from __future__ import annotations

import subprocess

from backend import process_scanner


def test_parse_ps_output_normalizes_fields_and_detects_harness_hints():
    output = """
    PID    PPID TT       ELAPSED COMMAND         COMMAND
    101    100  pts/4    12      codex           /usr/bin/codex resume thread-1
    102    100  ?        21      python3         /opt/openclaude run
    103    100  pts/8    7       bash            bash
    """

    records = process_scanner.parse_ps_output(output)

    assert [record.pid for record in records] == [101, 102, 103]
    assert records[0].tty == "pts/4"
    assert records[0].elapsed_seconds == 12
    assert records[0].harness_hint == "codex"
    assert records[1].tty is None
    assert records[1].harness_hint == "openclaude"
    assert records[2].harness_hint is None


def test_scan_processes_filters_to_harnesses_and_finds_terminal_parent(monkeypatch):
    output = """
    PID    PPID TT       ELAPSED COMMAND                COMMAND
    200    1    pts/1    500     kitty                  kitty
    201    200  pts/1    320     bash                   bash
    202    201  pts/1    15      codex                  codex --cwd /work/codex
    300    1    pts/2    480     gnome-terminal-server  /usr/lib/gnome-terminal-server
    301    300  pts/2    22      python3                /usr/local/bin/opencode dashboard
    400    1    ?        40      sleep                  sleep 60
    """

    def fake_run(*args, **kwargs):
        return subprocess.CompletedProcess(args=args, returncode=0, stdout=output)

    def fake_readlink(path: str) -> str:
        mapping = {
            "/proc/202/cwd": "/work/codex",
            "/proc/301/cwd": "/work/opencode",
        }
        return mapping[path]

    monkeypatch.setattr(process_scanner.subprocess, "run", fake_run)
    monkeypatch.setattr(process_scanner.os, "readlink", fake_readlink)

    records = process_scanner.scan_processes()

    assert [record.pid for record in records] == [202, 301]
    assert records[0].cwd == "/work/codex"
    assert records[0].terminal_program == "kitty"
    assert records[0].harness_hint == "codex"
    assert records[1].cwd == "/work/opencode"
    assert records[1].terminal_program == "gnome-terminal-server"
    assert records[1].harness_hint == "opencode"


def test_scan_processes_tolerates_proc_cwd_read_failures(monkeypatch):
    output = """
    PID    PPID TT       ELAPSED COMMAND         COMMAND
    500    1    pts/3    80      alacritty       alacritty
    501    500  pts/3    60      bash            bash
    502    501  pts/3    9       hermes          hermes serve
    """

    def fake_run(*args, **kwargs):
        return subprocess.CompletedProcess(args=args, returncode=0, stdout=output)

    def fake_readlink(path: str) -> str:
        raise PermissionError(path)

    monkeypatch.setattr(process_scanner.subprocess, "run", fake_run)
    monkeypatch.setattr(process_scanner.os, "readlink", fake_readlink)

    records = process_scanner.scan_processes()

    assert len(records) == 1
    assert records[0].pid == 502
    assert records[0].cwd is None
    assert records[0].terminal_program == "alacritty"
    assert records[0].harness_hint == "hermes"