"""Shared pytest fixtures and helpers."""
from __future__ import annotations

import sys
from dataclasses import dataclass
from pathlib import Path

import pytest


# --- Isolate persistent state paths from the real user's home ---------------


@pytest.fixture(autouse=True)
def _isolate_user_state(tmp_path, monkeypatch):
    """Redirect all per-user state files into a tmp dir.

    Ensures tests never clobber real settings, tokens, or state DB on the
    developer's machine.
    """
    fake_home = tmp_path / "home"
    fake_home.mkdir()
    monkeypatch.setattr(Path, "home", staticmethod(lambda: fake_home))

    # Re-import config so its module-level paths re-evaluate against the
    # patched home. We clear and re-import to reset cached module constants.
    import importlib
    from tagsync import config

    importlib.reload(config)
    yield
    # Leave things as-is after the test; tmp_path cleanup handles disk.


# --- Fake Dropbox API objects ------------------------------------------------
#
# The Dropbox SDK may or may not be installed in the test env. We don't want
# to require it, and the parts of core.py that need it are only reached via
# helpers we can monkeypatch out.


@dataclass
class FakeFileMetadata:
    """Stand-in for dropbox.files.FileMetadata."""
    name: str
    path_lower: str
    path_display: str


@dataclass
class FakeUserTag:
    tag_text: str


class FakeTag:
    """Stand-in for dropbox.files.Tag (union type)."""
    def __init__(self, tag_text: str) -> None:
        self._user = FakeUserTag(tag_text)

    def get_user_generated_tag(self) -> FakeUserTag:
        return self._user


@dataclass
class FakePathToTags:
    path: str
    tags: list


@dataclass
class FakeTagsResult:
    paths_to_tags: list


@pytest.fixture
def patched_core(monkeypatch):
    """Monkeypatch core's Dropbox-dependent helpers to controllable fakes.

    Tests receive a `state` dict where they can configure:
      - `files`: list of FakeFileMetadata returned by _list_all_files
      - `tags_by_path`: dict[path_lower -> list[str]] returned by _fetch_tags
    """
    from tagsync import core

    state = {
        "files": [],
        "tags_by_path": {},
        "fetch_calls": 0,
    }

    def fake_client(_token):
        return object()  # placeholder; never used because list/fetch are faked

    def fake_list(_dbx):
        return list(state["files"])

    def fake_fetch(_dbx, files):
        state["fetch_calls"] += 1
        for f in files:
            tag_names = sorted(state["tags_by_path"].get(f.path_lower, []))
            yield f, tag_names

    monkeypatch.setattr(core, "_dropbox_client", fake_client)
    monkeypatch.setattr(core, "_list_all_files", fake_list)
    monkeypatch.setattr(core, "_fetch_tags", fake_fetch)
    return state


# --- Marker-based skips ------------------------------------------------------


def pytest_collection_modifyitems(config, items):
    platform_skip = {
        "macos": sys.platform != "darwin",
        "windows": sys.platform != "win32",
    }
    for item in items:
        for mark_name, should_skip in platform_skip.items():
            if mark_name in item.keywords and should_skip:
                item.add_marker(
                    pytest.mark.skip(reason=f"requires {mark_name}")
                )