package weather

import (
	"context"
	"crypto/tls"
	"fmt"
	"net/url"
	"os"
	"time"

	"github.com/eclipse/paho.golang/autopaho"
	"github.com/eclipse/paho.golang/paho"
)

// MQTTConfig holds MQTT connection configuration
type MQTTConfig struct {
	Broker            string
	ClientID          string
	Username          string
	Password          string
	KeepAlive         time.Duration
	SessionExpiry     time.Duration
	Timeout           time.Duration
	OnPublishReceived []func(paho.PublishReceived) (bool, error)
}

// CreateMQTTClient creates a MQTT client with the given configuration
func CreateMQTTClient(ctx context.Context, cfg MQTTConfig,
	onConnect func(*autopaho.ConnectionManager, *paho.Connack)) (*autopaho.ConnectionManager, error) {

	serverURL, err := url.Parse(cfg.Broker)
	if err != nil {
		return nil, fmt.Errorf("invalid MQTT broker URL: %w", err)
	}

	cliCfg := autopaho.ClientConfig{
		ServerUrls: []*url.URL{serverURL},
		KeepAlive:  uint16(cfg.KeepAlive.Seconds()),
		ClientConfig: paho.ClientConfig{
			ClientID:          fmt.Sprintf("%s-%d", cfg.ClientID, os.Getpid()),
			OnPublishReceived: cfg.OnPublishReceived,
			OnServerDisconnect: func(d *paho.Disconnect) {

				// Default disconnect handler
			},
		},
		ConnectUsername: cfg.Username,
		ConnectPassword: []byte(cfg.Password),
		ConnectTimeout:  cfg.Timeout,
	}

	cliCfg.CleanStartOnInitialConnection = false
	cliCfg.SessionExpiryInterval = uint32(cfg.SessionExpiry.Seconds())

	if serverURL.Scheme == "ssl" || serverURL.Scheme == "tls" {
		cliCfg.TlsCfg = &tls.Config{
			MinVersion: tls.VersionTLS12,
		}
	}

	if onConnect != nil {
		cliCfg.OnConnectionUp = onConnect
	}

	cm, err := autopaho.NewConnection(ctx, cliCfg)
	if err != nil {
		return nil, fmt.Errorf("failed to create MQTT connection: %w", err)
	}

	err = cm.AwaitConnection(ctx)
	if err != nil {
		return nil, fmt.Errorf("failed to establish MQTT connection: %w", err)
	}

	return cm, nil
}