<?php

namespace Khofmann\Models\User;

use Exception;
use PDO;
use DateTime;
use Khofmann\Database\Database;
use Config\Config;
use JsonSerializable;

class User implements JsonSerializable
{
  private int $id;
  private string $username;
  private int $status;
  private string $email;
  private ?string $image;
  private bool $isAdmin;
  private DateTime $memberSince;
  private int $postCount;

  protected function __construct(int $id, string $username, int $status, string $email, string $timestamp, ?string $image, bool $isAdmin)
  {
    $this->id = $id;
    $this->username = $username;
    $this->status = $status;
    $this->email = $email;
    $this->image = $image;
    $this->isAdmin = $isAdmin;
    $this->memberSince = new DateTime($timestamp);
  }

  /*
  * Statics
  */

  public static function getByID(int $id): User
  {
    $db = Database::getInstance();
    $stmt = $db->prepare(
      "SELECT benutzer, status, email, image, isadmin, zeitstempel FROM egb_benutzer WHERE id = :ID"
    );
    $stmt->bindValue(":ID", $id);
    $stmt->execute();
    $data = $stmt->fetch();

    if (!$data) throw new Exception("NotFound");

    return new User($id, $data["benutzer"], $data["status"], $data["email"], $data["zeitstempel"], $data["image"], $data["isadmin"] === 1);
  }

  public static function getByEmail(string $email): User
  {
    $db = Database::getInstance();
    $stmt = $db->prepare(
      "SELECT id, benutzer, status, image, isadmin, zeitstempel FROM egb_benutzer WHERE email = :EMAIL"
    );
    $stmt->bindValue(":EMAIL", $email);
    $stmt->execute();
    $data = $stmt->fetch();

    if (!$data) throw new Exception("NotFound");

    return new User($data["id"], $data["benutzer"], $data["status"], $email, $data["zeitstempel"], $data["image"], $data["isadmin"] === 1);
  }

  public static function getByToken(string $token): User
  {
    $db = Database::getInstance();
    $stmt = $db->prepare(
      "SELECT id, benutzer, status, email, image, isadmin, zeitstempel FROM egb_benutzer WHERE token = :TOKEN"
    );
    $stmt->bindValue(":TOKEN", $token);
    $stmt->execute();
    $data = $stmt->fetch();

    if (!$data) throw new Exception("NotFound");

    return new User($data["id"], $data["benutzer"], $data["status"], $data["email"], $data["zeitstempel"], $data["image"], $data["isadmin"] === 1);
  }

  public static function logIn(string $email, string $password): array
  {
    $db = Database::getInstance();
    // Get user data
    $stmt = $db->prepare("SELECT * FROM egb_benutzer WHERE email LIKE :EMAIL AND status = 1");
    $stmt->bindValue(":EMAIL", $email);
    $stmt->execute();
    $data = $stmt->fetch();

    if ($data) {
      $user = new User($data["id"], $data["benutzer"], $data["status"], $email, $data["zeitstempel"], $data["image"], $data["isadmin"] === 1);
      if (password_verify($password, $data["passwort"])) {
        // REHASH for safety should it somehow change
        if (password_needs_rehash($data["passwort"], PASSWORD_DEFAULT)) {
          $newHash = password_hash($password, PASSWORD_DEFAULT);
          $stmt = $db->prepare("UPDATE egb_benutzer SET passwort = :PAS WHERE id = :ID");
          $stmt->bindValue(":PAS", $newHash);
          $stmt->bindValue(":ID", $user->getID());
          $stmt->execute();
        }
        // Generate token
        $stmt = $db->prepare("UPDATE egb_benutzer SET token = UUID() WHERE id = :ID");
        $stmt->bindValue(":ID", $user->getID());
        $stmt->execute();
        // Get token
        $stmt = $db->prepare("SELECT token FROM egb_benutzer WHERE id = :ID");
        $stmt->bindValue(":ID", $user->getID());
        $stmt->execute();
        $token = $stmt->fetch(PDO::FETCH_COLUMN, 0);
        // Return user and token
        if ($token) {
          return ["user" => $user, "token" => $token];
        }
        // Token generation failed
        throw new Exception("Failed");
      } else {
        // PW wrong
        throw new Exception("Invalid");
      }
    } else {
      // User does not exist
      throw new Exception("NotFound");
    }
  }

  /*
  * Members
  */

  public function logOut(): bool
  {
    $db = Database::getInstance();
    $stmt = $db->prepare("UPDATE egb_benutzer SET token = NULL WHERE id = :ID");
    $stmt->bindValue(":ID", $this->id);
    return $stmt->execute();
  }

  public function update(?string $username, ?string $password, $image = null)
  {
    $db = Database::getInstance();

    $error = false;
    if (!empty($username)) {
      $stmt = $db->prepare("UPDATE egb_benutzer SET benutzer = :USR WHERE id = :ID");
      $stmt->bindValue(":USR", $username);
      $stmt->bindValue(":ID", $this->id);
      $error = !$stmt->execute();
    }
    if ($error) throw new Exception("FailedUsername");

    if (!empty($password)) {
      $stmt = $db->prepare("UPDATE egb_benutzer SET passwort = :PAS WHERE id = :ID");
      $stmt->bindValue(":PAS", password_hash($password, PASSWORD_DEFAULT));
      $stmt->bindValue(":ID", $this->id);
      $error = !$stmt->execute();
    }
    if ($error) throw new Exception("FailedPassword");

    if (!empty($image)) {
      $destinationFilename = sprintf('%s.%s', uniqid(), $image->getExtension());
      $image->move(Config::getStoragePath() . "profilbilder/$destinationFilename");

      $stmt = $db->prepare("UPDATE egb_benutzer SET image = :IMG WHERE id = :ID");
      $stmt->bindValue(":IMG", $destinationFilename);
      $stmt->bindValue(":ID", $this->id);
      $error = !$stmt->execute();
    }
    if ($error) throw new Exception("FailedImage");

    return true;
  }

  public function delete()
  {
    $db = Database::getInstance();
    $stmt = $db->prepare("DELETE FROM egb_benutzer WHERE id = :ID");
    $stmt->bindValue(":ID", $this->id);
    return $stmt->execute();
  }

  /*
  * Getters
  */

  public function getID(): int
  {
    return $this->id;
  }

  public function getUsername(): string
  {
    return $this->username;
  }

  public function getStatus(): int
  {
    return $this->status;
  }

  public function getEmail(): string
  {
    return $this->email;
  }

  public function getImage(): ?string
  {
    return $this->image;
  }

  public function getIsAdmin(): bool
  {
    return $this->isAdmin;
  }

  public function getMemberSince(): DateTime
  {
    return $this->memberSince;
  }

  /*
  * JSON
  */

  public function jsonSerialize(): array
  {
    return [
      'id' => $this->getId(),
      'username' => $this->getUsername(),
      'status' => $this->getStatus(),
      'email' => $this->getEmail(),
      'image' => $this->getImage(),
      'isAdmin' => $this->getIsAdmin(),
      'memberSince' => $this->getMemberSince(),
    ];
  }
}