<?php
/**
 * Created by PhpStorm.
 * User: lucas
 * Date: 19/02/18
 * Time: 21:31
 */

namespace api\module;


use database\core\Repo;
use database\core\Repo_i;
use database\repo\category;
use database\repo\cours;
use database\repo\professor;
use database\repo\td;
use database\repo\tp;
use database\repo\ue;
use error\core\Err;
use error\core\Error;
use PhpOffice\PhpSpreadsheet\Exception;

class Excel
{

	private const startLineUE = 5;

	private const startLineProf = 10;

	public function post($args){

		if(isset($_FILES["file"]["tmp_name"])){
			//put everything in a try so we catch all PhpExcel exceptions and return a clean API Response
			try{
				$reader = new \PhpOffice\PhpSpreadsheet\Reader\Xls();
				$reader->setReadDataOnly(true);
				$spreadsheet = $reader->load($_FILES["file"]["tmp_name"]);

				$spreadsheet->setActiveSheetIndex(0);
				$UESpreadsheet = $spreadsheet->getActiveSheet();

				/*
				 * Setting Up state variables
				 */

				//current formation
				$formation = "";
				//current UE code
				$UECode = "";
				//current UE
				$UE = [];
				//array containing all the UEs
				$allUE = [];
				//array containing all the formations
				$allFormations = [];

				/*
				 * declare the lambda that will add finalized UE to the array
				 */
				$addEU = function() use (&$UECode,&$allUE,&$UE){
					if($UECode != ""){
						if(isset($allUE[$UECode])){
							$counter = 1;
							while(isset($allUE[$UECode.$counter])) $counter++;

							$allUE[$UECode.$counter] = $UE;

						}else{
							$allUE[$UECode] = $UE;
						}

						$UE = [];
					}
				};

				/*
				 * declaring the lambda tha twill extract the list of formation involved in the group
				 */
				$getFormations = function(?string $group) use (&$formation,&$allFormations) : array{
					if(!$group){
						if(!isset($allFormations[$formation])){
							$allFormations[$formation] = [
								"name" => $formation,
								"internal" => 1
							];
						}
						return [$formation];
					}

					//replace the generic "INFO" keyword by the actual formation
					$group = str_replace("INFO",$formation,$group);

					//split the string
					$groups = explode("+",$group);

					//trim the strings
					$groups = array_map('trim', $groups);

					//delete empty strings
					$groups = array_filter($groups);

					foreach ($groups as $group){
						if(!isset($allFormations[$group])){
							$allFormations[$group] = [
								"name" => $group,
								"internal" => strpos(strtolower($group),"info") !== false ? true : false
							];
						}
					}

					return $groups;
				};

				/*
				 * declaring the lambda that will compute the part of internal students in the course (used for stats purpose)
				 */
				$getInternalStudentPart = function(?string $group) use (&$formation, $getFormations) : float{

					if(!$group) return 1.0;

					$groups = $getFormations($group);

					if(!in_array($formation,$groups)){
						return 0.0;
					}else{
						return 1/count($groups);
					}
				};

				$exitWithNullException = function(){
					exit(json_encode(["error" => true, "message" => "NullCelException"]));
				};

				//starting the iteration
				foreach($UESpreadsheet->getRowIterator() as $row){
					//skip the first rows
					if($row->getRowIndex() < Excel::startLineUE) continue;


					$firstCellValue = ($UESpreadsheet->getCellByColumnAndRow(1,$row->getRowIndex()) ?? $exitWithNullException())->getValue();
					$secondCellValue = ($UESpreadsheet->getCellByColumnAndRow(2,$row->getRowIndex()) ?? $exitWithNullException())->getValue();

					//if the first value is not null and the second is, this means we change formation and rest the UUCode
					if($secondCellValue == "" and $firstCellValue != "") {$formation = $firstCellValue; $addEU(); $UECode = ""; continue; }

					//if no UE is set yet, find it
					if($UECode == "" and $firstCellValue != "") $UECode = $firstCellValue;

					//if the line is empty this means we change UE
					if($firstCellValue == "" and $secondCellValue == "") {$addEU(); $UECode = ""; continue;}

					//now we have a formation, a UE and we are sure the line is not empty, let's fill up this bad boy

