<?php

/**
 * TimeKeeper front page controller: shows the student's stats, checks a
 * submitted answer, and asks a question generator for the next question.
 *
 * Changes from the current repo version:
 *  - removed adminDev(): for every Main Admin it ran on every page load,
 *    printed debug dumps (the students' settings and stats, test numbers),
 *    hard-coded two students' user names, set the time zone, and generated a
 *    question from the unfinished "continents" generator
 *  - checkAnswer() called delete(..., true): the third argument is e107's
 *    debug flag, so the SQL was printed on the page after every answer.
 *    It's gone, and the user name is escaped
 *  - generators are loaded with require_once and an absolute path (include
 *    plus ./relative paths depended on the working directory and could
 *    redeclare a class)
 *  - getQuestion(): generalKnowledge fell through into elements (no break);
 *    countries/flags/capitalCities built an elements2 object after including
 *    continents.php (class not found). Subjects that aren't built yet now
 *    show a plain message instead
 *  - getScores()/getLastQuestion(): MPREFIX instead of `e107.e107_...`, user
 *    escaped, and a student with no answers this month gets zeros (not
 *    null) for the stats
 *  - showMessage(): user name escaped
 *  - someone with neither the student nor the teacher class now sees a
 *    message instead of an empty page
 *  - division and rounding are switched on (rounding at 50,000, division at 300,000)
 *  - new word_problems subject (switched off: see $subjectsList); the old
 *    worded_* subjects were mapped to the spelling generator and are gone
 */
require_once __DIR__ . '/TkAnswerStore.php';

class TK2 {

    private $data = [];
    private $subjectsList = [
        // Math
        [['numbers', 1, 0], // number sequences
            ['addition', 1, 10000], // Numeracy adding
            ['subtraction', 1, 20000], // Numeracy minus'
            ['multiplication', 1, 200000], // Numeracy times'
            ['division', 1, 300000], // Numeracy deviding
            ['rounding', 1, 50000], // Numeracy rounding (money to the nearest 5 cents)
            ['word_problems', 0, 250000], // Worded maths problems: change the 0 to a 1 to switch them on
        ],
        // English
        [['spelling', 1, 0], // Plain spelling
            ['anagrams', 1, 4000000], // Shuffle letters in a word
        ],
        // General knowledge
        [['generalKnowledge', 0, 0], // Name kinda says it all
        ],
        // Science
        [['elements', 1, 150000], // Periodic table of elements
        ],
        // Geography
        [['continents', 0, 0], // Point to the continent
            ['countries', 0, 0], // Point to the country
            ['flags', 0, 0], // Name the country by the flag picture
            ['capitalCities', 0, 0], // Name the capital for a country
        ],
        // History
        // Art
        [['artists', 0, 0], // Name the artist for famous paintings
        ],
        // Technology
        // language
        [['malaySpelling', 0, 0], // This could be interesting
        ],
        // Health - Health and Physical Education
        [['nameBodyParts', 0, 0], // Name the body parts from the images or point to the part
            ['nameBodyOrgans', 0, 0], // Name the organs or what they do
            ['basicFirstAid', 0, 0], // Some BASIC things to know for first aid
        ],
    ];

    /**
     * Run the timekeeper functionality
     */
    public function run(): void {
        $isStudent = check_class("TIMEKEEPER_STUDENT");
        $isTeacher = check_class("TIMEKEEPER_TEACHER");

        if ($isStudent) {
            $this->student();
        }
        if ($isTeacher) {
            $this->teacher();
        }
        if (!$isStudent && !$isTeacher) {
            e107::getRender()->tablerender('TimeKeeper', USER ? 'Your account has no TimeKeeper role (student or teacher).' : 'Please log in to use TimeKeeper.');
        }
    }

    /**
     * Run the sequence for teachers
     */
    private function teacher(): void {

    }

    /**
     * Run the sequence for students
     */
    private function student(): void {
        $user = e107::getUser()->getLoginName();

        $this->checkAnswer($user);

        $this->getScores($user);
        $this->showMessage();

        // If the last question has not been answered ask again.
        if ($this->getLastQuestion()) {
            return;
        }

        $this->getSubject();
        $this->getQuestion();
    }

    /**
     * Check if the last question was answered and check the answer
     * @param string $user
     */
    private function checkAnswer($user): void {
        $subject = filter_input(INPUT_POST, 'subject');
        if (is_string($subject) && $subject !== '') {
            require_once __DIR__ . '/answerChecker2.php';
            $ac = new answerChecker2();
            $ac->checkQuestionSubject($subject, $user);

            $db = e107::getDb();
            $db->delete('tkLastQuestion', "user = '" . $db->escape($user) . "'");
        }
    }

