<?php
setlocale(LC_ALL, "de_DE@euro", "de_DE", "de", "ge");
set_include_path(get_include_path() . PATH_SEPARATOR . "./lib/");

// Configs
require_once "config/participo.php";
require_once $config["basePath"] . "/config/cwsvJudo.config.php";

// Libs
require_once "participoLib/user.php";

participo::init($cwsvJudoConfig);

$pmelo = new PmElo();

class PmElo
{
    /** initialize the pmelo session */
    function __construct()
    {
        // starting/continuing a session
        session_start();

        // create 'pmelo' section in the sessions data
        if (!array_key_exists("pmelo", $_SESSION)) {
            $_SESSION["pmelo"] = [];
        }
        // - data storage for id-s of chosen fighters
        if (!array_key_exists("fighterIds", $_SESSION["pmelo"])) {
            $_SESSION["pmelo"]["fighterIds"] = [];
        }

        // load/recreate ranking data
        if (!is_file(self::$pmeloJson)) {
            $this->log["info"][] =
                "Couldn't find `" . self::$pmeloJson . "`. Create a new one!";
            file_put_contents(self::$pmeloJson, json_encode([]));
        }

        // init members
        $this->trainees = self::getTrainees();
        $this->rankings = $this->createRankings();
        $this->fighters = [];
        foreach ($_SESSION["pmelo"]["fighterIds"] as $id) {
            $this->fighters[$id] = $this->trainees[$id];
        }

        // @todo Can be split. Some actions need the members to be already filled, some could be done earlier.
        // check for action in post data
        if (array_key_exists("pmelo", $_POST)) {
            // setting the current fighters
            // - meaning: fighter list is automatically updated by posted fighters
            if (array_key_exists("fighterIds", $_POST["pmelo"])) {
                $_SESSION["pmelo"]["fighterIds"] =
                    $_POST["pmelo"]["fighterIds"];

                header("Location: pmelo");
            }

            if (array_key_exists("promote", $_POST["pmelo"])) {
                $promote = $_POST["pmelo"]["promote"];
                $this->promote(
                    $promote["promoteeId"],
                    $promote["promoteeRank"],
                    $promote["degradeeId"],
                    $promote["degradeeRank"]
                );

                header("Location: pmelo");
            }

        }

        // save the updated ranking
        // @todo should be in destructor
        self::saveRankings($this->rankings);
    }

    ////
    // html code injection
    ///

    /** Echo the fighterInputForm */
    public function htmlFighterInputForm(){
        echo($this->getFighterInputForm($this->trainees));
    }

    /** Echo the fighterTable */
    public function htmlFighterTable(){
        echo($this->getFighterTable($this->fighters, $this->rankings));
    }

    /** Echo logOutput */
    public function htmlLogOutput(){
        echo($this->getLogOutput($this->log));
    }

    ////
    // saving and loading
    ////

    /** load all active trainees into a id=>User assoc array */
    static private function getTrainees()
    {
        $traineeList = array_map(
            "User::fromDbArray",
            User::dbSelectWithAttribute(4)
        );
        $traineeAssocArray = [];
        foreach ($traineeList as $trainee) {
            $traineeAssocArray[$trainee->getId()] = $trainee;
        }
        return $traineeAssocArray;
    }

    /** load ranking from json file  */
    static private function loadRankings()
    {
        return json_decode(file_get_contents(self::$pmeloJson));
    }

    /** save a ranking to json file */
    static private function saveRankings(array $rankings)
    {
        file_put_contents(self::$pmeloJson, json_encode($rankings));
    }

    ////
    // member functions
    ////

    /** create the ranking for the current session
     * 
     * - load saved ranking from file
     * - remove old trainees
     * - add new trainees
     */
    private function createRankings()
    {
        // load the last state of the ranking
        $loadedRanking = self::loadRankings();

        // check if the ranked trainees still are in training
        $cleanRanking = [];
        // - trainees that aren't currently in the ranking for later inserting
        $toBeInsertedTrainees = $this->trainees;
        foreach ($loadedRanking as $id) {
            if (array_key_exists($id, $this->trainees)) {
                // userId is still in training, so append it to the cleaned up ranking
                $cleanRanking[] = $id;
                // trainees already in the ranking we won't have to insert manual
                unset($toBeInsertedTrainees[$id]);
            }
        }

