import os
import subprocess
import sys
import tempfile

HERE = os.path.dirname(os.path.abspath(__file__))
SCRIPT = os.path.join(HERE, "shadow_lint.py")


def run(src):
    # Each case gets its own directory. The fixture used to be one fixed path,
    # /tmp/scratchpad/test_shadow.py, shared by every process on the host: two
    # concurrent runs of this gate (another lane, a second CHECK) overwrote
    # each other's source between the write and shadow_lint's read, so a case
    # graded a neighbour's fixture -- measured 10/10 concurrent rounds red,
    # with e.g. the import case reporting the loop-target case's finding.
    with tempfile.TemporaryDirectory(prefix="shadow_case_") as d:
        p = os.path.join(d, "case.py")
        with open(p, "w") as fh:
            fh.write(src)
        r = subprocess.run([sys.executable, SCRIPT, p], capture_output=True, text=True)
    return r.returncode, r.stdout + r.stderr

def test_param_shadow():
    rc, out = run("x = 1\ndef f(x):\n    return x\n")
    assert rc == 1
    assert "function-param" in out and "'x'" in out

def test_no_shadow():
    rc, out = run("x = 1\ndef f(y):\n    return x + y\n")
    assert rc == 0, out

def test_import_shadow():
    rc, out = run("import os\ndef f():\n    import os\n    return os\n")
    assert rc == 1 and "import" in out

def test_loop_target_shadow():
    rc, out = run("def outer():\n    i = 0\n    def inner():\n        for i in range(3):\n            pass\n")
    assert rc == 1 and "loop-target" in out

def test_comprehension_shadow():
    rc, out = run("x = 1\ny = [x for x in range(3)]\n")
    assert rc == 1 and "comprehension" in out

def test_with_as_shadow():
    rc, out = run("def outer():\n    f = 1\n    def inner():\n        with open('/dev/null') as f:\n            pass\n")
    assert rc == 1 and "with-as" in out

def test_fixture_isolation():
    """Regression: the fixture path must be per call, not one host-wide file.

    With the old fixed /tmp/scratchpad path, two gate runs in the same second
    graded each other's source -- measured 10/10 concurrent rounds red, e.g.
    the import case reporting `shadowed name 'i' (loop-target)`.
    """
    import inspect, threading
    assert "TemporaryDirectory" in inspect.getsource(run), "run() needs a per-call temp dir"
    got = {}
    cases = {
        "import": "import os\ndef f():\n    import os\n    return os\n",
        "with-as": "def outer():\n    f = 1\n    def inner():\n        with open('/dev/null') as f:\n            pass\n",
    }
    def one(key, src):
        got[key] = run(src)
    threads = [threading.Thread(target=one, args=(k, s)) for k, s in cases.items()]
    for t in threads:
        t.start()
    for t in threads:
        t.join()
    assert got["import"][0] == 1 and "import" in got["import"][1]
    assert got["with-as"][0] == 1 and "with-as" in got["with-as"][1]

if __name__ == "__main__":
    for name in [n for n in globals() if n.startswith("test_")]:
        globals()[name]()
        print("PASS", name)
    print("ALL PASS")