import json
import os
import subprocess
import sys

_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))


def _py_env():
    env = os.environ.copy()
    env["PYTHONPATH"] = _ROOT
    return env


def _run_import_without_zep(module_name, symbol):
    script = f"""
import builtins
original_import = builtins.__import__

def guarded_import(name, *args, **kwargs):
    if name == 'zep_cloud' or name.startswith('zep_cloud.'):
        raise RuntimeError('zep_imported_during_local_service_import')
    return original_import(name, *args, **kwargs)

builtins.__import__ = guarded_import
from app.services.{module_name} import {symbol} as imported_symbol
print(imported_symbol.__name__)
"""
    return subprocess.run(
        [sys.executable, "-c", script],
        capture_output=True,
        text=True,
        env=_py_env(),
        check=False,
    )


def _run_import_explicit_zep(module_name, symbol):
    """Fresh import that REQUIRES zep_cloud, to prove explicit Zep paths still resolve."""
    script = f"""
import builtins
original_import = builtins.__import__
_zep_seen = []

def tracking_import(name, *args, **kwargs):
    if name == 'zep_cloud' or name.startswith('zep_cloud.'):
        _zep_seen.append(name)
    return original_import(name, *args, **kwargs)

builtins.__import__ = tracking_import
from app.services.{module_name} import {symbol} as imported_symbol
print(imported_symbol.__name__)
print('ZEP_LOADED' if _zep_seen else 'NO_ZEP')
"""
    return subprocess.run(
        [sys.executable, "-c", script],
        capture_output=True,
        text=True,
        env=_py_env(),
        check=False,
    )


def test_local_service_import_does_not_eagerly_import_zep_client():
    result = _run_import_without_zep("local_graph_memory_updater", "LocalGraphMemoryUpdater")
    assert result.returncode == 0, result.stderr
    assert result.stdout.strip() == "LocalGraphMemoryUpdater"


def test_local_simulation_manager_import_does_not_eagerly_import_zep_client():
    result = _run_import_without_zep("simulation_manager", "SimulationManager")
    assert result.returncode == 0, result.stderr
    assert result.stdout.strip() == "SimulationManager"


def test_local_simulation_runner_import_does_not_eagerly_import_zep_client():
    result = _run_import_without_zep("simulation_runner", "SimulationRunner")
    assert result.returncode == 0, result.stderr
    assert result.stdout.strip() == "SimulationRunner"


def test_local_report_agent_import_does_not_eagerly_import_zep_client():
    result = _run_import_without_zep("report_agent", "ReportAgent")
    assert result.returncode == 0, result.stderr
    assert result.stdout.strip() == "ReportAgent"


def test_local_graph_builder_import_does_not_eagerly_import_zep_client():
    result = _run_import_without_zep("graph_builder", "GraphBuilderService")
    assert result.returncode == 0, result.stderr
    assert result.stdout.strip() == "GraphBuilderService"


def test_explicit_zep_tools_service_import_still_resolves():
    # The lazy refactor must not break explicit Zep-only consumers.
    result = _run_import_explicit_zep("zep_tools", "ZepToolsService")
    assert result.returncode == 0, result.stderr
    lines = result.stdout.strip().splitlines()
    assert lines[0] == "ZepToolsService"
    assert "ZEP_LOADED" in lines


def test_explicit_zep_entity_reader_import_still_resolves():
    result = _run_import_explicit_zep("zep_entity_reader", "ZepEntityReader")
    assert result.returncode == 0, result.stderr
    lines = result.stdout.strip().splitlines()
    assert lines[0] == "ZepEntityReader"
    assert "ZEP_LOADED" in lines


_IDENTITY_PROBE = """
import json
from app.services.memory_activity import AgentActivity as Shared
from app.services.zep_graph_memory_updater import ZepGraphMemoryUpdater

zep_alias = getattr(ZepGraphMemoryUpdater, "AgentActivity", None)
if zep_alias is None:
    import app.services.zep_graph_memory_updater as zup
    zep_alias = getattr(zup, "AgentActivity", None)

print(json.dumps(
    {
        "zep_alias_resolved": zep_alias is not None,
        "shared_identity": zep_alias is Shared,
        "module": Shared.__module__,
    },
    ensure_ascii=False,
))
"""


def test_local_and_zep_activity_contract_share_identity():
    result = subprocess.run(
        [sys.executable, "-c", _IDENTITY_PROBE],
        capture_output=True,
        text=True,
        env=_py_env(),
        check=False,
    )
    assert result.returncode == 0, result.stderr
    payload = json.loads(result.stdout.strip())
    # When the Zep updater aliases the shared class, identity must be exact.
    if payload["zep_alias_resolved"]:
        assert payload["shared_identity"] is True
        assert payload["module"] == "app.services.memory_activity"


_GRAPH_BUILDER_SEAM_PROBE = """
from app.services import graph_builder
assert getattr(graph_builder, "Zep", None) is None
from app.services import GraphBuilderService as Cls
# The seam is a module-level sentinel that callers monkeypatch; it must remain
# reassignable without constructing a real Zep client at import time.
graph_builder.Zep = "sentinel"
print(getattr(graph_builder, "Zep", None))
"""


def test_graph_builder_zep_seam_is_preserved_and_reassignable():
    result = subprocess.run(
        [sys.executable, "-c", _GRAPH_BUILDER_SEAM_PROBE],
        capture_output=True,
        text=True,
        env=_py_env(),
        check=False,
    )
    assert result.returncode == 0, result.stderr
    assert result.stdout.strip() == "sentinel"