package plc

import (
	"context"
	"log/slog"
	"time"

	goplc "bjhardman.cn/bjhardman/goplc"
	"bjhardman.cn/bjhardman/goplc/s7"

	"bj_power_mes/internal/eventbus"
)

type Manager struct {
	client goplc.Client
	bus    eventbus.Bus
}

func Build(conf PlcConf, bus eventbus.Bus) *Manager {
	m := &Manager{bus: bus}
	client := s7.NewClient(conf.Host,
		s7.WithMaxRetries(-1),
		s7.WithConnectionType(s7.ConnectionType(conf.ConnectType)),
		s7.WithOnConnected(func() {
			slog.Info("PLC connected", "host", conf.Host)
			m.publishConnectionEvent(true)
		}),
		s7.WithOnDisconnected(func(err error) {
			if err != nil {
				slog.Error("PLC disconnected with error", "host", conf.Host, "error", err)
			} else {
				slog.Warn("PLC disconnected", "host", conf.Host)
			}
			m.publishConnectionEvent(false)
		}),
		s7.WithOnReconnecting(func(attempt int) {
			slog.Info("PLC reconnecting", "host", conf.Host, "attempt", attempt)
		}),
	)
	m.client = client
	go func() {
		_ = client.Connect()
	}()

	return m
}

func (m *Manager) publishConnectionEvent(connected bool) {
	if m.bus == nil {
		return
	}
	_ = m.bus.Publish(context.Background(), eventbus.Event{
		ID:        "conn-" + time.Now().Format("20060102150405.000"),
		Type:      eventbus.EventConnectionStatusUpdated,
		Source:    "plc-manager",
		Timestamp: time.Now(),
		Payload: map[string]any{
			"plcConnected": connected,
		},
	})
}

// NewManager creates a Manager with a pre-built PLC client.
func NewManager(client goplc.Client) *Manager {
	return &Manager{client: client}
}

func (m *Manager) GetPlc() (rc goplc.Client) {
	return m.client
}

func (m *Manager) IsConnected() bool {
	return m.client != nil && m.client.IsConnected()
}