class_name Net
extends Node
## LAN-Mehrspieler: der Host führt das Spiel, Mitspieler senden Aktionen und erhalten
## Zustandsbilder aus ihrer Sicht (fremde Hände bleiben verborgen).

signal lobby_changed
signal started(seat: int)
signal snapshot_received(snap: Dictionary)
signal action_applied
signal ended(reason: String)
signal migrated             # nach einem Host-Ausfall: dieser Rechner führt das Spiel jetzt
signal status_changed

const PORT := 24455

var peer: ENetMultiplayerPeer
var is_host := false
var connected := false
var my_name := "Spieler"
var my_pick := {"looks": {}}  # eigene Kartenoptik (Seltenheit), die der Gegner sieht
var names := {}           # peer_id -> Name (nur im Host vollständig, sonst Kopie)
var picks := {}           # peer_id -> {"looks": {...}} (Host)
var seats := {}           # peer_id -> Spielerindex (Host)
var my_seat := -1
var game: Game            # Host
var status := ""
var waiting := {}         # Name -> {"seat": int, "since": float}: Platz nach Verbindungsabbruch freihalten
var rejoin_seconds := 60.0
var spectator := false    # eigene Rolle: nur zuschauen
var spectators := {}      # Host: peer_id -> Name
var successor_ip := ""    # Mitspieler: Adresse des Nachfolge-Hosts
var i_am_successor := false
var backup := {}          # Nachfolger: voller Spielstand nach jeder Aktion
var backup_names := {}    # Nachfolger: Platz -> Name aller Menschen
var last_winner := ""     # Mitspieler: Sieger laut letztem Zustandsbild
var reconnecting := false


func _ready() -> void:
    multiplayer.peer_connected.connect(_on_peer_connected)
    multiplayer.peer_disconnected.connect(_on_peer_disconnected)
    multiplayer.connected_to_server.connect(_on_connected)
    multiplayer.connection_failed.connect(func():
        if not reconnecting:
            _fail("Verbindung fehlgeschlagen"))
    multiplayer.server_disconnected.connect(_on_server_lost)


func host(port: int = PORT) -> Error:
    peer = ENetMultiplayerPeer.new()
    var err := peer.create_server(port, 8)  # ein Mitspieler, der Rest Zuschauer
    if err != OK:
        status = "Kann nicht hosten (Port %d belegt?)" % port
        return err
    multiplayer.multiplayer_peer = peer
    is_host = true
    connected = true
    names = {1: my_name}
    picks = {1: my_pick}
    spectators = {}
    status = "Warte auf Mitspieler …"
    lobby_changed.emit()
    return OK


func join(ip: String, port: int = PORT) -> Error:
    peer = ENetMultiplayerPeer.new()
    var err := peer.create_client(ip, port)
    if err != OK:
        status = "Adresse ungültig"
        return err
    multiplayer.multiplayer_peer = peer
    is_host = false
    status = "Verbinde mit %s …" % ip
    return OK


func leave() -> void:
    if multiplayer.multiplayer_peer != null:
        multiplayer.multiplayer_peer.close()
    multiplayer.multiplayer_peer = OfflineMultiplayerPeer.new()
    peer = null
    is_host = false
    connected = false
    names = {}
    picks = {}
    seats = {}
    waiting = {}
    my_seat = -1
    game = null
    status = ""
    spectator = false
    spectators = {}
    successor_ip = ""
    i_am_successor = false
    backup = {}
    backup_names = {}
    last_winner = ""


func local_addresses() -> Array:
    return Array(IP.get_local_addresses()).filter(func(a): return "." in a and not a.begins_with("127."))


func _fail(reason: String) -> void:
    status = reason
    ended.emit(reason)
    leave()


func _on_connected() -> void:
    connected = true
    status = "Verbunden"
    register.rpc_id(1, my_name, my_pick, spectator)


# --- Host-Wechsel ---------------------------------------------------------------
# Der Host schickt dem Mitspieler mit der kleinsten Kennung nach jeder Aktion den vollen
# Spielstand und allen die Adresse dieses Nachfolgers. Fällt der Host aus, eröffnet der
# Nachfolger das Spiel neu, die anderen verbinden sich mit ihm und kehren auf ihre Plätze zurück.

func _successor_id() -> int:
    var ids: Array = seats.keys().filter(func(id): return id != 1)
    ids.sort()
    return ids[0] if not ids.is_empty() else -1


func _update_successor() -> void:
    if not is_host or game == null:
        return
    var succ := _successor_id()
    var ip := ""
    if succ > 0 and peer != null and peer.get_peer(succ) != null:
        ip = peer.get_peer(succ).get_remote_address()
    for id in seats:
        if id != 1:
            set_successor.rpc_id(id, ip, id == succ)


