<?php

class Session {
    
    private static $instance;
    private static $currentModule;
    private static $configFields;
    
    public static function getInstance() {
        if (!self::$instance) {
            self::$instance = new self;
            self::$currentModule = RootController::getModuleName();
            self::$configFields = array('sortField', 'sortMode', 'filterText');
            if (in_array(self::$currentModule, array('customers', 'invoice', 'quotation'))) {
                self::$configFields[] = 'maintenanceDateRangeFrom';
                self::$configFields[] = 'maintenanceDateRangeTo';
            }
            if (in_array(self::$currentModule, array('invoices'))) {
                self::$configFields[] = 'invoiceDateRangeFrom';
                self::$configFields[] = 'invoiceDateRangeTo';
                self::$configFields[] = 'showPaidInvoices';
            }
            
            if (!isset($_SESSION['listConfig'])) {
                $_SESSION['listConfig'] = array();
            }
            
            $listModule = self::$currentModule;
            
            # prepare
            if (!isset($_SESSION['listConfig'][$listModule])) {
                $_SESSION['listConfig'][$listModule] = array();
            }
            foreach (self::$configFields as $field) {
                if ($field == 'filterText') {
                    if ( ! (isset($_SESSION['listConfig'][$listModule]['filterText'])  &&  is_array($_SESSION['listConfig'][$listModule][$field]))) {
                        $_SESSION['listConfig'][$listModule][$field] = array();
                    }
                } else {
                    #if (!isset($_SESSION['listConfig'][$listModule][$field])) {
                    #    $_SESSION['listConfig'][$listModule][$field] = '';
                    #}
                }
            }
            
            # set from possible request data
            if ( ! empty($listModule)) {
                foreach (self::$configFields as $configField) {
                    if (isset($_REQUEST['listConfig_'.$listModule.'_'.$configField])) {
//                        if (isset($_REQUEST[])) {
//                            
//                        } else {
                            $_SESSION['listConfig'][$listModule][$configField] = $_REQUEST['listConfig_'.$listModule.'_'.$configField];
//                        }
                    }
                }
            } else {
                $bt = debug_backtrace(); $backtraceFlat = '['.__CLASS__.'::'.__FUNCTION__.' / line '.__LINE__.' ] [caller: '.$bt[0]['file'].' / line '.$bt[0]['line'].']';
                Errors::log('empty listModule. '.$backtraceFlat);
            }
        }
        return self::$instance;
    }
    
    public function getCurrentModule() {
        return self::$currentModule;
    }
    
    public function getListConfig($configField, $defaultValue=null, $listModule=null, $subField=null) {
        if (!$listModule) {
            $listModule = self::$currentModule;
        }
        
        $returnValue = false;
        
        if (empty($listModule)) {
            $bt = debug_backtrace(); $backtraceFlat = '['.__CLASS__.'::'.__FUNCTION__.' / line '.__LINE__.' ] [caller: '.$bt[0]['file'].' / line '.$bt[0]['line'].']';
            Errors::log('empty listModule. '.$backtraceFlat);
        }
        
        if (isset($_SESSION['listConfig'][$listModule])) {
            if (in_array($configField, self::$configFields)) {
                if (isset($_SESSION['listConfig'][$listModule][$configField])) {
                    if (is_array($_SESSION['listConfig'][$listModule][$configField])) {
                        if (isset($_SESSION['listConfig'][$listModule][$configField][$subField])) {
                            $returnValue = $_SESSION['listConfig'][$listModule][$configField][$subField];
                        #} else {
                        #    $bt = debug_backtrace(); $backtraceFlat = '['.__CLASS__.'::'.__FUNCTION__.' / line '.__LINE__.' ] [caller: '.$bt[0]['file'].' / line '.$bt[0]['line'].']';
                        #    Errors::log('unknown listConfig subField: '.$subField.' '.$backtraceFlat);
                        }
                    } else {
                        $returnValue = $_SESSION['listConfig'][$listModule][$configField];
                    }
                } else {
                    # use default value
                }
            } else {
                $bt = debug_backtrace(); $backtraceFlat = '['.__CLASS__.'::'.__FUNCTION__.' / line '.__LINE__.' ] [caller: '.$bt[0]['file'].' / line '.$bt[0]['line'].']';
                Errors::log('unknown listConfig field: '.$configField.' '.$backtraceFlat);
            }
        } else {
            $bt = debug_backtrace(); $backtraceFlat = '['.__CLASS__.'::'.__FUNCTION__.' / line '.__LINE__.' ] [caller: '.$bt[0]['file'].' / line '.$bt[0]['line'].']';
            Errors::log('listConfig module \''.$listModule.'\' doesn\'t exist: '.$backtraceFlat);
        }
        
        if ($returnValue === false) {
            if ($defaultValue || $defaultValue === '' || $defaultValue === '0') {
                $returnValue = $defaultValue;
                if (isset($_SESSION['listConfig'][$listModule][$configField])  &&  is_array($_SESSION['listConfig'][$listModule][$configField])) {
                    $_SESSION['listConfig'][$listModule][$configField][$subField] = $defaultValue;
                } else {
                    $_SESSION['listConfig'][$listModule][$configField] = $defaultValue;
                }
            } else {
                $bt = debug_backtrace(); $backtraceFlat = '['.__CLASS__.'::'.__FUNCTION__.' / line '.__LINE__.' ] [caller: '.$bt[0]['file'].' / line '.$bt[0]['line'].']';
                Errors::log('can\'t use invalid listConfig default for configField: '.$configField.' '.$backtraceFlat);
            }
        }
        return $returnValue;
    }
    
    public function setListConfig($configField, $value, $listModule) {
        if (isset($_SESSION['listConfig'][$listModule])) {
            if (in_array($configField, self::$configFields)) {
                $_SESSION['listConfig'][$listModule][$configField] = $value;
            } else {
                $bt = debug_backtrace(); $backtraceFlat = '['.__CLASS__.'::'.__FUNCTION__.' / line '.__LINE__.' ] [caller: '.$bt[0]['file'].' / line '.$bt[0]['line'].']';
                Errors::log('unknown listConfig field: '.$configField.' '.$backtraceFlat);
            }
        } else {
            $bt = debug_backtrace(); $backtraceFlat = '['.__CLASS__.'::'.__FUNCTION__.' / line '.__LINE__.' ] [caller: '.$bt[0]['file'].' / line '.$bt[0]['line'].']';
            Errors::log('unknown listConfig module: '.$listModule.' '.$backtraceFlat);
        }
    }
}