import json
import pytest
from unittest.mock import patch, AsyncMock


# ---------------------------------------------------------------------------
# read_article tool tests
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_read_article_success():
    """read_article returns success with content when _fetch_full_article succeeds."""
    from fabledassistant.services.tools import execute_tool

    with patch(
        "fabledassistant.services.rss._fetch_full_article",
        new_callable=AsyncMock,
        return_value="Article body text here.",
    ):
        result = await execute_tool(user_id=1, tool_name="read_article", arguments={"url": "https://example.com/article"})

    assert result["success"] is True
    assert result["type"] == "article_content"
    assert result["url"] == "https://example.com/article"
    assert result["content"] == "Article body text here."
    assert result["truncated"] is False


@pytest.mark.asyncio
async def test_read_article_fetch_failure():
    """read_article returns success=False when _fetch_full_article returns None."""
    from fabledassistant.services.tools import execute_tool

    with patch(
        "fabledassistant.services.rss._fetch_full_article",
        new_callable=AsyncMock,
        return_value=None,
    ):
        result = await execute_tool(user_id=1, tool_name="read_article", arguments={"url": "https://example.com/broken"})

    assert result["success"] is False
    assert "Could not fetch" in result["error"]


@pytest.mark.asyncio
async def test_read_article_truncates_at_40k():
    """read_article truncates content at 40,000 chars and sets truncated=True."""
    from fabledassistant.services.tools import execute_tool

    long_content = "x" * 50_000

    with patch(
        "fabledassistant.services.rss._fetch_full_article",
        new_callable=AsyncMock,
        return_value=long_content,
    ):
        result = await execute_tool(user_id=1, tool_name="read_article", arguments={"url": "https://example.com/long"})

    assert result["success"] is True
    assert len(result["content"]) == 40_000
    assert result["truncated"] is True


@pytest.mark.asyncio
async def test_read_article_empty_url():
    """read_article returns success=False when URL is empty."""
    from fabledassistant.services.tools import execute_tool

    result = await execute_tool(user_id=1, tool_name="read_article", arguments={"url": ""})
    assert result["success"] is False
    assert "No URL provided" in result["error"]


# ---------------------------------------------------------------------------
# History builder tests
# ---------------------------------------------------------------------------

def _build_history(messages: list[dict]) -> list[dict]:
    """Replicate the fixed history builder from routes/chat.py."""
    history = []
    for msg in messages:
        if msg["role"] == "system":
            continue
        msg_dict = {"role": msg["role"], "content": msg.get("content") or ""}
        tool_calls = msg.get("tool_calls")
        if tool_calls:
            msg_dict["tool_calls"] = [
                {"function": {"name": tc["function"], "arguments": tc["arguments"]}}
                for tc in tool_calls
            ]
            history.append(msg_dict)
            for tc in tool_calls:
                history.append({"role": "tool", "content": json.dumps(tc.get("result", {}))})
        else:
            history.append(msg_dict)
    return history


def test_history_builder_replays_tool_calls():
    """History builder with tool_calls produces assistant entry + tool result entry."""
    messages = [
        {
            "role": "assistant",
            "content": "",
            "tool_calls": [
                {
                    "function": "read_article",
                    "arguments": {"url": "https://example.com"},
                    "result": {"success": True, "content": "Article text"},
                }
            ],
        },
        {"role": "user", "content": "Summarize it", "tool_calls": None},
    ]
    history = _build_history(messages)

    assert len(history) == 3
    assert history[0]["role"] == "assistant"
    assert history[0]["tool_calls"][0]["function"]["name"] == "read_article"
    assert history[1]["role"] == "tool"
    assert json.loads(history[1]["content"])["success"] is True
    assert history[2]["role"] == "user"
    assert history[2]["content"] == "Summarize it"


def test_history_builder_no_tool_calls_unchanged():
    """History builder with tool_calls=None produces same output as before."""
    messages = [
        {"role": "user", "content": "Hello", "tool_calls": None},
        {"role": "assistant", "content": "Hi there!", "tool_calls": None},
    ]
    history = _build_history(messages)

    assert len(history) == 2
    assert history[0] == {"role": "user", "content": "Hello"}
    assert history[1] == {"role": "assistant", "content": "Hi there!"}