"""Shared pytest fixtures + reporter hooks for caption-test test suite.

Provides:
  - proj_dir, path2cfg: real repository paths for integration-style tests
    that load actual gin presets from in/config_files/.
  - clear_gin: autouse fixture that wipes gin global state before every test
    (gin keeps bindings in module-level singleton; tests must not leak).

Reporter hooks print "✅/❌ <docstring>" next to each test's PASSED/FAILED
line in -v mode.

Preset name lists live in a separate module (`tests/_presets.py`) so test
files can import them with a plain `import _presets` — no relative imports,
no need for tests/ to be a package.
"""

from __future__ import annotations

from pathlib import Path

import gin
import pytest


DINOV3_PRESETS = (
    "gtauav_balanced",
    "gtauav_balanced_asym",
    "gtauav_baseline",
    "gtauav_baseline_asym",
    "gtauav_image_heavy",
    "gtauav_text_heavy",
)
 
STRIPNET_PRESETS = (
    "gtauav_balanced_stripnet",
    "gtauav_balanced_stripnet_unfrozen",
    "gtauav_baseline_stripnet",
    "gtauav_baseline_stripnet_unfrozen",
)
 
ALL_TRAINING_PRESETS = DINOV3_PRESETS + STRIPNET_PRESETS

# --- gin hygiene -----------------------------------------------------------


@pytest.fixture(autouse=True)
def clear_gin():
    """Wipe gin's global binding state before AND after each test.

    Gin keeps bindings in module-level singletons; without this fixture, a
    test that loads a config (or even just calls gin.parse_config_file in a
    helper) leaks bindings into the next test, leading to flaky failures
    like 'Unknown configurable' or wrong field values.
    """
    gin.clear_config()
    yield
    gin.clear_config()


# --- real-repo paths -------------------------------------------------------


@pytest.fixture
def proj_dir() -> Path:
    """Path to repository root (the directory that contains src/, tests/, in/)."""
    return Path(__file__).resolve().parent.parent


@pytest.fixture
def path2cfg(proj_dir: Path) -> str:
    """Trailing-slashed path to in/config_files/, matching `src/main.py`.

    Per REQUIREMENTS_GIN_STYLE.md §5, src/main.py builds this path as
    `f"{proj_dir}in/config_files/"`. Tests that exercise the real repo
    layout should use this fixture verbatim instead of constructing it
    independently.
    """
    return f"{proj_dir}/in/config_files/"


# --- reporter hooks --------------------------------------------------------


def _docstring_summary(item: pytest.Item) -> str | None:
    """Return the first non-empty line of a test's docstring, or None."""
    func = getattr(item, "function", None) or getattr(item, "obj", None)
    if func is None or not getattr(func, "__doc__", None):
        return None
    for line in func.__doc__.strip().splitlines():
        stripped = line.strip()
        if stripped:
            return stripped
    return None


# Cache nodeid → docstring summary, populated at collection time so the
# logreport hook can look them up without re-introspecting the test function.
_LAST_SEEN_SUMMARY: dict[str, str] = {}


def pytest_collection_modifyitems(
    config: pytest.Config,
    items: list[pytest.Item],
) -> None:
    """Cache each item's docstring summary for later use by the status hook."""
    for item in items:
        summary = _docstring_summary(item)
        if summary:
            _LAST_SEEN_SUMMARY[item.nodeid] = summary


def pytest_runtest_logreport(report: pytest.TestReport) -> None:
    """Print test results with parametrized tests grouped under one header.

    Non-parametrized test:
        ✅  <docstring summary>

    Parametrized test (first occurrence of the group):
        <docstring summary>
          ✅  <param>

    Parametrized test (subsequent occurrences):
          ✅  <param>

    Pytest emits 3 reports per test (setup → call → teardown). We hook the
    `call` phase — the one where pass/fail is actually decided.
    """
    if report.when != "call":
        return

    summary = _LAST_SEEN_SUMMARY.get(report.nodeid, "(no docstring)")
    if report.passed:
        icon = "✅"
    elif report.failed:
        icon = "❌"
    else:
        icon = "⏭️"

    # Detect parametrization: pytest encodes params as `nodeid[param1-param2-...]`.
    if "[" in report.nodeid and report.nodeid.endswith("]"):
        base_id, _, param_part = report.nodeid.partition("[")
        param_label = param_part[:-1] or "empty" # strip trailing ']'

        # Print docstring header only on first encounter of this group.
        # Leading "\n" separates the header from pytest's progress dot.
        if base_id not in _PRINTED_GROUP_HEADERS:
            print(f"\n{summary}")
            _PRINTED_GROUP_HEADERS.add(base_id)
        print(f"  {icon}  {param_label}")
    else:
        print(f"  {icon}  {summary}")


# Tracks which parametrized test groups have already had their docstring
# header printed. Reset implicitly at the start of each pytest run because
# Python re-imports conftest.py.
_PRINTED_GROUP_HEADERS: set[str] = set()