## Platz -> Name aller Menschen (auch der gerade fehlenden), für die Rückkehr nach dem Wechsel.
func _seat_names() -> Dictionary:
    var out := {}
    for id in seats:
        out[seats[id]] = names.get(id, "")
    for pname in waiting:
        out[waiting[pname].seat] = pname
    return out


@rpc("authority", "reliable")
func set_successor(ip: String, me: bool) -> void:
    successor_ip = ip
    i_am_successor = me


@rpc("authority", "reliable")
func receive_backup(snap: Dictionary, seat_names: Dictionary) -> void:
    backup = snap
    backup_names = seat_names


func _on_server_lost() -> void:
    if is_host:
        return
    if last_winner != "":
        _fail("Host hat das Spiel beendet")
    elif i_am_successor and not backup.is_empty():
        _become_host()
    elif successor_ip != "":
        status = "Host weg, verbinde mit dem Nachfolger …"
        status_changed.emit()
        _reconnect(successor_ip)
    else:
        _fail("Host hat das Spiel beendet")


func _become_host() -> void:
    var snap := backup
    var seat_names := backup_names
    var seat := my_seat
    if multiplayer.multiplayer_peer != null:
        multiplayer.multiplayer_peer.close()
    var err := FAILED
    for attempt in 5:
        err = host()
        if err == OK:
            break
        await get_tree().create_timer(1.0).timeout
    if err != OK:
        _fail("Host weg, Übernahme fehlgeschlagen")
        return
    game = Game.from_snapshot(snap)
    seats = {1: seat}
    my_seat = seat
    waiting = {}
    for s in seat_names:
        if int(s) != seat:
            waiting[seat_names[s]] = {"seat": int(s), "since": Time.get_unix_time_from_system()}
    game.say("%s übernimmt als Host." % my_name)
    status = "Du bist jetzt Host, die anderen verbinden neu …"
    successor_ip = ""
    i_am_successor = false
    backup = {}
    migrated.emit()


func _reconnect(ip: String) -> void:
    reconnecting = true
    await get_tree().create_timer(2.0).timeout
    for attempt in 5:
        if join(ip) == OK:
            var t := 0.0
            while not connected and t < 4.0 and multiplayer.multiplayer_peer.get_connection_status() == MultiplayerPeer.CONNECTION_CONNECTING:
                await get_tree().process_frame
                t += get_process_delta_time()
            if connected:
                reconnecting = false
                return
        await get_tree().create_timer(1.0).timeout
    reconnecting = false
    _fail("Nachfolge-Host nicht erreichbar")


func _on_peer_connected(_id: int) -> void:
    pass


func _on_peer_disconnected(id: int) -> void:
    if not is_host:
        return
    var pname: String = names.get(id, "")
    names.erase(id)
    picks.erase(id)
    spectators.erase(id)
    if game != null and seats.has(id):
        var p: Game.Player = game.players[seats[id]]
        if game.winner == "":
            waiting[pname] = {"seat": seats[id], "since": Time.get_unix_time_from_system()}
            game.say("%s hat die Verbindung verloren, der Platz bleibt %d s frei." % [p.name, int(rejoin_seconds)])
        seats.erase(id)
        _update_successor()
        action_applied.emit()
    lobby_update.rpc(names, spectators)
    lobby_changed.emit()


## Host, je Bild: wartende Spieler überspringen; nach Ablauf der Frist scheiden sie aus.
func tick() -> void:
    if not is_host or game == null or game.winner != "":
        return
    var now := Time.get_unix_time_from_system()
    for pname in waiting.keys():
        var w: Dictionary = waiting[pname]
        var p: Game.Player = game.players[w.seat]
        if now - float(w.since) > rejoin_seconds:
            waiting.erase(pname)
            game.say("%s kehrt nicht zurück und scheidet aus." % p.name)
            game.damage(p, 999)
            game.cleanup()
            game.check_end()
            if game.winner == "" and game.current() == p:
                game.end_turn()  # sonst bliebe das Spiel beim Ausgeschiedenen hängen
            action_applied.emit()
        elif game.current() == p:
            game.say("%s ist nicht da, der Zug wird übersprungen." % p.name)
            game.end_turn()
            action_applied.emit()


@rpc("any_peer", "reliable")
func register(name: String, pick: Dictionary, as_spectator: bool = false) -> void:
    if not is_host:
        return
    var id := multiplayer.get_remote_sender_id()
    if as_spectator:
        spectators[id] = name
        lobby_update.rpc(names, spectators)
        lobby_changed.emit()
        if game != null:
            start_game.rpc_id(id, -1)
            receive_snapshot.rpc_id(id, game.snapshot(-2))
        return
    if game != null:
        # Laufendes Spiel: nur Rückkehr auf einen freigehaltenen Platz
        if waiting.has(name):
            seats[id] = waiting[name].seat
            names[id] = name
            waiting.erase(name)
            game.say("%s ist zurück." % name)
            start_game.rpc_id(id, seats[id])
            receive_snapshot.rpc_id(id, game.snapshot(seats[id]))
            _update_successor()
            action_applied.emit()
        else:
            status = "%s wollte beitreten, das Spiel läuft schon" % name
        return
    names[id] = name
    picks[id] = pick
    lobby_update.rpc(names, spectators)
    lobby_changed.emit()


