"""Tests for US-017: P2P gossip, relay node, and TLS infrastructure."""

from __future__ import annotations

import json
import threading
import time
from pathlib import Path
from unittest.mock import MagicMock, patch


# ---------------------------------------------------------------------------
# identity tests
# ---------------------------------------------------------------------------

def test_load_or_create_identity_generates_peer_id(tmp_path):
    from meshnet_p2p.identity import load_or_create_identity

    identity = load_or_create_identity(tmp_path / "identity.json")
    assert len(identity["peer_id"]) == 16
    assert "public_key_pem" in identity
    assert "private_key_pem" in identity


def test_identity_is_stable_across_loads(tmp_path):
    from meshnet_p2p.identity import load_or_create_identity

    path = tmp_path / "identity.json"
    first = load_or_create_identity(path)
    second = load_or_create_identity(path)
    assert first["peer_id"] == second["peer_id"]
    assert first["public_key_pem"] == second["public_key_pem"]


def test_identity_different_for_different_paths(tmp_path):
    from meshnet_p2p.identity import load_or_create_identity

    a = load_or_create_identity(tmp_path / "a.json")
    b = load_or_create_identity(tmp_path / "b.json")
    # Extremely unlikely to collide
    assert a["peer_id"] != b["peer_id"]


# ---------------------------------------------------------------------------
# TLS / certificate tests
# ---------------------------------------------------------------------------

def test_generate_self_signed_cert_creates_files(tmp_path):
    from meshnet_p2p.tls import generate_self_signed_cert

    cert_p, key_p = generate_self_signed_cert(
        cert_path=tmp_path / "cert.pem",
        key_path=tmp_path / "key.pem",
        common_name="localhost",
    )
    assert cert_p.exists()
    assert key_p.exists()
    assert cert_p.stat().st_size > 100
    assert key_p.stat().st_size > 100


def test_generate_self_signed_cert_is_idempotent(tmp_path):
    from meshnet_p2p.tls import generate_self_signed_cert

    args = dict(cert_path=tmp_path / "cert.pem", key_path=tmp_path / "key.pem", common_name="test")
    generate_self_signed_cert(**args)
    mtime1 = (tmp_path / "cert.pem").stat().st_mtime

    generate_self_signed_cert(**args)
    mtime2 = (tmp_path / "cert.pem").stat().st_mtime
    assert mtime1 == mtime2  # file not regenerated


def test_cert_fingerprint_returns_sha256_prefix(tmp_path):
    from meshnet_p2p.tls import generate_self_signed_cert, cert_fingerprint

    cert_p, key_p = generate_self_signed_cert(
        cert_path=tmp_path / "cert.pem",
        key_path=tmp_path / "key.pem",
        common_name="test",
    )
    fp = cert_fingerprint(cert_p)
    assert fp.startswith("sha256:")
    assert len(fp) == len("sha256:") + 64  # 32 bytes hex = 64 chars


def test_make_server_ssl_context_loads_cert(tmp_path):
    import ssl
    from meshnet_p2p.tls import generate_self_signed_cert, make_server_ssl_context

    cert_p, key_p = generate_self_signed_cert(
        cert_path=tmp_path / "cert.pem",
        key_path=tmp_path / "key.pem",
        common_name="test",
    )
    ctx = make_server_ssl_context(cert_p, key_p)
    assert isinstance(ctx, ssl.SSLContext)


# ---------------------------------------------------------------------------
# PeerRegistry tests
# ---------------------------------------------------------------------------

def test_peer_registry_register_and_list():
    from meshnet_relay.peer_registry import PeerRegistry

    reg = PeerRegistry()
    ws_mock = MagicMock()
    reg.register("peer1", "http://1.2.3.4:8001", ws_mock)

    assert len(reg) == 1
    peers = reg.list_peers()
    assert len(peers) == 1
    assert peers[0]["peer_id"] == "peer1"


def test_peer_registry_all_except_excludes_sender():
    from meshnet_relay.peer_registry import PeerRegistry

    reg = PeerRegistry()
    reg.register("a", "http://a:8001", MagicMock())
    reg.register("b", "http://b:8001", MagicMock())
    reg.register("c", "http://c:8001", MagicMock())

    others = reg.all_except("a")
    assert len(others) == 2
    assert all(e.peer_id != "a" for e in others)


def test_peer_registry_unregister_removes_peer():
    from meshnet_relay.peer_registry import PeerRegistry

    reg = PeerRegistry()
    reg.register("x", "http://x:8001", MagicMock())
    reg.unregister("x")
    assert len(reg) == 0
    assert reg.get("x") is None


