from __future__ import annotations

import os
import subprocess
import time
from pathlib import Path
from typing import cast

import pytest

from pyro_mcp.workspace_shells import (
    create_local_shell,
    get_local_shell,
    remove_local_shell,
    shell_signal_arg_help,
    shell_signal_names,
)


def _read_until(
    workspace_id: str,
    shell_id: str,
    text: str,
    *,
    timeout_seconds: float = 5.0,
) -> dict[str, object]:
    deadline = time.time() + timeout_seconds
    payload = get_local_shell(workspace_id=workspace_id, shell_id=shell_id).read(
        cursor=0,
        max_chars=65536,
    )
    while text not in str(payload["output"]) and time.time() < deadline:
        time.sleep(0.05)
        payload = get_local_shell(workspace_id=workspace_id, shell_id=shell_id).read(
            cursor=0,
            max_chars=65536,
        )
    return payload


def test_workspace_shells_round_trip(tmp_path: Path) -> None:
    session = create_local_shell(
        workspace_id="workspace-1",
        shell_id="shell-1",
        cwd=tmp_path,
        display_cwd="/workspace",
        cols=120,
        rows=30,
    )
    try:
        assert session.summary()["state"] == "running"
        write = session.write("printf 'hello\\n'", append_newline=True)
        assert write["input_length"] == 16
        payload = _read_until("workspace-1", "shell-1", "hello")
        assert "hello" in str(payload["output"])
        assert cast(int, payload["next_cursor"]) >= cast(int, payload["cursor"])
        assert isinstance(payload["truncated"], bool)
        session.write("sleep 60", append_newline=True)
        signaled = session.send_signal("INT")
        assert signaled["signal"] == "INT"
    finally:
        closed = session.close()
        assert closed["closed"] is True


def test_workspace_shell_registry_helpers(tmp_path: Path) -> None:
    session = create_local_shell(
        workspace_id="workspace-2",
        shell_id="shell-2",
        cwd=tmp_path,
        display_cwd="/workspace/subdir",
        cols=80,
        rows=24,
    )
    assert get_local_shell(workspace_id="workspace-2", shell_id="shell-2") is session
    assert shell_signal_names() == ("HUP", "INT", "TERM", "KILL")
    assert "HUP" in shell_signal_arg_help()
    with pytest.raises(RuntimeError, match="already exists"):
        create_local_shell(
            workspace_id="workspace-2",
            shell_id="shell-2",
            cwd=tmp_path,
            display_cwd="/workspace/subdir",
            cols=80,
            rows=24,
        )
    removed = remove_local_shell(workspace_id="workspace-2", shell_id="shell-2")
    assert removed is session
    assert remove_local_shell(workspace_id="workspace-2", shell_id="shell-2") is None
    with pytest.raises(ValueError, match="does not exist"):
        get_local_shell(workspace_id="workspace-2", shell_id="shell-2")
    closed = session.close()
    assert closed["closed"] is True


def test_workspace_shells_error_after_exit(tmp_path: Path) -> None:
    session = create_local_shell(
        workspace_id="workspace-3",
        shell_id="shell-3",
        cwd=tmp_path,
        display_cwd="/workspace",
        cols=120,
        rows=30,
    )
    session.write("exit", append_newline=True)
    deadline = time.time() + 5
    while session.summary()["state"] != "stopped" and time.time() < deadline:
        time.sleep(0.05)
    assert session.summary()["state"] == "stopped"
    with pytest.raises(RuntimeError, match="not running"):
        session.write("pwd", append_newline=True)
    with pytest.raises(RuntimeError, match="not running"):
        session.send_signal("INT")
    closed = session.close()
    assert closed["closed"] is True


def test_workspace_shells_reject_invalid_signal(tmp_path: Path) -> None:
    session = create_local_shell(
        workspace_id="workspace-4",
        shell_id="shell-4",
        cwd=tmp_path,
        display_cwd="/workspace",
        cols=120,
        rows=30,
    )
    try:
        with pytest.raises(ValueError, match="unsupported shell signal"):
            session.send_signal("BOGUS")
    finally:
        session.close()


def test_workspace_shells_init_failure_closes_ptys(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    def _boom(*args: object, **kwargs: object) -> object:
        raise RuntimeError("boom")

    monkeypatch.setattr(subprocess, "Popen", _boom)
    with pytest.raises(RuntimeError, match="boom"):
        create_local_shell(
            workspace_id="workspace-5",
            shell_id="shell-5",
            cwd=tmp_path,
            display_cwd="/workspace",
            cols=120,
            rows=30,
        )


def test_workspace_shells_write_and_signal_runtime_errors(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    real_killpg = os.killpg
    session = create_local_shell(
        workspace_id="workspace-6",
        shell_id="shell-6",
        cwd=tmp_path,
        display_cwd="/workspace",
        cols=120,
        rows=30,
    )
    try:
        with session._lock:  # noqa: SLF001
            session._master_fd = None  # noqa: SLF001
            session._input_pipe = None  # noqa: SLF001
        with pytest.raises(RuntimeError, match="transport is unavailable"):
            session.write("pwd", append_newline=True)

        with session._lock:  # noqa: SLF001
            master_fd, slave_fd = os.pipe()
            os.close(slave_fd)
            session._master_fd = master_fd  # noqa: SLF001

        def _raise_write(fd: int, data: bytes) -> int:
            del fd, data
            raise OSError("broken")

        monkeypatch.setattr("pyro_mcp.workspace_shells.os.write", _raise_write)
        with pytest.raises(RuntimeError, match="failed to write"):
            session.write("pwd", append_newline=True)

        def _raise_killpg(pid: int, signum: int) -> None:
            del pid, signum
            raise ProcessLookupError()

        monkeypatch.setattr("pyro_mcp.workspace_shells.os.killpg", _raise_killpg)
        with pytest.raises(RuntimeError, match="not running"):
            session.send_signal("INT")
        monkeypatch.setattr("pyro_mcp.workspace_shells.os.killpg", real_killpg)
    finally:
        try:
            session.close()
        except Exception:
            pass


def test_workspace_shells_refresh_process_state_updates_exit_code(tmp_path: Path) -> None:
    session = create_local_shell(
        workspace_id="workspace-7",
        shell_id="shell-7",
        cwd=tmp_path,
        display_cwd="/workspace",
        cols=120,
        rows=30,
    )
    try:
        class StubProcess:
            def poll(self) -> int:
                return 7

        session._process = StubProcess()  # type: ignore[assignment]  # noqa: SLF001
        session._refresh_process_state()  # noqa: SLF001
        assert session.summary()["state"] == "stopped"
        assert session.summary()["exit_code"] == 7
    finally:
        try:
            session.close()
        except Exception:
            pass