<?php

class Application_Model_Datatables {

    /*
     * query used to return data for a paginated/searchable datatable.
     */
    public static function findEntries($con, $displayColumns, $fromTable, $data, $dataProp = "aaData")
    {
        $where = array();

        if ($data["sSearch"] !== "") {
            $searchTerms = explode(" ", $data["sSearch"]);
        }

        $selectorCount = "SELECT COUNT(*) ";
        $selectorRows = "SELECT ".join(",", $displayColumns)." ";

        $sql = $selectorCount." FROM ".$fromTable;
        $sqlTotalRows = $sql;

        if (isset($searchTerms)) {
            $searchCols = array();
            for ($i = 0; $i < $data["iColumns"]; $i++) {
                if ($data["bSearchable_".$i] == "true") {
                    $searchCols[] = $data["mDataProp_{$i}"];
                }
            }

            $outerCond = array();

            foreach ($searchTerms as $term) {
                $innerCond = array();

                foreach ($searchCols as $col) {
                    $escapedTerm = pg_escape_string($term);
                    $innerCond[] = "{$col}::text ILIKE '%{$escapedTerm}%'";
                }
                $outerCond[] = "(".join(" OR ", $innerCond).")";
            }
            $where[] = "(".join(" AND ", $outerCond).")";
        }
        // End Where clause

        // Order By clause
        $orderby = array();
        for ($i = 0; $i < $data["iSortingCols"]; $i++){
            $num = $data["iSortCol_".$i];
            $orderby[] = $data["mDataProp_{$num}"]." ".$data["sSortDir_".$i];
        }
        $orderby[] = "id";
        $orderby = join("," , $orderby);
        // End Order By clause

        $displayLength = intval($data["iDisplayLength"]);
        if (count($where) > 0) {
            $where = join(" AND ", $where);
            $sql = $selectorCount." FROM ".$fromTable." WHERE ".$where;
            $sqlTotalDisplayRows = $sql;

            $sql = $selectorRows." FROM ".$fromTable." WHERE ".$where." ORDER BY ".$orderby;

            //limit the results returned.
            if ($displayLength !== -1) {
                $sql .= " OFFSET ".$data["iDisplayStart"]." LIMIT ".$displayLength;
            }
        }
        else {
            $sql = $selectorRows." FROM ".$fromTable." ORDER BY ".$orderby;

            //limit the results returned.
            if ($displayLength !== -1) {
                $sql .= " OFFSET ".$data["iDisplayStart"]." LIMIT ".$displayLength;
            }
        }

        try {
            $r = $con->query($sqlTotalRows);
            $totalRows = $r->fetchColumn(0);

            if (isset($sqlTotalDisplayRows)) {
                $r = $con->query($sqlTotalDisplayRows);
                $totalDisplayRows = $r->fetchColumn(0);
            }
            else {
                $totalDisplayRows = $totalRows;
            }

            $r = $con->query($sql);
            $r->setFetchMode(PDO::FETCH_ASSOC);
            $results = $r->fetchAll();
        }
        catch (Exception $e) {
            Logging::debug($e->getMessage());
        }

        return array(
            "sEcho" => intval($data["sEcho"]),
            "iTotalDisplayRecords" => intval($totalDisplayRows),
            "iTotalRecords" => intval($totalRows),
            $dataProp => $results
        );
    }
}