from pathlib import Path
import os

from agent_process_dashboard.procfs import parse_stat, scan_processes


def stat_line(
    pid: int,
    comm: str,
    *,
    ppid: int = 1,
    utime: int = 7,
    stime: int = 8,
    start: int = 900,
    rss: int = 15,
) -> str:
    return (
        f"{pid} ({comm}) S {ppid} {pid} {pid} 0 0 0 0 0 0 0 "
        f"{utime} {stime} 0 0 20 0 4 0 {start} 4096 {rss}"
    )


def write_proc(proc: Path, pid: int, comm: str, *, ppid: int = 1, start: int = 900) -> None:
    path = proc / str(pid)
    path.mkdir()
    (path / "stat").write_text(stat_line(pid, comm, ppid=ppid, start=start))
    (path / "status").write_text(f"Name:\t{comm}\nUid:\t{os.getuid()}\t{os.getuid()}\t{os.getuid()}\t{os.getuid()}\nThreads:\t4\n")
    (path / "cmdline").write_bytes(f"{comm}\0--api-key\0secret-value\0".encode())
    (path / "statm").write_text("20 10 0 0 0 0 0\n")
    (path / "cgroup").write_text("0::/user.slice\n")


def test_parse_stat_handles_spaces_and_parentheses():
    parsed = parse_stat(stat_line(123, "name with ) parens", ppid=9, start=12345))

    assert parsed.pid == 123
    assert parsed.comm == "name with ) parens"
    assert parsed.ppid == 9
    assert parsed.start_time_ticks == 12345
    assert parsed.utime_ticks == 7
    assert parsed.stime_ticks == 8


def test_scan_processes_builds_identity_and_masks_cmdline(tmp_path):
    proc = tmp_path
    (proc / "sys/kernel/random").mkdir(parents=True)
    (proc / "sys/kernel/random/boot_id").write_text("boot-1\n")
    (proc / "uptime").write_text("1000.00 0.00\n")
    write_proc(proc, 101, "codex", start=500)

    samples = scan_processes(proc, current_uid_only=True)

    assert len(samples) == 1
    sample = samples[0]
    assert sample.process_key == f"boot-1:101:500:{os.getuid()}"
    assert sample.argv == ("codex", "--api-key", "<redacted>")
    assert sample.argv_masked_count == 1


def test_pid_reuse_changes_process_key(tmp_path):
    proc = tmp_path
    (proc / "sys/kernel/random").mkdir(parents=True)
    (proc / "sys/kernel/random/boot_id").write_text("boot-1\n")
    (proc / "uptime").write_text("1000.00 0.00\n")
    write_proc(proc, 101, "codex", start=500)
    first = scan_processes(proc)[0]
    (proc / "101/stat").write_text(stat_line(101, "codex", start=700))

    second = scan_processes(proc)[0]

    assert first.process_key != second.process_key


def test_missing_stat_is_ignored(tmp_path):
    proc = tmp_path
    (proc / "sys/kernel/random").mkdir(parents=True)
    (proc / "sys/kernel/random/boot_id").write_text("boot-1\n")
    (proc / "uptime").write_text("1000.00 0.00\n")
    (proc / "999").mkdir()

    assert scan_processes(proc) == []