        // get the ids of the to be inserted trainees sorted by the birthday
        $newTraineesIds = array_map(function ($u) {
            return $u->getId();
        }, $toBeInsertedTrainees);
        usort($newTraineesIds, function ($lhs, $rhs) {
            return $this->trainees[$lhs]->getStrBirthday() <
                $this->trainees[$rhs]->getStrBirthday()
                ? -1
                : ($this->trainees[$lhs]->getStrBirthday() >
                $this->trainees[$rhs]->getStrBirthday()
                    ? 1
                    : 0);
        });

        // now we do a mergesort (step)
        $updatedRanking = [];
        $idxNewTrainees = count($newTraineesIds) - 1;
        $idxRanking = count($cleanRanking) - 1;
        // - while we can merge, we merge
        while ($idxRanking >= 0 && $idxNewTrainees >= 0) {
            if (
                $this->trainees[$cleanRanking[$idxRanking]]->getDateOfBirth() >
                $this->trainees[
                    $newTraineesIds[$idxNewTrainees]
                ]->getDateOfBirth()
            ) {
                array_unshift($updatedRanking, $cleanRanking[$idxRanking]);
                $idxRanking -= 1;
            } else {
                array_unshift(
                    $updatedRanking,
                    $newTraineesIds[$idxNewTrainees]
                );
                $idxNewTrainees -= 1;
            }
        }
        while ($idxRanking >= 0) {
            array_unshift($updatedRanking, $cleanRanking[$idxRanking]);
            $idxRanking -= 1;
        }
        while ($idxNewTrainees >= 0) {
            array_unshift($updatedRanking, $newTraineesIds[$idxNewTrainees]);
            $idxNewTrainees -= 1;
        }
        return $updatedRanking;
    }

    /** promote a fighter
     * 
     * Promotion means two fighter switch places
     * 
     * $promoteeId (int>0) id to promote
     * $promopteeRank (int>0) current rank of the one to be promoted
     * $degradeeId (int>0) id to demote
     * $degradeeRank (int>0) new rank of the promotee
     */
    private function promote(
        int $promoteeId,
        int $promoteeRank,
        int $degradeeId,
        int $degradeeRank
    ) {
        // input sanitation
        filterId($promoteeId);
        filterId($promoteeRank);
        filterId($degradeeId);
        filterId($degradeeRank);
        // check if both id are in the current fighter list
        if (
            array_key_exists($promoteeId, $this->fighters) &&
            array_key_exists($degradeeId, $this->fighters)
        ) {
            // check their current rank
            if (
                $this->rankings[$promoteeRank] == $promoteeId &&
                $this->rankings[$degradeeRank] == $degradeeId
            ) {
                // @todo check if they are rank neighbors in the fighter list
                if (true) {
                    // do the actual switch
                    $this->rankings[$promoteeRank] = $degradeeId;
                    $this->rankings[$degradeeRank] = $promoteeId;
                }
            }
        }
        // save the updated ranking
        $this->saveRankings($this->rankings);
    }

    ////
    // helper for output generation
    ////

    /** Assemble the Input form for the fighter selection
     * 
     * $trainees (array(participo::user)) list of trainees that can be selected for fighting
     * 
     * return fighterInputForm as html code
     */
    static private function getFighterInputForm(array $trainees){
        $style = [
            'classes'=>[
                'input-field' => "input-field col s12"
            ]
        ];

        $retHtml =
            '<form id="pmelo-form-fighters" action="pmelo" method="post">'
                // selects have to be wrapped into an .input-field, limitation of materializeCss
                .'<div class='.$style['classes']['input-field'].'>'
                    .'<select name="pmelo[fighterIds][]" id="pmelo-form-fighters-select" multiple>'
                        .'<option value="" disabled selected>Kämpfer auswählen</option>';
        foreach ($trainees as $trainee) {
            $retHtml .=
                        '<option value="'.$trainee->getId().'">'.
                            $trainee->getFirstname().' '.$trainee->getName().
                        '</option>';
        }
        $retHtml .= 
                    '</select>'.
                    '<label for="pmelo-form-fighters-select">'.
                        'Kämpfer auswählen'.
                    '</label>'.
                    '<input type="submit" value="Liste erstellen">'.
                '</div>'.
            '</form>';
        return $retHtml;
    }

