import re
import subprocess

BIN = "./lab3"
STAT_RE = re.compile(
    r"STAT:.*size=(\d+).*depth=(\d+).*min_size=(\d+).*processes=(\d+).*valid=(\d+).*time=([\d.]+)"
)


def run(args):
    p = subprocess.run([BIN, *args], text=True, capture_output=True)
    if p.returncode != 0:
        print("STDOUT:\n", p.stdout)
        print("STDERR:\n", p.stderr)
        raise AssertionError(f"command failed: {args}")
    m = STAT_RE.search(p.stderr)
    assert m and m.group(5) == "1", f"bad stat: {p.stderr}"
    return p, m


def ints(s):
    return [int(x) for x in s.split()] if s.strip() else []


def test_01_printed_small_random_array_sorted():
    p, _ = run(["--size", "97", "--depth", "3", "--min-size", "8", "--print"])
    a = ints(p.stdout)
    assert len(a) == 97
    assert a == sorted(a)


def test_02_seed_makes_random_input_reproducible():
    a = run(
        ["--size", "128", "--depth", "2", "--min-size", "8", "--seed", "42", "--print"]
    )[0].stdout
    b = run(
        ["--size", "128", "--depth", "2", "--min-size", "8", "--seed", "42", "--print"]
    )[0].stdout
    c = run(
        ["--size", "128", "--depth", "2", "--min-size", "8", "--seed", "43", "--print"]
    )[0].stdout
    assert a == b
    assert a != c


def test_03_zero_depth_sequential_fallback():
    _, m = run(["--size", "1000", "--depth", "0", "--min-size", "1"])
    assert m.group(4) == "1"


def test_04_depth_two_full_tree_process_count():
    _, m = run(["--size", "4096", "--depth", "2", "--min-size", "16"])
    assert m.group(4) == "7", m.group(0)


def test_05_depth_three_full_tree_process_count():
    _, m = run(["--size", "8192", "--depth", "3", "--min-size", "16"])
    assert m.group(4) == "15", m.group(0)


def test_06_min_size_stops_forking():
    _, m = run(["--size", "1000", "--depth", "5", "--min-size", "1000"])
    assert m.group(4) == "1", m.group(0)


def test_07_odd_size_sorted_correctly():
    p, _ = run(
        ["--size", "999", "--depth", "4", "--min-size", "17", "--seed", "77", "--print"]
    )
    a = ints(p.stdout)
    assert len(a) == 999
    assert a == sorted(a)


def test_08_single_element_array():
    p, m = run(["--size", "1", "--depth", "5", "--min-size", "1", "--print"])
    a = ints(p.stdout)
    assert len(a) == 1
    assert m.group(4) == "1"


def test_09_empty_array():
    p, m = run(["--size", "0", "--depth", "5", "--min-size", "1", "--print"])
    assert p.stdout.strip() == ""
    assert m.group(4) == "1"


def test_10_timeline_log_has_events_and_pid_fields():
    p, _ = run(["--size", "128", "--depth", "2", "--min-size", "8", "--log"])
    assert "START PID=" in p.stdout
    assert "END PID=" in p.stdout
    assert "PPID=" in p.stdout
    assert "depth=" in p.stdout


def test_11_help_has_no_mode_argument():
    p = subprocess.run([BIN, "--help"], text=True, capture_output=True)
    assert p.returncode == 0
    assert "--mode" not in p.stdout
    assert "--seed" in p.stdout


def test_12_unknown_mode_is_rejected():
    p = subprocess.run([BIN, "--mode", "random"], text=True, capture_output=True)
    assert p.returncode != 0
    assert "unknown argument" in p.stderr


if __name__ == "__main__":
    tests = [
        test_01_printed_small_random_array_sorted,
        test_02_seed_makes_random_input_reproducible,
        test_03_zero_depth_sequential_fallback,
        test_04_depth_two_full_tree_process_count,
        test_05_depth_three_full_tree_process_count,
        test_06_min_size_stops_forking,
        test_07_odd_size_sorted_correctly,
        test_08_single_element_array,
        test_09_empty_array,
        test_10_timeline_log_has_events_and_pid_fields,
        test_11_help_has_no_mode_argument,
        test_12_unknown_mode_is_rejected,
    ]

    for t in tests:
        t()
        print(f"OK {t.__name__}")