<?php

class SQLite {

  private PDO $_db;

  public function __construct(string $database, string $username, string $password) {

    $this->_db = new PDO('sqlite:' . $database, $username, $password);
    $this->_db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $this->_db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
    $this->_db->setAttribute(PDO::ATTR_TIMEOUT, 600);

    $this->_db->query('
      CREATE TABLE IF NOT EXISTS "page" (
        "pageId"	INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
        "httpCode"	INTEGER,
        "timeAdded"	INTEGER NOT NULL,
        "timeUpdated"	INTEGER,
        "title"	TEXT,
        "data"	TEXT,
        "description"	TEXT,
        "keywords"	TEXT,
        "url"	TEXT NOT NULL
      )
    ');

    $this->_db->query('
      CREATE TABLE IF NOT EXISTS "image" (
        "imageId"	INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
        "pageId"	INTEGER NOT NULL,
        "alt"	TEXT NOT NULL,
        "src"	TEXT NOT NULL
      )
    ');

    // FTS5
    $this->_db->query('
      CREATE VIRTUAL TABLE IF NOT EXISTS `ftsPage` USING fts5(`url`, `title`, `description`, `keywords`, `data`, tokenize=`unicode61`, content=`page`, content_rowid=`pageId`)
    ');

    $this->_db->query('
      CREATE TRIGGER IF NOT EXISTS `pageInsert` AFTER INSERT ON `page` BEGIN
        INSERT INTO ftsPage(`rowid`, `url`, `title`, `description`, `keywords`, `data`) VALUES (`new`.`pageId`, `new`.`url`, `new`.`title`, `new`.`description`, `new`.`keywords`, `new`.`data`);
      END
    ');

    $this->_db->query('
      CREATE TRIGGER IF NOT EXISTS `pageDelete` AFTER DELETE ON `page` BEGIN
        INSERT INTO ftsPage(`ftsPage`, `rowid`, `url`, `title`, `description`, `keywords`, `data`) VALUES ("delete", `old`.`pageId`, `old`.`url`, `old`.`title`, `old`.`description`, `old`.`keywords`, `old`.`data`);
      END
    ');

    $this->_db->query('
      CREATE TRIGGER IF NOT EXISTS `pageUpdate` UPDATE ON `page` BEGIN
        INSERT INTO ftsPage(`ftsPage`, `rowid`, `url`, `title`, `description`, `keywords`, `data`) VALUES ("delete", `old`.`pageId`, `old`.`url`, `old`.`title`, `old`.`description`, `old`.`keywords`, `old`.`data`);
        INSERT INTO ftsPage(`rowid`, `url`, `title`, `description`, `keywords`, `data`) VALUES (`new`.`pageId`, `new`.`url`, `new`.`title`, `new`.`description`, `new`.`keywords`, `new`.`data`);
      END
    ');
  }

  public function getTotalPages() {

    $query = $this->_db->prepare('SELECT COUNT(*) AS `total` FROM `page`');

    $query->execute();

    return $query->fetch()->total;
  }

  public function getPage(string $url) {

    $query = $this->_db->prepare('SELECT * FROM `page` WHERE `url` = ?');

    $query->execute([$url]);

    return $query->fetch();
  }

  public function updatePage(int $pageId, string $title, string $description, string $keywords, string $data, int $timeUpdated) {

    $query = $this->_db->prepare('UPDATE `page` SET `title` = ?, `description` = ?, `data` = ?, `timeUpdated` = ? WHERE `pageId` = ?');

    $query->execute([$title, $description, $data, $timeUpdated, $pageId]);

    return $query->rowCount();
  }

  public function addPage(string $title, string $description, string $keywords, string $data, int $timeAdded) {

    $query = $this->_db->prepare('INSERT INTO `page` (`title`, `description`, `data`, `timeAdded`) VALUES (?, ?, ?, ?)');

    $query->execute([$title, $description, $data, $timeAdded]);

    return $this->_db->lastInsertId();
  }

  public function initPage(string $url, int $timeAdded) {

    $query = $this->_db->prepare('INSERT INTO `page` (`url`, `timeAdded`) VALUES (?, ?)');

    $query->execute([$url, $timeAdded]);

    return $this->_db->lastInsertId();
  }

  public function addImage(int $pageId, string $src, string $alt) {

    $query = $this->_db->prepare('INSERT INTO `image` (`pageId`, `src`, `alt`) VALUES (?, ?, ?)');

    $query->execute([$pageId, $src, $alt]);

    return $this->_db->lastInsertId();
  }

  public function deleteImages(int $pageId) {

    $query = $this->_db->prepare('DELETE FROM `image` WHERE `pageId` = ?');

    $query->execute([$pageId]);

    return $query->rowCount();
  }

  public function getPageQueue(int $limit, int $timeFrom) {

    $query = $this->_db->prepare('SELECT * FROM `page` WHERE `timeUpdated` IS NULL OR `timeUpdated` < ? ORDER BY `pageId` LIMIT ' . (int) $limit);

    $query->execute([$timeFrom]);

    return $query->fetchAll();
  }

  public function updatePageQueue(string $pageId, int $timeUpdated, int $httpCode) {

    $query = $this->_db->prepare('UPDATE `page` SET `timeUpdated` = ?, `httpCode` = ? WHERE `pageId` = ? LIMIT 1');

    $query->execute([$timeUpdated, $httpCode, $pageId]);

    return $query->rowCount();
  }

  public function searchPages(string $q) {

    $query = $this->_db->prepare('SELECT `title`, `description`, `url` FROM `ftsPage` WHERE `data` MATCH ? ORDER BY `rank`');

    $query->execute([$q]);

    return $query->fetchAll();
  }

  public function searchPagesTotal(string $q) {

    $query = $this->_db->prepare('SELECT COUNT(*) AS `total` FROM `ftsPage` WHERE `data` MATCH ?');

    $query->execute([$q]);

    return $query->fetch()->total;
  }
}