package main

import (
	"context"
	"log/slog"

	"git.asio.asia/nixevol/NixMsg/internal/app/message"
	"git.asio.asia/nixevol/NixMsg/internal/app/port"
)

// appUplink 把 broker 生命周期接到消息连接表与投递推送。
// 其余业务上行帧暂转交 next（可为空 Stub）；完整 HandleUplink 分发留后续波次。
type appUplink struct {
	msg   *message.App
	conns *message.MemoryConns
	next  port.UplinkHandler
	log   *slog.Logger
}

func (u *appUplink) OnSessionEstablished(ctx context.Context, conn port.ConnInfo) error {
	u.conns.Set(conn.EndpointID, message.LiveConn{
		ConnID:        conn.ConnID,
		MaxPacketSize: conn.MaxPacketSize,
	})
	if u.next != nil {
		return u.next.OnSessionEstablished(ctx, conn)
	}
	return nil
}

func (u *appUplink) OnHandshakeComplete(ctx context.Context, hs port.HandshakeInfo) error {
	live := message.LiveConn{
		ConnID:          hs.ConnID,
		MaxReceiveBytes: hs.MaxReceiveBytes,
		MaxPacketSize:   hs.MaxPacketSize,
	}
	u.conns.Set(hs.EndpointID, live)
	if err := u.msg.OnHandshakeComplete(ctx, hs.EndpointID, live); err != nil {
		u.log.Error("message handshake", "endpoint", hs.EndpointID, "err", err)
		return err
	}
	if u.next != nil {
		return u.next.OnHandshakeComplete(ctx, hs)
	}
	return nil
}

func (u *appUplink) OnDisconnect(ctx context.Context, conn port.ConnInfo, reason port.DisconnectReason) {
	live, ok := u.conns.Current(conn.EndpointID)
	isCurrent := ok && live.ConnID == conn.ConnID
	if err := u.msg.OnDisconnect(ctx, conn.EndpointID, conn.ConnID, isCurrent); err != nil {
		u.log.Error("message disconnect", "endpoint", conn.EndpointID, "err", err)
	}
	u.conns.Clear(conn.EndpointID, conn.ConnID)
	if u.next != nil {
		u.next.OnDisconnect(ctx, conn, reason)
	}
}

func (u *appUplink) HandleUplink(ctx context.Context, conn port.ConnInfo, payload []byte) error {
	if u.next != nil {
		return u.next.HandleUplink(ctx, conn, payload)
	}
	return nil
}

// presenceConnTable 把消息连接表暴露给 presence.ConnTable。
type presenceConnTable struct {
	conns *message.MemoryConns
}

func (p *presenceConnTable) IsOnline(endpointID string) bool {
	_, ok := p.conns.Current(endpointID)
	return ok
}

func (p *presenceConnTable) CurrentConn(endpointID string) (port.ConnID, bool) {
	live, ok := p.conns.Current(endpointID)
	if !ok {
		return "", false
	}
	return live.ConnID, true
}