<?php

namespace Blog\Model;

use Blog\Model\Database;
use PDOException;
use Random\RandomException;

class UserModel extends Database
{
    /**
     * @throws RandomException
     */
    public function createUser($values){

        $salt = bin2hex(random_bytes(16));

        $hash = hash('sha256', $values["password"] . $salt);

        $guid = $this->createUUID();

        $pdo = $this->linkDB();

        $sql = "INSERT INTO user (`id`, `name`,`vorname`,`email`,`passwort`,`salt`,`role`) 
                VALUES (:guid, :name, :firstname, :email, :password, :salt, :role)";

        try {
            $sth = $pdo->prepare($sql);
            $sth->execute([
                ":guid" => $guid,
                ":name" => $values["lastname"],
                ":firstname" => $values["name"],
                ":email" => $values["email"],
                ":password" => $hash,
                ":salt" => $salt,
                ":role" => $values["role"]
            ]);
        } catch (PDOException $e) {
            new \Blog\Library\ErrorMsg("Fehler beim Schreiben der Daten.", $e);
            die;
        }

        return true;
    }

    public function getUserByEmail($email){
        $pdo = $this->linkDB();
        $sql = "SELECT * FROM user WHERE email = :email";
        $sth = $pdo->prepare($sql);
        $sth->execute([":email" => $email]);
        return $sth->fetch();
    }

    public function getUserById($id){
        $pdo = $this->linkDB();
        $sql = "SELECT * FROM user WHERE id = :id";
        $sth = $pdo->prepare($sql);
        $sth->execute([":id" => $id]);
        return $sth->fetch();
    }

    public function deleteUser($id){
        $pdo = $this->linkDB();
        $sql = "DELETE FROM user WHERE id = :id";
        $sth = $pdo->prepare($sql);
        $sth->bindParam(":id", $id);
        $sth->execute();
    }

    public function updateUserData($id, $values){
        $pdo = $this->linkDB();
        $fields = [];
        $params = [':id' => $id];

        if(!empty($values["password"])){
            $salt = bin2hex(random_bytes(16));
            $hash = hash('sha256', $values["password"] . $salt);
            $fields["password"] = "´passwort´ = :password";
            $fields["salt"] = "´salt´ = :salt";
            $params[":password"] = $hash;
            $params[":salt"] = $salt;
        }

        foreach (['name','vorname','email'] as $col) {
            if (isset($values[$col])) {
                $fields[]           = "`{$col}` = :{$col}";
                $params[":{$col}"]  = $values[$col];
            }
        }

        $sql = "UPDATE user 
        SET " . implode(", ", $fields) . "
        where id = :id";

        try {
            $sth = $pdo->prepare($sql);
            $sth->execute($params);
        } catch (PDOException $e) {
            new \Blog\Library\ErrorMsg("Fehler beim Aktualisieren der Daten.", $e);
            die;
        }

    }

    private function writeNewAddress($values) {
        $guid = $this->createUUID();

        $sql = "INSERT INTO ort (`id`, `stadt`, `strasse`, `plz`) VALUES (
            :guid, :stadt, :strasse, :plz);";

        $pdo = $this->linkDB();

        try {
            $sth = $pdo->prepare($sql);
            $sth->execute(array(":guid" => $guid,
                ":stadt" => $values["stadt"],
                ":strasse" => $values["strasse"],
                ":plz" => $values["plz"],
            ));
            return $guid;
        } catch (PDOException $e) {
            new \Blog\Library\ErrorMsg("Fehler beim Schreiben der Daten.", $e); 
            die;
        }
    }

    public function writeNewCourse($values, $kursleiterId)
    {
        // Bleibt übrig wenn Adresse erstellt wird aber Kurs nicht weil Error
        $addressId = $this->writeNewAddress($values);

        $guid = $this->createUUID();

        $sql = "INSERT INTO kurs (`id`, `name`, `preis`, `dauer`, `rabatt`, `kategorie`, `beschreibung`, `kurseleiter`, `ort_id`) VALUES (
            :guid, :name, :preis, :dauer, :rabatt, :kategorie, :beschreibung, :kurseleiter, :ort_id);";

        $pdo = $this->linkDB();

        try {
            $sth = $pdo->prepare($sql);
            $sth->execute(array(":guid" => $guid,
                ":name" => $values["name"],
                ":preis" => $values["preis"],
                ":dauer" => $values["dauer"],
                ":rabatt" => $values["rabatt"],
                ":kategorie" => $values["kategorie"],
                ":beschreibung" => $values["beschreibung"],
                ":kurseleiter" => $kursleiterId,
                "ort_id" => $addressId
            ));
        } catch (PDOException $e) {
            new \Blog\Library\ErrorMsg("Fehler beim Schreiben der Daten.", $e); 
            die;
        }
                
        return true;
    }

    public function getMyCourses() {
        $personId = $_SESSION["user_id"];
        $isKursleiter = $_SESSION["user_role"] === "leiter";

