package xmppsig

import (
	"sync"

	"dev.narayana.im/narayana/telegabber/calls/signaling"
	"dev.narayana.im/narayana/telegabber/xmpp/jingle"

	"github.com/pion/webrtc/v4"
)

// per-call state shared by Caller and Callee
type xmppBase struct {
	a      *Adapter
	remote string
	// full JID we act as on the wire; falls back to a.cfg.LocalJID
	localJID string
	// CallerSide/CalleeSide for Bind's MediaConnected wiring
	side signaling.Side

	mu            sync.Mutex
	sid           string
	session       *jingle.Session
	bridge        *signaling.Bridge
	pc            *webrtc.PeerConnection
	remoteSDPSeen bool
	onRemoteSDP   func(sdp string)

	// pion fires OnTrack during SetRemoteDescription, before any handler
	// the orchestrator might want to install - so hookTrack runs a permanent
	// forwarder at PC construction and buffers into pendingTracks until
	// SetTrackHandler arrives
	onTrackFn     func(t *webrtc.TrackRemote)
	pendingTracks []*webrtc.TrackRemote
}

func (b *xmppBase) set(sid string, sess *jingle.Session) {
	b.mu.Lock()
	b.sid, b.session = sid, sess
	b.mu.Unlock()
}

// attaches the bridge and wires pion's connection-state callback
func (b *xmppBase) Bind(br *signaling.Bridge) {
	b.mu.Lock()
	b.bridge = br
	pc := b.pc
	side := b.side
	b.mu.Unlock()
	hookPCState(pc, br, side)
}

func (b *xmppBase) bridgeRef() *signaling.Bridge {
	b.mu.Lock()
	defer b.mu.Unlock()
	return b.bridge
}

func (b *xmppBase) sessionRef() *jingle.Session {
	b.mu.Lock()
	defer b.mu.Unlock()
	return b.session
}

func (b *xmppBase) cleanup() {
	b.mu.Lock()
	sid := b.sid
	b.mu.Unlock()
	if sid == "" {
		return
	}
	b.a.cfg.Manager.Unregister(sid)
}

func (b *xmppBase) PeerConnection() *webrtc.PeerConnection {
	b.mu.Lock()
	defer b.mu.Unlock()
	return b.pc
}

func (b *xmppBase) SetOnRemoteSDP(fn func(sdp string)) {
	b.mu.Lock()
	b.onRemoteSDP = fn
	b.mu.Unlock()
}

// must run before the first SetRemoteDescription, or pion's first
// OnTrack event is lost
func (b *xmppBase) hookTrack(pc *webrtc.PeerConnection) {
	pc.OnTrack(func(t *webrtc.TrackRemote, _ *webrtc.RTPReceiver) {
		b.mu.Lock()
		fn := b.onTrackFn
		if fn == nil {
			b.pendingTracks = append(b.pendingTracks, t)
			b.mu.Unlock()
			return
		}
		b.mu.Unlock()
		fn(t)
	})
}

// swaps in the real handler and drains buffered tracks
func (b *xmppBase) SetTrackHandler(fn func(t *webrtc.TrackRemote)) {
	b.mu.Lock()
	b.onTrackFn = fn
	pending := b.pendingTracks
	b.pendingTracks = nil
	b.mu.Unlock()
	for _, t := range pending {
		fn(t)
	}
}

// fires the orchestrator hook exactly once per call
func (b *xmppBase) onRemoteDescription(sdp string) {
	b.mu.Lock()
	if b.remoteSDPSeen {
		b.mu.Unlock()
		return
	}
	b.remoteSDPSeen = true
	hook := b.onRemoteSDP
	b.mu.Unlock()
	if hook != nil {
		hook(sdp)
	}
}