"""Unit tests for the IPC layer."""

from __future__ import annotations

import asyncio
import os
import sys
import tempfile
from pathlib import Path

import pytest

from pyra.daemon.ipc import (
    IpcClient,
    IpcMessage,
    IpcResponse,
    IpcServer,
    decode_message,
    encode_message,
    is_unix_socket,
)


@pytest.fixture
def sock_path():
    """Short socket path that fits within macOS's 104-char AF_UNIX limit."""
    with tempfile.TemporaryDirectory(dir="/tmp") as d:
        yield Path(d) / "t.sock"


# ── Protocol encode / decode ──────────────────────────────────────────────────

def test_encode_appends_newline() -> None:
    data = encode_message({"cmd": "ping"})
    assert data.endswith(b"\n")


def test_encode_is_valid_json() -> None:
    import json
    data = encode_message({"cmd": "status", "extra": 42})
    assert json.loads(data) == {"cmd": "status", "extra": 42}


def test_decode_roundtrip() -> None:
    msg: IpcMessage = {"cmd": "stop"}
    assert decode_message(encode_message(msg)) == msg


def test_decode_strips_newline() -> None:
    assert decode_message(b'{"cmd": "stop"}\n')["cmd"] == "stop"


def test_decode_raises_on_bad_json() -> None:
    with pytest.raises(ValueError, match="Invalid IPC message"):
        decode_message(b"not json\n")


def test_decode_raises_on_empty_line() -> None:
    with pytest.raises(ValueError):
        decode_message(b"\n")


# ── is_unix_socket ────────────────────────────────────────────────────────────

def test_is_unix_socket_matches_platform() -> None:
    if sys.platform == "win32":
        assert not is_unix_socket()
    else:
        assert is_unix_socket()


# ── Server + client roundtrip (Unix only) ─────────────────────────────────────

@pytest.mark.skipif(sys.platform == "win32", reason="Unix socket test")
async def test_server_client_ping(sock_path: Path) -> None:
    async def handler(msg: IpcMessage) -> IpcResponse:
        return {"ok": True, "data": {"pong": True}}

    server = IpcServer(sock_path, handler)
    await server.start()
    try:
        resp = await IpcClient(sock_path).send({"cmd": "ping"})
        assert resp["ok"] is True
        assert resp["data"]["pong"] is True
    finally:
        await server.stop()


@pytest.mark.skipif(sys.platform == "win32", reason="Unix socket test")
async def test_server_echoes_error_for_bad_json(sock_path: Path) -> None:
    async def handler(msg: IpcMessage) -> IpcResponse:
        return {"ok": True, "data": {}}

    server = IpcServer(sock_path, handler)
    await server.start()
    try:
        reader, writer = await asyncio.open_unix_connection(str(sock_path))
        writer.write(b"not valid json\n")
        await writer.drain()
        line = await asyncio.wait_for(reader.readline(), timeout=3.0)
        resp = decode_message(line)
        assert resp["ok"] is False
        assert "error" in resp["data"]
    finally:
        try:
            writer.close()
        except Exception:
            pass
        await server.stop()


@pytest.mark.skipif(sys.platform == "win32", reason="Unix socket test")
async def test_handler_response_returned_to_client(sock_path: Path) -> None:
    async def handler(msg: IpcMessage) -> IpcResponse:
        if msg.get("cmd") == "status":
            return {"ok": True, "data": {"uptime": 99.0}}
        return {"ok": False, "data": {"error": "unknown"}}

    server = IpcServer(sock_path, handler)
    await server.start()
    try:
        resp = await IpcClient(sock_path).send({"cmd": "status"})
        assert resp["ok"] is True
        assert resp["data"]["uptime"] == 99.0

        resp2 = await IpcClient(sock_path).send({"cmd": "bogus"})
        assert resp2["ok"] is False
    finally:
        await server.stop()


@pytest.mark.skipif(sys.platform == "win32", reason="Unix socket test")
async def test_client_raises_when_no_server(sock_path: Path) -> None:
    client = IpcClient(sock_path)
    with pytest.raises((ConnectionRefusedError, FileNotFoundError, OSError)):
        await client.send({"cmd": "ping"})


@pytest.mark.skipif(sys.platform == "win32", reason="Unix socket test")
async def test_socket_file_chmod_600(sock_path: Path) -> None:
    async def handler(msg: IpcMessage) -> IpcResponse:
        return {"ok": True, "data": {}}

    server = IpcServer(sock_path, handler)
    await server.start()
    try:
        mode = oct(sock_path.stat().st_mode & 0o777)
        assert mode == oct(0o600), f"Expected 0o600, got {mode}"
    finally:
        await server.stop()


@pytest.mark.skipif(sys.platform == "win32", reason="Unix socket test")
async def test_stop_removes_socket_file(sock_path: Path) -> None:
    async def handler(msg: IpcMessage) -> IpcResponse:
        return {"ok": True, "data": {}}

    server = IpcServer(sock_path, handler)
    await server.start()
    assert sock_path.exists()
    await server.stop()
    assert not sock_path.exists()