solon/server/fetch.php

<?php

# API logic

// 1. make login request
// 2. call the desired function (get specific page)
// 3. parse that page into a json file
// 4. return that json file to the caller

require 'vendor/autoload.php';

use Goutte\Client;
use Symfony\Component\DomCrawler\Crawler;

$client = new Client();

function make_login_request($username, $password) {
    global $client;

    $url = "https://aplikace.skolaonline.cz/SOL/Prihlaseni.aspx";
    $headers = [
        "__EVENTTARGET" => "dnn\$ctr994\$SOLLogin\$btnODeslat",
        "__EVENTARGUMENT" => "",
        "__VIEWSTATE" => "",
        "__VIEWSTATEGENERATOR" => "",
        "__VIEWSTATEENCRYPTED" => "",
        "__PREVIOUSPAGE" => "",
        "__EVENTVALIDATION" => "",
        "dnn\$dnnSearch\$txtSearch" => "",
        "JmenoUzivatele" => $username,  # username
        "HesloUzivatele" => $password,  # password
        "ScrollTop" => "",
        "__dnnVariable" => "",
        "__RequestVerificationToken" => ""
    ];

    $client->request("POST", $url, $headers=$headers);

    if ($client->getResponse()->getStatusCode() != 200) {
        return false;
    } else {
        return true;
    }
}

function parse_teacher($onmouseover) {
    if ($onmouseover == null) {
        $onmouseover = "Učitel:~ ~";
    }
    $explode_on_teacher = explode("Učitel:", $onmouseover); // [0] => something, [1] => teacher and something, 0 can be ignored
    $explode_on_first_tilda = explode("~", $explode_on_teacher[1]);
    $explode_on_second_tilda = explode("~", $explode_on_first_tilda[1]);
    $teacher = $explode_on_second_tilda[0];

    if (strstr($teacher, ">")) {
        $teacher = explode("<", explode(">", $teacher)[1])[0];
    }

    return $teacher;    
}

function get_time($times, $index) {
    foreach ($times as $cell) { 
        $current_hour = explode(".", $cell->filter(".KuvHeaderNadpis")->text())[0];  
        if ($index == $current_hour) {
            return explode(" - ", $cell->filter(".KuvHeaderText")->text());
        }
    }
}

function parse_substitute($substitutes) {
    if ($substitutes->count() == 0) {
        return 0;
    } else {
        return 1;
    }
}

function parse_cell($cell, $cell_counter, $times) {
    $is_empty = false;
    if ($cell->filter(".KuvBunkaRozvrhNadpis")->count() == 0) {
        $is_empty = true;
    }

    if (!$is_empty && $cell->filter("table")->filter(".KuvSuplovanaHodina")->count() == 0) {
        $name = $cell->filter(".KuvBunkaRozvrhNadpis")->first()->text();
        $maybe_place = $cell->filter(".KuvBunkaRozvrhText")->first()->html();
        if ($maybe_place == null) {
            $maybe_place = "<br>";
        }
        $place = explode("<br>", $maybe_place)[1];
        if ($place == null) {
            $place = "";
        }
        $teacher = parse_teacher($cell->filter("table")->filter("td")->first()->attr("onmouseover"));
        $is_substitute = parse_substitute($cell->filter(".KuvSuplujiciHodina"));
        $number = $cell_counter;
        $start = get_time($times, $cell_counter)[0]; // gives [start, end]
        $end = get_time($times, $cell_counter)[1];
    
        return [
            "name" => $name,
            "place" => $place,
            "teacher" => $teacher,
            "is_substitute" => $is_substitute,
            "number" => $number,
            "start" => $start,
            "end" => $end
        ];
    } else {
        $number = $cell_counter;
        $start = get_time($times, $cell_counter)[0];
        $end = get_time($times, $cell_counter)[1];
    
        return [
            "name" => "Volno",
            "place" => "Volno",
            "teacher" => "Volno",
            "is_substitute" => "Volno",
            "number" => $number,
            "start" => $start,
            "end" => $end
        ];
    }
}

function parse_cal_week($crawler) {
    $week = [];

    $table = $crawler->filter("#CCADynamicCalendarTable");

    $rows_ = $table->filter("tr");
    $times_ = $rows_->first()->filter("th");
    $times = [];
    $rows = [];
   
    $rows_->each(function (Crawler $node, $i) use (&$rows) {
        $rows[] = $node;
    }); 
    array_shift($rows);

    $times_->each(function (Crawler $node, $i) use (&$times) {
        $times[] = $node;
    });
    array_shift($times);

    foreach ($rows as $row) { // for every day do:
        $filtered_names = $row->filter(".KuvHeaderNadpis");
        $filtered_dates = $row->filter(".KuvHeaderText");
        
        if ($filtered_names->count() > 0 && $filtered_dates->count() > 0) {
            $name = $filtered_names->first()->text();
            $date = $filtered_dates->first()->text();        
            $subjects = [];
            $cells_ = $row->filter(".DctCell");
            $cells = [];
            $cells_->each(function (Crawler $node, $i) use (&$cells) {
                $cells[] = $node;
            }); 
           
            $cell_counter = 1; // start from 1
            foreach ($cells as $cell) {
                $subject = parse_cell($cell, $cell_counter, $times);
                $colspan = $cell->attr("colspan");
                $cell_counter += 1;
                if ($colspan != null) {
                    array_push($subjects, $subject);
                    for ($i = 1; $i < $colspan; $i++) {
                        $subject = parse_cell($cell, $cell_counter, $times);
                        $cell_counter += 1;
                        array_push($subjects, $subject);
                    }
                } else {
                    array_push($subjects, $subject);
                }
            }

            // get rid of trash lectures from the end
            while ($subjects[count($subjects)-1]["name"] == "Volno") {
                array_pop($subjects);
            }

            $day = [
                "name" => $name, 
                "date" => $date, 
                "subjects" => $subjects
            ];
            array_push($week, $day);
        }
    }

    return $week;
}

function get_cal_week() {
    global $client;

    $url = "https://aplikace.skolaonline.cz/SOL/App/Kalendar/KZK001_KalendarTyden.aspx";

    $crawler = $client->request("GET", $url);

    if ($client->getResponse()->getStatusCode() != 200) {
        return "Could not fetch weelky calendar data";
    } else {
        return parse_cal_week($crawler);
    }
}

function create_json_file($body, $status_code) {
    $json = ["body" => $body, "status_code" => $status_code];

    return json_encode($json);
}

if (!isset($_POST["username"]) || !isset($_POST["password"])) {
    echo create_json_file(json_encode("Credentials not supplied"), 1); // status 1 => failure
} else {
    if (!make_login_request($_POST["username"], $_POST["password"])) {
        echo create_json_file("Invalid credentials", 1);
    }

    if ($_POST["cal_week"]) {
        echo create_json_file(get_cal_week(), 0);
    }

    #if ($_POST["cal_tdy_tmr"]) {
    #    echo create_json_file(get_cal_tdy_tmr(), 0);
    #}

    #if ($_POST["grades"]) {
    #    echo create_json_file(get_grades(), 0);
    #}
}

?>