<?php
namespace local_treestudyplan;
require_once($CFG->libdir.'/externallib.php');
class period {
const TABLE = "local_treestudyplan_period";
private static $CACHE = [];
private static $PAGECACHE = [];
private $r; // Holds database record
private $id;
private $page;
public function aggregator(){
return $this->studyplan->aggregator();
}
// Cache constructors to avoid multiple creation events in one session.
public static function findById($id): self {
if(!array_key_exists($id,self::$CACHE)){
self::$CACHE[$id] = new self($id);
}
return self::$CACHE[$id];
}
/**
* Find a period by page and period number [1..$page->periods()]
*/
public static function find(studyplanpage $page,$periodnr): self{
global $DB;
if($periodnr < 1){
// Clamp period index
$periodnr = 1;
}
try{
$id = $DB->get_field(self::TABLE,"id",["page_id"=>$page->id(), "period" => $periodnr],MUST_EXIST);
$period = self::findById($id);
} catch(\dml_missing_record_exception $x){
// Period does not exist - create one ...
// Make a best guess estimate of the start and end date, based on surrounding periods,
// or specified duration of the page and the sequence of the periods
$pcount = $page->periods();
$ystart = $page->startdate()->getTimestamp();
$yend = $page->enddate()->getTimestamp();
// Estimate the period's timing to make a reasonable first guess
$ydelta = $yend - $ystart;
$ptime = $ydelta / $pcount;
try{
// Check if we have a previous period to glance the end date of as a reference
$startdate = $DB->get_field(self::TABLE,"enddate",["page_id"=>$page->id(), "period" => $periodnr-1],MUST_EXIST);
$pstart = strtotime($startdate)+(24*60*60); // Add one day
} catch(\dml_missing_record_exception $x2){
// If not, do a fair guess
$pstart = $ystart + (($periodnr-1)*$ptime);
}
try{
// Check if we have a next period to glance the start date of as a reference
$enddate = $DB->get_field(self::TABLE,"startdate",["page_id"=>$page->id(), "period" => $periodnr+1],MUST_EXIST);
$pstart = strtotime($enddate)-(24*60*60); // subtract one day
} catch(\dml_missing_record_exception $x2){
// If not, do a fair guess
$pend = $pstart + $ptime;
}
// And create the period
$period = self::add([
'page_id' => $page->id(),
'period' => $periodnr,
'fullname' => \get_string("period_default_fullname","local_treestudyplan",$periodnr),
'shortname' => \get_string("period_default_shortname","local_treestudyplan",$periodnr),
'startdate' => date("Y-m-d",$pstart),
'enddate' => date("Y-m-d",$pend),
]);
}
return $period;
}
// Cache constructors to avoid multiple creation events in one session.
public static function findForPage(studyplanpage $page): array {
if(!array_key_exists($page->id(),self::$PAGECACHE)){
$periods = [];
// find and add the periods to an array with the period sequence as a key
for($i=1; $i <= $page->periods(); $i++){
$period = self::find($page,$i);
$periods[$i] = $period;
}
self::$PAGECACHE[$page->id()] = $periods;
}
return self::$PAGECACHE[$page->id()];
}
private function __construct($id) {
global $DB;
$this->id = $id;
$this->r = $DB->get_record(self::TABLE,['id' => $id]);
$this->page = studyplanpage::findById($this->r->page_id);
}
public function id(){
return $this->id;
}
public function studyplan() : studyplan {
return $this->page->studyplan();
}
public function page(){
return $this->page;
}
public function shortname(){
return $this->r->shortname;
}
public function fullname(){
return $this->r->fullname;
}
public function period(){
return $this->r->period;
}
public function startdate(){
return new \DateTime($this->r->startdate);
}
public function enddate(){
if($this->r->enddate && strlen($this->r->enddate) > 0){
return new \DateTime($this->r->enddate);
}
else{
// return a date 100 years into the future
return (new \DateTime($this->r->startdate))->add(new \DateInterval("P100Y"));
}
}
public static function structure($value=VALUE_REQUIRED){
return new \external_single_structure([
"id" => new \external_value(PARAM_INT, 'id of period'),
"fullname" => new \external_value(PARAM_TEXT, 'Full name of period'),
"shortname"=> new \external_value(PARAM_TEXT, 'Short name of period'),
"period" => new \external_value(PARAM_INT, 'period sequence'),
"startdate" => new \external_value(PARAM_TEXT, 'start date of period'),
"enddate" => new \external_value(PARAM_TEXT, 'end date of period'),
],'Period info',$value);
}
public function model(){
return [
'id' => $this->r->id,
'fullname' => $this->r->fullname,
'shortname' => $this->r->shortname,
'period' => $this->r->period,
'startdate' => $this->r->startdate,
'enddate' => $this->r->enddate,
];
}
/**
* Do not use directly to add periods, unless performing import
* The static find() and findForPage() functions create the period if needed
*/
public static function add($fields){
global $DB;
if(!isset($fields['page_id'])){
throw new \InvalidArgumentException("parameter 'page_id' missing");
}
if(!isset($fields['period'])){
throw new \InvalidArgumentException("parameter 'period' missing");
}
if($DB->record_exists(self::TABLE,["page_id"=>$fields["page_id"], "period"=>$fields["period"]])){
throw new \InvalidArgumentException("record already exists for specified page and period");
}
$addable = ['page_id','fullname','shortname','period','startdate','enddate'];
$info = [ ];
foreach($addable as $f){
if(array_key_exists($f,$fields)){
$info[$f] = $fields[$f];
}
}
$id = $DB->insert_record(self::TABLE, $info);
unset(self::$PAGECACHE[$fields['page_id']]); // invalidate the cache for this page
return self::findById($id); // make sure the new page is immediately cached
}
public function edit($fields){
global $DB;
$editable = ['fullname','shortname','startdate','enddate'];
$info = ['id' => $this->id,];
foreach($editable as $f){
if(array_key_exists($f,$fields)){
$info[$f] = $fields[$f];
}
}
$DB->update_record(self::TABLE, $info);
//reload record after edit
$this->r = $DB->get_record(self::TABLE,['id' => $this->id],"*",MUST_EXIST);
unset(self::$PAGECACHE[$this->r->page_id]); // invalidate the cache for this page
return $this;
}
public function delete(){
global $DB;
$DB->delete_records(self::TABLE, ['id' => $this->id]);
unset(self::$PAGECACHE[$this->r->page_id]); // invalidate the cache for this page
return success::success();
}
public static function page_structure($value=VALUE_REQUIRED){
return new \external_multiple_structure(self::structure(),"The periods in the page",$value);
}
public static function page_model(studyplanpage $page){
$model = [];
foreach(self::findForPage($page) as $p){
$model[] = $p->model();
}
return $model;
}
}