picoclaw/pkg/channels/manager.go

// PicoClaw - Ultra-lightweight personal AI agent
// Inspired by and based on nanobot: https://github.com/HKUDS/nanobot
// License: MIT
//
// Copyright (c) 2026 PicoClaw contributors

package channels

import (
	"context"
	"errors"
	"fmt"
	"math"
	"net/http"
	"sync"
	"time"

	"golang.org/x/time/rate"

	"github.com/sipeed/picoclaw/pkg/bus"
	"github.com/sipeed/picoclaw/pkg/config"
	"github.com/sipeed/picoclaw/pkg/constants"
	"github.com/sipeed/picoclaw/pkg/health"
	"github.com/sipeed/picoclaw/pkg/logger"
	"github.com/sipeed/picoclaw/pkg/media"
	"github.com/sipeed/picoclaw/pkg/utils"
)

const (
	defaultChannelQueueSize = 100
	defaultRateLimit        = 10 // default 10 msg/s
	maxRetries              = 3
	rateLimitDelay          = 1 * time.Second
	baseBackoff             = 500 * time.Millisecond
	maxBackoff              = 8 * time.Second
)

// channelRateConfig maps channel name to per-second rate limit.
var channelRateConfig = map[string]float64{
	"telegram": 20,
	"discord":  1,
	"slack":    1,
	"line":     10,
}

type channelWorker struct {
	ch      Channel
	queue   chan bus.OutboundMessage
	done    chan struct{}
	limiter *rate.Limiter
}

type Manager struct {
	channels     map[string]Channel
	workers      map[string]*channelWorker
	bus          *bus.MessageBus
	config       *config.Config
	mediaStore   media.MediaStore
	dispatchTask *asyncTask
	mux          *http.ServeMux
	httpServer   *http.Server
	mu           sync.RWMutex
}

type asyncTask struct {
	cancel context.CancelFunc
}

func NewManager(cfg *config.Config, messageBus *bus.MessageBus, store media.MediaStore) (*Manager, error) {
	m := &Manager{
		channels:   make(map[string]Channel),
		workers:    make(map[string]*channelWorker),
		bus:        messageBus,
		config:     cfg,
		mediaStore: store,
	}

	if err := m.initChannels(); err != nil {
		return nil, err
	}

	return m, nil
}

// initChannel is a helper that looks up a factory by name and creates the channel.
func (m *Manager) initChannel(name, displayName string) {
	f, ok := getFactory(name)
	if !ok {
		logger.WarnCF("channels", "Factory not registered", map[string]any{
			"channel": displayName,
		})
		return
	}
	logger.DebugCF("channels", "Attempting to initialize channel", map[string]any{
		"channel": displayName,
	})
	ch, err := f(m.config, m.bus)
	if err != nil {
		logger.ErrorCF("channels", "Failed to initialize channel", map[string]any{
			"channel": displayName,
			"error":   err.Error(),
		})
	} else {
		// Inject MediaStore if channel supports it
		if m.mediaStore != nil {
			if setter, ok := ch.(interface{ SetMediaStore(s media.MediaStore) }); ok {
				setter.SetMediaStore(m.mediaStore)
			}
		}
		m.channels[name] = ch
		m.workers[name] = newChannelWorker(name, ch)
		logger.InfoCF("channels", "Channel enabled successfully", map[string]any{
			"channel": displayName,
		})
	}
}

func (m *Manager) initChannels() error {
	logger.InfoC("channels", "Initializing channel manager")

	if m.config.Channels.Telegram.Enabled && m.config.Channels.Telegram.Token != "" {
		m.initChannel("telegram", "Telegram")
	}

	if m.config.Channels.WhatsApp.Enabled && m.config.Channels.WhatsApp.BridgeURL != "" {
		m.initChannel("whatsapp", "WhatsApp")
	}

	if m.config.Channels.Feishu.Enabled {
		m.initChannel("feishu", "Feishu")
	}

	if m.config.Channels.Discord.Enabled && m.config.Channels.Discord.Token != "" {
		m.initChannel("discord", "Discord")
	}

	if m.config.Channels.MaixCam.Enabled {
		m.initChannel("maixcam", "MaixCam")
	}

	if m.config.Channels.QQ.Enabled {
		m.initChannel("qq", "QQ")
	}

	if m.config.Channels.DingTalk.Enabled && m.config.Channels.DingTalk.ClientID != "" {
		m.initChannel("dingtalk", "DingTalk")
	}

	if m.config.Channels.Slack.Enabled && m.config.Channels.Slack.BotToken != "" {
		m.initChannel("slack", "Slack")
	}

	if m.config.Channels.LINE.Enabled && m.config.Channels.LINE.ChannelAccessToken != "" {
		m.initChannel("line", "LINE")
	}

	if m.config.Channels.OneBot.Enabled && m.config.Channels.OneBot.WSUrl != "" {
		m.initChannel("onebot", "OneBot")
	}

	if m.config.Channels.WeCom.Enabled && m.config.Channels.WeCom.Token != "" {
		m.initChannel("wecom", "WeCom")
	}

	if m.config.Channels.WeComApp.Enabled && m.config.Channels.WeComApp.CorpID != "" {
		m.initChannel("wecom_app", "WeCom App")
	}

	logger.InfoCF("channels", "Channel initialization completed", map[string]any{
		"enabled_channels": len(m.channels),
	})

	return nil
}

// SetupHTTPServer creates a shared HTTP server with the given listen address.
// It registers health endpoints from the health server and discovers channels
// that implement WebhookHandler and/or HealthChecker to register their handlers.
func (m *Manager) SetupHTTPServer(addr string, healthServer *health.Server) {
	m.mux = http.NewServeMux()

