import os
import subprocess
import sys
import time

from beaver_gateway.backends.processes import Processes, _command, subtree

SLEEP = "import time; time.sleep(60)"
NEST = (
    "import subprocess, sys, time; "
    f"subprocess.Popen([sys.executable, '-c', {SLEEP!r}]); time.sleep(60)"
)


def spawn(code: str) -> subprocess.Popen[bytes]:
    return subprocess.Popen([sys.executable, "-c", code])


def rows_under(processes: Processes, pid: int, count: int) -> list[dict]:
    deadline = time.monotonic() + 5
    while time.monotonic() < deadline:
        rows = subtree(processes.tree_parents_first(), pid)
        if len(rows) >= count:
            return rows
        time.sleep(0.05)
    msg = f"{pid} never grew to {count} processes"
    raise AssertionError(msg)


def test_the_tree_shows_what_the_gateway_started_and_what_it_costs() -> None:
    child = spawn(SLEEP)
    try:
        processes = Processes()
        (row,) = rows_under(processes, child.pid, 1)
        assert row["parent"] == os.getpid()
        assert row["depth"] == 0
        assert row["rss"] > 0
        assert row["cpu"] is None
        assert "time.sleep" in row["command"]
        (again,) = rows_under(processes, child.pid, 1)
        assert again["cpu"] is not None
    finally:
        child.kill()
        child.wait()


def test_kill_takes_the_branch_and_nothing_the_gateway_did_not_start() -> None:
    parent = spawn(NEST)
    try:
        processes = Processes()
        top, nested = rows_under(processes, parent.pid, 2)
        assert (top["depth"], nested["depth"]) == (0, 1)
        assert not processes.kill_own_descendant(os.getpid())
        assert not processes.kill_own_descendant(os.getppid())
        assert processes.kill_own_descendant(parent.pid)
        parent.wait(timeout=5)
        alive = {row["pid"] for row in processes.tree_parents_first()}
        assert not alive & {top["pid"], nested["pid"]}
    finally:
        parent.kill()
        parent.wait()


def test_a_subtree_ends_at_the_next_sibling() -> None:
    rows = [
        {"pid": 1, "depth": 0},
        {"pid": 2, "depth": 1},
        {"pid": 3, "depth": 2},
        {"pid": 4, "depth": 1},
        {"pid": 5, "depth": 0},
    ]
    assert [(r["pid"], r["depth"]) for r in subtree(rows, 2)] == [(2, 0), (3, 1)]
    assert [r["pid"] for r in subtree(rows, 1)] == [1, 2, 3, 4]
    assert subtree(rows, 9) == []
    assert subtree(rows, None) == []


def test_a_command_line_keeps_prompts_and_configs_to_itself() -> None:
    argv = [
        "/opt/claude/claude",
        "--model",
        "m",
        "--system-prompt",
        "you are a beaver",
        "--mcp-config",
        '{"gateway": {"headers": {"Authorization": "Bearer abc"}}}',
        "x" * 100,
    ]
    assert _command(argv) == (
        "claude --model m --system-prompt … --mcp-config … " + "x" * 80 + "…"
    )
    assert _command([]) == ""