    /**
     * Show the last question asked if it hasn't been answered.
     * @return bool True when a question was shown.
     */
    private function getLastQuestion(): bool {
        $db = e107::getDb();
        $lastQuestion = $db->retrieve("SELECT LastQuestionHtml FROM `" . MPREFIX . "tkLastQuestion` WHERE user = '" . $db->escape($this->data['user']) . "' ORDER BY id DESC LIMIT 1");

        if (!empty($lastQuestion)) {
            e107::getRender()->tablerender('Last Question', base64_decode($lastQuestion));
            return true;
        }
        return false;
    }

    /**
     * Get the question based on selected subject
     * @return void
     */
    private function getQuestion(): void {
        switch ($this->data['selectedSubject']) {
            case 'numbers':
                require_once __DIR__ . '/questionGenerators/math/numbers2.php';
                $questionGen = new numbers2($this->data['user']);
                $questionGen->getNumbers();
                break;
            case 'addition':
            case 'subtraction':
            case 'multiplication':
            case 'division':
            case 'rounding':
                require_once __DIR__ . '/questionGenerators/math/numeracy2.php';
                $questionGen = new numeracy2($this->data['user'], $this->data['selectedSubject']);
                $questionGen->getNumeracy();
                break;
            case 'word_problems':
                require_once __DIR__ . '/questionGenerators/math/math_word_problems.php';
                $questionGen = new math_word_problems($this->data['user']);
                $questionGen->getWordProblem();
                break;
            case 'spelling':
                require_once __DIR__ . '/questionGenerators/english/spelling2.php';
                $questionGen = new spelling2($this->data['user']);
                $questionGen->getSpellingWord();
                break;
            case 'anagrams':
                require_once __DIR__ . '/questionGenerators/english/anagrams.php';
                $questionGen = new anagrams($this->data['user']);
                $questionGen->getanagram();
                break;
            case 'elements':
                require_once __DIR__ . '/questionGenerators/science/elements2.php';
                $questionGen = new elements2($this->data['user']);
                $questionGen->getElements();
                break;
            case 'generalKnowledge':
            case 'continents':
            case 'countries':
            case 'flags':
            case 'capitalCities':
            case 'artists':
            case 'malaySpelling':
            case 'nameBodyParts':
            case 'nameBodyOrgans':
            case 'basicFirstAid':
            default:
                // Not built yet (or unknown): none of these are in the random pool.
                e107::getRender()->tablerender('TimeKeeper', 'This subject is not available yet. Please refresh the page.');
                break;
        }
    }

    /**
     * Get the list of available subjects and select a random one.
     * @return void
     */
    private function getSubject(): void {
        $usableSubjects = [];
        foreach ($this->subjectsList as $subjects) {
            foreach ($subjects as $subject) {
                if ($subject[1] === 1 && $this->data['difficulty'] >= $subject[2]) {
                    $usableSubjects[] = $subject[0];
                }
            }
        }

        if (empty($usableSubjects)) {
            $usableSubjects[] = 'numbers';
        }

        $this->data['selectedSubject'] = $usableSubjects[mt_rand(0, count($usableSubjects) - 1)];
    }

    /**
     * Show an initial stats message to the user.
     * @return void
     */
    private function showMessage(): void {
        $text = "You have answered " . (int) $this->data['cntr'] . " questions this month.<br/>"
                . "Your accuacy for the month is " . htmlspecialchars((string) $this->data['percent']) . "%.<br/>"
                . "Your difficulty is set at " . htmlspecialchars((string) $this->data['difficulty']) . ".<br/><br/>";

        e107::getRender()->tablerender('Your stats ' . htmlspecialchars(ucfirst($this->data['user'])), $text);
    }

    /**
     * Get the initial values needed to generate a sane question.
     * @param string $user
     * @return void
     */
    private function getScores($user): void {
        $db = e107::getDb();
        $u = $db->escape($user);

        $returnArray = [];
        $returnArray['totalQuestionCount'] = (int) $db->count('tkReport', '(id)', "username = '{$u}'");

        $db->gen("SELECT COUNT(id) AS cntr, CAST((SUM(correct)/COUNT(id)*100) AS DECIMAL(5,2)) AS percent
            FROM `" . MPREFIX . "tkReport` WHERE username = '{$u}'
            AND answereddatestamp >= UNIX_TIMESTAMP(CURRENT_DATE() - INTERVAL 1 MONTH)
            AND answereddatestamp <= UNIX_TIMESTAMP(CURRENT_DATE() + INTERVAL 1 DAY)");
        $row = $db->fetch();

        $returnArray['cntr'] = is_array($row) ? (int) $row['cntr'] : 0;
        $returnArray['percent'] = (is_array($row) && $row['percent'] !== null) ? (float) $row['percent'] : 0;
        $returnArray['user'] = $user;
        $returnArray['difficulty'] = $returnArray['totalQuestionCount'] * $returnArray['percent'];

        $this->data = $returnArray;
    }

}