        $pdo = $this->linkDB();

        if ($isKursleiter) {
            $sql = "SELECT k.id, k.name, k.preis, k.dauer, k.rabatt, k.kategorie, k.beschreibung, k.ort_id,
                        o.stadt, o.strasse, o.plz, b.note, b.kommentar
                    FROM kurs AS k
                    JOIN ort AS o ON o.id = k.ort_id
                    LEFT JOIN bewertungen AS b ON b.kurs_id = k.id
                    WHERE k.kursleiter = :personId
                    ORDER BY k.name";
        } else {
            $sql = "SELECT k.id, k.name, k.preis, k.dauer, k.rabatt, k.kategorie, k.beschreibung, k.ort_id,
                        o.stadt, o.strasse, o.plz, b.note, b.kommentar
                    FROM kurs_user AS ku
                    JOIN kurs AS k ON k.id = ku.kurs_id
                    JOIN ort AS o ON o.id = k.ort_id
                    LEFT JOIN bewertungen AS b ON b.kurs_id = k.id
                    WHERE ku.user_id = :personId
                    ORDER BY k.name";
        }

        try {
            $sth = $pdo->prepare($sql);
            $sth->execute([':personId' => $personId]);
            return $sth->fetchAll(\PDO::FETCH_ASSOC);
        } catch (PDOException $e) {
            new \Blog\Library\ErrorMsg("Fehler beim Lesen der Daten.", $e); 
            die;
        }
    }
    public function getAllCourses() {
        $pdo = $this->linkDB();
        $userId = $_SESSION['user_id'] ?? null;

        if ($userId === null) {
            $sql = "SELECT 
                        k.id, k.name, k.preis, k.dauer, k.rabatt, k.kategorie, k.beschreibung, k.ort_id,
                        o.stadt, o.strasse, o.plz, b.note, b.kommentar,
                        0 AS isTeilnehmer
                    FROM kurs AS k
                    JOIN ort AS o ON o.id = k.ort_id
                    LEFT JOIN bewertungen AS b ON b.kurs_id = k.id";
            $params = [];
        } else {
            $sql = "SELECT 
                        k.id, k.name, k.preis, k.dauer, k.rabatt, k.kategorie, k.beschreibung, k.ort_id,
                        o.stadt, o.strasse, o.plz, b.note, b.kommentar,
                        CASE WHEN ku.user_id IS NULL THEN 0 ELSE 1 END AS isTeilnehmer
                    FROM kurs AS k
                    JOIN ort AS o ON o.id = k.ort_id
                    LEFT JOIN bewertungen AS b ON b.kurs_id = k.id
                    LEFT JOIN kurs_user AS ku ON ku.kurs_id = k.id AND ku.user_id = :userId";
            $params = ['userId' => $userId];
        }

        try {
            $sth = $pdo->prepare($sql);
            $sth->execute($params);
            return $sth->fetchAll(\PDO::FETCH_ASSOC);
        } catch (PDOException $e) {
            new \Blog\Library\ErrorMsg("Fehler beim Lesen der Daten.", $e); 
            die;
        }
    }

    public function updateCourse($course) {
        $pdo = $this->linkDB();

        try {
            if (isset($course['ort_id'])) {
                $this->updateAddress($course);
                $addressId = $course['ort_id'];
            } else {
                $addressId = $this->writeNewAddress($course);
            }

            $sql = "UPDATE kurs SET 
                        `name` = :name,
                        `preis` = :preis,
                        `dauer` = :dauer,
                        `rabatt` = :rabatt,
                        `kategorie` = :kategorie,
                        `beschreibung` = :beschreibung,
                        `ort_id` = :ort_id
                    WHERE `id` = :id";

            $sth = $pdo->prepare($sql);
            $sth->execute([
                ':id' => $course['id'],
                ':name' => $course['name'],
                ':preis' => $course['preis'],
                ':dauer' => $course['dauer'],
                ':rabatt' => $course['rabatt'],
                ':kategorie' => $course['kategorie'],
                ':beschreibung' => $course['beschreibung'],
                ':ort_id' => $addressId
            ]);

        } catch (PDOException $e) {
            new \Blog\Library\ErrorMsg("Fehler beim Aktualisieren des Kurses.", $e);
            die;
        }

        return true;
    }

    public function updateAddress($data) {
        $pdo = $this->linkDB();

        if (!isset($data['ort_id'])) {
            throw new \Exception("Keine Adress-ID vorhanden zum Aktualisieren.");
        }

        $sql = "UPDATE ort SET 
                    `strasse` = :strasse,
                    `stadt` = :stadt,
                    `plz` = :plz
                WHERE `id` = :id";

        try {
            $sth = $pdo->prepare($sql);
            $sth->execute([
                ':id' => $data['ort_id'],
                ':strasse' => $data['strasse'],
                ':stadt' => $data['stadt'],
                ':plz' => $data['plz']
            ]);
        } catch (PDOException $e) {
            new \Blog\Library\ErrorMsg("Fehler beim Aktualisieren der Adresse.", $e);
            die;
        }

        return true;
    }

    public function enroll($courseId, $userId) {
        $pdo = $this->linkDB();

        try {
            $checkSql = "SELECT COUNT(*) FROM kurs_user WHERE user_id = :user_id AND kurs_id = :kurs_id";
            $checkStmt = $pdo->prepare($checkSql);
            $checkStmt->execute([
                ':user_id' => $userId,
                ':kurs_id' => $courseId
            ]);

            if ($checkStmt->fetchColumn() > 0) {
                return false;
            }

            $insertSql = "INSERT INTO kurs_user (user_id, kurs_id) VALUES (:user_id, :kurs_id)";
            $insertStmt = $pdo->prepare($insertSql);
            $insertStmt->execute([
                ':user_id' => $userId,
                ':kurs_id' => $courseId
            ]);

        } catch (PDOException $e) {
            new \Blog\Library\ErrorMsg("Fehler beim Einschreiben in den Kurs.", $e);
            die;
        }

        return true;
    }

}