from __future__ import annotations

import importlib


def test_mcp_runtime_config_defaults_to_stdio(monkeypatch):
    monkeypatch.delenv("JARCA_MCP_TRANSPORT", raising=False)
    monkeypatch.delenv("JARCA_MCP_HOST", raising=False)
    monkeypatch.delenv("JARCA_MCP_PORT", raising=False)
    monkeypatch.delenv("JARCA_MCP_STREAMABLE_HTTP_PATH", raising=False)

    server = importlib.import_module("jarca_ledger_mcp.adapters.mcp.server")
    config = server.get_mcp_runtime_config()

    assert config.transport == "stdio"
    assert config.host == "127.0.0.1"
    assert config.port == 8000
    assert config.streamable_http_path == "/mcp"


def test_mcp_runtime_config_accepts_streamable_http_env(monkeypatch):
    monkeypatch.setenv("JARCA_MCP_TRANSPORT", "streamable-http")
    monkeypatch.setenv("JARCA_MCP_HOST", "0.0.0.0")
    monkeypatch.setenv("JARCA_MCP_PORT", "8765")
    monkeypatch.setenv("JARCA_MCP_STREAMABLE_HTTP_PATH", "/ledger-mcp")

    server = importlib.import_module("jarca_ledger_mcp.adapters.mcp.server")
    config = server.get_mcp_runtime_config()

    assert config.transport == "streamable-http"
    assert config.host == "0.0.0.0"
    assert config.port == 8765
    assert config.streamable_http_path == "/ledger-mcp"


def test_mcp_runtime_config_rejects_invalid_transport(monkeypatch):
    monkeypatch.setenv("JARCA_MCP_TRANSPORT", "websocket")

    server = importlib.import_module("jarca_ledger_mcp.adapters.mcp.server")

    try:
        server.get_mcp_runtime_config()
    except ValueError as exc:
        assert "JARCA_MCP_TRANSPORT" in str(exc)
    else:
        raise AssertionError("invalid MCP transport should be rejected")