<?php
class DataBase
{
	const DEFAULT_DURATION = '+7 day';
	const OPTIONS_DURATION = array(
		'day' => '+1 day',
		'week' => '+7 day',
		'2week' => '+14 day',
		'month' => '+1 month'
	);

	private $db;

	public function __construct()
	{
		$this->init();
	}

	public function init()
	{
		try {
			$this->db = new PDO('sqlite:test.db');
			$this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
		} catch (PDOException $e) {
			echo $e->getMessage();
			return null;
		}
		$stmt = $this->db->prepare('PRAGMA foreign_keys = 1;');
		$stmt->execute();
	}

	public function isInit()
	{
		return isset($this->db);
	}

	public function buildTables()
	{
		$stmt = $this->db->prepare("
			CREATE TABLE IF NOT EXISTS clouds(
				id_cloud INTEGER PRIMARY KEY,
				code     TEXT NOT NULL UNIQUE,
				size     INTEGER NOT NULL DEFAULT 3,
				text     TEXT,
				delete_t TIMESTAMP DEFAULT
					(datetime('now', '" . self::DEFAULT_DURATION . "'))
			);
		");
		$stmt->execute();
		$stmt = $this->db->prepare("
			CREATE TABLE IF NOT EXISTS words(
				id_word  INTEGER PRIMARY KEY,
				word     TEXT NOT NULL,
				count    INT DEFAULT 1,
				cloud_id INT NOT NULL,
				FOREIGN KEY (cloud_id)
					REFERENCES clouds(id_cloud) ON UPDATE CASCADE
					ON DELETE CASCADE
			);
		");
		$stmt->execute();
	}

	public function addWord(string $cloud, string $word)
	{
		if (empty($word)) {
			return false;
		}
		$stmt = $this->db->prepare("
			SELECT *
			FROM   clouds
			WHERE  code = :id;
		");
		$stmt->bindValue(':id', $cloud, PDO::PARAM_STR);
		$stmt->execute();
		$cloudId = null;
		if ($data = $stmt->fetch()) {
			$cloudId = $data['id_cloud'];
		} else {
			return false;
		}
		$stmt = $this->db->prepare("
			SELECT *
			FROM   words
			WHERE  cloud_id = :cid
			AND    word = :w;
		");
		$stmt->bindValue(':cid', $cloudId, PDO::PARAM_INT);
		$stmt->bindValue(':w', $word, PDO::PARAM_STR);
		$stmt->execute();
		if ($data = $stmt->fetch()) {
			$wordId = $data['id_word'];
			$stmt = $this->db->prepare("
				UPDATE words
				SET    count = count + 1
				WHERE  id_word = :id;
			");
			$stmt->bindValue(':id', $wordId, PDO::PARAM_INT);
			$stmt->execute();
		} else {
			$stmt = $this->db->prepare("
				INSERT INTO words(word, cloud_id)
				VALUES           (:w, :cid);
			");
			$stmt->bindValue(':w', $word, PDO::PARAM_STR);
			$stmt->bindValue(':cid', $cloudId, PDO::PARAM_INT);
			$stmt->execute();
		}
	}
	public function getWords(string $id)
	{
		$stmt = $this->db->prepare("
			SELECT *
			FROM   words
			JOIN   clouds
			ON     words.cloud_id = clouds.id_cloud
			WHERE  code = :id;
		");
		$stmt->bindValue(':id', $id);
		$stmt->execute();
		$words = [];
		$values = [];
		while ($data = $stmt->fetch()) {
			$words[] = array($data['word'], $data['count']);
			$values[] = $data['count'];
			$total += $data['count'];
		}

		array_multisort($values, SORT_DESC, $words);
		return $words;
	}

	public function getWordsPercentage(string $id)
	{
		$words = $this->getWords($id);
		$total = 0;
		foreach ($words as $word) {
			$total += $word[1];
		}
		foreach ($words as $key => $word) {
			$words[$key] = array($word[0], $word[1] / $total);
		}

		return $words;
	}

	public function getWordsMax(string $id)
	{
		$words = $this->getWords($id);
		$max = 0;
		foreach ($words as $word) {
			$max = max($max, $word[1]);
		}
		foreach ($words as $key => $word) {
			$words[$key] = array($word[0], $word[1] / $max);
		}

		return $words;
	}

	public function createCloud(
		string $ref,
		string $text = '',
		int $size = null,
		string $duration = null)
	{
		if (!isset($size)) {
			$size = 3;
		}
		if (!isset($duration)) {
			$duration = self::DEFAULT_DURATION;
		} elseif (!in_array($duration, self::OPTIONS_DURATION)) {
			$duration = self::DEFAULT_DURATION;
		}
		$duration = date('Y-m-d H:i:s', strtotime($duration));
		$stmt = $this->db->prepare("
			INSERT INTO clouds(code, text, size, delete_t)
			VALUES      (:code, :text, :size, :duration);
		");
		$stmt->bindValue(':code', $ref);
		$stmt->bindValue(':text', $text);
		$stmt->bindValue(':size', $size);
		$stmt->bindValue(':duration', $duration, PDO::PARAM_STR);
		try {
			$stmt->execute();
		} catch (PDOEXception $e) {
			return false;
		}
		return true;
	}

	public function getCloudSize(string $ref)
	{
		$stmt = $this->db->prepare("
			SELECT *
			FROM   clouds
			WHERE  code= :code;
		");
		$stmt->bindValue(':code', $ref, PDO::PARAM_STR);
		$stmt->execute();
		if ($data = $stmt->fetch()) {
			return $data['size'];
		}
		return null;
	}

	public function getCloudText(string $ref)
	{
		$stmt = $this->db->prepare("
			SELECT *
			FROM   clouds
			WHERE  code= :code;
		");
		$stmt->bindValue(':code', $ref, PDO::PARAM_STR);
		$stmt->execute();
		if ($data = $stmt->fetch()) {
			return $data['text'];
		}
		return null;
	}

	public function cleanCloud()
	{
		$stmt = $this->db->prepare("
			DELETE
			FROM  clouds
			WHERE delete_t < CURRENT_TIMESTAMP;
		");
		$stmt->execute();
		return true;
	}

	public function isCloud(string $id)
	{
		$stmt = $this->db->prepare("
			SELECT *
			FROM   clouds
			WHERE  code = :id;
		");
		$stmt->bindValue(':id', $id, PDO::PARAM_STR);
		$stmt->execute();
		if ($stmt->fetch()) {
			return true;
		}
		return false;
	}

}