<?

require_once('class.Database.phpm');

class GenericObject {

    # Member Variables

    private $id;
    private $table_name;

    private $database_fields;
    private $loaded;
    private $modified_fields;

    # Methods

    public function Reload() {
        try {
            $db = Database::instance();
        } catch (Exception $e) {
            // no point continuing
            die("Unable to connect to the database");
        }

        $id = $this->id;
        $table_name = $this->table_name;
        $db->select("SELECT * FROM \"$table_name\" WHERE id='$id'");
        $result_fields = $db->select("SELECT * FROM \"$table_name\" WHERE id='$id'");
        $this->database_fields = $result_fields;
        $this->loaded = 1;
        if (sizeof($this->modified_fields) > 0) {
            foreach ($this->modified_fields as $key => $value) {
                $this->modified_fields[$key] = false;
            }
        }
    }

    private function Load() {
        $this->Reload();
        $this->loaded = 1;
    }

    public function ForceLoaded() {
        $this->loaded = 1;
    }

    public function GetField($field) {
        if ($this->loaded == 0) {
            $this->Load();
        }
        return $this->database_fields[$field];
    }

    public function GetAllFields() {
        if ($this->loaded == 0) {
            $this->Load();
        }
        return($this->database_fields);
    }

    public function GetID() {
        return $this->id;
    }

    public function Initialize($table_name, $tuple_id = "") {
        $this->table_name = $table_name;
        $this->id = $tuple_id;
    }

    public function SetField($field, $value) {
        if ($this->loaded == 0) {
            if ($this->id) {
                $this->Load();
            }
        }
        $this->database_fields[$field] = $value;
        $this->modified = 1;
        $this->modified_fields[$field] = true;
    }

    public function Destroy() {
        $id = $this->id;
        $table_name = $this->table_name;
        if ($id) {
            $db = Database::instance();
            $stmt = "DELETE FROM \"" . $table_name . "\" WHERE id='" . $id . "'";
            $db->delete($stmt);
        }
    }

    public function Save() {
        $id = $this->id;
        $table_name = $this->table_name;
        $database_fields = $this->database_fields;
        $db = Database::instance();

        if (!$id) {
            # then the id hasn't been set so this is a new record, and hence set loaded to false
            $this->loaded = 0;
        }

        if ($this->loaded == 0) {
            # assume this is a new entity and therefor use the insert function
            if ($this->id = $db->insert($table_name, $database_fields)) {
                $this->loaded = 1;
                return true;
            }
        } else {
            # then an existing record is being updated.  Build an array of updated fields.

            $sWhere = "id = " . $this->id;
            $table_name = $this->table_name;
            $arUpdates = array(); // key -> value array of the fields to be updated
            $db = Database::instance();

            foreach ($this->database_fields as $key => $value) {
                if ($this->modified_fields[$key] == true) {
                    $arUpdates[$key] = $value;
                }
            }

            # now call the DB object's update method, using $sWhere to limit the effect
            if ($db->update($table_name, $arUpdates, $sWhere)) {
                return true;
            }
        }

        # if we've got this far, then either the insert or update methods failed so...
        return false;
    }
}

<?
    class GenericObjectCollection {

        # Member Variables
        var $table_name;
        var $class_name;

        var $items_per_page;
        var $item_count = 0;

        var $id_array;

        var $obj_array;

        function __construct($table_name, $class_name) {
            $this->table_name = $table_name;
            $this->class_name = $class_name;
        }

        function AddTuple($id) {
            if (!$this->id_array) {
                $this->id_array = array();
            };
            array_push($this->id_array, $id);
            $this->item_count = sizeof($this->id_array);
            }

        function SetPageSize($items_per_page) {
            $this->items_per_page = $items_per_page;
        }

        function GetItemCount() {
            return $this->item_count;
        }

        function GetNumPages() {
            return(ceil($this->item_count / $this->items_per_page));
        }

        function _GetCommaSeparatedIDList($start_lim = 0, $end_lim = -1) {
            $s = "";
            if ($end_lim == -1) {
                $end_lim = sizeof($this->id_array)-1;
            };
            for ($i=$start_lim; $i<=$end_lim; $i++) {
                if (is_numeric($this->id_array[$i])) {
                    $s = $s . $this->id_array[$i] . ",";
                };
            };
            $s = substr($s, 0, strlen($s) - 1);
            return $s;
        }

        function _GetIndexFromTupleID($tuple_id) {
            $index = -1;
            for ($i=0; $i<=sizeof($this->id_array)-1; $i++) {
                if ($this->id_array[$i] == $tuple_id) {
                    $index = $i;
                };
            };
            return $index;
        }

        function PopulateObjectArray($page_num = 0) {
            $items_per_page = $this->items_per_page;
            if ($this->item_count > 0) {
                if ($page_num > 0) {
                    $start_lim = ($items_per_page * ($page_num - 1));
                    $end_lim = ($start_lim + $items_per_page) - 1;
                    if ($end_lim > ($this->item_count-1)) {
                        $end_lim = $this->item_count - 1;
                    };
                    $stmt = "SELECT * FROM " . $this->table_name . " WHERE id IN (" . $this->_GetCommaSeparatedIDList($start_lim, $end_lim). ")";
                } else {
                    $stmt = "SELECT * FROM " . $this->table_name . " WHERE id IN (" . $this->_GetCommaSeparatedIDList(). ")";
                };
                # Perform SQL query 
                $db = Database::instance();
                $result_rows = $db->getAll($stmt);

                for ($i=0; $i<=sizeof($result_rows)-1; $i++) {
                    $this_row = $result_rows[$i];
                    $this_db_row_id = $this_row["id"];
                    $this_index = $this->_GetIndexFromTupleID($this_db_row_id);
                    if ($this_index >= 0) {
                        $refObjArrayIndexObj = &$this->obj_array[$this_index];
                        $s = "\$refObjArrayIndexObj = new " . $this->class_name . "(" . $this_db_row_id . ");";
                        eval($s);
                        $refObjArrayIndexObj->ForceLoaded();
                        foreach ($this_row as $key => $value) {
                            if (!(is_numeric($key))) {
                                $refObjArrayIndexObj->SetField($key, $value);
                            };
                        };
                    };
                };
            };
        }

        function RetrievePopulatedObjects($page_num = 0) {
            if ($page_num > 0) {
                $items_per_page = $this->items_per_page;
                # Calculate start and end limits from page number.
                $start_lim = ($items_per_page * ($page_num - 1));
                $end_lim = ($start_lim + $items_per_page) - 1;
                    if ($end_lim > ($this->item_count-1)) {
                        $end_lim = $this->item_count - 1;
                    };        
            } else {
                $start_lim = 0;
                $end_lim = $this->item_count - 1;
            };
            $return_array = array();
            $counter = 0;
            for ($i=$start_lim; $i<=$end_lim; $i++) {
                $return_array[$counter] = $this->obj_array[$i];
                $counter++;
            };
            return($return_array);
        }
  }
?>