<?PHP
/** 
 * Class for serverside spreadsheet data injecting
 * Reqs: unzip.PHP,zip.PHP (containing any utility functions able to unzip files & zip folders)
 *
 * Author: Poborak
 */
class DataInjector
{    
    //spreadsheet file,we inject data into this one
    const SPREADSHEET_FILE="datafile.xlsx";   
    // specific worksheet into which data are being injected    
    const SPREADSHEET_WORKSHEET_FILE="/xl/worksheets/sheet7.xml"; 
    //working directory,spreadsheet is extracted here
    const WSPACE_DIR="Wspace";
    // query for obtaining data from DB
    const STORE_QUERY = "SELECT * FROM stores ORDER BY store_number ASC"; 

    private $dbConn;
    private $storesData;

    /**
     * @param   MysqLi  $dbConn
     */
    function __construct(MysqLi $dbConn) {   
        $this->dbConn = $dbConn;
    }

    /**
     * Main method for whole injection process
     * First data are gathered from DB and spreadsheet is decompressed to workspace.
     * Then injection takes place and spreadsheet is ready to be rebuilt again by zipping.
     *
     * @return   boolean    Informace o úspěchu
     */     
    public function injectData() {

        if (!$this->getStoresInfoFromDB()) return false;        
        if (!$this->explodeSpreadsheet(self::SPREADSHEET_FILE,self::WSPACE_DIR)) return false;                      
        if (!$this->injectDataToSpreadsheet(self::WSPACE_SUBDIR.self::SPREADSHEET_WORKSHEET_FILE)) return false;            
        if (!$this->implodeSpreadsheet(self::SPREADSHEET_FILE,self::WSPACE_DIR)) return false;
        return true;
    }

    /**
     * Decompress spreadsheet file to folder
     *
     * @param   string  $spreadsheet
     * @param   string  $targetFolder
     *
     * @return   boolean    success/fail 
     */   
    private function explodeSpreadsheet($spreadsheet,$targetFolder) {
        return unzip($spreadsheet,$targetFolder);
    }

    /**
     * Compress source folder to spreadsheet file
     *
     * @param   string  $spreadsheet    
     * @param   string  $sourceFolder
     *
     * @return   boolean    success/fail 
     */   
    private function implodeSpreadsheet($spreadsheet,$sourceFolder) {
        return zip($sourceFolder,$spreadsheet);
    }

    /**
     * Loads data from DB to member variable $storesDetails (as array)
     *
     * @return   boolean    success/fail 
     */ 
    private function getStoresInfoFromDb() {
        unset($this->storesData);       

        if ($stmt = $this->dbConn->prepare(self::STORE_QUERY)) {
            $stmt->execute();
            $stmt->bind_result($store_number,$store_regional_manager,$store_manager,$store_city,$store_address);
            while ($stmt->fetch()) {
                $this->storesData[trim($store_number)] = array(trim($store_regional_manager),trim($store_manager),trim($store_address),trim($store_city));
            }           
            $stmt->close();
        }   
        return true;        
    }

    /**
     * Injects data from member variable $storesDetails to spreadsheet $ws
     *
     * @param   string  $ws target worksheet
     *
     * @return   boolean    success/fail
     */ 
    private function injectDataToSpreadsheet($ws) {
         $worksheet = file_get_contents($ws);    
         if ($worksheet === false or empty($this->storesData) return false;

         $xml = simplexml_load_string($worksheet);  
         if (!$xml) return false;

        // Loop through $storesDetails array containing rows of data
        foreach ($this->storesData as $std){

            // For each row of data create new row in excel worksheet
            $newRow = $xml->sheetData->addChild('row'); 

            // Loop through columns values in rowdata
            foreach ($std as $cbd){                      
                // Save each column value into next column in worksheets row 
                 foreach ($this->storesData as $cbd){
                    $newCell = $newRow->addChild('c'); 
                    $newCell->addAttribute('t',"inlineStr");
                    $newIs = $newCell->addChild('is');
                    // text has to be saved as utf-8 (otherwise the spreadsheet file become corrupted)
                    if (!mb_check_encoding($cbd,'utf-8')) $cbd = iconv("cp1250","utf-8",$cbd); 
                    $newT = $newIs->addChild('t',$cbd);                     
                }
             }
         }

         // Save xml data back to worksheet file
         if (file_put_contents($ws,$xml->asXML()) !== false) return true;           
    }
}
?>