"""T046: Tests for finetune_service — written FIRST (TDD), must FAIL before implementation."""
import asyncio
import pytest
from unittest.mock import MagicMock, AsyncMock, patch

from app.core.exceptions import LLMCallError
from app.models.finetune_models import (
    FinetuneStartRequest,
    FinetuneStartResponse,
    FinetuneStatusResponse,
)


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

def _make_llm(job_id: str = "glm-ft-test", status: str = "running", progress: int | None = None):
    """Return a mock that looks like ZhipuAIClient with ._client.fine_tuning.jobs.*"""
    create_resp = MagicMock()
    create_resp.id = job_id

    retrieve_resp = MagicMock()
    retrieve_resp.status = status
    retrieve_resp.progress = progress
    retrieve_resp.error_message = None  # explicitly set to avoid MagicMock auto-attribute

    llm = MagicMock()
    llm._client.fine_tuning.jobs.create.return_value = create_resp
    llm._client.fine_tuning.jobs.retrieve.return_value = retrieve_resp
    return llm


# ---------------------------------------------------------------------------
# submit_finetune
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_submit_finetune_returns_job_id():
    from app.services.finetune_service import submit_finetune

    llm = _make_llm(job_id="glm-ft-abc123")
    req = FinetuneStartRequest(
        jsonl_url="s3://bucket/train.jsonl",
        base_model="glm-4",
        hyperparams={"n_epochs": 3},
    )

    result = await submit_finetune(req, llm)

    assert isinstance(result, FinetuneStartResponse)
    assert result.job_id == "glm-ft-abc123"


@pytest.mark.asyncio
async def test_submit_finetune_calls_sdk_with_correct_params():
    from app.services.finetune_service import submit_finetune

    llm = _make_llm(job_id="glm-ft-xyz")
    req = FinetuneStartRequest(
        jsonl_url="s3://bucket/train.jsonl",
        base_model="glm-4",
        hyperparams={"n_epochs": 5},
    )

    await submit_finetune(req, llm)

    llm._client.fine_tuning.jobs.create.assert_called_once_with(
        training_file="s3://bucket/train.jsonl",
        model="glm-4",
        hyperparameters={"n_epochs": 5},
    )


@pytest.mark.asyncio
async def test_submit_finetune_none_hyperparams_passes_empty_dict():
    """hyperparams=None should be passed as {} to the SDK."""
    from app.services.finetune_service import submit_finetune

    llm = _make_llm(job_id="glm-ft-nohp")
    req = FinetuneStartRequest(
        jsonl_url="s3://bucket/train.jsonl",
        base_model="glm-4",
    )

    await submit_finetune(req, llm)

    llm._client.fine_tuning.jobs.create.assert_called_once_with(
        training_file="s3://bucket/train.jsonl",
        model="glm-4",
        hyperparameters={},
    )


@pytest.mark.asyncio
async def test_submit_finetune_raises_llm_call_error_on_sdk_failure():
    from app.services.finetune_service import submit_finetune

    llm = MagicMock()
    llm._client.fine_tuning.jobs.create.side_effect = RuntimeError("SDK exploded")

    req = FinetuneStartRequest(
        jsonl_url="s3://bucket/train.jsonl",
        base_model="glm-4",
    )

    with pytest.raises(LLMCallError):
        await submit_finetune(req, llm)


# ---------------------------------------------------------------------------
# get_finetune_status — status mapping
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
@pytest.mark.parametrize("sdk_status,expected", [
    ("running", "RUNNING"),
    ("succeeded", "SUCCESS"),
    ("failed", "FAILED"),
    ("pending", "RUNNING"),      # unknown → conservative RUNNING
    ("queued", "RUNNING"),       # unknown → conservative RUNNING
    ("cancelled", "RUNNING"),    # unknown → conservative RUNNING
])
async def test_get_finetune_status_maps_status(sdk_status, expected):
    from app.services.finetune_service import get_finetune_status

    llm = _make_llm(status=sdk_status)

    result = await get_finetune_status("glm-ft-test", llm)

    assert isinstance(result, FinetuneStatusResponse)
    assert result.status == expected
    assert result.job_id == "glm-ft-test"


@pytest.mark.asyncio
async def test_get_finetune_status_includes_progress():
    from app.services.finetune_service import get_finetune_status

    llm = _make_llm(status="running", progress=42)
    result = await get_finetune_status("glm-ft-test", llm)

    assert result.progress == 42


@pytest.mark.asyncio
async def test_get_finetune_status_raises_llm_call_error_on_sdk_failure():
    from app.services.finetune_service import get_finetune_status

    llm = MagicMock()
    llm._client.fine_tuning.jobs.retrieve.side_effect = RuntimeError("SDK exploded")

    with pytest.raises(LLMCallError):
        await get_finetune_status("glm-ft-bad", llm)