<?php
class DataBase
{
	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, '
		      . 'create_t TIMESTAMP DEFAULT CURRENT_TIMESTAMP);'
		);
		$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);
		//echo 'test';
		//var_dump($words);
		$total = 0;
		foreach ($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);
		//echo 'test';
		//var_dump($words);
		$max = 0;
		foreach ($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)
	{
		$stmt = $this->db->prepare('INSERT INTO clouds(code) VALUES(:code);');
		$stmt->bindValue(':code', $ref);
		try {
			$stmt->execute();
		} catch (PDOEXception $e) {
			return false;
		}
		return true;
	}

	public function cleanCloud()
	{
		$stmt = $this->db->prepare('DELETE FROM clouds '
		      . "WHERE create_t < (SELECT datetime('now', '-1 week'));"
		);
		$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;
	}

}