					//if the required field is not set this means we are at the header of the UE
					if(!isset($UE["required"])){
						$UE["name"] = ($UESpreadsheet->getCellByColumnAndRow(2,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue();
						$UE["required"] = ($UESpreadsheet->getCellByColumnAndRow(3,$row->getRowIndex()) ?? $exitWithNullException())->getValue();
						$UE["TotalVH"] = ($UESpreadsheet->getCellByColumnAndRow(4,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue();

						$UE["CourseVH"] = ($UESpreadsheet->getCellByColumnAndRow(5,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: 0.0;
						$UE["CourseGroup"] = ($UESpreadsheet->getCellByColumnAndRow(6,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: 0;

						$UE["TdVH"] = ($UESpreadsheet->getCellByColumnAndRow(8,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: 0.0;
						$UE["TdGroup"] = ($UESpreadsheet->getCellByColumnAndRow(9,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: 0;

						$UE["TpVH"] = ($UESpreadsheet->getCellByColumnAndRow(11,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: 0.0;
						$UE["TpGroup"] = ($UESpreadsheet->getCellByColumnAndRow(12,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: 0;

						continue;
					}

					//we have a new group! if the array is not set, initialize it
					if(!isset($UE["groups"])) $UE["groups"] = [
						"Course" => [],
						"TD" => [],
						"TP" => []
					];

					//compute Course
					if (($UESpreadsheet->getCellByColumnAndRow(5,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue()){
						$UE["groups"]["Course"][] = [
							"VH" => ($UESpreadsheet->getCellByColumnAndRow(5,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue(),
							"internalStudentPart" => $getInternalStudentPart(($UESpreadsheet->getCellByColumnAndRow(6,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue()),
							"formations" => $getFormations(($UESpreadsheet->getCellByColumnAndRow(6,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue()),
							"professor" => ($UESpreadsheet->getCellByColumnAndRow(7,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: null
						];
					}

					//compute TDs
					if(($UESpreadsheet->getCellByColumnAndRow(8,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue()){
						$UE["groups"]["TD"][] = [
							"VH" => ($UESpreadsheet->getCellByColumnAndRow(8,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue(),
							"internalStudentPart" => $getInternalStudentPart(($UESpreadsheet->getCellByColumnAndRow(9,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue()),
							"formations" => $getFormations(($UESpreadsheet->getCellByColumnAndRow(6,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue()),
							"professor" => ($UESpreadsheet->getCellByColumnAndRow(10,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: null
						];
					}

					//compute TPs
					if(($UESpreadsheet->getCellByColumnAndRow(11,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue()){
						$UE["groups"]["TP"][] = [
							"VH" => ($UESpreadsheet->getCellByColumnAndRow(11,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue(),
							"internalStudentPart" => $getInternalStudentPart(($UESpreadsheet->getCellByColumnAndRow(12,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue()),
							"formations" => $getFormations(($UESpreadsheet->getCellByColumnAndRow(6,$row->getRowIndex()) ?? $exitWithNullException())->getCalculatedValue()),
							"professor" => ($UESpreadsheet->getCellByColumnAndRow(13,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: null
						];
					}

				}

				/*
				 * Now we compute the professor list to get the full name , the number of hour he must do and the category he is in
				 */

				$spreadsheet->setActiveSheetIndex(1);
				$ProfSpreadshit = $spreadsheet->getActiveSheet();

				//array containing all the professors
				$allProf = [];

				//current professor category
				$currentCategory = "";

				//category as represented in the excel (as a number)
				$currentCategoryIndex = 0;

				foreach($ProfSpreadshit->getRowIterator() as $row){

					//skip the first lines
					if($row->getRowIndex() < Excel::startLineProf) continue;

					$firstCellValue = ($ProfSpreadshit->getCellByColumnAndRow(2,$row->getRowIndex()) ?? $exitWithNullException())->getValue();
					$secondCellValue = ($ProfSpreadshit->getCellByColumnAndRow(3,$row->getRowIndex()) ?? $exitWithNullException())->getValue();

					//skip empty lines
					if(!$firstCellValue and !$secondCellValue) continue;

					//if the first cell contains something and not the second, it means that we change category
					if($firstCellValue && !$secondCellValue){
						$currentCategory = $firstCellValue;
						$currentCategoryIndex++;
					}