# ---------------------------------------------------------------------------
# GossipClient + RelayServer integration test
# ---------------------------------------------------------------------------

def _start_relay(host="127.0.0.1", port=0):
    from meshnet_relay.server import RelayServer
    server = RelayServer(host=host, port=port)
    actual_port = server.start()
    return server, actual_port


def test_gossip_fanout_through_relay():
    """Node B publishes node-join; node A receives it within 2 seconds."""
    from meshnet_p2p.gossip import GossipClient, TOPIC_NODE_JOIN

    relay, port = _start_relay()
    relay_url = f"ws://127.0.0.1:{port}/ws"

    client_a = GossipClient(relay_url=relay_url, peer_id="peer_a")
    client_b = GossipClient(relay_url=relay_url, peer_id="peer_b")

    received = []
    client_a.subscribe(TOPIC_NODE_JOIN, lambda env: received.append(env))

    client_a.start()
    client_b.start()

    assert client_a.wait_connected(timeout=5), "client_a failed to connect to relay"
    assert client_b.wait_connected(timeout=5), "client_b failed to connect to relay"

    # Give both peers time to register with relay
    time.sleep(0.2)

    client_b.publish(TOPIC_NODE_JOIN, {"addr": "http://192.168.1.10:8001", "peer_id": "peer_b"})

    deadline = time.monotonic() + 2.0
    while time.monotonic() < deadline and not received:
        time.sleep(0.05)

    client_a.stop()
    client_b.stop()
    relay.stop()

    assert received, "client_a did not receive node-join message from client_b"
    assert received[0]["topic"] == TOPIC_NODE_JOIN
    assert received[0]["from_peer"] == "peer_b"


def test_gossip_dedup_prevents_processing_duplicate_message_ids():
    """A message with a duplicate msg_id is only processed once."""
    from meshnet_p2p.gossip import GossipClient, TOPIC_NODE_JOIN

    relay, port = _start_relay()
    relay_url = f"ws://127.0.0.1:{port}/ws"

    client_a = GossipClient(relay_url=relay_url, peer_id="peer_a2")
    client_b = GossipClient(relay_url=relay_url, peer_id="peer_b2")

    received = []
    client_a.subscribe(TOPIC_NODE_JOIN, lambda env: received.append(env))

    client_a.start()
    client_b.start()
    client_a.wait_connected(5)
    client_b.wait_connected(5)
    time.sleep(0.2)

    # Publish once
    client_b.publish(TOPIC_NODE_JOIN, {"test": "dedup"})
    time.sleep(0.5)

    count = len(received)

    client_a.stop()
    client_b.stop()
    relay.stop()

    # Should have received exactly one message (not duplicated)
    assert count <= 1


def test_relay_server_peer_list_grows_on_connect():
    """Relay registry grows when clients connect."""
    from meshnet_p2p.gossip import GossipClient

    relay, port = _start_relay()
    relay_url = f"ws://127.0.0.1:{port}/ws"

    client = GossipClient(relay_url=relay_url, peer_id="solo_peer")
    client.start()
    client.wait_connected(5)
    time.sleep(0.3)  # let peer-register message process

    peer_count = len(relay.registry)
    client.stop()
    relay.stop()

    assert peer_count >= 1


def test_relay_circuit_relay_proxies_message():
    """A node behind NAT (client_a) receives a message via circuit relay from client_b."""
    import websockets.sync.client  # type: ignore[import]
    from meshnet_relay.server import RelayServer

    relay = RelayServer(host="127.0.0.1", port=0)
    port = relay.start()

    # client_a connects to gossip hub and registers
    received_via_relay = []
    ready = threading.Event()

    def run_nat_client():
        import websockets.sync.client as wsc
        with wsc.connect(f"ws://127.0.0.1:{port}/ws") as ws:
            ws.send(json.dumps({
                "topic": "peer-register",
                "version": 1,
                "from_peer": "nat_peer",
                "msg_id": "reg-001",
                "timestamp": "2026-06-29T00:00:00Z",
                "ttl": 3,
                "payload": {"peer_id": "nat_peer", "addr": ""},
            }))
            # consume peer-list response
            ws.recv()
            ready.set()
            # wait for a relayed message
            try:
                msg = ws.recv(timeout=3)
                received_via_relay.append(json.loads(msg))
            except Exception:
                pass

    nat_thread = threading.Thread(target=run_nat_client, daemon=True)
    nat_thread.start()
    ready.wait(timeout=5)
    time.sleep(0.1)  # ensure peer is in registry