    /** Assemble the ranking table of the fighters
     * 
     * $fighters (array(id=>participo::User)) list of fighters in the active round
     * $ranking (array(rank=>id)) ranking of the current selected fighters
     * 
     * return fighter ranking table as html code
     */
    static private function getFighterTable(array $fighters, array $rankings){
        $retHtml = 
            '<table>'.
                '<thead><tr><th>Platz</th><th>Name</th><th>Aufstieg</th></tr></thead>'.
                '<tbody>';
        if (!empty($fighters)) {
            // cache the predecessor in the ranking for the promoting form
            $lastOne = null;
            foreach ($rankings as $rank => $id) {
                if (array_key_exists($id, $fighters)) {
                    $fighter = $fighters[$id];
                    $retHtml .= '<tr>'.
                        '<td>'.$rank.'</td>'.
                        '<td>'.join(' ', [$fighter->getFirstName(), $fighter->getName()]).'</td>';
                    if (!is_null($lastOne)){
                        $retHtml .= '<td>'.self::getPromoteButton(
                            $fighter->getId(),$rank,
                            $lastOne["id"],$lastOne["rank"]
                        ).'</td>';
                    }
                    $retHtml .= '</tr>';
                    $lastOne = ["id" => $fighter->getId(), "rank" => $rank];
                }
            }
        }
        $retHtml .=
                '</tbody>'.
            '</table>';
        
        return $retHtml;
    }

    /** Assemble a Promote button
     * 
     * $promoteeId (int>0) id to promote
     * $promoteeRank (int>0) current rank of the promotee
     * $degradeeId (int>0) id to demote
     * $degradeeRank (int>0) rank of the to be demoted
     */
    static private function getPromoteButton(
        int $promoteeId,
        int $promoteeRank,
        int $degradeeId,
        int $degradeeRank
    ) {
        return "<form action=\"pmelo\" method=\"post\">" .
            "<input type= \"hidden\" name=\"pmelo[promote][promoteeId]\" value=\"" . $promoteeId . "\" />" .
            "<input type= \"hidden\" name=\"pmelo[promote][promoteeRank]\" value=\"" . $promoteeRank . "\" />" .
            "<input type= \"hidden\" name=\"pmelo[promote][degradeeId]\" value=\"" . $degradeeId . "\" />" .
            "<input type= \"hidden\" name=\"pmelo[promote][degradeeRank]\" value=\"" . $degradeeRank . "\">" .
            "<input class=\"btn\" type=\"submit\" value=\"^\">".
        "</form>";
    }

    /** Assemble the log Output
     * 
     * $log (array logLevel=>array(messages)) lists of log messages per logLevel
     * 
     * return logOutput as html code
     */
    private static function getLogOutput(array $log){
        $retHtml =
            '<ul class="collection with-header">'.
                '<li class="collection-header"><h3>Logs</h3></li>';
        foreach ($log as $logLevel => $messages) {
            if (!empty($messages)) {
                $retHtml .= 
                '<li class="collection-item">'.
                    '<ul class="collection with-header">'.
                        '<li class="collection-header">'.$logLevel.'</li>';
                foreach ($messages as $message) {
                    $retHtml .= 
                        '<li>'.$message.'</li>';
                }
                $retHtml .=
                    '</ul>'.
                '</li>';
            }
        }
    
        return $retHtml;
    }

    /** simple logger to a logging buffer  */
    private function var_log(
        $variable,
        string $prefix = null,
        string $logChannel = "info"
    ) {
        if (!in_array($logChannel, ["info", "warning", "error"])) {
            $logChannel = "info";
        }
        $prefix = !empty($prefix) ? $prefix . ": " : "";
        $this->log[$logChannel][] = $prefix . var_export($variable, true);
    }

    ////
    // member variables
    ////

    /** current chosen trainees for fighting [id=>participo::User] */
    public $fighters = null;
    /** current trainees available for fighting as [id=>participo::User] */
    public $trainees = null;
    /** the current ranking as [rank=>id] */
    public $rankings = null;
    /** a place to save log messages for later output */
    public $log = ["error" => [], "warning" => [], "info" => []];

    static $pmeloJson = "./pmeloRanking.json";
}