"""Tests for the preprocessor system (Step 1 — Local Agent V2).

Run:
    pytest tests/test_preprocessors.py -v
    pytest tests/test_preprocessors.py -v --preprocess-dir /path/to/folder

The folder must contain cases.yaml + data/.
"""

from __future__ import annotations

import re
from pathlib import Path

import pytest
import yaml

from app.core.langfuse_client import get_langfuse
from app.core.preprocessors import detect_content_type, preprocess

_DEFAULT_DIR = Path(__file__).parent / "fixtures" / "preprocessors"

_GENERATORS = {
    "binary_noise": "some\x00\x01\x02\x03\x04\x05content" * 20,
}


def _fixtures_dir(config) -> Path:
    override = config.getoption("--preprocess-dir")
    return Path(override) if override else _DEFAULT_DIR


def _load_cases(config) -> list[dict]:
    return yaml.safe_load((_fixtures_dir(config) / "cases.yaml").read_text(encoding="utf-8"))


def _content(case: dict, data_dir: Path) -> str:
    if "generate" in case:
        return _GENERATORS[case["generate"]]
    return (data_dir / case["file"]).read_text(encoding="utf-8")


def _lf_score(name: str, value: float) -> None:
    lf = get_langfuse()
    if lf:
        trace = lf.trace(name=f"eval-{name}")
        lf.score(trace_id=trace.id, name=name, value=value, data_type="NUMERIC")
        lf.flush()


# ── parametrize at collection time via pytest hook ────────────────────

def pytest_generate_tests(metafunc):
    if "preprocess_case" not in metafunc.fixturenames:
        return
    cases = _load_cases(metafunc.config)
    test_name = metafunc.function.__name__
    if test_name == "test_detect":
        subset = [c for c in cases if "detect" in c]
    else:
        subset = [c for c in cases if "process" in c]
    metafunc.parametrize("preprocess_case", subset, ids=[c["id"] for c in subset])


# ── detect ────────────────────────────────────────────────────────────

def test_detect(preprocess_case, pytestconfig) -> None:
    case = preprocess_case
    data_dir = _fixtures_dir(pytestconfig) / "data"
    raw = _content(case, data_dir)
    filename = case.get("file", "")
    ct = detect_content_type(filename, raw)
    expected = case["detect"]
    _lf_score(f"preprocess.detect.{case['id']}", 1.0 if ct == expected else 0.0)
    assert ct == expected, f"[{case['id']}] expected {expected!r}, got {ct!r}"


# ── preprocess ────────────────────────────────────────────────────────

def test_preprocess(preprocess_case, pytestconfig) -> None:
    case = preprocess_case
    data_dir = _fixtures_dir(pytestconfig) / "data"
    raw = _content(case, data_dir)
    result = preprocess(case["process"], raw)

    if case.get("no_html"):
        assert not re.search(r"<[^>]+>", result.clean_text), "clean_text contains HTML tags"

    if "min_chars" in case:
        assert len(result.clean_text) >= case["min_chars"], \
            f"clean_text too short: {len(result.clean_text)} < {case['min_chars']}"

    if "ratio_lt" in case:
        ratio = len(result.clean_text) / len(raw)
        assert ratio < case["ratio_lt"], f"compression ratio {ratio:.2f} >= {case['ratio_lt']}"

    for key in case.get("has_meta", []):
        assert result.metadata.get(key), f"metadata missing {key!r} (got {result.metadata})"

    for item in ([case["contains"]] if isinstance(case.get("contains"), str) else case.get("contains", [])):
        assert item in result.clean_text, f"clean_text missing {item!r}"

    for item in ([case["excludes"]] if isinstance(case.get("excludes"), str) else case.get("excludes", [])):
        assert item not in result.clean_text, f"clean_text contains forbidden {item!r}"

    if "content_type" in case:
        assert result.content_type == case["content_type"], \
            f"expected content_type {case['content_type']!r}, got {result.content_type!r}"