	// Register health endpoints
	if healthServer != nil {
		healthServer.RegisterOnMux(m.mux)
	}

	// Discover and register webhook handlers and health checkers
	for name, ch := range m.channels {
		if wh, ok := ch.(WebhookHandler); ok {
			m.mux.Handle(wh.WebhookPath(), wh)
			logger.InfoCF("channels", "Webhook handler registered", map[string]any{
				"channel": name,
				"path":    wh.WebhookPath(),
			})
		}
		if hc, ok := ch.(HealthChecker); ok {
			m.mux.HandleFunc(hc.HealthPath(), hc.HealthHandler)
			logger.InfoCF("channels", "Health endpoint registered", map[string]any{
				"channel": name,
				"path":    hc.HealthPath(),
			})
		}
	}

	m.httpServer = &http.Server{
		Addr:         addr,
		Handler:      m.mux,
		ReadTimeout:  30 * time.Second,
		WriteTimeout: 30 * time.Second,
	}
}

func (m *Manager) StartAll(ctx context.Context) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	if len(m.channels) == 0 {
		logger.WarnC("channels", "No channels enabled")
		return nil
	}

	logger.InfoC("channels", "Starting all channels")

	dispatchCtx, cancel := context.WithCancel(ctx)
	m.dispatchTask = &asyncTask{cancel: cancel}

	for name, channel := range m.channels {
		logger.InfoCF("channels", "Starting channel", map[string]any{
			"channel": name,
		})
		if err := channel.Start(ctx); err != nil {
			logger.ErrorCF("channels", "Failed to start channel", map[string]any{
				"channel": name,
				"error":   err.Error(),
			})
		}
	}

	// Start per-channel workers
	for name, w := range m.workers {
		go m.runWorker(dispatchCtx, name, w)
	}

	// Start the dispatcher that reads from the bus and routes to workers
	go m.dispatchOutbound(dispatchCtx)

	// Start shared HTTP server if configured
	if m.httpServer != nil {
		go func() {
			logger.InfoCF("channels", "Shared HTTP server listening", map[string]any{
				"addr": m.httpServer.Addr,
			})
			if err := m.httpServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
				logger.ErrorCF("channels", "Shared HTTP server error", map[string]any{
					"error": err.Error(),
				})
			}
		}()
	}

	logger.InfoC("channels", "All channels started")
	return nil
}

func (m *Manager) StopAll(ctx context.Context) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	logger.InfoC("channels", "Stopping all channels")

	// Shutdown shared HTTP server first
	if m.httpServer != nil {
		shutdownCtx, cancel := context.WithTimeout(ctx, 5*time.Second)
		defer cancel()
		if err := m.httpServer.Shutdown(shutdownCtx); err != nil {
			logger.ErrorCF("channels", "Shared HTTP server shutdown error", map[string]any{
				"error": err.Error(),
			})
		}
		m.httpServer = nil
	}

	// Cancel dispatcher
	if m.dispatchTask != nil {
		m.dispatchTask.cancel()
		m.dispatchTask = nil
	}

	// Close all worker queues and wait for them to drain
	for _, w := range m.workers {
		close(w.queue)
	}
	for _, w := range m.workers {
		<-w.done
	}

	// Stop all channels
	for name, channel := range m.channels {
		logger.InfoCF("channels", "Stopping channel", map[string]any{
			"channel": name,
		})
		if err := channel.Stop(ctx); err != nil {
			logger.ErrorCF("channels", "Error stopping channel", map[string]any{
				"channel": name,
				"error":   err.Error(),
			})
		}
	}

	logger.InfoC("channels", "All channels stopped")
	return nil
}

// newChannelWorker creates a channelWorker with a rate limiter configured
// for the given channel name.
func newChannelWorker(name string, ch Channel) *channelWorker {
	rateVal := float64(defaultRateLimit)
	if r, ok := channelRateConfig[name]; ok {
		rateVal = r
	}
	burst := int(math.Max(1, math.Ceil(rateVal/2)))

	return &channelWorker{
		ch:      ch,
		queue:   make(chan bus.OutboundMessage, defaultChannelQueueSize),
		done:    make(chan struct{}),
		limiter: rate.NewLimiter(rate.Limit(rateVal), burst),
	}
}