					//if the line is valid
					if(($ProfSpreadshit->getCellByColumnAndRow(3,$row->getRowIndex()) ?? $exitWithNullException())->getValue() and ($ProfSpreadshit->getCellByColumnAndRow(4,$row->getRowIndex()) ?? $exitWithNullException())->getValue()){
						$allProf[($ProfSpreadshit->getCellByColumnAndRow(3,$row->getRowIndex()) ?? $exitWithNullException())->getValue()] = [
							"categoryLabel" => $currentCategory,
							"categoryIndex" => $currentCategoryIndex,
							"lastName" => explode(" ",($ProfSpreadshit->getCellByColumnAndRow(4,$row->getRowIndex()) ?? $exitWithNullException())->getValue(),2)[1],
							"firstName" => explode(" ",($ProfSpreadshit->getCellByColumnAndRow(4,$row->getRowIndex()) ?? $exitWithNullException())->getValue(),2)[0],
							"hoursToDo" => ($ProfSpreadshit->getCellByColumnAndRow(5,$row->getRowIndex()) ?? $exitWithNullException())->getValue() ?: 0
						];
					}

				}

				/*
				 * adding data to the database
				 */

				//professors

				/** @var professor $profRepo */
				$profRepo = Repo::getRepo("professor");

				/** @var category $catRepo */
				$catRepo = Repo::getRepo("category");

				foreach ($allProf as $initials => &$prof){
					//create or update the professor category
					$catRepo->createOrUpdate($prof["categoryIndex"], utf8_decode($prof["categoryLabel"]));

					//create the professor, as some names are missing, we replace them by something else
					if(!$prof["lastName"]) $prof["lastName"] = "missingLastName";
					if(!$prof["firstName"]) $prof["firstName"] = "missingFirstName";

					$prof["dbId"] = $profRepo->exists(utf8_decode($prof["lastName"]), utf8_decode($prof["firstName"]));
					if(!$prof["dbId"]){
						$prof["dbId"] = $profRepo->create( utf8_decode($prof["lastName"]), utf8_decode($prof["firstName"]), $prof["categoryIndex"], $prof["hoursToDo"],  $initials);
					}
				}

				//formation and retreive the databse IDs
				/** @var \database\repo\formation $formRepo */
				$formRepo = Repo::getRepo("formation");

				foreach ($allFormations as &$form){
					$form["dbId"] = $formRepo->exists( utf8_decode($form["name"]));
					if(!$form["dbId"]){
						$form["dbId"] = $formRepo->create( utf8_decode($form["name"]), $form["internal"]);
					}
				}

				//UEs and corresponding groups

				/** @var ue $ueRepo */
				$ueRepo = Repo::getRepo("ue");

				/** @var cours $coursRepo */
				$coursRepo = Repo::getRepo("cours");

				/** @var td $tdRepo */
				$tdRepo = Repo::getRepo("td");

				/** @var tp $tpRepo */
				$tpRepo = Repo::getRepo("tp");

				foreach ($allUE as $codeUE => $UE){
					$ueRepo->create(utf8_decode($codeUE),
									utf8_decode($UE["name"]),
									$UE["required"] == "OBL",
									$UE["CourseVH"],
									$UE["TdVH"],
									$UE["TpVH"]);
					if(isset($UE["groups"])){
						foreach ($UE["groups"] as $type => $groups){
							foreach ($groups as $group){
								$formations = [];
								foreach ($group["formations"] as $format){
									if(isset($allFormations[$format]["dbId"])){
										$formations[] = $allFormations[$format]["dbId"];
									}
								}

								switch ($type){
									case "Course":
										$coursRepo->create(	utf8_decode($codeUE),
															$allProf[$group["professor"]]["dbId"],
															$group["VH"],
															$formations);
										break;
									case "TD":
										$tdRepo->create(utf8_decode($codeUE),
														$allProf[$group["professor"]]["dbId"],
														$group["VH"],
														$formations);
										break;
									case "TP":
										$tpRepo->create(utf8_decode($codeUE),
														$allProf[$group["professor"]]["dbId"],
														$group["VH"],
														$formations);
										break;
								}

							}
						}
					}
				}

				return [ 'data' => ["professors" => $allProf, "formations" => $allFormations, "UEs" => $allUE ] ];
			}catch (Exception $e){
				return [ 'error' => new Error(Err::UnknownError) ];
			}

		}else{
			return [ 'error' => new Error(Err::UploadError) ];
		}
	}

}