"""Tests for diagnose/_llm_client.py — thinking-tag stripping and content extraction."""
from __future__ import annotations

import pytest


def _resp(content: str | None) -> dict:
    if content is None:
        return {"choices": []}
    return {"choices": [{"message": {"content": content}}]}


class TestExtractContent:
    def test_returns_plain_content(self):
        from app.services.diagnose._llm_client import extract_content
        assert extract_content(_resp("hello world")) == "hello world"

    def test_returns_none_on_empty_choices(self):
        from app.services.diagnose._llm_client import extract_content
        assert extract_content({"choices": []}) is None

    def test_returns_none_on_empty_content(self):
        from app.services.diagnose._llm_client import extract_content
        assert extract_content(_resp("")) is None

    def test_strips_single_think_block(self):
        from app.services.diagnose._llm_client import extract_content
        raw = "<think>Let me reason about this…</think>\nThe answer is 42."
        assert extract_content(_resp(raw)) == "The answer is 42."

    def test_strips_multi_line_think_block(self):
        from app.services.diagnose._llm_client import extract_content
        raw = "<think>\nStep 1: consider X\nStep 2: consider Y\n</think>\n\nFinal answer here."
        result = extract_content(_resp(raw))
        assert result == "Final answer here."
        assert "<think>" not in result

    def test_strips_multiple_think_blocks(self):
        from app.services.diagnose._llm_client import extract_content
        raw = "<think>first</think> actual <think>second</think> content"
        result = extract_content(_resp(raw))
        assert "<think>" not in result
        assert "actual" in result
        assert "content" in result

    def test_strips_case_insensitive(self):
        from app.services.diagnose._llm_client import extract_content
        raw = "<THINK>hidden</THINK> visible"
        result = extract_content(_resp(raw))
        assert result == "visible"

    def test_returns_none_when_only_thinking_remains(self):
        from app.services.diagnose._llm_client import extract_content
        raw = "<think>only thinking, no output</think>"
        assert extract_content(_resp(raw)) is None

    def test_content_without_thinking_unchanged(self):
        from app.services.diagnose._llm_client import extract_content
        raw = "Redis OOM at 03:00 — key eviction triggered by batch job."
        assert extract_content(_resp(raw)) == raw


class TestStripJsonFences:
    def test_strips_json_fence(self):
        from app.services.diagnose._llm_client import strip_json_fences
        raw = "```json\n[{\"a\": 1}]\n```"
        assert strip_json_fences(raw) == '[{"a": 1}]'

    def test_strips_plain_fence(self):
        from app.services.diagnose._llm_client import strip_json_fences
        raw = "```\nhello\n```"
        assert "```" not in strip_json_fences(raw)


class TestExtractFirstJsonArray:
    def test_extracts_array_from_mixed_text(self):
        from app.services.diagnose._llm_client import extract_first_json_array
        raw = 'Here is the result:\n[{"id": 1}, {"id": 2}]\nThat is all.'
        result = extract_first_json_array(raw)
        import json
        parsed = json.loads(result)
        assert len(parsed) == 2

    def test_returns_original_when_no_array(self):
        from app.services.diagnose._llm_client import extract_first_json_array
        raw = "no array here"
        assert extract_first_json_array(raw) == raw