"""Unit tests for M08 — LLM async client (`loosecanvas.llm_client`).

These tests use ``httpx.MockTransport`` so NO live llama.cpp server is required.
Any test that needs a real server is guarded with ``pytest.mark.skipif``.
"""

from __future__ import annotations

import json
import os
from typing import Any

import httpx
import pytest
from loosecanvas.llm_client import LLMClient, LLMClientError, strip_thought_blocks

LIVE_ENV_VAR = "LOOSECANVAS_RUN_LLM_INTEGRATION"


def _chat_response(content: str) -> dict[str, Any]:
    return {"choices": [{"message": {"content": content}}]}


# --------------------------------------------------------------------------- #
# base_url resolution                                                         #
# --------------------------------------------------------------------------- #
def test_default_base_url_is_8080(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.delenv("LLAMA_CPP_PORT", raising=False)
    client = LLMClient()
    assert client.base_url == "http://localhost:8080"


def test_base_url_reads_llama_cpp_port(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("LLAMA_CPP_PORT", "9999")
    client = LLMClient()
    assert client.base_url == "http://localhost:9999"


def test_explicit_base_url_overrides_env(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("LLAMA_CPP_PORT", "9999")
    client = LLMClient(base_url="http://override:1234")
    assert client.base_url == "http://override:1234"


# --------------------------------------------------------------------------- #
# complete() request body                                                     #
# --------------------------------------------------------------------------- #
async def test_complete_posts_to_chat_completions_with_defaults() -> None:
    captured: dict[str, Any] = {}

    def handler(request: httpx.Request) -> httpx.Response:
        captured["url"] = str(request.url)
        captured["body"] = json.loads(request.content)
        return httpx.Response(200, json=_chat_response("hi"))

    client = LLMClient(base_url="http://test", transport=httpx.MockTransport(handler))
    result = await client.complete([{"role": "user", "content": "x"}])

    assert result == "hi"
    assert captured["url"] == "http://test/v1/chat/completions"
    body = captured["body"]
    assert body["chat_template_kwargs"] == {"enable_thinking": False}
    assert body["stop"] == ["<turn|>"]
    # max_tokens is omitted by default (un-capped generation up to n_ctx).
    assert "max_tokens" not in body
    assert body["temperature"] == 1.0
    assert body["top_p"] == 0.95
    assert body["top_k"] == 64
    assert "response_format" not in body


async def test_complete_includes_max_tokens_when_supplied() -> None:
    captured: dict[str, Any] = {}

    def handler(request: httpx.Request) -> httpx.Response:
        captured["body"] = json.loads(request.content)
        return httpx.Response(200, json=_chat_response("ok"))

    client = LLMClient(base_url="http://test", transport=httpx.MockTransport(handler))
    await client.complete([{"role": "user", "content": "x"}], max_tokens=42)
    assert captured["body"]["max_tokens"] == 42


async def test_complete_omits_response_format_when_none() -> None:
    captured: dict[str, Any] = {}

    def handler(request: httpx.Request) -> httpx.Response:
        captured["body"] = json.loads(request.content)
        return httpx.Response(200, json=_chat_response("ok"))

    client = LLMClient(base_url="http://test", transport=httpx.MockTransport(handler))
    await client.complete([{"role": "user", "content": "x"}])
    assert "response_format" not in captured["body"]


async def test_complete_includes_response_format_when_supplied() -> None:
    captured: dict[str, Any] = {}
    response_format = {
        "type": "json_schema",
        "json_schema": {
            "name": "scene_plan",
            "strict": True,
            "schema": {"type": "object"},
        },
    }

    def handler(request: httpx.Request) -> httpx.Response:
        captured["body"] = json.loads(request.content)
        return httpx.Response(200, json=_chat_response("ok"))

    client = LLMClient(base_url="http://test", transport=httpx.MockTransport(handler))
    await client.complete(
        [{"role": "user", "content": "x"}], response_format=response_format
    )
    assert captured["body"]["response_format"] == response_format


async def test_complete_passes_enable_thinking_true() -> None:
    captured: dict[str, Any] = {}

    def handler(request: httpx.Request) -> httpx.Response:
        captured["body"] = json.loads(request.content)
        return httpx.Response(200, json=_chat_response("ok"))

    client = LLMClient(base_url="http://test", transport=httpx.MockTransport(handler))
    await client.complete([{"role": "user", "content": "x"}], enable_thinking=True)
    assert captured["body"]["chat_template_kwargs"] == {"enable_thinking": True}


async def test_complete_returns_message_content() -> None:
    def handler(request: httpx.Request) -> httpx.Response:
        return httpx.Response(200, json=_chat_response('{"v": "YES"}'))

    client = LLMClient(base_url="http://test", transport=httpx.MockTransport(handler))
    result = await client.complete([{"role": "user", "content": "x"}])
    assert result == '{"v": "YES"}'


# --------------------------------------------------------------------------- #
# retry / error semantics                                                     #
# --------------------------------------------------------------------------- #
async def test_4xx_raises_without_retry() -> None:
    calls: list[int] = []

    def handler(request: httpx.Request) -> httpx.Response:
        calls.append(1)
        return httpx.Response(400, json={"error": "bad request"})

    client = LLMClient(base_url="http://test", transport=httpx.MockTransport(handler))
    with pytest.raises(LLMClientError):
        await client.complete([{"role": "user", "content": "x"}])
    assert len(calls) == 1


async def test_single_503_then_200_succeeds() -> None:
    calls: list[int] = []

    def handler(request: httpx.Request) -> httpx.Response:
        calls.append(1)
        if len(calls) == 1:
            return httpx.Response(503, json={"error": "busy"})
        return httpx.Response(200, json=_chat_response("recovered"))

    client = LLMClient(base_url="http://test", transport=httpx.MockTransport(handler))
    result = await client.complete([{"role": "user", "content": "x"}])
    assert result == "recovered"
    assert len(calls) == 2


async def test_two_consecutive_503_raise() -> None:
    calls: list[int] = []

    def handler(request: httpx.Request) -> httpx.Response:
        calls.append(1)
        return httpx.Response(503, json={"error": "busy"})

    client = LLMClient(base_url="http://test", transport=httpx.MockTransport(handler))
    with pytest.raises(LLMClientError):
        await client.complete([{"role": "user", "content": "x"}])
    assert len(calls) == 2


# --------------------------------------------------------------------------- #
# strip_thought_blocks                                                        #
# --------------------------------------------------------------------------- #
def test_strip_thought_blocks_removes_block() -> None:
    text = '<|channel>thought\nsome internal reasoning<channel|>{"v": "YES"}'
    assert strip_thought_blocks(text) == '{"v": "YES"}'


def test_strip_thought_blocks_noop_on_clean_text() -> None:
    text = '{"v": "YES"}'
    assert strip_thought_blocks(text) == '{"v": "YES"}'


# --------------------------------------------------------------------------- #
# live-server-only (skipped unless explicitly enabled)                        #
# --------------------------------------------------------------------------- #
@pytest.mark.skipif(
    os.environ.get(LIVE_ENV_VAR) != "1",
    reason=f"Set {LIVE_ENV_VAR}=1 to run live llama.cpp readiness checks.",
)
async def test_wait_for_ready_against_live_server() -> None:
    client = LLMClient()
    await client.wait_for_ready(timeout=10.0)