"""High-level scenario runner used by the package and CLI entrypoints."""

from __future__ import annotations

import logging
import sys
from pathlib import Path

from rag_eval.adapters.http import HttpAppAdapter
from rag_eval.adapters.python import PythonFunctionAdapter
from rag_eval.config.loader import load_scenario
from rag_eval.metrics.factory import build_metric_pipeline
from rag_eval.reporting.writers import write_run_artifacts
from rag_eval.settings import EvaluationSettings
from rag_eval.shared.models import Scenario

from .evaluator import Evaluator

logger = logging.getLogger("rag_eval.execution.runner")


def _setup_logging(log_file: Path | None = None, level: int = logging.INFO) -> None:
    """Configure root logger: always write to stderr, optionally also to a file."""
    fmt = "%(asctime)s  %(levelname)-8s  %(name)s  %(message)s"
    datefmt = "%H:%M:%S"

    handlers: list[logging.Handler] = [logging.StreamHandler(sys.stderr)]
    if log_file is not None:
        log_file.parent.mkdir(parents=True, exist_ok=True)
        fh = logging.FileHandler(log_file, encoding="utf-8")
        fh.setFormatter(logging.Formatter(fmt, datefmt=datefmt))
        handlers.append(fh)

    logging.basicConfig(level=level, format=fmt, datefmt=datefmt, handlers=handlers, force=True)
    # Also show ragas internal logs at WARNING so we can see LLM errors
    logging.getLogger("ragas").setLevel(logging.WARNING)
    logging.getLogger("httpx").setLevel(logging.WARNING)
    logging.getLogger("openai").setLevel(logging.WARNING)


def build_adapter(scenario: Scenario):
    """Instantiate the adapter required by the resolved scenario, if any."""
    if scenario.app_adapter is None:
        return None
    if scenario.app_adapter.type == "http":
        return HttpAppAdapter(scenario.app_adapter)
    if scenario.app_adapter.type == "python":
        return PythonFunctionAdapter(scenario.app_adapter)
    raise ValueError(f"Unsupported adapter type: {scenario.app_adapter.type}")


def run_scenario(
    scenario_path: str,
    settings: EvaluationSettings | None = None,
    log_file: Path | None = None,
    log_level: int = logging.INFO,
):
    """Run one scenario end to end and persist its reporting artifacts."""
    _setup_logging(log_file=log_file, level=log_level)
    logger.info("[runner] run_scenario  path=%s", scenario_path)

    settings = settings or EvaluationSettings()
    if not settings.openai_api_key:
        raise EnvironmentError("OPENAI_API_KEY must be set before running the evaluator.")

    scenario = load_scenario(scenario_path)
    logger.info("[runner] scenario loaded: name=%s  mode=%s  max_samples=%s",
                scenario.scenario_name, scenario.mode, scenario.runtime.max_samples)

    adapter = build_adapter(scenario)
    pipeline = build_metric_pipeline(scenario, settings)
    evaluator = Evaluator(scenario=scenario, metric_pipeline=pipeline, app_adapter=adapter)
    result = evaluator.evaluate()
    write_run_artifacts(result)
    logger.info("[runner] artifacts written for run_id=%s", result.run_id)
    return result