<?php

require 'vendor/autoload.php';

$dotenv = Dotenv\Dotenv::createImmutable(realpath('..'));
$dotenv->load();
$dotenv->required(['DB_TYPE', 'DB_HOST', 'DB_NAME', 'DB_USER', 'DB_PASSWORD']);


class DB {
	private $link;


	public function __construct() {
		if (! is_resource($this->link)) {
			$dsn = $_ENV['DB_TYPE'].':dbname='.$_ENV['DB_NAME'].';host='.$_ENV['DB_HOST'].';port='.$_ENV['DB_PORT'];
			$driver_options = array(
				PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8'",
				PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
				PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
			 );
			$this->link = new PDO($dsn, $_ENV['DB_USER'], $_ENV['DB_PASSWORD'], $driver_options);
		}
	}

	public function get_all_contacts($task = null) {
		$query = '
			SELECT c.id, c.surname, c.firstname, c.email, c.phone, c.creation_date, c.active
			FROM contacts c
			LEFT JOIN notifications as n ON (n.contact_id = c.id)
			LEFT JOIN tasks as t ON (n.task_id = t.id)
		';

		if (! is_null($task)) {
			$query .= ' WHERE t.id = '.$task;
		}
		return $this->query($query);
	}


	public function get_all_tasks($status = null) {
		if (is_null($status)) {
			$query = '
				SELECT DISTINCT t.id, t.host, t.type, t.params, t.frequency, t.creation_date, t.last_execution, t.active, t.group_id, h.status, h.output, g.name as group_name
				FROM `tasks` as t
				LEFT JOIN `tasks_history` as h ON (h.task_id = t.id)
				LEFT JOIN `groups` as g ON (g.id = t.group_id)
				WHERE (t.last_execution IS NULL OR h.datetime = t.last_execution)
				ORDER BY group_name ASC
			';
		}
		else {
			$query = '
				SELECT DISTINCT t.id, t.host, t.type, t.params, t.creation_date, t.last_execution, t.active, t.group_id
				FROM tasks as t
				JOIN tasks_history as h ON (h.task_id = t.id)
				WHERE h.status = '.intval($status).' AND h.datetime = t.last_execution
				ORDER BY group_id DESC
			';
		}

		return $this->query($query);
	}

	public function get_all_history($task = null, $limit = 100) {
		$args = [
			':limit'	=> $limit
		];

		$query = '
			SELECT id, status, datetime, task_id
			FROM tasks_history
		';

		if (! is_null($task)) {
			$query .= ' WHERE task_id = :task_id';
			$args[':task_id'] = $task;
		}
		$query .= ' ORDER BY datetime DESC LIMIT :limit ';

		return $this->query($query, $args);
	}

	public function get_task_last_status($task) {
		$result = $this->query('SELECT t.id, th.status FROM tasks_history th JOIN tasks t ON (th.task_id = t.id) WHERE t.id = :task ORDER BY datetime DESC LIMIT 1', [':task' => $task]);
		foreach ($result as $r) {
			return $r['status'];
		}
	}


	public function query($query, $args = null) {
		$result = $this->prepare($query, $args);

		if (! $result->execute()) {
			throw new DatabaseException($result->errorInfo()[2]. ' in ('.$query.')');
		}

		return $result->fetchAll();
	}

	private function prepare($query, $args = null) {
		if (! $result = $this->link->prepare($query)) {
			throw new DatabaseException('Cannot prepare query ('.$query.') for execution');
		}

		if (! is_null($args)) {
			foreach ($args as $n => $v) {
				$type = gettype($v);

				switch ($type) {

					case 'boolean':
						$cast = PDO::PARAM_BOOL;
					break;

					case 'integer':
						$cast = PDO::PARAM_INT;
					break;

					case 'null':
						$cast = PDO::PARAM_NULL;
					break;

					case 'double':
					case 'string':
					default:
						$cast = PDO::PARAM_STR;

				}
				$result->bindValue($n, $v, $cast);
			}
		}
		return $result;
	}

	public function insert($query, $args = null) {
		$result = $this->prepare($query, $args);

		if (! $result->execute()) {
			throw new DatabaseException($result->errorInfo()[2]. ' in ('.$query.')');
		}

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

$db = new DB;


class DatabaseException extends Exception {}


?>