    # client_b connects via circuit relay path
    def send_via_relay():
        try:
            import websockets.sync.client as wsc
            with wsc.connect(f"ws://127.0.0.1:{port}/relay/nat_peer") as ws:
                ws.send(json.dumps({"topic": "direct-relay-test", "payload": {"hi": "there"}}))
                time.sleep(0.3)
        except Exception:
            pass

    relay_thread = threading.Thread(target=send_via_relay, daemon=True)
    relay_thread.start()
    relay_thread.join(timeout=3)
    nat_thread.join(timeout=3)
    relay.stop()

    assert received_via_relay, "NAT'd peer did not receive message via circuit relay"


def test_relay_rpc_round_trips_http_request_to_peer():
    """Relay /rpc/<peer> sends one HTTP-shaped request to a connected peer."""
    import websockets.sync.client as wsc  # type: ignore[import]
    from meshnet_relay.server import RelayServer

    relay = RelayServer(host="127.0.0.1", port=0)
    port = relay.start()
    ready = threading.Event()

    def run_peer():
        with wsc.connect(f"ws://127.0.0.1:{port}/ws") as ws:
            ws.send(json.dumps({
                "topic": "peer-register",
                "version": 1,
                "from_peer": "rpc_peer",
                "msg_id": "rpc-reg-001",
                "payload": {"peer_id": "rpc_peer", "addr": ""},
            }))
            ws.recv()
            ready.set()
            envelope = json.loads(ws.recv(timeout=3))
            payload = envelope["payload"]
            ws.send(json.dumps({
                "topic": "relay-http-response",
                "version": 1,
                "from_peer": "rpc_peer",
                "payload": {
                    "request_id": payload["request_id"],
                    "status": 200,
                    "headers": {"Content-Type": "application/json"},
                    "body": json.dumps({"ok": True, "path": payload["path"]}),
                },
            }))

    peer_thread = threading.Thread(target=run_peer, daemon=True)
    peer_thread.start()
    assert ready.wait(timeout=5)

    with wsc.connect(f"ws://127.0.0.1:{port}/rpc/rpc_peer") as ws:
        ws.send(json.dumps({
            "request_id": "req-1",
            "method": "POST",
            "path": "/v1/chat/completions",
            "headers": {"Content-Type": "application/json"},
            "body": "{}",
        }))
        response = json.loads(ws.recv(timeout=5))

    relay.stop()
    peer_thread.join(timeout=3)

    assert response["status"] == 200
    assert json.loads(response["body"]) == {"ok": True, "path": "/v1/chat/completions"}


def test_node_relay_bridge_reconnects_after_failed_connection(monkeypatch):
    """Node-side relay bridge keeps retrying its outbound WebSocket connection."""
    import websockets.sync.client as wsc  # type: ignore[import]
    from meshnet_node.relay_bridge import RelayHttpBridge

    attempts = []

    class FakeWebSocket:
        def __enter__(self):
            return self

        def __exit__(self, exc_type, exc, tb):
            return False

        def send(self, _message):
            pass

        def recv(self, timeout=1):
            raise TimeoutError

    def fake_connect(url, open_timeout=5):
        attempts.append((url, open_timeout))
        if len(attempts) == 1:
            raise OSError("temporary relay outage")
        return FakeWebSocket()

    monkeypatch.setattr(wsc, "connect", fake_connect)

    bridge = RelayHttpBridge(
        relay_url="ws://relay.example/ws",
        peer_id="peer-reconnect",
        local_base_url="http://127.0.0.1:8001",
        advertised_addr="http://127.0.0.1:8001",
        reconnect_interval=0.01,
    )
    try:
        info = bridge.start()
        assert info.relay_addr == "ws://relay.example/rpc/peer-reconnect"
        assert bridge.wait_connected(timeout=1.0)
    finally:
        bridge.stop()

    assert len(attempts) >= 2


# ---------------------------------------------------------------------------
# Tracker gossip fields tests
# ---------------------------------------------------------------------------

def _start_tracker_and_register(extra_fields: dict) -> dict:
    """Helper: start tracker, register node with extra gossip fields, return response."""
    import http.server
    import json as _json
    import urllib.request

