from unittest.mock import MagicMock, patch

import httpx
import pytest
from openai import RateLimitError

import translate
from translate import translate_feed, translate_html


# ── Helpers ───────────────────────────────────────────────────────────────────

def _openai_response(text: str) -> MagicMock:
    m = MagicMock()
    m.choices = [MagicMock()]
    m.choices[0].message.content = text
    return m


def _rate_limit_error() -> RateLimitError:
    req = httpx.Request("POST", "https://api.openai.com/v1/chat/completions")
    resp = httpx.Response(429, request=req)
    return RateLimitError("Rate limit exceeded", response=resp, body=None)


# ── translate() ───────────────────────────────────────────────────────────────

def test_translate_empty_string_unchanged(db_conn):
    with patch("translate._client") as mock_client:
        result = translate.translate("", "sk", db_conn)
        assert result == ""
        mock_client.chat.completions.create.assert_not_called()


def test_translate_whitespace_unchanged(db_conn):
    with patch("translate._client") as mock_client:
        result = translate.translate("   ", "sk", db_conn)
        assert result == "   "
        mock_client.chat.completions.create.assert_not_called()


def test_translate_calls_openai_on_cache_miss(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.return_value = _openai_response("Ahoj")
        result = translate.translate("Hello", "sk", db_conn)
        assert result == "Ahoj"
        mock_client.chat.completions.create.assert_called_once()


def test_translate_returns_cache_on_hit(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.return_value = _openai_response("Ahoj")
        translate.translate("Hello", "sk", db_conn)
        result = translate.translate("Hello", "sk", db_conn)
        assert result == "Ahoj"
        assert mock_client.chat.completions.create.call_count == 1


def test_translate_on_error_returns_original(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.side_effect = Exception("API down")
        result = translate.translate("Hello", "sk", db_conn)
        assert result == "Hello"


def test_translate_error_not_cached(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.side_effect = Exception("API down")
        translate.translate("Hello", "sk", db_conn)

        mock_client.chat.completions.create.side_effect = None
        mock_client.chat.completions.create.return_value = _openai_response("Ahoj")
        result = translate.translate("Hello", "sk", db_conn)

        assert result == "Ahoj"
        assert mock_client.chat.completions.create.call_count == 2


# ── _call_openai() retry / backoff ────────────────────────────────────────────

def test_call_openai_retries_on_rate_limit(db_conn):
    with patch("translate.time.sleep"), \
         patch("translate._client") as mock_client:
        mock_client.chat.completions.create.side_effect = [
            _rate_limit_error(),
            _rate_limit_error(),
            _openai_response("Preložený"),
        ]
        result = translate._call_openai("Hello", "sk")
        assert result == "Preložený"
        assert mock_client.chat.completions.create.call_count == 3


def test_call_openai_raises_after_max_retries():
    with patch("translate.time.sleep"), \
         patch("translate._client") as mock_client:
        mock_client.chat.completions.create.side_effect = _rate_limit_error()
        with pytest.raises(RateLimitError):
            translate._call_openai("Hello", "sk")
        assert mock_client.chat.completions.create.call_count == 5


def test_call_openai_backoff_increases():
    with patch("translate.time.sleep") as mock_sleep, \
         patch("translate._client") as mock_client:
        mock_client.chat.completions.create.side_effect = [
            _rate_limit_error(),
            _rate_limit_error(),
            _rate_limit_error(),
            _openai_response("ok"),
        ]
        translate._call_openai("Hello", "sk")
        delays = [c.args[0] for c in mock_sleep.call_args_list]
        assert delays == [1.0, 2.0, 4.0]


# ── translate_html() ──────────────────────────────────────────────────────────

def test_translate_html_preserves_img_tags(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.return_value = _openai_response("<p>Ahoj</p>")
        result = translate_html('<p>Hello</p><img src="photo.jpg" alt="x">', "sk", db_conn)
        assert '<img src="photo.jpg" alt="x">' in result
        assert "Ahoj" in result


def test_translate_html_strips_img_before_api_call(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.return_value = _openai_response("<p>Ahoj</p>")
        translate_html('<p>Hello</p><img src="photo.jpg">', "sk", db_conn)
        sent = mock_client.chat.completions.create.call_args[1]["messages"][1]["content"]
        assert "<img" not in sent


# ── translate_feed() ──────────────────────────────────────────────────────────

_RSS = b"""<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <title>Channel</title>
    <item>
      <title>Hello</title>
      <description>World</description>
    </item>
  </channel>
</rss>"""

_ATOM = b"""<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <title>Feed</title>
  <entry>
    <title>Hello</title>
    <summary>World</summary>
  </entry>
</feed>"""

_EMPTY_TAGS = b"""<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title></title>
      <description/>
    </item>
  </channel>
</rss>"""


def test_translate_feed_rss_translates_content(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.return_value = _openai_response("Ahoj")
        result = translate_feed(_RSS, "sk", db_conn)
        assert b"Ahoj" in result


def test_translate_feed_rss_calls_openai_per_tag(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.return_value = _openai_response("X")
        translate_feed(_RSS, "sk", db_conn)
        # title (plain) + description (html) = 2 distinct texts → 2 calls
        assert mock_client.chat.completions.create.call_count == 2


def test_translate_feed_invalid_xml_raises(db_conn):
    with pytest.raises(ValueError, match="Invalid XML"):
        translate_feed(b"not xml <<<", "sk", db_conn)


def test_translate_feed_empty_tags_no_crash(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.return_value = _openai_response("X")
        result = translate_feed(_EMPTY_TAGS, "sk", db_conn)
        assert b"<rss" in result
        mock_client.chat.completions.create.assert_not_called()


def test_translate_feed_atom_does_not_crash(db_conn):
    with patch("translate._client") as mock_client:
        mock_client.chat.completions.create.return_value = _openai_response("X")
        result = translate_feed(_ATOM, "sk", db_conn)
        assert b"<feed" in result