import os
import pty
import select

import pytest

from tamq.terminal import (
    TerminalOutputError,
    format_delivery,
    terminal_frame,
    write_terminal_output,
)


def test_delivery_format_escapes_controls_and_marks_operator_origin():
    assert format_delivery("repo-a", "first\nsecond\x1b[31m", "operator_input") == (
        "From:repo-a/o: first\nFrom:repo-a/o: second\\x1b[31m"
    )
    assert format_delivery("repo-a", "worker", "worker_output") == (
        "From:repo-a: worker"
    )


def test_terminal_frame_scrolls_only_rows_above_the_cursor():
    assert terminal_frame(
        "repo-a", "hello", "operator_input", cursor_y=8, pane_height=24
    ) == (
        "\x1b7\x1b[1;8r\x1b[8;1H"
        "\n\rFrom:repo-a/o: hello"
        "\x1b[r\x1b8"
    )


def test_terminal_frame_falls_back_when_stable_region_is_not_safe():
    expected = "\r\nFrom:repo-a: hello\r\n"
    assert terminal_frame("repo-a", "hello", "worker_output", cursor_y=0, pane_height=24) == expected
    assert terminal_frame(
        "repo-a", "hello", "worker_output", cursor_y=8, pane_height=24, alternate_on=True
    ) == expected


def test_terminal_output_reaches_pty_output_but_not_input():
    master, slave = pty.openpty()
    try:
        tty_path = os.ttyname(slave)
        write_terminal_output(tty_path, terminal_frame("repo-a", "hello", "worker_output"))

        readable, _, _ = select.select([master], [], [], 1)
        assert readable == [master]
        assert b"From:repo-a: hello" in os.read(master, 4096)
        readable_input, _, _ = select.select([slave], [], [], 0)
        assert readable_input == []
    finally:
        os.close(master)
        os.close(slave)


def test_terminal_output_rejects_non_pty_paths(tmp_path):
    target = tmp_path / "ordinary-file"
    target.write_text("untouched", encoding="utf-8")
    with pytest.raises(TerminalOutputError, match="non-PTY"):
        write_terminal_output(target, "message")
    assert target.read_text(encoding="utf-8") == "untouched"