    from meshnet_tracker.server import TrackerServer

    tracker = TrackerServer(host="127.0.0.1", port=0)
    port = tracker.start()
    url = f"http://127.0.0.1:{port}"

    payload = {
        "endpoint": f"http://127.0.0.1:8001",
        "shard_start": 0,
        "shard_end": 7,
        "model": "stub-model",
        "hardware_profile": {},
        "score": 1.0,
        **extra_fields,
    }
    data = _json.dumps(payload).encode()
    req = urllib.request.Request(
        f"{url}/v1/nodes/register",
        data=data,
        headers={"Content-Type": "application/json"},
        method="POST",
    )
    with urllib.request.urlopen(req, timeout=5) as r:
        resp = _json.loads(r.read())

    tracker.stop()
    return resp


def test_tracker_derives_relay_url_from_public_self_url():
    from meshnet_tracker.server import TrackerServer, derive_relay_url_from_public_tracker_url

    assert derive_relay_url_from_public_tracker_url("https://ai.neuron.d-popov.com") == (
        "wss://ai.neuron.d-popov.com/ws"
    )
    assert derive_relay_url_from_public_tracker_url("http://127.0.0.1:8081") is None

    tracker = TrackerServer(cluster_self_url="https://ai.neuron.d-popov.com")
    port = tracker.start()
    try:
        import json as _json
        import urllib.request

        with urllib.request.urlopen(f"http://127.0.0.1:{port}/v1/network/map", timeout=5) as resp:
            body = _json.loads(resp.read())
        assert body["relay_url"] == "wss://ai.neuron.d-popov.com/ws"
    finally:
        tracker.stop()


def test_tracker_accepts_relay_addr_in_registration():
    resp = _start_tracker_and_register({
        "relay_addr": "ws://relay.meshnet.ai:8765/relay/abc123",
        "cert_fingerprint": "sha256:deadbeef",
        "peer_id": "abc123def456ef01",
    })
    assert "node_id" in resp


def test_tracker_accepts_registration_without_gossip_fields():
    """Existing registrations without P2P fields still work."""
    resp = _start_tracker_and_register({})
    assert "node_id" in resp


def test_tracker_network_map_exposes_relay_and_registered_peer():
    import json as _json
    import urllib.request

    from meshnet_tracker.server import TrackerServer

    tracker = TrackerServer(host="127.0.0.1", port=0, relay_url="wss://ai.neuron.d-popov.com/ws")
    port = tracker.start()
    url = f"http://127.0.0.1:{port}"
    try:
        req = urllib.request.Request(
            f"{url}/v1/nodes/register",
            data=_json.dumps({
                "endpoint": "http://192.0.2.10:7000",
                "model": "stub-model",
                "shard_start": 0,
                "shard_end": 31,
                "relay_addr": "wss://ai.neuron.d-popov.com/rpc/peer123",
                "peer_id": "peer123",
            }).encode(),
            headers={"Content-Type": "application/json"},
            method="POST",
        )
        with urllib.request.urlopen(req, timeout=5):
            pass
        with urllib.request.urlopen(f"{url}/v1/network/map", timeout=5) as resp:
            body = _json.loads(resp.read())
    finally:
        tracker.stop()

    assert body["relay_url"] == "wss://ai.neuron.d-popov.com/ws"
    assert body["nodes"][0]["relay_addr"] == "wss://ai.neuron.d-popov.com/rpc/peer123"
    assert body["nodes"][0]["peer_id"] == "peer123"


# ---------------------------------------------------------------------------
# mDNS (no-op without zeroconf installed)
# ---------------------------------------------------------------------------

def test_mdns_discovery_is_available_flag():
    from meshnet_p2p.mdns import MdnsDiscovery

    disc = MdnsDiscovery(peer_id="test", port=8001)
    # is_available() should be bool regardless of zeroconf install status
    assert isinstance(disc.is_available(), bool)


def test_mdns_start_and_stop_without_zeroconf(monkeypatch):
    from meshnet_p2p import mdns as mdns_mod
    monkeypatch.setattr(mdns_mod, "_HAS_ZEROCONF", False)
    from meshnet_p2p.mdns import MdnsDiscovery

    disc = MdnsDiscovery(peer_id="x", port=8001)
    disc.start()  # should not raise
    disc.stop()   # should not raise