<?php
class DB {
    private $pdo;

    public function __construct() {
        try {
            if (!file_exists('db.sqlite') {
                $this->pdo = new PDO("sqlite:db.sqlite");
                $this->createTables();
                syslog(LOG_INFO,"New SQLite Database was created.");
            }
            else {
                $this->pdo = new PDO("sqlite:db.sqlite");
                $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
                $this->pdo->exec("PRAGMA foreign_keys = ON");
            }
        } catch (PDOException $e) {
            syslog(LOG_EMERG,"Could not connect to the database: " . $e->getMessage());
            die("Could not connect to the database: " . $e->getMessage());
        }
    }

    public function createTables() {
        $sql = "
            CREATE TABLE IF NOT EXISTS devices (
                id INTEGER PRIMARY KEY,
                device_id TEXT NOT NULL,
                mac_address TEXT NOT NULL,
                ip_address TEXT NOT NULL,
                firmware_version TEXT NOT NULL,
                temperature_offset INTEGER DEFAULT 0,
                humidity_offset INTEGER DEFAULT 0,
                last_updated TEXT DEFAULT CURRENT_TIMESTAMP,
                last_seen TEXT DEFAULT CURRENT_TIMESTAMP
            );
            CREATE TABLE IF NOT EXISTS readings (
                dev_id INTEGER PRIMARY KEY,
                temperature INTEGER NOT NULL,
                humidity INTEGER NOT NULL,
                FOREIGN KEY(dev_id) REFERENCES devices(id) ON UPDATE CASCADE ON DELETE CASCADE
            );

        ";
        try {
            $this->pdo->exec($sql);
            echo "Table 'devices' and 'readings' created successfully.";
        } catch (PDOException $e) {
            die("Error creating table: " . $e->getMessage());
        }
    }

    public function addDevice($deviceData) {
        $sql = "
            INSERT INTO devices (device_id, mac_address, ip_address, firmware_version, temperature_offset, humidity_offset, last_updated, last_seen)
            VALUES (:device_id, :mac_address, :ip_address, :firmware_version, :temperature_offset, :humidity_offset, :last_updated, :last_seen)
        ";
        try {
            $stmt = $this->pdo->prepare($sql);
            $stmt->execute($deviceData);
            return $this->pdo->lastInsertId();
        } catch (PDOException $e) {
            die("Error inserting device: " . $e->getMessage());
        }
    }

    public function getDevices() {
        $sql = "SELECT * FROM devices";
        try {
            $stmt = $this->pdo->query($sql);
            return $stmt->fetchAll(PDO::FETCH_ASSOC);
        } catch (PDOException $e) {
            die("Error fetching devices: " . $e->getMessage());
        }
    }

    public function getDeviceById($id) {
        $sql = "SELECT * FROM devices WHERE id = :id";
        try {
            $stmt = $this->pdo->prepare($sql);
            $stmt->execute(['id' => $id]);
            return $stmt->fetch(PDO::FETCH_ASSOC);
        } catch (PDOException $e) {
            die("Error fetching device: " . $e->getMessage());
        }
    }

    public function updateDevice($id, $deviceData) {
        $sql = "
            UPDATE devices
            SET device_id = :device_id,
                mac_address = :mac_address,
                ip_address = :ip_address,
                firmware_version = :firmware_version,
                temperature_offset = :temperature_offset,
                humidity_offset = :humidity_offset,
                last_updated = :last_updated,
                last_seen = :last_seen
            WHERE id = :id
        ";
        try {
            $stmt = $this->pdo->prepare($sql);
            $deviceData['id'] = $id;
            $stmt->execute($deviceData);
            return $stmt->rowCount();
        } catch (PDOException $e) {
            die("Error updating device: " . $e->getMessage());
        }
    }

    public function deleteDevice($id) {
        $sql = "DELETE FROM devices WHERE id = :id";
        try {
            $stmt = $this->pdo->prepare($sql);
            $stmt->execute(['id' => $id]);
            return $stmt->rowCount();
        } catch (PDOException $e) {
            die("Error deleting device: " . $e->getMessage());
        }
    }

    public function createOrUpdateReading($deviceID, $temperature, $humidity) {
        $sql = "SELECT COUNT(*) FROM readings WHERE dev_id = :dev_id";
        try {
            $stmt = $this->pdo->prepare($sql);
            $stmt->execute(['dev_id' => $deviceID]);
            $exists = $stmt->fetchColumn() > 0;

            if ($exists) {
                $sql = "
                    UPDATE readings
                    SET temperature = :temperature,
                        humidity = :humidity
                    WHERE dev_id = :dev_id
                ";
                $stmt = $this->pdo->prepare($sql);
                $stmt->execute([
                "dev_id" => $deviceID,
                "temperature" => $temperature,
                "humidity" => $humidity
                ]);
                return $stmt->rowCount();
            } else {
                $sql = "
                    INSERT INTO readings (dev_id, temperature, humidity)
                    VALUES (:dev_id, :temperature, :humidity)
                ";
                $stmt = $this->pdo->prepare($sql);
                $stmt->execute($readingData);
                return $this->pdo->lastInsertId();
            }
        } catch (PDOException $e) {
            die("Error creating or updating reading: " . $e->getMessage());
        }
    }
}

/*
$newDevice = [
    'device_id' => 'device123',
    'mac_address' => '00:1B:44:11:3A:B7',
    'ip_address' => '192.168.1.2',
    'firmware_version' => '1.0.1',
    'temperature_offset' => 0,
    'humidity_offset' => 0,
    'last_updated' => date('Y-m-d H:i:s'),
    'last_seen' => date('Y-m-d H:i:s')
];
$deviceDb->addDevice($newDevice);

$devices = $deviceDb->getDevices();
print_r($devices);
*/
?>