<?php
/*
=========================================================
EXAM-GATE ENTERPRISE
---------------------------------------------------------
File:
admin/save_question.php

Version:
3.0.0

Description:
Save Question

Compatible:
JSON Edition

Author:
Zamex Link Limited
=========================================================
*/
require_once "../config/core.php";
/*
=========================================================
SESSION SECURITY
=========================================================
*/

if(!isLoggedIn())
{
    header("Location:login.php");
    exit;
}

/*
=========================================================
POST VALIDATION
=========================================================
*/

if($_SERVER["REQUEST_METHOD"]!="POST")
{
    die("Invalid Request.");
}

$examID = trim($_POST["exam_id"] ?? "");

$questionID = trim($_POST["question_id"] ?? "");

$questionType = trim($_POST["type"] ?? "MCQ");

$question = trim($_POST["question"] ?? "");

$marks = (int)($_POST["marks"] ?? 1);

if($examID=="")
{
    die("Exam ID Missing.");
}

if($questionID=="")
{
    die("Question ID Missing.");
}

if($question=="")
{
    die("Question cannot be empty.");
}

/*
=========================================================
DIRECTORIES
=========================================================
*/

$examFolder =
EXAMS_PATH .
"/" .
$examID;

if(!is_dir($examFolder))
{
    die("Invalid Examination.");
}

$questionFolder =
$examFolder .
"/QUESTIONS-" .
$examID;

if(!is_dir($questionFolder))
{
    mkdir($questionFolder,0755,true);
}

/*
=========================================================
UPLOAD DIRECTORY
=========================================================
*/

$imageFolder =
$questionFolder .
"/IMAGES";

if(!is_dir($imageFolder))
{
    mkdir($imageFolder,0755,true);
}

/*
=========================================================
IMAGE UPLOAD
=========================================================
*/

$imageName="";

if(
isset($_FILES["question_image"])
&&
$_FILES["question_image"]["error"]==0
)
{

$extension =
strtolower(
pathinfo(
$_FILES["question_image"]["name"],
PATHINFO_EXTENSION
)
);

$allowed = [

"jpg",
"jpeg",
"png",
"gif",
"webp"

];

if(in_array($extension,$allowed))
{

$imageName =
$questionID .
"." .
$extension;

move_uploaded_file(

$_FILES["question_image"]["tmp_name"],

$imageFolder .
"/" .
$imageName

);

}

}

/*
=========================================================
BUILD QUESTION RECORD
=========================================================
*/

$questionData = [

"question_id"=>$questionID,

"exam_id"=>$examID,

"type"=>$questionType,

"question"=>$question,

"marks"=>$marks,

"image"=>$imageName,

"option_a"=>trim($_POST["option_a"] ?? ""),

"option_b"=>trim($_POST["option_b"] ?? ""),

"option_c"=>trim($_POST["option_c"] ?? ""),

"option_d"=>trim($_POST["option_d"] ?? ""),

"option_e"=>trim($_POST["option_e"] ?? ""),

"correct_answer"=>trim($_POST["correct_answer"] ?? ""),

"true_false_answer"=>trim($_POST["true_false_answer"] ?? ""),

"blank_answer"=>trim($_POST["blank_answer"] ?? ""),

"short_answer"=>trim($_POST["short_answer"] ?? ""),

"essay_marking"=>trim($_POST["essay_marking"] ?? ""),

"practical_instruction"=>trim($_POST["practical_instruction"] ?? ""),

"created_date"=>date("Y-m-d"),

"created_time"=>date("H:i:s"),

"last_modified"=>date("Y-m-d H:i:s")

];

/*
=========================================================
SAVE JSON
=========================================================
*/

$questionFile =
$questionFolder .
"/" .
$questionID .
".json";

write_json(
$questionFile,
$questionData
);

/*
=========================================================
CENTRAL LOG
=========================================================
*/

writeLog(

"Question Saved",

[
"exam"=>$examID,
"question"=>$questionID,
"type"=>$questionType
]

);

/*
=========================================================
CHECK FOR EXISTING QUESTION
=========================================================
*/

if(
    file_exists($questionFile)
    &&
    !isset($_POST["overwrite"])
)
{
    /*
    Existing Question IDs are expected when editing.
    Future edit_question.php will submit overwrite=1.
    */
}

/*
=========================================================
VERIFY SAVE
=========================================================
*/

if(!file_exists($questionFile))
{
    die("Unable to save question.");
}

/*
=========================================================
CLEAR DRAFT FLAG
=========================================================
*/

$_SESSION["last_saved_question"] = $questionID;
$_SESSION["last_saved_exam"] = $examID;
$_SESSION["last_saved_time"] = date("Y-m-d H:i:s");

/*
=========================================================
SAVE & NEXT
=========================================================
*/

if(isset($_POST["save_next"]))
{
    header(
        "Location: question_builder.php?exam=" .
        urlencode($examID) .
        "&status=saved"
    );

    exit;
}

/*
=========================================================
RETURN TO QUESTION MANAGER
=========================================================
*/

header(
    "Location: question_manager.php?exam=" .
    urlencode($examID) .
    "&status=saved"
);

exit;