@rpc("authority", "reliable")
func lobby_update(n: Dictionary, sp: Dictionary = {}) -> void:
    names = n
    spectators = sp
    lobby_changed.emit()


## Host: Duell mit dem ersten Mitspieler starten; allein gegen die KI.
func start_battle() -> void:
    var ids: Array = names.keys()
    ids.sort()
    ids = ids.slice(0, 2)
    var r := Game.make_rng()
    var players := []
    seats = {}
    for id in ids:
        var pick: Dictionary = picks.get(id, {})
        var p := Game.Player.new(names[id], true, Game.START_LIFE)
        for cid in pick.get("looks", {}):
            if Cards.has_id(cid):
                p.looks[cid] = int(pick.looks[cid])
        players.append(p)
    if players.size() < 2:
        players.append(DeckGen.random_opponent())
    game = Game.new(players[0], players[1], r)
    game.start()
    for id in ids:
        seats[id] = game.players.find(players[ids.find(id)])
    my_seat = seats[1]
    for id in ids:
        if id != 1:
            start_game.rpc_id(id, seats[id])
    for id in spectators:
        start_game.rpc_id(id, -1)
    _update_successor()
    started.emit(my_seat)


@rpc("authority", "reliable")
func start_game(seat: int) -> void:
    my_seat = seat
    started.emit(seat)


## Host: Zustand an alle senden (Mitspieler aus ihrer Sicht, Zuschauer ohne Verborgenes,
## der Nachfolger zusätzlich den vollen Spielstand).
func broadcast() -> void:
    if not is_host or game == null:
        return
    for id in seats:
        if id != 1:
            receive_snapshot.rpc_id(id, game.snapshot(seats[id]))
    for id in spectators:
        receive_snapshot.rpc_id(id, game.snapshot(-2))
    var succ := _successor_id()
    if succ > 0:
        receive_backup.rpc_id(succ, game.snapshot(-1), _seat_names())


@rpc("authority", "reliable")
func receive_snapshot(snap: Dictionary) -> void:
    last_winner = str(snap.get("winner", ""))
    snapshot_received.emit(snap)


## Mitspieler: Aktion an den Host schicken.
func send_action(action: Dictionary) -> void:
    if is_host:
        _apply(1, action)
    else:
        request_action.rpc_id(1, action)


@rpc("any_peer", "reliable")
func request_action(action: Dictionary) -> void:
    if not is_host:
        return
    _apply(multiplayer.get_remote_sender_id(), action)


func _apply(id: int, action: Dictionary) -> void:
    if game == null or not seats.has(id):
        return
    var p: Game.Player = game.players[seats[id]]
    if game.winner != "":
        return
    if game.current() != p:
        return
    match str(action.get("type", "")):
        "play":
            var idx := int(action.get("hand", -1))
            if idx < 0 or idx >= p.hand.size():
                return
            game.play_card(p, p.hand[idx], bool(action.get("face_down", false)))
        "reveal":
            var cr := game.find_creature(int(action.get("uid", -1)))
            if cr != null:
                game.reveal(p, cr)
        "attack":
            var cr := game.find_creature(int(action.get("uid", -1)))
            var t = resolve_ref(action.get("target"))
            if cr != null and t != null:
                game.attack(cr, t)
        "draw":
            game.draw(p)
        "fuse":  # zwei Wesen (uid, other) oder zwei Handkarten (hand, other_hand)
            var a = game.find_creature(int(action.get("uid", -1)))
            var b = game.find_creature(int(action.get("other", -1)))
            var i := int(action.get("hand", -1))
            var j := int(action.get("other_hand", -1))
            if a == null and i >= 0 and j >= 0 and i < p.hand.size() and j < p.hand.size():
                a = p.hand[i]
                b = p.hand[j]
            if a != null and b != null:
                game.fuse(p, a, b)
        "end":
            game.end_turn()
        _:
            return
    action_applied.emit()


func resolve_ref(ref):
    if ref == null or not (ref is Dictionary):
        return null
    if ref.get("kind") == "creature":
        return game.find_creature(int(ref.get("uid", -1)))
    var i := int(ref.get("index", -1))
    if i >= 0 and i < game.players.size():
        return game.players[i]
    return null


static func ref_dict(target) -> Dictionary:
    if target is Game.Creature:
        return {"kind": "creature", "uid": target.uid}
    return {"kind": "player", "index": target.order}