"""Tests for cross-agent-halt and cross-agent-resume (TDD)."""

from __future__ import annotations

import os
import subprocess
import textwrap
from pathlib import Path

import pytest

HALT_SCRIPT = Path(__file__).resolve().parent.parent / "cross-agent-comms" / "cross-agent-halt"
RESUME_SCRIPT = Path(__file__).resolve().parent.parent / "cross-agent-comms" / "cross-agent-resume"


def _run(script: Path, args: list[str], env: dict | None = None) -> subprocess.CompletedProcess:
    return subprocess.run([str(script), *args], capture_output=True, text=True, env=env)


@pytest.fixture
def isolated_env(tmp_path, monkeypatch):
    """Isolated HOME + a fake systemctl that records calls without acting."""
    fake_home = tmp_path / "home"
    fake_home.mkdir()
    fake_bin = tmp_path / "bin"
    fake_bin.mkdir()
    # Fake systemctl: no-op, exit 0.
    fake_systemctl = fake_bin / "systemctl"
    fake_systemctl.write_text("#!/usr/bin/env bash\nexit 0\n")
    fake_systemctl.chmod(0o755)
    # Fake ssh: succeed only for known-good host.
    fake_ssh = fake_bin / "ssh"
    fake_ssh.write_text(textwrap.dedent("""\
        #!/usr/bin/env bash
        # Find the destination arg (skip flags).
        target=""
        for arg in "$@"; do
          case "$arg" in
            -*|*=*) ;;
            *@*|localhost|*.local|*.invalid) target="$arg"; break ;;
            *) target="$arg"; break ;;
          esac
        done
        case "$target" in
          *invalid*|*unreachable*) exit 255 ;;
          *) exit 0 ;;
        esac
    """))
    fake_ssh.chmod(0o755)

    monkeypatch.setenv("HOME", str(fake_home))
    # Prepend our fake bin so systemctl + ssh are intercepted, but keep real /bin etc.
    monkeypatch.setenv("PATH", f"{fake_bin}:{os.environ.get('PATH', '')}")
    return fake_home


# ---- cross-agent-halt ----


def test_halt_help(isolated_env):
    result = _run(HALT_SCRIPT, ["--help"], env={**os.environ, "HOME": str(isolated_env),
                                                 "PATH": os.environ["PATH"]})
    assert result.returncode == 0
    assert "halt" in result.stdout.lower()


def test_halt_creates_halt_file(isolated_env):
    halt_file = isolated_env / ".config" / "cross-agent-comms" / "HALT"
    assert not halt_file.exists()
    result = _run(HALT_SCRIPT, [], env={**os.environ, "HOME": str(isolated_env),
                                         "PATH": os.environ["PATH"]})
    assert result.returncode == 0
    assert halt_file.exists()


def test_halt_with_reason_writes_body(isolated_env):
    result = _run(HALT_SCRIPT, ["pausing for incident review"],
                  env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert result.returncode == 0
    halt_file = isolated_env / ".config" / "cross-agent-comms" / "HALT"
    assert halt_file.exists()
    assert "pausing for incident review" in halt_file.read_text()


def test_halt_idempotent(isolated_env):
    """Running halt twice doesn't error."""
    halt_file = isolated_env / ".config" / "cross-agent-comms" / "HALT"
    r1 = _run(HALT_SCRIPT, [], env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert r1.returncode == 0
    assert halt_file.exists()
    r2 = _run(HALT_SCRIPT, [], env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert r2.returncode == 0
    assert halt_file.exists()


def test_halt_does_not_pkill(isolated_env):
    """Per design: halt does NOT call pkill. Verify by checking no pkill process gets launched."""
    # Replace pkill in PATH with something that fails loudly so we'd see if halt invoked it.
    fake_bin = isolated_env.parent / "bin"
    pkill = fake_bin / "pkill"
    pkill.write_text("#!/usr/bin/env bash\necho 'PKILL CALLED' >&2\nexit 99\n")
    pkill.chmod(0o755)
    result = _run(HALT_SCRIPT, [], env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert result.returncode == 0
    assert "PKILL CALLED" not in result.stderr


def test_halt_tailnet_reports_per_peer(isolated_env):
    """--tailnet iterates peers.toml and reports per-peer status."""
    cfg = isolated_env / ".config" / "cross-agent-comms"
    cfg.mkdir(parents=True)
    (cfg / "peers.toml").write_text(textwrap.dedent("""\
        [peers.velox]
        host = "velox"
        ssh_user = "cjennings"

        [peers.bogus]
        host = "definitely-unreachable.invalid"
        ssh_user = "cjennings"
    """))
    result = _run(HALT_SCRIPT, ["--tailnet"],
                  env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    # Partial halt → exit 1.
    assert result.returncode == 1
    assert "velox" in result.stdout
    assert "bogus" in result.stdout
    # ✓ marker for velox, ✗ for bogus.
    assert "✓" in result.stdout
    assert "✗" in result.stdout
    assert "PARTIAL" in result.stdout or "partial" in result.stdout.lower()


def test_halt_tailnet_all_reachable_exits_zero(isolated_env):
    cfg = isolated_env / ".config" / "cross-agent-comms"
    cfg.mkdir(parents=True)
    (cfg / "peers.toml").write_text(textwrap.dedent("""\
        [peers.velox]
        host = "velox"
        ssh_user = "cjennings"
    """))
    result = _run(HALT_SCRIPT, ["--tailnet"],
                  env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert result.returncode == 0
    assert "velox" in result.stdout


# ---- cross-agent-resume ----


def test_resume_help(isolated_env):
    result = _run(RESUME_SCRIPT, ["--help"],
                  env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert result.returncode == 0
    assert "resume" in result.stdout.lower()


def test_resume_removes_halt_file(isolated_env):
    halt_file = isolated_env / ".config" / "cross-agent-comms" / "HALT"
    halt_file.parent.mkdir(parents=True)
    halt_file.write_text("halted")
    assert halt_file.exists()
    result = _run(RESUME_SCRIPT, [],
                  env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert result.returncode == 0
    assert not halt_file.exists()


def test_resume_when_no_halt_active_succeeds(isolated_env):
    """No HALT to clear is not an error."""
    result = _run(RESUME_SCRIPT, [],
                  env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert result.returncode == 0


def test_resume_prints_per_session_instructions(isolated_env):
    """Resume must surface that polling does NOT auto-resume."""
    halt_file = isolated_env / ".config" / "cross-agent-comms" / "HALT"
    halt_file.parent.mkdir(parents=True)
    halt_file.write_text("halted")
    result = _run(RESUME_SCRIPT, [],
                  env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert result.returncode == 0
    out = result.stdout.lower()
    assert "polling" in out
    assert "auto" in out or "explicit" in out or "session" in out


def test_resume_tailnet_partial_failure_exit_1(isolated_env):
    cfg = isolated_env / ".config" / "cross-agent-comms"
    cfg.mkdir(parents=True)
    (cfg / "peers.toml").write_text(textwrap.dedent("""\
        [peers.velox]
        host = "velox"

        [peers.bogus]
        host = "unreachable-host.invalid"
    """))
    halt_file = cfg / "HALT"
    halt_file.write_text("halted")
    result = _run(RESUME_SCRIPT, ["--tailnet"],
                  env={**os.environ, "HOME": str(isolated_env), "PATH": os.environ["PATH"]})
    assert result.returncode == 1
    assert "velox" in result.stdout
    assert "bogus" in result.stdout