<?php
class ApprovalStatus{

    const APP_ST_APPROVED = 1;
    const APP_ST_REJECTED = 0;

    private static $me = null;

    private function __construct(){}

    public static function getInstance(){
        if(empty(self::$me)){
            self::$me = new ApprovalStatus();
        }

        return self::$me;
    }


    public function isDirectApproval($employeeId){
        $emp = new Employee();
        $emp->Load("id = ?",array($employeeId));
        if(empty($emp->approver1) && empty($emp->approver2) && empty($emp->approver3)){
            return true;
        }
        return false;
    }

    public function getResolvedStatuses($type, $id){
        $employeeApproval = new EmployeeApproval();
        $eas = $employeeApproval->Find("type = ? and element = ? and status > -1 order by level", array($type, $id));
        return $eas;
    }

    public function approvalChainExists($type, $id){
        $list = $this->getAllStatuses($type, $id);
        return count($list) > 0;
    }

    public function getAllStatuses($type, $id){
        $employeeApproval = new EmployeeApproval();
        $eas = $employeeApproval->Find("type = ? and element = ? order by level", array($type, $id));
        return $eas;
    }

    public function initializeApprovalChain($type, $id){
        $element = new $type();
        $element->Load("id = ?",array($id));
        $employeeId = $element->employee;

        for($i = 1; $i < 4; $i++){
            $approver = $this->getApproverByLevel($i, $employeeId);
            if(!empty($approver)){
                $employeeApproval = new EmployeeApproval();
                $employeeApproval->type = $type;
                $employeeApproval->element = $id;
                $employeeApproval->approver = $approver;
                $employeeApproval->level = $i;
                $employeeApproval->status = -1;
                $employeeApproval->active = 0;
                $employeeApproval->created = date("Y-m-d H:i:s");
                $employeeApproval->updated = date("Y-m-d H:i:s");
                $ok = $employeeApproval->Save();
                if(!$ok){
                    LogManager::getInstance()->error("Error:".$employeeApproval->ErrorMsg());
                }
            }else{
                LogManager::getInstance()->error("Approver is empty level:".$i);
            }
        }
    }


    public function updateApprovalStatus($type, $id, $currentEmployee, $status){
        LogManager::getInstance()->error('updateApprovalStatus 1');
        if(!$this->approvalChainExists($type, $id)){
            LogManager::getInstance()->error('updateApprovalStatus 2');
            return new IceResponse(IceResponse::SUCCESS, array(NULL, NULL));    
        }

        if($status != 0 && $status != 1){
            return new IceResponse(IceResponse::ERROR, "Invalid data");
        }

        $element = new $type();
        $element->Load("id = ?",array($id));
        $employeeId = $element->employee;

        $eas = $this->getAllStatuses($type, $id);
        $level = 0;
        //check if the element is already rejected
        foreach($eas as $ea){
            if($ea->status == 0){
                return new IceResponse(IceResponse::ERROR, "This item is already rejected");
            }else if($ea->active == 1){
                $level = intval($ea->level);
            }
        }

        LogManager::getInstance()->error('level '.$level);

        $currentAL = NULL;
        if($level > 0){
            $currentAL = new EmployeeApproval();
            $currentAL->Load("type = ? and element = ? and level = ?",array($type, $id, $level));
        }

        $nextAL = null;
        if($level < 3){
            $nextAL = new EmployeeApproval();
            $nextAL->Load("type = ? and element = ? and level = ?",array($type, $id, intval($level)+1));

            LogManager::getInstance()->error('next AL '.print_r($nextAL,true));
            if(empty($nextAL->id)){
                $nextAL = NULL;
            }
        }

        //Check if the current employee is allowed to approve
        if($level > 0 && $currentEmployee != $currentAL->approver){
            return new IceResponse(IceResponse::ERROR, "You are not allowed to approve or reject");
        }

        if(!empty($currentAL)){
            //Now mark the approval status
            $currentAL->status = $status;
            $currentAL->Save();
        }

        if(!empty($nextAL)) {
            foreach ($eas as $ea) {
                if ($ea->id == $nextAL->id) {
                    $nextAL->active = 1;
                    $nextAL->Save();
                } else {
                    $ea->active = 0;
                    $ea->Save();
                }
            }
        }

        if(!empty($currentAL)){
            $oldCurrAlId = $currentAL->id;
            $currentAL = new EmployeeApproval();
            $currentAL->Load("id = ?",array($oldCurrAlId));
        }


        return new IceResponse(IceResponse::SUCCESS, array($currentAL, $nextAL));

    }


    private function getApproverByLevel($level, $employeeId){
        $emp = new Employee();
        $emp->Load("id = ?",array($employeeId));
        $approver = NULL;
        $alevel = "approver".$level;
        return $emp->$alevel;
    }

}