// runWorker processes outbound messages for a single channel, splitting
// messages that exceed the channel's maximum message length.
func (m *Manager) runWorker(ctx context.Context, name string, w *channelWorker) {
	defer close(w.done)
	for {
		select {
		case msg, ok := <-w.queue:
			if !ok {
				return
			}
			maxLen := 0
			if mlp, ok := w.ch.(MessageLengthProvider); ok {
				maxLen = mlp.MaxMessageLength()
			}
			if maxLen > 0 && len([]rune(msg.Content)) > maxLen {
				chunks := utils.SplitMessage(msg.Content, maxLen)
				for _, chunk := range chunks {
					chunkMsg := msg
					chunkMsg.Content = chunk
					m.sendWithRetry(ctx, name, w, chunkMsg)
				}
			} else {
				m.sendWithRetry(ctx, name, w, msg)
			}
		case <-ctx.Done():
			return
		}
	}
}

// sendWithRetry sends a message through the channel with rate limiting and
// retry logic. It classifies errors to determine the retry strategy:
//   - ErrNotRunning / ErrSendFailed: permanent, no retry
//   - ErrRateLimit: fixed delay retry
//   - ErrTemporary / unknown: exponential backoff retry
func (m *Manager) sendWithRetry(ctx context.Context, name string, w *channelWorker, msg bus.OutboundMessage) {
	// Rate limit: wait for token
	if err := w.limiter.Wait(ctx); err != nil {
		// ctx cancelled, shutting down
		return
	}

	var lastErr error
	for attempt := 0; attempt <= maxRetries; attempt++ {
		lastErr = w.ch.Send(ctx, msg)
		if lastErr == nil {
			return
		}

		// Permanent failures — don't retry
		if errors.Is(lastErr, ErrNotRunning) || errors.Is(lastErr, ErrSendFailed) {
			break
		}

		// Last attempt exhausted — don't sleep
		if attempt == maxRetries {
			break
		}

		// Rate limit error — fixed delay
		if errors.Is(lastErr, ErrRateLimit) {
			select {
			case <-time.After(rateLimitDelay):
				continue
			case <-ctx.Done():
				return
			}
		}

		// ErrTemporary or unknown error — exponential backoff
		backoff := min(time.Duration(float64(baseBackoff)*math.Pow(2, float64(attempt))), maxBackoff)
		select {
		case <-time.After(backoff):
		case <-ctx.Done():
			return
		}
	}

	// All retries exhausted or permanent failure
	logger.ErrorCF("channels", "Send failed", map[string]any{
		"channel": name,
		"chat_id": msg.ChatID,
		"error":   lastErr.Error(),
		"retries": maxRetries,
	})
}

func (m *Manager) dispatchOutbound(ctx context.Context) {
	logger.InfoC("channels", "Outbound dispatcher started")

	for {
		select {
		case <-ctx.Done():
			logger.InfoC("channels", "Outbound dispatcher stopped")
			return
		default:
			msg, ok := m.bus.SubscribeOutbound(ctx)
			if !ok {
				continue
			}

			// Silently skip internal channels
			if constants.IsInternalChannel(msg.Channel) {
				continue
			}

			m.mu.RLock()
			_, exists := m.channels[msg.Channel]
			w, wExists := m.workers[msg.Channel]
			m.mu.RUnlock()

			if !exists {
				logger.WarnCF("channels", "Unknown channel for outbound message", map[string]any{
					"channel": msg.Channel,
				})
				continue
			}

			if wExists {
				select {
				case w.queue <- msg:
				case <-ctx.Done():
					return
				}
			}
		}
	}
}

func (m *Manager) GetChannel(name string) (Channel, bool) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	channel, ok := m.channels[name]
	return channel, ok
}

func (m *Manager) GetStatus() map[string]any {
	m.mu.RLock()
	defer m.mu.RUnlock()

	status := make(map[string]any)
	for name, channel := range m.channels {
		status[name] = map[string]any{
			"enabled": true,
			"running": channel.IsRunning(),
		}
	}
	return status
}

func (m *Manager) GetEnabledChannels() []string {
	m.mu.RLock()
	defer m.mu.RUnlock()

	names := make([]string, 0, len(m.channels))
	for name := range m.channels {
		names = append(names, name)
	}
	return names
}

func (m *Manager) RegisterChannel(name string, channel Channel) {
	m.mu.Lock()
	defer m.mu.Unlock()
	m.channels[name] = channel
	m.workers[name] = newChannelWorker(name, channel)
}

func (m *Manager) UnregisterChannel(name string) {
	m.mu.Lock()
	defer m.mu.Unlock()
	if w, ok := m.workers[name]; ok {
		close(w.queue)
		<-w.done
	}
	delete(m.workers, name)
	delete(m.channels, name)
}

func (m *Manager) SendToChannel(ctx context.Context, channelName, chatID, content string) error {
	m.mu.RLock()
	_, exists := m.channels[channelName]
	w, wExists := m.workers[channelName]
	m.mu.RUnlock()

	if !exists {
		return fmt.Errorf("channel %s not found", channelName)
	}

	msg := bus.OutboundMessage{
		Channel: channelName,
		ChatID:  chatID,
		Content: content,
	}

	if wExists {
		select {
		case w.queue <- msg:
			return nil
		case <-ctx.Done():
			return ctx.Err()
		}
	}

	// Fallback: direct send (should not happen)
	channel, _ := m.channels[channelName]
	return channel.Send(ctx, msg)
}