from __future__ import annotations
import itertools
import os
import typing as t

import pytest

import openllm


if t.TYPE_CHECKING:
  from openllm_core._typing_compat import LiteralBackend

_MODELING_MAPPING = {
  'flan_t5': 'google/flan-t5-small',
  'opt': 'facebook/opt-125m',
  'baichuan': 'baichuan-inc/Baichuan-7B',
}
_PROMPT_MAPPING = {
  'qa': 'Answer the following yes/no question by reasoning step-by-step. Can you write a whole Haiku in a single tweet?'
}


def parametrise_local_llm(
  model: str
) -> t.Generator[tuple[str, openllm.LLMRunner[t.Any, t.Any] | openllm.LLM[t.Any, t.Any]], None, None]:
  if model not in _MODELING_MAPPING:
    pytest.skip(f"'{model}' is not yet supported in framework testing.")
  backends: tuple[LiteralBackend, ...] = ('pt',)
  for backend, prompt in itertools.product(backends, _PROMPT_MAPPING.keys()):
    yield prompt, openllm.LLM(_MODELING_MAPPING[model], backend=backend)


def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
  if os.getenv('GITHUB_ACTIONS') is None:
    if 'prompt' in metafunc.fixturenames and 'llm' in metafunc.fixturenames:
      metafunc.parametrize(
        'prompt,llm', [(p, llm) for p, llm in parametrise_local_llm(metafunc.function.__name__[5:-15])]
      )


def pytest_sessionfinish(session: pytest.Session, exitstatus: int):
  # If no tests are collected, pytest exists with code 5, which makes the CI fail.
  if exitstatus == 5:
    session.exitstatus = 0