from __future__ import annotations

import multiprocessing
import subprocess
from pathlib import Path

import pytest

import tools.rag.rebuild_index as rebuild


def hold_lock(lock_path: str, ready, release) -> None:
    with rebuild.acquire_reindex_lock(Path(lock_path)):
        ready.set()
        release.wait(timeout=10)


def test_only_one_process_can_reindex(tmp_path: Path) -> None:
    lock_file = tmp_path / "reindex.lock"
    context = multiprocessing.get_context("fork")
    ready = context.Event()
    release = context.Event()
    process = context.Process(
        target=hold_lock,
        args=(str(lock_file), ready, release),
    )
    process.start()

    try:
        assert ready.wait(timeout=5)

        with pytest.raises(
            rebuild.ReindexInProgressError,
            match="už prebieha",
        ):
            with rebuild.acquire_reindex_lock(lock_file):
                pass
    finally:
        release.set()
        process.join(timeout=5)

    assert process.exitcode == 0

    with rebuild.acquire_reindex_lock(lock_file):
        pass


def test_rebuild_runs_pipeline_in_correct_order(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    calls: list[str] = []

    monkeypatch.setattr(
        rebuild,
        "git_pull",
        lambda root: calls.append("git_pull"),
    )
    import tools.sync_indexes as sync
    monkeypatch.setattr(sync, 'synchronize_indexes', lambda wiki, data:
        calls.append('sqlite_and_neo4j') or {'documents_scanned': 1, 'chunks_created': 1,
            'counts': {'fts_chunks': 1}, 'index_version': {'version': 'both'}})

    result = rebuild.rebuild_index(
        pull_git=True,
        lock_file=tmp_path / "lock",
    )

    assert calls == ["git_pull", "sqlite_and_neo4j"]
    assert result["documents_scanned"] == 1
    assert result["chunks_created"] == 1
    assert result["counts"]["fts_chunks"] == 1
    assert result['index_version'] == {'version': 'both'}


def test_rebuild_pulls_and_locks_the_requested_snapshot_paths(tmp_path, monkeypatch):
    import tools.sync_indexes as sync
    wiki = tmp_path / 'alternate-wiki'
    data = tmp_path / 'alternate-data'
    seen = []
    monkeypatch.setattr(rebuild, 'git_pull', lambda root: seen.append(('pull', root)))
    def synchronized(root, target):
        assert (data / '.reindex.lock').exists()
        seen.append(('sync', root, target))
        return {'index_version': {'version': 'alternate'}}
    monkeypatch.setattr(sync, 'synchronize_indexes', synchronized)
    result = rebuild.rebuild_index(pull_git=True, wiki_root=wiki, data_dir=data)
    assert seen == [('pull', wiki), ('sync', wiki, data)]
    assert result['index_version']['version'] == 'alternate'


def test_git_pull_uses_fast_forward_only(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    repo = tmp_path / "repo"
    (repo / ".git").mkdir(parents=True)
    captured = {}

    def fake_run(args, **kwargs):
        captured["args"] = args
        captured["kwargs"] = kwargs
        return subprocess.CompletedProcess(args, 0, stdout="OK", stderr="")

    monkeypatch.setattr(rebuild.subprocess, "run", fake_run)

    rebuild.git_pull(repo)

    assert captured["args"] == ["git", "pull", "--ff-only"]
    assert captured["kwargs"]["cwd"] == repo
    assert captured["kwargs"]["timeout"] == rebuild.GIT_PULL_TIMEOUT_SECONDS


def test_git_pull_rejects_non_repository(tmp_path: Path) -> None:
    directory = tmp_path / "not-repo"
    directory.mkdir()

    with pytest.raises(RuntimeError, match="Nie je to git repozitár"):
        rebuild.git_pull(directory)


def test_git_pull_reports_timeout(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    repo = tmp_path / "repo"
    (repo / ".git").mkdir(parents=True)

    def timeout(*args, **kwargs):
        raise subprocess.TimeoutExpired(cmd="git pull", timeout=120)

    monkeypatch.setattr(rebuild.subprocess, "run", timeout)

    with pytest.raises(RuntimeError, match="prekročil limit"):
        rebuild.git_pull(repo)


def test_git_pull_reports_nonzero_exit(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    repo = tmp_path / "repo"
    (repo / ".git").mkdir(parents=True)

    monkeypatch.setattr(
        rebuild.subprocess,
        "run",
        lambda *args, **kwargs: subprocess.CompletedProcess(
            args[0],
            1,
            stdout="",
            stderr="chyba",
        ),
    )

    with pytest.raises(RuntimeError, match="návratovým kódom 1"):
        rebuild.git_pull(repo)