['id']
    ];
  }
}
class RPB_Woo {
  static function init(){
    // Beim Add-to-Cart: unsere Hidden Inputs mitnehmen
    add_filter('woocommerce_add_cart_item_data',[__CLASS__,'attach_cart_data'],10,3);
    // Preis setzen
    add_action('woocommerce_before_calculate_totals',[__CLASS__,'override_price'],20);
    // Fees (Breakdown) anhängen
    add_action('woocommerce_cart_calculate_fees',[__CLASS__,'add_fees'],20);
    // In Order übernehmen
    add_action('woocommerce_checkout_create_order_line_item',[__CLASS__,'save_item_meta'],10,4);
  }

  static function attach_cart_data($item_data, $product_id, $variation_id){
    $keys=['rpb_total','rpb_currency','rpb_breakdown','rpb_de_id','rpb_ua_id'];
    foreach($keys as $k){ if(isset($_POST[$k])) $item_data[$k] = sanitize_text_field($_POST[$k]); }
    return $item_data;
  }

  static function override_price($cart){
    if(is_admin() && !defined('DOING_AJAX')) return;
    foreach($cart->get_cart() as $cart_item){
      if(isset($cart_item['rpb_total'])){
        $cart_item['data']->set_price( floatval($cart_item['rpb_total']) );
      }
    }
  }

  static function add_fees($cart){
    foreach($cart->get_cart() as $cart_item){
      if(empty($cart_item['rpb_breakdown'])) continue;
      $c = json_decode($cart_item['rpb_breakdown'], true);
      if(!$c) continue;
      $cur = $cart_item['rpb_currency'] ?? get_woocommerce_currency();
      // Option: nur 1 Fee (Gesamt) oder 3 Fees (Breakdown). Hier 3:
      $cart->add_fee('Vorlauf',  floatval($c['vorlauf_eur'] ?? 0));
      $cart->add_fee('Mainrun',  floatval($c['mainrun_eur'] ?? 0));
      $cart->add_fee('Nachlauf', floatval($c['nachlauf_eur'] ?? 0));
      // Summe der Fees = Gesamtpreis; Da wir oben den Artikelpreis schon auf total gesetzt haben,
      // kannst du alternativ: Artikel auf 0 setzen und nur Fees nutzen. Entscheide nach Darstellung.
      break; // nur einmal, wenn 1 Item
    }
  }

  static function save_item_meta($item, $cart_item_key, $values, $order){
    $keys=['rpb_total','rpb_currency','rpb_breakdown','rpb_de_id','rpb_ua_id'];
    foreach($keys as $k){ if(isset($values[$k])) $item->add_meta_data($k, $values[$k], true); }
  }
}